I've already bought a replacement tranny but haven't put it in yet. I'm now second-guessing myself that my tranny is bad but I want opinions. My truck is a '94 with a 318 so I think it's a 46RH tranny. Sorry this is a little long.

Anyway, the tranny worked great until early this year when the truck's rear diff started making noise. I didn't drive the truck for 2 months till I got around to replacing bearings in the diff. But since then the tranny never worked right. It shifted late and the torque converter clutch didn't work. I had never changed the fluid in the truck, though I'd only had it for 20k miles. Fluid was red though a little dark, and smelled kind of like diesel fuel.

I did a fluid and filter change but it didn't help. There was a funny smell from the tranny and it was getting hot, and I found that the cooler was clogged Not sure if it was clogged before the fluid change or not. Flushed out the cooler, changed fluid and filter again, then the torque conveter clutch worked again but it still shifted funny. Then 5 miles later the tranny quit, got the truck towed and found the filter clogged with crap that had the consistency of wet clay. New fluid and filter again and the tranny worked again, shifting is better but still late, though the torque converter clutch shuddered violently at 45-50 MPH.

I originally thought the wet clay was a very bad sign that means the tranny is coming apart. But my new theory is that the fluid changes stirred up the crap that was already in the tranny and clogged the cooler and filter, and maybe all I need to do is flush or change the fluid a few more times. But a flush isn't free and ATF+4 isn't either and I don't want to keep chasing ghosts.

So I'm wondering if I should just put in the replacement tranny and be done with it, or if I should try a flush or just keep up the fluid and filter changes and see what happens? I don't want to sink any more money into the truck if I don't need to, but I also don't want to swap a tranny if I don't need to.

Thanks for reading.

 

Sounds like you've went threw alot of trouble thus far with a few little positive results. If the tranny is spitting out clay like fluid odds are you wouldnt be able to clean it properly without a complete tear down. Tranny's in general are sensitive to heat, sludge etc...tobegin with, So odds are at this pointit may be in vein to continue messing with it.

If you've got a good replacement I would opt for that direction.

Otherwise I would take it to a tranny shop and have it serviced with a professional flush, filter etc.

Good luck, Ive been threw the tranny blues and its no fun!

 

ok, i'm making a couple of assumptions...
transmission is original, 13 years old, probably has 150k+ miles on it, you don't want to work on your transmission every day, and you don't want to get towed home any more.
since you already have a new trans, i'd replace it and move on. also remove the check valve in the return line. i think most shops do this.

how much sludge was in the bottom of the pan? probably a good 1/8 - 1/4 layer ?
you're probably right about all this sludge releasing back into suspension, but you might go through this several times to ever get it cleaned out, and then you still have a 13 yr old trans thats gotten hot, and clogged up, and its just likely to wear you out with one problem after another. and lastly, i think a lot of the sludge is worn deposits from clutches and bands. key word is 'worn'.

 

Thanks guys. Yeah, the truck's got 150k on original drivetrain. Yeah I know replacing the tranny now would end my grief but if I just got 10k more out of the old tranny I'd be happy. Would give me time to rebuild the 360 sitting in my garage and put in the new engine and tranny together.

Maybe I'll try one more fluid and filter change and if nothing improves I'll just swap it. And hope I don't have to get the truck towed again...