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shift kit pro's and cons [message #317730] Thu, 18 May 2017 08:58 Go to next message
joewilly is currently offline  joewilly   United States
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Registered: April 2016
Location: Victor,Ia
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Junior Member
the GMC I'm looking at buying has a shift kit installed , is this a good thing or bad ?
have read a few previous posts stating that Manny doesn't recommend them. but why?
and how complicated is it to remove and can it be done fairly easily ( by me )without doing harm to tranny?
thanks to all for info
Joe


jwilly
Re: shift kit pro's and cons [message #317737 is a reply to message #317730] Thu, 18 May 2017 10:00 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
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Location: S.E. Michigan
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joewilly wrote on Thu, 18 May 2017 09:58
the GMC I'm looking at buying has a shift kit installed , is this a good thing or bad ?
have read a few previous posts stating that Manny doesn't recommend them. but why?
and how complicated is it to remove and can it be done fairly easily ( by me )without doing harm to tranny?
thanks to all for info
Joe

Joe,

If Manny thought it was a good idea, he would do it. As to is it worth removing or killing the deal, you will have to ask Manny. He will answer both and you can take his answers to the bank.

Matt


Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Still Loving OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit
Re: shift kit pro's and cons [message #317747 is a reply to message #317730] Thu, 18 May 2017 10:40 Go to previous messageGo to next message
A Hamilto is currently offline  A Hamilto   United States
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Registered: April 2011
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joewilly wrote on Thu, 18 May 2017 08:58
...Manny doesn't recommend them. but why?...

Don't know. Don't care. If Manny takes them out and throws them away, that is all I need to know. It doesn't belong in the transmission.


73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"Every day I become more convinced that I am the only person left on the planet that recognizes nonsense for what it is."
Re: shift kit pro's and cons [message #317752 is a reply to message #317730] Thu, 18 May 2017 11:07 Go to previous messageGo to next message
roy1 is currently offline  roy1   United States
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Don't do it or you could damage your engine. It cost me 2 engines. First one over reved in low gear when I accidentally pulled it into low thinking it was super. You can't pull the trans into low if the rpm is too high with the stock trans but with a shift kit it will go into low. 2nd one damaged the thrust bearing from extremely hard upshufts. After this I had Manny remove the kit and redo the trans. If you are a flatlander you may never have a problem but living in a mountain state is hard on drive trains cause you are always working it hard climbing steep grades while towing. You can remove the shift kit but you will need to move some steel balls around and a few other things best to remove the valve body and send it to manny to put it back to stock.

Roy Keen Minden,NV 76 X Glenbrook

[Updated on: Thu, 18 May 2017 11:12]

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Re: [GMCnet] shift kit pro's and cons [message #317762 is a reply to message #317752] Thu, 18 May 2017 12:48 Go to previous messageGo to next message
Keith V is currently offline  Keith V   United States
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the guy who built the trans for my vette said that shift kits are designed to shift hard so the driver thinks it is better, but it's not a good shift and is hard on the transmission.

To do it right he changed some internal programming in the trans.

The vettes trans will go into whatever gear you tell it to, It also does shift very hard on WOT, but putting around it shifts nice.


I would not put a shift kit in anything, much less a motorhome.

I would let Manny update it however.

________________________________
From: Gmclist on behalf of roy keen
Sent: Thursday, May 18, 2017 11:07:14 AM
To: gmclist-AT-list-DOT-gmcnet-DOT-org
Subject: Re: [GMCnet] shift kit pro's and cons

Don't do it or you could damage your engine. It cost me 2 engines. First one over reved in low gear when I accidentally pulled it into low thinking
it was super. You can't pull the trans into low if the rpm is too high with the stock trans but with a shift kit it will go into low. 2nd one damaged
the thrust bearing from extremely hard upshufts. After this I had Manny remove the kit and redo the trans. If you are a flatlander you may never have
a problem but living in a mountain state is hard on drive trains cause you are always working it hard climbing steep grades while towing.
--
Roy Keen
Minden,NV
76 X Glenbrook

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Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
69 Vette
29 Dodge
Re: [GMCnet] shift kit pro's and cons [message #317769 is a reply to message #317762] Thu, 18 May 2017 15:10 Go to previous messageGo to next message
sgltrac is currently offline  sgltrac   United States
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Agreed. If Manny says no shift kit then no shift kit it is.

