Home » Public Forums » GMCnet » Transmission (Shifting Problems)
| Transmission [message #136199] |
Wed, 27 July 2011 01:05  |
George Beckman
Messages: 1085
Registered: October 2008
Location: Colfax, CA
Karma: 11
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Senior Member |
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We are about 500 miles from home. The transmission is not shifting as normal. It is not shifting into low at stop signs and sometimes lags when it should shift up. If I put the shifter in low it always starts in low. When I shift to second, the transmission shifts instantly 90% of the time. Shifting into 3rd is a little more iffy and it sometimes takes a minute to decide to do that. If, on a hill, and I shift to second it shifts instantly. One time at about 30 it shifted into second without me moving the shifter. Otherwise, once in 3rd gear, it runs great.
I understand that this could be anything from a modulator to needing a new transmission. Oil is beautiful. It is not getting hot, nor has it been hot. It is not slipping.
Modulator seem like a logical place to start, although I notice that extreme vacuum did not help shifting. It is not adjustable.
The governor also seems to be a likely suspect. I have headers, can I get the governor off without removing the headers? Speedometer and cruise work fine.
What do you think?
'74 Eleganza, SE, Howell + EBL
Best Wishes,
George
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| Re: [GMCnet] Transmission [message #136201 is a reply to message #136199] |
Wed, 27 July 2011 01:17  |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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You will need to loosen the header to access the governor.
On Tue, Jul 26, 2011 at 11:05 PM, George Beckman <gbeckman@pggp.com> wrote:
>
>
> We are about 500 miles from home. Â The transmission is not shifting as normal. Â It is not shifting into low at stop signs and sometimes lags when it should shift up. Â If I put the shifter in low it always starts in low. Â When I shift to second, the transmission shifts instantly 90% of the time. Â Shifting into 3rd is a little more iffy and it sometimes takes a minute to decide to do that. If, on a hill, and I shift to second it shifts instantly. Â One time at about 30 it shifted into second without me moving the shifter. Otherwise, once in 3rd gear, it runs great.
> Â I understand that this could be anything from a modulator to needing a new transmission. Â Oil is beautiful. Â It is not getting hot, nor has it been hot. Â It is not slipping.
>
> Modulator seem like a logical place to start, although I notice that extreme vacuum did not help shifting. Â It is not adjustable.
>
> The governor also seems to be a likely suspect. Â I have headers, can I get the governor off without removing the headers? Â Speedometer and cruise work fine.
>
> What do you think?
> --
> '74 Eleganza, SE, Howell + EBL
> Best Wishes,
> George
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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--
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| Re: Transmission [message #136206 is a reply to message #136199] |
Wed, 27 July 2011 03:20 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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It sure sounds like modulator problems to me. I said this to Dan when he had his problem and it turned out to be the governor so I'm not always correct.
I would start by making sure that the vacuum to the modulator is correct. Start the engine and check the vacuum at the line that plugs into the modulator. You could have a leak in either of the two hoses in the vacuum line between the modulator and the intake manifold. You could also have a blockage in the restrictor in the steel line located on the top of the intake manifold passenger side near the end of the line.
You also could have a broken diaphragm in the modulator it's self. Look for oil in the vacuum hose on the modulator end.
My reason for not suspecting the governor is you say it will not go into low at a stop. I had that problem once and it was the modulator out of adjustment.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: [GMCnet] Transmission [message #136221 is a reply to message #136199] |
Wed, 27 July 2011 07:18 |
Steven Ferguson
Messages: 3447
Registered: May 2006
Karma: 0
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Senior Member |
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I put up with that for years. It's the governor.
On Tue, Jul 26, 2011 at 11:05 PM, George Beckman <gbeckman@pggp.com> wrote:
>
>
> We are about 500 miles from home. The transmission is not shifting as
> normal. It is not shifting into low at stop signs and sometimes lags when
> it should shift up. If I put the shifter in low it always starts in low.
> When I shift to second, the transmission shifts instantly 90% of the time.
> Shifting into 3rd is a little more iffy and it sometimes takes a minute to
> decide to do that. If, on a hill, and I shift to second it shifts instantly.
> One time at about 30 it shifted into second without me moving the shifter.
> Otherwise, once in 3rd gear, it runs great.
> I understand that this could be anything from a modulator to needing a new
> transmission. Oil is beautiful. It is not getting hot, nor has it been
> hot. It is not slipping.
