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| Re: [GMCnet] Reviving the Cad 500 [message #164497 is a reply to message #164470] |
Wed, 28 March 2012 20:19   |
klassic kampers
Messages: 93
Registered: July 2008
Location: greer,s.c./ellijay,ga
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Ken, I feel your pain...sounds like something a vw bus owner would say doesn't it?......When I was working at a major vw service shop in spartanburg, sc back in the mid 1970s one of our guys had a ford vehicle at home that kept knocking out thrust bearings......we had many nascar friends in town back then(cotton owens, bud moore, mario rossi, john green)and I do not remember which one provided the info but they told my co-worker to absolutely not have the engine crankshaft parallel to the ground......he then raised the nose of the engine 1/2" and the thrust bearing never failed again......the nascar person stated the crankshaft was jumping from front to rear and back when running.....most likely not your problem but I had to offer...
Mike Stewart
1973 GMC 26' Canyonlands /
1973 B.S.A. B50 street tracker-----
Greer,S.C/Ellijay,Ga
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| Re: [GMCnet] Reviving the Cad 500 [message #164521 is a reply to message #164497] |
Wed, 28 March 2012 22:10 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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Ken, you won't like me for this, but when I was a young GMI student, I started at Saginaw Transmission running the durability dyno on the night shift. We ran the trasmissions 24/7 at wot untill they failed. At that time the motive power came from the lineup of GM engines. We quickly found out that Buick and Cadillac engines had very poor durability under these conditions with Buick being by far the worst. Even though the Olds engines were very durable, they didn't have the power output we needed. We finally settled on Pontiac big blocks as by far the most powerfull and durable engines, and we were a Chevrolet division ! Since that time, I have very little respect for Buick and Cadillac engines from a durability standpoint. I think there are many other similar experiences of the era. As a young kid I was surprised that the higher status divisions had the worst designed and quality mechanical components, but after many years I realized thet they had the fewest resources. These day of course that has all changed. Frankly, the last engine I would put in my GMC is a Cadillac. I will catch a lot of flack for this but so be it.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: [GMCnet] Reviving the Cad 500 [message #164522 is a reply to message #164521] |
Wed, 28 March 2012 22:14 |
rssbob
Messages: 259
Registered: January 2004
Location: La Mesa, Ca. (San Diego a...
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So what are you running if not a Caddy?
On Mar 28, 2012, at 8:10 PM, Bob de Kruyff wrote:
>
>
> Ken, you won't like me for this, but when I was a young GMI student, I started at Saginaw Transmission running the durability dyno on the night shift. We ran the trasmissions 24/7 at wot untill they failed. At that time the motive power came from the lineup of GM engines. We quickly found out that Buick and Cadillac engines had very poor durability under these conditions with Buick being by far the worst. Even though the Olds engines were very durable, they didn't have the power output we needed. We finally settled on Pontiac big blocks as by far the most powerfull and durable engines, and we were a Chevrolet division ! Since that time, I have very little respect for Buick and Cadillac engines from a durability standpoint. I think there are many other similar experiences of the era. As a young kid I was surprised that the higher status divisions had the worst designed and quality mechanical components, but after many years I realized thet they had the fewest resources. Thes
e
> day of course that has all changed. Frankly, the last engine I would put in my GMC is a Cadillac. I will catch a lot of flack for this but so be it.
> --
> Bob de Kruyff
> 78 Eleganza
> Chandler, AZ
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Bob Sobrito
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La Mesa, Ca
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| Re: [GMCnet] Reviving the Cad 500 [message #164526 is a reply to message #164522] |
Wed, 28 March 2012 22:37 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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| rssbob wrote on Wed, 28 March 2012 21:14 |
So what are you running if not a Caddy?