Sully
77 eleganza 2
Seattle
On Thu, May 18, 2017 at 10:49 AM Keith V wrote:

> the guy who built the trans for my vette said that shift kits are designed
> to shift hard so the driver thinks it is better, but it's not a good shift
> and is hard on the transmission.
>
> To do it right he changed some internal programming in the trans.
>
> The vettes trans will go into whatever gear you tell it to, It also does
> shift very hard on WOT, but putting around it shifts nice.
>
>
> I would not put a shift kit in anything, much less a motorhome.
>
> I would let Manny update it however.
>
> ________________________________
> From: Gmclist on behalf of roy keen roynpaula-AT-charter-DOT-net>
> Sent: Thursday, May 18, 2017 11:07:14 AM
> To: gmclist-AT-list-DOT-gmcnet-DOT-org
> Subject: Re: [GMCnet] shift kit pro's and cons
>
> Don't do it or you could damage your engine. It cost me 2 engines. First
> one over reved in low gear when I accidentally pulled it into low thinking
> it was super. You can't pull the trans into low if the rpm is too high
> with the stock trans but with a shift kit it will go into low. 2nd one
> damaged
> the thrust bearing from extremely hard upshufts. After this I had Manny
> remove the kit and redo the trans. If you are a flatlander you may never
> have
> a problem but living in a mountain state is hard on drive trains cause you
> are always working it hard climbing steep grades while towing.
> --
> Roy Keen
> Minden,NV
> 76 X Glenbrook
>
> _______________________________________________
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Sully 77 Royale basket case. Future motorhome land speed record holder(bucket list) Seattle, Wa.
Re: shift kit pro's and cons [message #317785 is a reply to message #317730] Fri, 19 May 2017 07:50 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
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Location: Woodstock, IL
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The idea behind Transgo and other kits was to speed up the shift event and have less overlap. This in theory minimized the time the clutch packs were slipping in a sacrificial manner. However this increases stresses elsewhere as the stored RPM energy had to be rapidly disipated. The guys at Hydramatic were the best in the business at programing-- balancing comfort, drivability, durability and performance. That is 4 vectors kind of like trying to have the old "balancing eggs on eggs" task work out. They were designed to shift seamlessly imperceptible under light throttle and firm as loads increased. If you think about it in an 11k vehicle the loads are always high as if towing. Also going to harder shifts is a bad idea with FWD where uneven traction surfaces can jerk you into another lane with hard shifts.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: shift kit pro's and cons [message #317786 is a reply to message #317730] Fri, 19 May 2017 07:58 Go to previous messageGo to next message
Russell K. is currently offline  Russell K.   United States
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Registered: October 2016
Location: Dunedin, Florida
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Member
Joe,
Don't be discouraged by the shift kit. Our '78 Eleganza, with the 403, had a Danny Dunn transmission installed in 2003, and it has a shift kit. I do not intend to start an argument, but some think the shift kit is OK. I posted some information about it here:

http://www.gmcmhphotos.com/photos/g7043-danny-dunn-transmission-information.html

Our GMC has been actively used by its previous owners, with no other transmission repairs recorded by them. We have only owned it since August of 2016, but use it frequently. We just drove it 700 miles round trip to the Florida Keys for the GMC Sunshine Statesmen Rally with no trouble at all. (By the way, I highly recommend joining your local GMC club; the information and help you'll receive from them is priceless!) I did put in a rebuilt governor assembly, and a new vacuum line on the modulator; but other than that, the transmission works great!! It does have a firm shift, and I drive it conservatively, but the transmission works just fine. I live in Florida, and I haven't driven it in the Mountains since we drove it home from New York, where we bought it. I get a consistent 10 mpg.

I say go for it! Buy it. Use it. Enjoy it. If the transmission fails, fix it. I know a guy. *wink*

If my tranny ever fails, I'll probably call Manny for a 'new' one.
Russell


Russell Keith 1978 Eleganza II Dunedin, Florida
Re: shift kit pro's and cons [message #317790 is a reply to message #317730] Fri, 19 May 2017 08:25 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
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Registered: October 2006
Location: Woodstock, IL
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Senior Member
Yes "Shift Kit" is a blanket statement. Some are mild, some are extreme, some are finicky. Most manufacturers had them in different flavors so you can't paint with a wide brush and expect to be accurate.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: [GMCnet] shift kit pro's and cons [message #317791 is a reply to message #317785] Fri, 19 May 2017 08:37 Go to previous messageGo to next message
Keith V is currently offline  Keith V   United States
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Registered: March 2008
Location: Mounds View,MN
Karma: 3
Senior Member
The big problem with user installed shift kits is they cant address int he internal changes needed ( as I remember from my transmission guy ) they can only change the valve body programming.

Stock transmission use clutch overlap to smooth out the shifting, but that means two gears are applied at the same time for a while.

A performance transmission does not do that. It's easier on the transmission, but a bit harder on the rest of the driveline, esp on high performance cars pushing the limits of the components.