>
> Modulator seem like a logical place to start, although I notice that
> extreme vacuum did not help shifting. It is not adjustable.
>
> The governor also seems to be a likely suspect. I have headers, can I get
> the governor off without removing the headers? Speedometer and cruise work
> fine.
>
> What do you think?
> --
> '74 Eleganza, SE, Howell + EBL
> Best Wishes,
> George
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Steve Ferguson
Sierra Vista, AZ
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| Re: Transmission [message #136238 is a reply to message #136199] |
Wed, 27 July 2011 08:20 |
Rick Williams
Messages: 256
Registered: July 2004
Karma: 0
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Senior Member |
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The modulator is be adjusted for shift points but adjusting it can also compensate somewhat for a bad governor. I had a governor problem that was helped by adjusting the modulator. We go down this road every once and a while and many people don't want to believe it is the governor. The modulator is cheap and easy to change so I would go there first, but I am betting on the governor.
Rick
Rick Williams
Bliss, Michigan
1978 Eleganza II
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| Re: [GMCnet] Transmission [message #136289 is a reply to message #136199] |
Wed, 27 July 2011 13:58 |
Richard Smith
Messages: 14
Registered: February 2004
Karma: 0
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Junior Member |
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George
A possible cause of your shift problems could be the steel vac line
from the manifold to the modulator.
At the top of the steel line where it is connected to the rubber hose
and usually hidden by the rubber hose are some depressions in the
steel line (these are there to soften shift for Toros). Cut them off
just before the outward bump.
Slide the hose back on over the large bump.
These small passages in the steel line can become clogged, especially
after backfiring. Do dont need to ask how I know!!
Everyone should do this to improve shifting, according to the GMC Guru.
Good Luck
Richard 76 Glenbrook
at the Castle in Colorado
On Wed, Jul 27, 2011 at 12:05 AM, George Beckman <gbeckman@pggp.com> wrote:
>
>
> We are about 500 miles from home. The transmission is not shifting as normal. It is not shifting into low at stop signs and sometimes lags when it should shift up. If I put the shifter in low it always starts in low. When I shift to second, the transmission shifts instantly 90% of the time. Shifting into 3rd is a little more iffy and it sometimes takes a minute to decide to do that. If, on a hill, and I shift to second it shifts instantly. One time at about 30 it shifted into second without me moving the shifter. Otherwise, once in 3rd gear, it runs great.
> I understand that this could be anything from a modulator to needing a new transmission. Oil is beautiful. It is not getting hot, nor has it been hot. It is not slipping.
>
> Modulator seem like a logical place to start, although I notice that extreme vacuum did not help shifting. It is not adjustable.
>
> The governor also seems to be a likely suspect. I have headers, can I get the governor off without removing the headers? Speedometer and cruise work fine.
>
> What do you think?
> --
> '74 Eleganza, SE, Howell + EBL
> Best Wishes,
> George
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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| Re: [GMCnet] Transmission [message #136445 is a reply to message #136289] |
Thu, 28 July 2011 15:05 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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| Richard Smith wrote on Wed, 27 July 2011 13:58 |
George
A possible cause of your shift problems could be the steel vac line
from the manifold to the modulator.
At the top of the steel line where it is connected to the rubber hose
and usually hidden by the rubber hose are some depressions in the
steel line (these are there to soften shift for Toros). Cut them off
just before the outward bump.
Slide the hose back on over the large bump.
These small passages in the steel line can become clogged, especially
after backfiring. Do dont need to ask how I know!!
Everyone should do this to improve shifting, according to the GMC Guru.
Good Luck
Richard 76 Glenbrook
at the Castle in Colorado
On Wed, Jul 27, 2011 at 12:05 AM, George Beckman
|
I suggested that be looked at in a previous posting. I do not know about cutting it off though. I had that block up and had to clean it out one time. Mine was blocked so bad that I removed it and applied air pressure to the opposite end while I heated the restrictor with a torch to eventually remove the blockage.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Transmission [message #363801 is a reply to message #136199] |
Mon, 03 May 2021 12:24 |
JohnL455
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
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Senior Member |
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Start with examining all vac hoses for soft or hard/ cracked lines. Not just the ones directly on the steel line.
John Lebetski
Woodstock, IL
77 Eleganza II
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| [GMCnet] Re: transmission [message #363802 is a reply to message #363799] |
Mon, 03 May 2021 15:48 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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We can ship you Manny's Trans with HD convertor
On Mon, May 3, 2021 at 8:17 AM evan schroedel wrote:
> Missoula Mt.