On Mar 28, 2012, at 8:10 PM, Bob de Kruyff wrote:
>
>
> Ken, you won't like me for this, but when I was a young GMI student, I started at Saginaw Transmission running the durability dyno on the night shift. We ran the trasmissions 24/7 at wot untill they failed. At that time the motive power came from the lineup of GM engines. We quickly found out that Buick and Cadillac engines had very poor durability under these conditions with Buick being by far the worst. Even though the Olds engines were very durable, they didn't have the power output we needed. We finally settled on Pontiac big blocks as by far the most powerfull and durable engines, and we were a Chevrolet division ! Since that time, I have very little respect for Buick and Cadillac engines from a durability standpoint. I think there are many other similar experiences of the era. As a young kid I was surprised that the higher status divisions had the worst designed and quality mechanical components, but after many years I realized thet they had the fewest resources. Thes
e
> day of course that has all changed. Frankly, the last engine I would put in my GMC is a Cadillac. I will catch a lot of flack for this but so be it.
> --
> Bob de Kruyff
> 78 Eleganza
> Chandler, AZ
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Stock 403
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: [GMCnet] Reviving the Cad 500 [message #164636 is a reply to message #164425] |
Thu, 29 March 2012 18:03 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Richard,
I did have a weirdly worn transmission input bushing, but I'm convinced
that was due to the definitely misaligned flex plate. Which, incidentally,
doesn't do a lot of flexing on a Cadillac, IMHO. It's just too thick and
has no weakening cuts like some I've seen.
We have had some discussion of mis-aligned transmission/engine interfaces,
including the replacement of dowels with offset ones. Frankly, I discount
that possibility in this case because the transmission lived peaceably with
my Olds engine (and possibly several others), and the Cad engine presumably
had a good marriage with its transmission during its first 76,000 miles
with no thrust bearing damage. I find it unlikely, statistically, that the
two would have trouble with a new coupling between them.
Just looking at the various thrust bearings for Chevy, Olds, and Cadillac
engines, I'd guess that the 210 lbf rating I've seen for the Chevy 454 is
pretty close to the same as the others -- not much is allowed, in other
words.
No question I'll post anything I learn relative to the failures -- no
matter how embarrassing it may turn out to be -- I'm 'WAY too old &
independent to worry about my reputation. :-)
Ken H.
On Wed, Mar 28, 2012 at 2:48 AM, Richard Brown wrote:
> A question; If I remember correctly, wasn't the bushing that the torque
> converter snout rides in replaced because of uneven wear? I remember
> reading that some dowel pin holes were drilled slightly offset from the
> factory. Could a mis-aligned transmission mounting cause thrust bearing
> problems? This may have already been discussed, but if so I missed it. I've
> heard that some engines are more tolerant than others in this regard. I do
> remember a discussion about a possible overpressure of the torque converter
> because of a restricted cooler. I'm asking because I know someone who just
> had to replace his torque converter & bushing on his GM car. The mechanic
> used a standard bellhousing & a dial indicator to check the alignment &
> install offset dowel pins. I didn't see how it was done but just know what
> was done. After the alignment, a rebuilt transmission was installed & so
> far it's doing OK. While the trans & motor was out, he rebuilt the motor
> and noticed
> that the thrust bearing clearance was pretty loose. If the solution is
> found, I'd like to pass the info on. It's possible that since Cadillac
> engines were never fitted with manual transmissions, they are less tolerant
> of excessive thrust to the crank. Some earlier Olds 455s were fitted with
> manual transmissions, so perhaps they are more able to stand the stress.
>
>
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Ken Henderson
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Large Wiring Diagrams
76 X-Birchaven
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| Re: [GMCnet] Reviving the Cad 500 [message #164638 is a reply to message #164431] |
Thu, 29 March 2012 18:12 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
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Johnny,
I understand. I suspect that I'll give up and replace the transmission
before I get that far into an autopsy. Especially since, as I just wrote
to Richard, both the transmission and the engine seem to have had
successful marriages before I hitched them up.
The chain side doesn't seem to me a very likely prospect for causing this
problem -- its sprockets, bearing supports, and bearings pretty well
isolate it from receiving or issuing any damage. However, the input
splined shaft(s) are a different matter. Manny's warned me that he always
chucks them in a lathe to check them for straightness and suggested I do
the same because he DOES find some of them bent. They're also subject to
wear which could cause TC binding.
Back to work tomorrow, probably.
Ken H.
