Water in tranny

[Tyler Rea]

Well last weekend I took my truck out and got convinced into driving through a mud hole that left me sitting shin deep in water. I have a 76 Chevy pickup with a Turbo 350 After getting pulled out and driving my truck home I checked all my fluids and my tranny fluid looked like strawberry milk so I dropped the pan and changed the gasket, fluid, and filter. It started to occasionally slip. But I also recently changed my motor mounts which pulled my linkage out of adjustment so I thought it was just because of that so I adjusted it the best i could and it hasn't slipped since but when putting it in park it acts like it's still in neutral and will roll. I have to jiggle the shifter a little to get it all the way into park. Also, when At high rpms if I go full throttle my truck will sort of vibrate and shake and I can feel a routine clunking at my feet. I have absolutely no experience with transmissions and I need some advice on what to look at or do to it. I did some research online and a lot of people say when water gets into the tranny it most likely needs to be rebuilt.

 

[74 Shortbed]

All you did was change the fluid in the pan, you have just as much in the converter that' s still contaminated.. Two things you can do, switch converters(or have yours cleaned), or flush the system, undo the return line and put a hose on into a bucket and and run it and pour fluid through it until fluid is nice and red.

 

[Tyler Rea]

All you did was change the fluid in the pan, you have just as much in the converter that' s still contaminated.. Two things you can do, switch converters(or have yours cleaned), or flush the system, undo the return line and put a hose on into a bucket and and run it and pour fluid through it until fluid is nice and red.

Well I changed the fluid and ran to town and came back and checked it and it was white again so I changed the fluid a second time and it's stayed red since

 

[74 Shortbed]

Well I changed the fluid and ran to town and came back and checked it and it was white again so I changed the fluid a second time and it's stayed red since

Still have same issues??.

 

[Tyler Rea]

Still have same issues??.

Yup and getting worse

 

[74 Shortbed]

Yup and getting worse

Sounds like it's time to tear it down before it destroys itself.

 

[HotRodPC]

Sounds like the water has already taken it's toll on a clutch pack or two. Sometimes water in the valve body can quickly start rusting in a valve too and hang a valve up.

 

[HotRodPC]

Is this a Turbo 350 or a Turbo 400? Either way, if it went **** up due to water, A basic banner rebuild kit will make it good as new again. New Seals, New Gaskets, New Sealing rings, new clutches and I'd probably replace the band too and a new filter. Prolly well under $100 delivered to your door. Then get you a new reman converter for about $80 unless you're 100% confident you got all the water out of it, but for $80 of insurance I'd replace. The old converter may be caked with clutch material and the new rebuild and new fluid will break that **** loose and run it through your new rebuild.

 

[HotRodPC]

The band isn't used alot, so if it looks OK, clean it with some brake clean and let it dry real good and you could reuse it, but IIRC, they're only about $12 so may as well go new with it too. No need to spend the cash for steels, and if you do indeed some, I have some good used ones. I don't mind reusing steels so long as they're not chewed on, discolored from heat, or heat checked.

 

[Tyler Rea]

Hey guys sorry for the late post. But I got it checked out and it's definitely gonna be toasted if I keep driving it. So now I've been wondering about the difference between a th350 and th400. I've done some research on them but all the forums I've looked in have been about drag cars running insane amounts of horsepower. I have a sbc 400 in my truck and I know that they put out a decent amount of torque and was wondering what would be better for my truck. It's a 4wd and After ruining my last tranny in the mud I've decided I'm not gonna take it in the woods as much. What do you think would be a better purchase? Getting my 350 rebuilt or going for a th400?

 

[yevgenievich]

Good th350 rebuild will handle it fine, a good th400 will handle things better. If towing and bigger tires in the future, can be beneficial to go to th400. Otherwise might be not worth the trouble(adapters and possibly driveshaft changes)

 

[Snoots]

A TH350 will eat about 30 to 35 HP and a 400 about 45 to 50.
400 is heavier and more reciprocating mass.
A stout built TH350 should satisfy you. One with something like an RV setup.

 

[Tyler Rea]

So I went the th400 route and I've been learning to rebuild it with one of the local shops. The 400 came out of a humvee and I've heard that humvee trannies won't work in a square body is that true?

 

[HotRodPC]

Hmm??? Never heard that. Not sure what the reason would be that they wouldn't work? Is it an output shaft length different or something? Are you talking an actual Military H1?

 

[Tyler Rea]

Hmm??? Never heard that. Not sure what the reason would be that they wouldn't work? Is it an output shaft length different or something? Are you talking an actual Military H1?

Yes a real Humvee but I found out it fits now just looking for a 400 to 205 adapter. Anyone have one for sale?