>
> Sent from my iPhone
>
>> On May 3, 2021, at 9:13 AM, Jim Kanomata wrote:
>>
>> Where are you located?
>>
>>
>>> On Mon, May 3, 2021 at 7:59 AM wrote:
>>>
>>> I'm going to r and r it myself i heard some stuff on Manny's trans also
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>>
>>
>>
>> --
>> Jim Kanomata
>> Applied/GMC, Newark,CA
>> jimk@appliedairfilters.com
>> http://www.gmcrvparts.com
>> 1-800-752-7502
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.gmcrvparts.com
1-800-752-7502
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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| [GMCnet] Re: transmission [message #363803 is a reply to message #363802] |
Mon, 03 May 2021 17:06 |
Evan
Messages: 8
Registered: April 2021
Karma: -1
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Junior Member |
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What’s the cost and by heavy duty converter are talking lower stall rate ?
Sent from my iPhone
> On May 3, 2021, at 2:48 PM, Jim Kanomata wrote:
>
> We can ship you Manny's Trans with HD convertor
>
>
>> On Mon, May 3, 2021 at 8:17 AM evan schroedel wrote:
>>
>> Missoula Mt.
>>
>> Sent from my iPhone
>>
>>>> On May 3, 2021, at 9:13 AM, Jim Kanomata wrote:
>>>
>>> Where are you located?
>>>
>>>
>>>> On Mon, May 3, 2021 at 7:59 AM wrote:
>>>>
>>>> I'm going to r and r it myself i heard some stuff on Manny's trans also
>>>> _______________________________________________
>>>> GMCnet mailing list
>>>> Unsubscribe or Change List Options:
>>>>
>>>
>>>
>>> --
>>> Jim Kanomata
>>> Applied/GMC, Newark,CA
>>> jimk@appliedairfilters.com
>>> http://www.gmcrvparts.com
>>> 1-800-752-7502
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>>
>
>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk@appliedairfilters.com
> http://www.gmcrvparts.com
> 1-800-752-7502
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
_______________________________________________
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| [GMCnet] Re: transmission [message #363805 is a reply to message #363803] |
Mon, 03 May 2021 22:47 |
jimk
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
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Senior Member |
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The HD Torque convertors describe hoe the veins are all braised and the
bushing bearing is needle bearing. Since the veins are same as original, no
change in stall.
Lot of rebuilt transmission come with recycled convertors that are weak and
break down.
On our MH, they take a beating and need that extra.
On Mon, May 3, 2021 at 3:06 PM evan schroedel wrote:
> What’s the cost and by heavy duty converter are talking lower stall rate ?
>
> Sent from my iPhone
>
>> On May 3, 2021, at 2:48 PM, Jim Kanomata wrote:
>>
>> We can ship you Manny's Trans with HD convertor
>>
>>
>>> On Mon, May 3, 2021 at 8:17 AM evan schroedel
> wrote:
>>>
>>> Missoula Mt.
>>>
>>> Sent from my iPhone
>>>
>>>> > On May 3, 2021, at 9:13 AM, Jim Kanomata
> wrote:
>>>>
>>>> Where are you located?
>>>>
>>>>
>>>> > On Mon, May 3, 2021 at 7:59 AM wrote:
>>>> >
>>>> > I'm going to r and r it myself i heard some stuff on Manny's trans
> also
>>>> > _______________________________________________
>>>> > GMCnet mailing list
>>>> > Unsubscribe or Change List Options:
>>>> >
>>>>
>>>>
>>>> --
>>>> Jim Kanomata
>>>> Applied/GMC, Newark,CA
>>>> jimk@appliedairfilters.com
>>>> http://www.gmcrvparts.com
>>>> 1-800-752-7502
>>>> _______________________________________________
>>>> GMCnet mailing list
>>>> Unsubscribe or Change List Options:
>>> _______________________________________________
>>> GMCnet mailing list
>>> Unsubscribe or Change List Options:
>>>
>>
>>
>> --
>> Jim Kanomata
>> Applied/GMC, Newark,CA
>> jimk@appliedairfilters.com
>> http://www.gmcrvparts.com
>> 1-800-752-7502
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
>
--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.gmcrvparts.com
1-800-752-7502
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
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