On Wed, Mar 28, 2012 at 9:00 AM, Johnny Bridges wrote:
> The intent is to ensure that the surface which bolts up to both the
> transmission and the engine block is flat - i.e. not warped in such a way
> that the two are being held at an angle. If the trans nput shaft and the
> crankshaft centerline aren't precisely parallel, will not this put a bit of
> an end load on one or both due to a flex in the drive chain? I expect the
> drive system is designed to tolerate substantial side loads on the
> sprockets, but there's not likely to be a lot of provision for end loading,
> since in normal operation there hadn't ought to be any.
> It's a very unlikely scenario admittedly... but you're down to the
> 'unlikelies' at this point, are you not? Easy to check at any rate.
>
>
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76 X-Palm Beach
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| Re: [GMCnet] Reviving the Cad 500 [message #164811 is a reply to message #164638] |
Sat, 31 March 2012 18:06 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Really great day today -- NOT!!!
Yesterday and this morning I connected pressure gauges at the torque
converter output, in the return from the ATF filter (which follows the
in-radiator cooler), and in the diagnostic port.
This afternoon, Stick and I ran all of the pressure tests on page 7-13 of
the X7525 manual. The results were pretty well centered in the normal
range except for those in Super and Low range, which were low. Disrupting
Manny's Saturday rain-watching, I called him for consultation. He says
those low readings indicate a leaking accumulator, which I can live with --
it's not relevant to the current problem.
The pressure readings on the cooler circuit were pretty much in the range
of 20-30 psi, with the return only 3-5 psi lower than the supply. The
highest converter output pressure recorded was 40 psi, with 30 psi return
-- probably a reading anomaly. Those are all "open circuit" measurements.
To test the condition of the TH-425's pressure regulator, and the
potential damage from a blocked cooler, I blocked flow in the circuit by
clamping a rubber hose. We than ran with the transmission in Drive and the
engine at 1000, 1500, and 2000 rpm. The corresponding pressures were 80,
100, and 100 psi -- close to Manny's predictions.
The highest reading we recorded anywhere was 160 psi at the diagnostic port
at 1000 rpm in Reverse. I suspect that was a false reading, because none
of the other readings, all of which were repeated at least 3 times, was
above 122 psi.
So, it appears that the transmission is NOT responsible for my thrust
bearing failures. While we have no way to directly test the pressure in
the converter, the output pressure should be pretty close. And as shown by
the blocked cooling circuit measurements, that pressure should never be
above 100 psi. While having that much pressure continuously could over
stress the thrust bearing, the un-blocked 20-25 psi would not.
Manny and I discussed a number of different possibilities without forming
any new hypothesis.
I'm completely baffled and directionless right now.
Ken H.
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Ken Henderson
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Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] Reviving the Cad 500 [message #164828 is a reply to message #162802] |
Sat, 31 March 2012 20:08 |
kingd
Messages: 592
Registered: June 2004
Karma: 2
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To Ken K. I've been reading this saga like a book. How about this. The Transmission got along with the engine it was attached to. The Cad engine got along with the trans it was attached to. Something is different now that the trans that was on the Olds engine is now on the Caddy. If you still have the Olds engine is there any way you check all the mounting surfaces etc on the Olds vs the Caddy to make sure the trans "fits" on the Cad just like it did on the Olds ? I'm not sure what you would be looking for but the different engine is the BIG variable in this situation.
DAVE KING
DAVE KING
lurker, wannabe
Toronto, Ontario, Canada
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| Re: [GMCnet] Reviving the Cad 500 [message #164829 is a reply to message #164811] |
Sat, 31 March 2012 20:11 |
shawnee
Messages: 422
Registered: February 2004
Location: NC
Karma: 0
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| Ken Henderson wrote on Sat, 31 March 2012 19:06 |
Really great day today -- NOT!!!
Yesterday and this morning I connected pressure gauges at the torque
converter output, in the return from the ATF filter (which follows the
in-radiator cooler), and in the diagnostic port.
This afternoon, Stick and I ran all of the pressure tests on page 7-13 of
the X7525 manual. The results were pretty well centered in the normal
range except for those in Super and Low range, which were low. Disrupting
Manny's Saturday rain-watching, I called him for consultation. He says
those low readings indicate a leaking accumulator, which I can live with --
it's not relevant to the current
The pressure readings on the cooler circuit were pretty much in the range
of 20-30 psi, with the return only 3-5 psi lower than the supply. The
highest converter output pressure recorded was 40 psi, with 30 psi return
-- probably a reading anomaly. Those are all "open circuit" measurements.