________________________________
From: Gmclist on behalf of John R.Lebetski
Sent: Friday, May 19, 2017 7:50:59 AM
To: gmclist-AT-list-DOT-gmcnet-DOT-org
Subject: Re: [GMCnet] shift kit pro's and cons

The idea behind Transgo and other kits was to speed up the shift event and have less overlap. This in theory minimized the time the clutch packs were
slipping in a sacrificial manner. However this increases stresses elsewhere as the stored RPM energy had to be rapidly disipated. The guys at
Hydramatic were the best in the business at programing-- balancing comfort, drivability, durability and performance. That is 4 vectors kind of like
trying to have the old "balancing eggs on eggs" task work out. They were designed to shift seamlessly imperceptible under light throttle and firm as
loads increased. If you think about it in an 11k vehicle the loads are always high as if towing. Also going to harder shifts is a bad idea with FWD
where uneven traction surfaces can jerk you into another lane with hard shifts.
--
John Lebetski
Woodstock, IL
77 Eleganza II


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Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
69 Vette
29 Dodge
Re: [GMCnet] shift kit pro's and cons [message #317794 is a reply to message #317762] Fri, 19 May 2017 09:51 Go to previous messageGo to next message
BobDunahugh is currently offline  BobDunahugh   United States
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I've rebuilt many T400s, and a few T425s. As others have said. A very durable transmission. As an example. I just changed the trans in Barb's 73 GMC. That trans had never had any repairs made to it by the service records. And the extreme amount of grim built up on it. 220,000 mile, and pulling a toad. The key was timely fluid, and filter changes. Thus getting the junk out at each change. ( As a note. It never had synthetic put in it. ) So how could synthetics do better? GM's shift programming is excellent for our application. I've put shift kits in some of my trans at rebuild time. But to me. Our GMC's aren't the place to install one. Want mileage out of your T425. Let up a little at it's shift times. Change fluid, and filter at every 25,000 miles. Synthetic or not. I'm always pulling something. Much of the time my 403 is pulling up to 21,000 lbs GVW. And I have the 3:70 FD. Bob Dunahugh
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Re: [GMCnet] shift kit pro's and cons [message #317795 is a reply to message #317794] Fri, 19 May 2017 10:46 Go to previous messageGo to next message
joewilly is currently offline  joewilly   United States
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thanks for info, I'm going to give the owner another call and find out more about it,
he told me that Ken Frey did the work so I think it's installed correctly ,I may have to give Ken a call to find out more.
Joe


jwilly
Re: [GMCnet] shift kit pro's and cons [message #317802 is a reply to message #317795] Fri, 19 May 2017 18:26 Go to previous messageGo to next message
Kingsley Coach is currently offline  Kingsley Coach   United States
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Just curious..is Danny Dunn still doing transmissions??
Tks

Mike in NS

On Fri, May 19, 2017 at 12:47 PM, Joe williams wrote:

> thanks for info, I'm going to give the owner another call and find out
> more about it,
> he told me that Ken Frey did the work so I think it's installed correctly
> ,I may have to give Ken a call to find out more.
> Joe
> --
> jwilly
>
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--
Michael Beaton
1977 Kingsley 26-11
1977 Eleganza II 26-3
Antigonish, NS

Life is too short to hold a grudge; slash some tires and call it even !
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Re: [GMCnet] shift kit pro's and cons [message #317803 is a reply to message #317802] Fri, 19 May 2017 18:31 Go to previous messageGo to next message
powerjon is currently offline  powerjon   United States
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No not for a long time!

JR
> On May 19, 2017, at 7:26 PM, Kingsley Coach wrote:
>
> Just curious..is Danny Dunn still doing transmissions??
> Tks
>
> Mike in NS
>
> On Fri, May 19, 2017 at 12:47 PM, Joe williams wrote:
>
>> thanks for info, I'm going to give the owner another call and find out
>> more about it,
>> he told me that Ken Frey did the work so I think it's installed correctly
>> ,I may have to give Ken a call to find out more.
>> Joe
>> --
>> jwilly
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
>
>
> --
> Michael Beaton
> 1977 Kingsley 26-11
> 1977 Eleganza II 26-3
> Antigonish, NS
>
> Life is too short to hold a grudge; slash some tires and call it even !
> _______________________________________________
> GMCnet mailing list
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J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 30' Buskirk Stretch
75 Avion Under Reconstruction
Michigan
Re: shift kit pro's and cons [message #317811 is a reply to message #317730] Sat, 20 May 2017 14:28 Go to previous message
Chris Tyler is currently offline  Chris Tyler   United States
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Put in a number of 'shift kits' on SOBs years ago. These were Transgo brand as I recall, and were very mild- specificly for towing and RVs. THey only slightly firmed the shifts and required very little modification.

But you will definitly have issues if you put a high performance or race kit in heavy vehicle. It will increase the shock load, and although the 425 is a strong trans you will probably find the weak link.

That being said, ultra smooth barely perceptable Cadilac shifts come at the cost of slippage, and in a heavy high load vehicle would cause wear. I would imagine GM took settings into account for our applications

On a high powered light weight car, they do make a difference in durability.and performance. However, most trans guys I know do their own mods rather than a kit per se. Ill wager Manny boosts the line pressure a bit or tweaks something in the valve body a little without making the shits harder.


76 Glenbrook
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