Automatic tranny in 95 2500 Studders randomly

[xtrempickup]

--------------------------------------------------------------------------------

I dunno if this is in the right place, but this is the only place I saw anything about Transmissions. My truck is a 95 2500 GMC Sierra 4x4 ext cab 6ft bed with a 6.5L turbo and a automatic transmission. I bought the truck with 148K miles and had it trans serviced within a week because it would studder under load randomly. The trans place said the fluid was burnt up and the trans flush and filter might not help it. 152K miles later, it helped a little, but it still does this randomly. It studders, usually accelerating around 35mph I'm guessing trans shifting 2-3rd gear. It will do it on the highway under load above 40 mph sometimes. I was told these trucks had poor torque convertors and that this might be the problem, the convertor might not be holding right anymores. From personal experiences, can anybody tell me what they think might be the problem and what I should do. This doesnt happen everyday, keep that in mind, It will drive great for days sometimes and it wont act up at all, sort like the fact it shuts off on my randomly sometimes that I havent figured out the cause of yet either.

[B.A.M.6.2]

converter lock-up occurs allmost right after the 2-3 shift, that sounds like what you may be feeling; especially with those miles

[xtrempickup]

ok so if this is around when lock up occurs, then this probably means my convertor isnt locking up all the time anymore and holding. it wont accelerate, more or less studder when this happens. Do i need a new convertor? anybody?

[B.A.M.6.2]

it could be the clutch insde the torque is deteriorated, or the lock-up solinoid isn't working properly. There are a few other things that could factor in as this is an electronically controlled trans. It should be a 4L80-E and there were were various problems with some of these most of whitch should be addressed with a competent rebuild and update. I just suggest that because of the milage & fluid condition you stated.

[xtrempickup]

ok sounds like thats not gonna happen, I guess im driving it til the tranny falls out or hopefully I sell it before then. I hate complicated problems

[carymc]

There are many post on this forum about engine shuting down. Mine would miss/jump on a pull and at time would shut off completely after start. I had three problems.
(1) Engine shut down and restart quickly was PMD on injector pump. I got a pmd and heatsync move the pmd away from the injector pump, (see post of the forum about the problem).

(2) Engine shutter/jump on pull. This was either the fuel supply pump or the oil sending unit. I replace both at the same time and problem solved. My oil preasure increased is why I said I had three problems.

[gmctd]

Check your lift pump, fuel filter, and OPS for proper operation - can also be the in-tank sock filter, and bad fuel.

Check your battery cables and posts for corrosion\oxidation, and the PCM\engine grounds on the passenger-side rear intake manifold.

The TCC brake switch and solenoid may be flaky, and the PCM pulses the line pressure solenoid to full pressure every few minutes to prevent sticking, so it does wear out as mileage increases.

The FSD\PMD, on the Inj Pump, may be failing, which causes the stalling\dying with restart till it dies, then no restart.

Some failures will log error codes - DTC's - in the PCM - any SES indication?

[xtrempickup]

lost the tranny shuddering, now i just have the fuel starvation problem. I changed the LP and fuel filter. been getting crappy mileage i have to say also. I have the new OPS, need to do it when the socket i got on order comes in.