To test the condition of the TH-425's pressure regulator, and the
potential damage from a blocked cooler, I blocked flow in the circuit by
clamping a rubber hose. We than ran with the transmission in Drive and the
engine at 1000, 1500, and 2000 rpm. The corresponding pressures were 80,
100, and 100 psi -- close to Manny's predictions.
The highest reading we recorded anywhere was 160 psi at the diagnostic port
at 1000 rpm in Reverse. I suspect that was a false reading, because none
of the other readings, all of which were repeated at least 3 times, was
above 122 psi.
So, it appears that the transmission is NOT responsible for my thrust
bearing failures. While we have no way to directly test the pressure in
the converter, the output pressure should be pretty close. And as shown by
the blocked cooling circuit measurements, that pressure should never be
above 100 psi. While having that much pressure continuously could over
stress the thrust bearing, the un-blocked 20-25 psi would not.
Manny and I discussed a number of different possibilities without forming
any new hypothesis.
I'm completely baffled and directionless right now.
Ken H.
Ken,
When you had the first failure, did you clean the oil cooler out real well? If you didn't, then the stuff in the oil filter could have come from there. I haven't been able to follow the net at Shawnee due to poor WiFi so I am sure you have done more.
_______________________________________________
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Gene Dotson
74 Canyonlands
www.bdub.net/Motorhome_Enhancements New Windows and Aluminum Radiators
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| Re: [GMCnet] Reviving the Cad 500 [message #164830 is a reply to message #164829] |
Sat, 31 March 2012 20:19 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Gene,
Yes, after the first failure, I DID clean the cooler and the, fortunately
short, JR lines thoroughly. The iron fuzz in the filter, on the magnets,
was from the new wear, NOT the old stuff, which I washed and brushed out
very carefully.
Ken H.
On Sat, Mar 31, 2012 at 9:11 PM, Gene Dotson wrote:
> > When you had the first failure, did you clean the oil cooler out real
> well? If you didn't, then the stuff in the oil filter could have come
> from there. I haven't been able to follow the net at Shawnee due to poor
> WiFi so I am sure you have done more.
>
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Ken Henderson
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Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] Reviving the Cad 500 [message #165073 is a reply to message #164811] |
Mon, 02 April 2012 18:28 |
GMC_LES
Messages: 569
Registered: October 2009
Location: Montreal
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Ken,
Is there any possibility that something running off the front of the crank is pulling it forward with enough force to load the thrust bearing?
Another very long shot might be a defect in the block oiling passages that is causing a restricted oil flow to the main journal with the thrust faces. Increasing oil flow to the thrust face by chamfering the bearing shell might actually have a negative effect if the oil flow was already on the low side. You'll find out for sure on this tear down as the bearing shell surfaces for the main with the thrust faces and the rods fed off that main should show signs of oil starvation if this is the case. I doubt this would be your situation though.
I might be smoking the wrong stuff!!
Les Burt
Montreal
On 2012-03-31, at 7:06 PM, Ken Henderson <hend4800@bellsouth.net> wrote:
> Really great day today -- NOT!!!
>
> Yesterday and this morning I connected pressure gauges at the torque
> converter output, in the return from the ATF filter (which follows the
> in-radiator cooler), and in the diagnostic port.
>
> This afternoon, Stick and I ran all of the pressure tests on page 7-13 of
> the X7525 manual. The results were pretty well centered in the normal
> range except for those in Super and Low range, which were low. Disrupting
> Manny's Saturday rain-watching, I called him for consultation. He says
> those low readings indicate a leaking accumulator, which I can live with --
> it's not relevant to the current problem.
>
> The pressure readings on the cooler circuit were pretty much in the range
> of 20-30 psi, with the return only 3-5 psi lower than the supply. The
> highest converter output pressure recorded was 40 psi, with 30 psi return
> -- probably a reading anomaly. Those are all "open circuit" measurements.
> To test the condition of the TH-425's pressure regulator, and the
> potential damage from a blocked cooler, I blocked flow in the circuit by
> clamping a rubber hose. We than ran with the transmission in Drive and the
> engine at 1000, 1500, and 2000 rpm. The corresponding pressures were 80,
> 100, and 100 psi -- close to Manny's predictions.
