700R4, question
Thread Starter
Staging Lane
Joined: Sep 2024
Posts: 58
Likes: 5
700R4, question I'd like to know if it is frowned on for us to re open old threads if there is something important to ask or add to them?
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Anyone have any ideas what this problem is?
New guy here 1st post other than the introduction deal. I have some ideas but would like to know what others think.
Brothers 88 Diesel Suburban been doing this since a rebuild about 16 years ago. No he doesn't use it much.
In his written words.
Shift manually into first, goes into 1st okay, then to 2nd, then rapidly, shifts back to first and stays there, will not up shift. Even if I stop and then reverse, it will still not shift up.
In drive if I go slow (up to 25 mph) it will shift up to 2nd and shift right back down to 1st, and stays till I come to a complete stop, and back up in reverse a little bit, and then back to drive and use a lot more throttle and then it will shift 1,2,3 etc. and will keep shifting normally when doing stop and go and normal driving.
----------
Anyone have any ideas what this problem is?
New guy here 1st post other than the introduction deal. I have some ideas but would like to know what others think.
Brothers 88 Diesel Suburban been doing this since a rebuild about 16 years ago. No he doesn't use it much.
In his written words.
Shift manually into first, goes into 1st okay, then to 2nd, then rapidly, shifts back to first and stays there, will not up shift. Even if I stop and then reverse, it will still not shift up.
In drive if I go slow (up to 25 mph) it will shift up to 2nd and shift right back down to 1st, and stays till I come to a complete stop, and back up in reverse a little bit, and then back to drive and use a lot more throttle and then it will shift 1,2,3 etc. and will keep shifting normally when doing stop and go and normal driving.
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From: BERWICK PA
It a guess of course but, Sounds like the release valve in the drum might be leaking maybe something in it . This would cause a 1-2-1 shift feel as when the 2-3 happened the oil would release the band but the leak would prevent apply of the 3-4 set .Just one idea on top of others mentioned. I also had a strange incident of this, I was teaching a new guy to build. He liked to wear these thin gloves to keep hands clean, Sometimes he would tear one. Well we got one on dyno and we had an intermittent 1-2-1 then sometimes normal 1-2-3 or a 1-2 even with 4th commanded.
Was and interesting time finding but I found it. Was a piece a piece of glove riding in he 3-4 groove in the input shaft and it would randomly block the feed hole lol. He stopped wearing gloves after that.
Was and interesting time finding but I found it. Was a piece a piece of glove riding in he 3-4 groove in the input shaft and it would randomly block the feed hole lol. He stopped wearing gloves after that.
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Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Thread Starter
Staging Lane
Joined: Sep 2024
Posts: 58
Likes: 5
Some shop did the work many years ago. Governor, I'd think is okay since it does upshift, read the 1st post. TV cable, it was a transmission shop so I'd think they know how to do that. Again it upshifts fine per 1st post.
Its the goofy needing to use reverse to clear it and then just step harder on the gas to make it work. Since it shifts there has to be Gov pressure, and that would over come the slow start Low TV pressure?
The step harder more rpms then okay shift would make higher TV pressure, but then it works okay then so again Gov pressure is doing its thing. I just think its a valve body spring issue of sorts.
Would the drum release still be an issue since it shifts okay as per the 1st post? Is manual low keeping the low reverse clutch applied? Yeah I know I need a gauge on it some day, that won't happen soon though.
Its the goofy needing to use reverse to clear it and then just step harder on the gas to make it work. Since it shifts there has to be Gov pressure, and that would over come the slow start Low TV pressure?
The step harder more rpms then okay shift would make higher TV pressure, but then it works okay then so again Gov pressure is doing its thing. I just think its a valve body spring issue of sorts.
Would the drum release still be an issue since it shifts okay as per the 1st post? Is manual low keeping the low reverse clutch applied? Yeah I know I need a gauge on it some day, that won't happen soon though.
LS1Tech Sponsor
Joined: Mar 2023
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From: BERWICK PA
Some shop did the work many years ago. Governor, I'd think is okay since it does upshift, read the 1st post. TV cable, it was a transmission shop so I'd think they know how to do that. Again it upshifts fine per 1st post.
Its the goofy needing to use reverse to clear it and then just step harder on the gas to make it work. Since it shifts there has to be Gov pressure, and that would over come the slow start Low TV pressure?
The step harder more rpms then okay shift would make higher TV pressure, but then it works okay then so again Gov pressure is doing its thing. I just think its a valve body spring issue of sorts.
Would the drum release still be an issue since it shifts okay as per the 1st post? Is manual low keeping the low reverse clutch applied? Yeah I know I need a gauge on it some day, that won't happen soon though.
Its the goofy needing to use reverse to clear it and then just step harder on the gas to make it work. Since it shifts there has to be Gov pressure, and that would over come the slow start Low TV pressure?
The step harder more rpms then okay shift would make higher TV pressure, but then it works okay then so again Gov pressure is doing its thing. I just think its a valve body spring issue of sorts.
Would the drum release still be an issue since it shifts okay as per the 1st post? Is manual low keeping the low reverse clutch applied? Yeah I know I need a gauge on it some day, that won't happen soon though.
__________________
Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
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Thread Starter
Staging Lane
Joined: Sep 2024
Posts: 58
Likes: 5
Yes I know per chart that it is applied. And I guess there would be a momentary release if 2nd goes in and then falls out. So the clutch would be releasing. So the problem has to be a valve issue of some sort. Which one?
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TECH Regular
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i think you really need to start with the basics here before worrying about valve body spring pressures. verify correct tv cable geometry and then adjustment (preferably with pan OFF) then take some pressure readings. The whole explanation reeks of someone non-technical trying to describe a problem that isn't related. Have you actually driven this vehicle? I deal with customers on a daily basis that say you must do "XYZ" for the problem to be replicated, when in reality "XYZ" has nothing to do with it.
i also question that if this has been doing this for 16 years after transmission work was preformed, why it was never taken back to the shop to get corrected?
i also question that if this has been doing this for 16 years after transmission work was preformed, why it was never taken back to the shop to get corrected?
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Joined: Mar 2023
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From: BERWICK PA
i think you really need to start with the basics here before worrying about valve body spring pressures. verify correct tv cable geometry and then adjustment (preferably with pan OFF) then take some pressure readings. The whole explanation reeks of someone non-technical trying to describe a problem that isn't related. Have you actually driven this vehicle? I deal with customers on a daily basis that say you must do "XYZ" for the problem to be replicated, when in reality "XYZ" has nothing to do with it.
i also question that if this has been doing this for 16 years after transmission work was preformed, why it was never taken back to the shop to get corrected?
i also question that if this has been doing this for 16 years after transmission work was preformed, why it was never taken back to the shop to get corrected?
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Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Frank formerly of Performabuilt, Now just me, What can I build for you today? Call or message me. Click sig pic for my facebook
Thread Starter
Staging Lane
Joined: Sep 2024
Posts: 58
Likes: 5
Yes but, I know the springs were stretched to match listed dimensions. So not a jump to a conclusion thing. I'd like to know spring loads per a specific dimension, to see if that stretching made one or more have more tension.
TECH Regular
Joined: Jan 2013
Posts: 463
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If you are dead set on valve body springs I would probably recommend the Transgo "SK" kit as it has valve body/shift valve springs as well as governor recal specifically for a diesel calibrated transmission. Their website has instructions which might be worth a read....
Thread Starter
Staging Lane
Joined: Sep 2024
Posts: 58
Likes: 5
Thank you for the advice, looks like that maybe very helpful. At some point in time will do pressure checks and make sure tv is set okay etc.