Tranny fixin' to go?

[woogs]

Howdy from Texas yall, I have a '95 C1500, 2WD, 5.7L, with an Automatic Transmission. I baught it from my Brother-in-law in May. The bushing on the slip yoke had seized up and it got hot and cracked the tail housing. I threw on a new tail housing, yoke, bushing and seal and it still drives and shifts. But I can't go over about 65. It shifts great up till then, and will maintain about 1800rpms at 65mph. But at about 67-68 it will downshift so I'm turning 3,000-3,500rpms and it starts bucking, and the speedometer needle starts jumping around. If this happens while it's still cool I can slow down and it will upshift again. But if I've already got it warm I can come to a complete stop and accelerate and it won't ever get out of 3rd no matter how fast I go. Also when it's that warm and I'm accelerating from a complete stop it feels like the lower gears are slipping. Does this sound like it's fixin' to go? and what might I oughta check? it's got 159k miles on it, and my brother-in-law was doing 80 when it siezed up. But he stopped immeditatly and had it towed.

thanks

-matt

[bobcat5544]

it's not the trans goning out, it's the speed sensor in the tail shaft houseing, make sure it is not damaged, and also look in side there should be a gear that goes around the out put tail shaft. one of the two are bad or the tail shaft houseing is a different design the the one that was on the trans before

[pwall]

Welcome to

[ken1mod]

agreed.

 

ken

[woogs]

Thanks, I completely forgot about that. It's been out prolly four times and I could have damaged it, and it was in there when the tail housing cracked. It'll be Sunday before I can get to it, but I'll let yall know how it turns out. Also I havn't been able to stop it from leaking fluid out the pin hole in the Slip yoke. I took it off and packed with with grease on recomendation from a mechanic, but that only stopped it a short while. The Fluid has gotten low enough that it only leaks now when I park it uphill. Any idea what to do with that?

thanks

-matt

[sleeper42]

this problem sounds very similar to mine. I have a 2000 Silverado 4x4 w/ the 5.3L. It only has 47k on it, and I'm not sure what's going on. When you punch it from a go it sounds like it's not gonna shift out of first sometimes. Othertimes it feels as though it's hunting to find the right gear when cruising at 70mph and you're looking to pass. So I'm assuming this would be the same issue? If so what's it cost to fix this?

[bobcat5544]

this problem sounds very similar to mine.  I have a 2000 Silverado 4x4 w/ the 5.3L.  It only has 47k on it, and I'm not sure what's going on.  When you punch it from a go it sounds like it's not gonna shift out of first sometimes.  Othertimes it feels as though it's hunting to find the right gear when cruising at 70mph and you're looking to pass.  So I'm assuming this would be the same issue?  If so what's it cost to fix this?

 

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If you would please explain exactly what your truck is doing, your problem most likely is not going to be the same as woogs Trans problem. do to his transmission is a 700R4 for a 2 wheel drive truck and yours has a 4L60E on a 4 wheel drive truck the main difference is woogs trans is half vacuum half electrical operated, and yours is fully control by the PCM

If your speed sensor was bad your trans will default to 2nd gear and will not shift out of 2nd

[sleeper42]

If you would please explain exactly what your truck is doing, your problem most likely is not going to be the same as woogs Trans problem. do to his transmission is a 700R4 for a 2 wheel drive truck and yours has a 4L60E on a 4 wheel drive truck the main difference is woogs trans is half vacuum half electrical operated, and yours is fully control by the PCM

If your speed sensor was bad your trans will default to 2nd gear and will not shift out of 2nd

 

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Ahh sorry I'm still a newbie to this truck. I only just acquired it recently. Basically here's the scoop. When I go to accelerate, let's just say floor it. It seems as though it maintains the same gear all the way to redline, but it doesn't feel as though it's gaining much momentum. Other times when I'm cruising at 70mph let's say up hill, it seems to have a hard time finding which gear to pick. So it switches back and forth, between downshifting and upshifting. When I go to pass someone it takes a while to kick down and pass. I'm not sure what the issue is. I hope it's nothing big, because I'm thinking of selling my forester and just Daily Drive this truck to save on payments.

[bobcat5544]

It sounds like some one has reprogrammed the trans shift points. the max rpm before the shift should not exceed 5400 rpm at max throttle if it exceeds 5400-6000 rpm then some did reprogram the PCM, do to at 5500 rpm the PCM will shut off the injectors to keep the engine from over revving.

Far as going up hill at a cruising speed its normal for the trans to flip flop back and forth from 3rd to 4th, the PCM uses the throttle positions sensor and the engine load sensor to determine what the best gear is at that time and if you don’t have the throttle down far enough it will flip flop

[sleeper42]

It sounds like some one has reprogrammed the trans shift points. the max rpm before the shift should not exceed 5400 rpm at max throttle if it exceeds 5400-6000 rpm then some did reprogram the PCM, do to at 5500 rpm the PCM will shut off the injectors to keep the engine from over revving.

Far as going up hill at a cruising speed its normal for the trans to flip flop back and forth from 3rd to 4th, the PCM uses the throttle positions sensor and the engine load sensor to determine what the best gear is at that time and if you don’t have the throttle down far enough it will flip flop

 

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ok thanks for the info. The vehicle has only been dealer serviced and I know when my father had the truck he took it in for this problem before. So I wonder if something was reprogrammed by the dealership. Thanks for the uphill info. I guess this is just normal for it to "hunt" for gears. I'll have to see if I can get the tranny shift program put back to normal.

[KICK]

ok thanks for the info. The vehicle has only been dealer serviced and I know when my father had the truck he took it in for this problem before. So I wonder if something was reprogrammed by the dealership. Thanks for the uphill info. I guess this is just normal for it to "hunt" for gears. I'll have to see if I can get the tranny shift program put back to normal.

 

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there is a simpler solution to the "gear hunting' problem than seeing if the shift program can be changed.

 

this solution involves moving the shift selector from the range ( such as 4 or OD) that is having "issues" to the next lower range such as ( 3 or D).

 

this solution is known to work wonders in all types of vehicles that are equipped with automatic transmissions and tall gearing.

[woogs]

thanks yall, I replaced my speed sensor and you were exactly right.

-matt

[superbee]

Kick's right, just turn the radio up. That'll fix it...

[bobcat5544]

thanks yall, I replaced my speed sensor and you were exactly right.

-matt

 

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Great, If you have any other probs just let me know

[woogs]

thanks yall, I replaced my speed sensor and you were exactly right.

-matt

 

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Great, If you have any other probs just let me know

 

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yeah, I may have an answer, but here's another problem I'm working on.

 

http://www.gm-trucks.com/forums/index.php?...topic=55994&hl=

 

thanks

-matt