>
> The highest reading we recorded anywhere was 160 psi at the diagnostic port
> at 1000 rpm in Reverse. I suspect that was a false reading, because none
> of the other readings, all of which were repeated at least 3 times, was
> above 122 psi.
>
> So, it appears that the transmission is NOT responsible for my thrust
> bearing failures. While we have no way to directly test the pressure in
> the converter, the output pressure should be pretty close. And as shown by
> the blocked cooling circuit measurements, that pressure should never be
> above 100 psi. While having that much pressure continuously could over
> stress the thrust bearing, the un-blocked 20-25 psi would not.
>
> Manny and I discussed a number of different possibilities without forming
> any new hypothesis.
>
> I'm completely baffled and directionless right now.
>
> Ken H.
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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Les Burt
Montreal
1975 Eleganza 26ft
A work in Progress
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| Re: [GMCnet] Reviving the Cad 500 [message #165074 is a reply to message #165073] |
Mon, 02 April 2012 18:43 |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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Senior Member |
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Ken and Les,
Ken -- are you the only one running a serpentine belt mod?
I know, blindly grasping at straws...
Dennis
| Les Burt wrote on Mon, 02 April 2012 18:28 |
Ken,
Is there any possibility that something running off the front of the crank is pulling it forward with enough force to load the thrust bearing?
Another very long shot might be a defect in the block oiling passages that is causing a restricted oil flow to the main journal with the thrust faces. Increasing oil flow to the thrust face by chamfering the bearing shell might actually have a negative effect if the oil flow was already on the low side. You'll find out for sure on this tear down as the bearing shell surfaces for the main with the thrust faces and the rods fed off that main should show signs of oil starvation if this is the case. I doubt this would be your situation though.
I might be smoking the wrong stuff!!
Les Burt
Montreal
On 2012-03-31, at 7:06 PM, Ken Henderson <hend4800@bellsouth.net> wrote:
> Really great day today -- NOT!!!
>
> Yesterday and this morning I connected pressure gauges at the torque
> converter output, in the return from the ATF filter (which follows the
> in-radiator cooler), and in the diagnostic port.
>
> This afternoon, Stick and I ran all of the pressure tests on page 7-13 of
> the X7525 manual. The results were pretty well centered in the normal
> range except for those in Super and Low range, which were low. Disrupting
> Manny's Saturday rain-watching, I called him for consultation. He says
> those low readings indicate a leaking accumulator, which I can live with --
> it's not relevant to the current problem.
>
> The pressure readings on the cooler circuit were pretty much in the range
> of 20-30 psi, with the return only 3-5 psi lower than the supply. The
> highest converter output pressure recorded was 40 psi, with 30 psi return
> -- probably a reading anomaly. Those are all "open circuit" measurements.
> To test the condition of the TH-425's pressure regulator, and the
> potential damage from a blocked cooler, I blocked flow in the circuit by
> clamping a rubber hose. We than ran with the transmission in Drive and the
> engine at 1000, 1500, and 2000 rpm. The corresponding pressures were 80,
> 100, and 100 psi -- close to Manny's predictions.
>
> The highest reading we recorded anywhere was 160 psi at the diagnostic port
> at 1000 rpm in Reverse. I suspect that was a false reading, because none
> of the other readings, all of which were repeated at least 3 times, was
> above 122 psi.
>
> So, it appears that the transmission is NOT responsible for my thrust
> bearing failures. While we have no way to directly test the pressure in
> the converter, the output pressure should be pretty close. And as shown by
> the blocked cooling circuit measurements, that pressure should never be
> above 100 psi. While having that much pressure continuously could over
> stress the thrust bearing, the un-blocked 20-25 psi would not.
>
> Manny and I discussed a number of different possibilities without forming
> any new hypothesis.
>
> I'm completely baffled and directionless right now.
>
> Ken H.
