Transmission Issue

[john65002]

Hi. New to the forum and this is third time trying to post something without having computer troubles so i'm going to keep it short lol.

I have a TH400 that was in a truck for about 6 years of sitting. Recently brought truck back to life. Transmission had water in it so we replaced filter, gasket, and fluid twice. Tried driving it yesterday and acts like its stuck in granny low(like a manual) as soon as you let off the gas. Its bad enough were it will almost lock the back wheels up. It also will not shift. I thought it might be the shift module but replaced that(as long as made sure there was proper vacuum) and still does the same thing. Any and all help is appreciated. Thank you.

 

[HotRodPC]

Sorry to hear of your posting problems. Hopefully your computer and not our server problems. Well, not literally, but I hope you get it figured out soon and it's not everyone else having a problem too. I'm getting along just fine on the forum, so I don't think it's us.

I hate to be the guy with the bad news, but I'm going to say 95% chance, and I only say 95% instead of 100% cuz I'd love to be wrong and gonna give 5% chance I am wrong. But, the trans is going to need rebuilt. I did one that say for just 6 months and got water in it. Trashed it. The part where it's like in granny gear, it's probably got a band servo stuck on or seized, and it's actually trying to be in 2 gears at the same time. Not really 2 gears at the same time, but a drum that is applied and trying to turn, it probably being held up by a band. Any # of things can be wrong, but it really needs to be tore down and gone through to be honest. Alone sitting for 6 years is enough to kill it, but there's still a 50/50 of at least short term revival depending on how the fluid looked, was it out in the weather or in a garage under a shelf, cold weather, hot weather, humid weather etc all matters when they sit. I've also seen them where mud dabbers got down in them and created mud in them. Just my honest opinion buddy.

Anyone else have a suggestion, agree or disagree please post up. Don't kill it just cuz I said so.

 

[crazy4offroad]

Valve body is one of the biggest things that suffers when water is present. You might try dropping the vb and cleaning all the valves, springs and ports and make sure everything is moving freely. Depending how much water though, other internals could be rusted up pretty bad from sitting so long. If you were just getting rid of it and getting the trans to work I would just do the vb but if you plan on running it I agree with HR, the trans needs an overhaul. You dont want it just crapping out all of a sudden one day at the most inopportune moment, towing, on a trail, on an extended drive somewhere.

 

[74 Shortbed]

Rust in the valve body, actually the tranny should be torn down and cleaned up..

 

[john65002]

Sorry to hear of your posting problems. Hopefully your computer and not our server problems. Well, not literally, but I hope you get it figured out soon and it's not everyone else having a problem too. I'm getting along just fine on the forum, so I don't think it's us.

I hate to be the guy with the bad news, but I'm going to say 95% chance, and I only say 95% instead of 100% cuz I'd love to be wrong and gonna give 5% chance I am wrong. But, the trans is going to need rebuilt. I did one that say for just 6 months and got water in it. Trashed it. The part where it's like in granny gear, it's probably got a band servo stuck on or seized, and it's actually trying to be in 2 gears at the same time. Not really 2 gears at the same time, but a drum that is applied and trying to turn, it probably being held up by a band. Any # of things can be wrong, but it really needs to be tore down and gone through to be honest. Alone sitting for 6 years is enough to kill it, but there's still a 50/50 of at least short term revival depending on how the fluid looked, was it out in the weather or in a garage under a shelf, cold weather, hot weather, humid weather etc all matters when they sit. I've also seen them where mud dabbers got down in them and created mud in them. Just my honest opinion buddy.

Anyone else have a suggestion, agree or disagree please post up. Don't kill it just cuz I said so.

Thanks for the reply. I have a 700r4 that for the time being, I might throw in it. I know 100% it shifts good and everything works, and even though it is mostly put down in the truck world, it would at least get the truck moving where I could drive it to town.

 

[HotRodPC]

The only bad news about using the 700r4 until you get the Th400 built is the face of length differences. Also spline count differences. So this means different transfer case, different adapter, modifications to the front and rear driveshafts. With all that being said, the Th400 build is your cheaper and most durable way out of this situation.

 

[john65002]

The only bad news about using the 700r4 until you get the Th400 built is the face of length differences. Also spline count differences. So this means different transfer case, different adapter, modifications to the front and rear driveshafts. With all that being said, the Th400 build is your cheaper and most durable way out of this situation.

I forgot to mention I have the same 208 that came with 700r4 also so won't be a problem there. However, after doing a little test today in the rain, I was able to see that my passenger side rear tire was the one that locks up when I let off the gas. However it doesn't always lock up. On another note aswell, the break are very very touchy. Barely touch the pedal and your stopped. I'm wondering if maybe it isn't tranny and its break stick and holding?

 

[highdesertrange]

sounds to me like you have a brake lock up issue. highdesertranger

 

[HotRodPC]

I forgot to mention I have the same 208 that came with 700r4 also so won't be a problem there. However, after doing a little test today in the rain, I was able to see that my passenger side rear tire was the one that locks up when I let off the gas. However it doesn't always lock up. On another note aswell, the break are very very touchy. Barely touch the pedal and your stopped. I'm wondering if maybe it isn't tranny and its break stick and holding?

Certainly could be. It doesn't take that long to pull the wheels and do a brake inspection. Probably going to be the rear brakes since you haven't mentioned anything about the steering have a pull to the left or the right. If one of the front brakes was hung up you'd know it and feel it in the steering. So I'd pull the rear wheels.