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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Dennis S
73 Painted Desert 230
Memphis TN Metro
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| Re: [GMCnet] Reviving the Cad 500 [message #165075 is a reply to message #165073] |
Mon, 02 April 2012 18:51 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Senior Member |
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Les,
The only thing unique about the front of my engine is the pair of
serpentine belts. No one I've talked to, including myself, thinks there's
any possibility of their causing axial loads on the crank. There were NO
signs of radial damage to the front bearing as I'd expect if there were a
problem. There's no reason the serpentine belts should cause more problem
than the V-belts. Also, with the excess end play, I can literally move the
crank fore and aft by hand, even with the belts in place.
As for oil starvation, that's unlikely: The #3 journal (where the thrust
is taken on the Cad) showed no different wear than any of the others --
just that minor amount caused by the circulating debris.
Today I talked to Marty at Maximum Torque Specialists. He thinks the
torque converter is the cause of my problems; he claims the housing CAN
expand enough to take up my 0.125" clearance. I'm still skeptical, but
with nothing else to blame, I'm going to replace the TC with the best one I
can find -- any suggestions? I'll also have the builder of this one tear
it down to see if they can find anything wrong with it.
After I drop the engine tomorrow, I'll be looking for any signs of
interference that I may have missed before. The general assumption, in the
transmission industry at least, seems to be that an expanded TC would
immediately cause massive damage to the transmission -- I saw NO signs of
any damage when I had the transmission partially disassembled to replace
the input bushing. Maybe the TH-425 is especially rugged in that area
because of the chain drive?
Ideas welcomed.
Ken H.
On Mon, Apr 2, 2012 at 7:28 PM, Les Burt wrote:
> Ken,
> Is there any possibility that something running off the front of the crank
> is pulling it forward with enough force to load the thrust bearing?
>
> Another very long shot might be a defect in the block oiling passages that
> is causing a restricted oil flow to the main journal with the thrust faces.
> Increasing oil flow to the thrust face by chamfering the bearing shell
> might actually have a negative effect if the oil flow was already on the
> low side. You'll find out for sure on this tear down as the bearing shell
> surfaces for the main with the thrust faces and the rods fed off that main
> should show signs of oil starvation if this is the case. I doubt this would
> be your situation though.
>
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] Reviving the Cad 500 [message #165077 is a reply to message #165074] |
Mon, 02 April 2012 18:54 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Senior Member |
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No, Paul Leavitt, at least, is running a serpentine belt also. I talked to
him today and he reports NO problems after about the same mileage I have on
my engine.
Ken H.
On Mon, Apr 2, 2012 at 7:43 PM, Dennis Sexton wrote:
> Ken -- are you the only one running a serpentine belt mod?
> I know, blindly grasping at straws...
>
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] Reviving the Cad 500 [message #165091 is a reply to message #162802] |
Mon, 02 April 2012 20:21 |
Richard Brown
Messages: 281
Registered: May 2009
Karma: 1
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Senior Member |
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JimB sells an Allison-style torque converter that may just be what the doctor ordered. I haven't owned one, but if it's any where near as good as the sensitized brake booster he sells, it's as good as they get. I like the booster, but be careful the first time you step on the brakes. I went from having so-so brakes to having toss-you-thru-the-windshield brakes. The improvement has to be felt to be believed.
Richard & Carol Brown
1974 Eleganza SE
"DILLIGAF"
Lindale, Tx. 75771
903-881-0192
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Richard & Carol Brown
1974 Eleganza SE
1174 Hickory Hills Dr.
Murchison, TX. 75778
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| Re: [GMCnet] Reviving the Cad 500 [message #165141 is a reply to message #165075] |
Tue, 03 April 2012 08:11 |
Carleton Douglas[1]
Messages: 174
Registered: March 2006
Karma: 0
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Senior Member |
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Ken you need to make a run stand and prove what is going on with the
engine, taking it in and out is to had on old guys like us. Manny can
give you some info on how he make his. That is all that I can think
of, in and out that hurts me thinking about it.
On Mon, Apr 2, 2012 at 4:51 PM, Ken Henderson <hend4800@bellsouth.net> wrote:
> Les,
>
> The only thing unique about the front of my engine is the pair of
> serpentine belts. No one I've talked to, including myself, thinks there's
> any possibility of their causing axial loads on the crank. There were NO
> signs of radial damage to the front bearing as I'd expect if there were a
> problem. There's no reason the serpentine belts should cause more problem
> than the V-belts. Also, with the excess end play, I can literally move the
> crank fore and aft by hand, even with the belts in place.
>
> As for oil starvation, that's unlikely: The #3 journal (where the thrust
> is taken on the Cad) showed no different wear than any of the others --
> just that minor amount caused by the circulating debris.
>
> Today I talked to Marty at Maximum Torque Specialists. He thinks the
> torque converter is the cause of my problems; he claims the housing CAN
> expand enough to take up my 0.125" clearance. I'm still skeptical, but
> with nothing else to blame, I'm going to replace the TC with the best one I
> can find -- any suggestions? I'll also have the builder of this one tear
> it down to see if they can find anything wrong with it.
>
> After I drop the engine tomorrow, I'll be looking for any signs of
> interference that I may have missed before. The general assumption, in the
> transmission industry at least, seems to be that an expanded TC would
> immediately cause massive damage to the transmission -- I saw NO signs of
> any damage when I had the transmission partially disassembled to replace
> the input bushing. Maybe the TH-425 is especially rugged in that area
> because of the chain drive?
>
> Ideas welcomed.
>
> Ken H.
>
>
>
> On Mon, Apr 2, 2012 at 7:28 PM, Les Burt wrote:
>
>> Ken,
>> Is there any possibility that something running off the front of the crank
>> is pulling it forward with enough force to load the thrust bearing?
>>
>> Another very long shot might be a defect in the block oiling passages that
>> is causing a restricted oil flow to the main journal with the thrust faces.
>> Increasing oil flow to the thrust face by chamfering the bearing shell
>> might actually have a negative effect if the oil flow was already on the
>> low side. You'll find out for sure on this tear down as the bearing shell
>> surfaces for the main with the thrust faces and the rods fed off that main
>> should show signs of oil starvation if this is the case. I doubt this would
>> be your situation though.
>>
>>
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--
Carleton Douglas
73 custom, by myself
Prescott, AZ
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| Re: [GMCnet] Reviving the Cad 500 [message #165179 is a reply to message #165077] |
Tue, 03 April 2012 11:15 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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Senior Member |
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| Ken Henderson wrote on Mon, 02 April 2012 16:54 |
No, Paul Leavitt, at least, is running a serpentine belt also. I talked to
him today and he reports NO problems after about the same mileage I have on
my engine.
Ken H.
On Mon, Apr 2, 2012 at 7:43 PM, Dennis Sexton wrote:
> Ken -- are you the only one running a serpentine belt mod?
> I know, blindly grasping at straws...
>
>
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I'm sure you have checked those pulleys closely. I bought a 455 olds 25 years ago that had a bad thrust due to a Diesel engine pulley? the guy was running. I rebuilt the engine and had the crank thrust welded. I put the correct pulley on it and no further problems.
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: [GMCnet] Reviving the Cad 500 [message #165215 is a reply to message #165075] |
Tue, 03 April 2012 16:14 |
Larry
Messages: 2875
Registered: January 2004
Location: Menomonie, WI
Karma: 10
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Senior Member |
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| Ken Henderson wrote on Mon, 02 April 2012 18:51 |
Today I talked to Marty at Maximum Torque Specialists. He thinks the
torque converter is the cause of my problems; he claims the housing CAN
expand enough to take up my 0.125" clearance. I'm still skeptical, but
with nothing else to blame, I'm going to replace the TC with the best one I
can find -- any suggestions? I'll also have the builder of this one tear
it down to see if they can find anything wrong with it.
|
Contact Dick Lewis at Midwest Performance Converter. He is building a number of converters for some of the guys that have 500 Cad motors.
800-262-2063
http/www.midwestconverter.com
Contact Bob Miller for a review on how he likes his. Sorry, don't have his # with me, but should be in the GMCMI Membership roster.
I'm skeptical also of a TC problem. Are you sure your line bore is straight, and when you plastigaged your motor, was the plastigage even all of the way across the whole bearing. I've seen crank grinders get lazy with their grinding and not trim the grinding wheel often enough to get a flat surface across the crank throws and mains meaning the grinding wheel wears most at the edges and then does not grind flat all of the way to the edge of the bearing surface. Just a thought...
Larry 
78 Royale w/500 Caddy
Menomonie, WI.
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