Stupid th-350

[Lt.Del]

Another thing to throw out here---I don't know if you are the only driver of the truck, but, I wonder if the extra stress is from putting it in reverse while still going forward, or, putting it in drive before coming to a complete stop in reverse.  I have been with people who have a bad habit of using the tranny as a break while backing up (putting it in drive before stopping, etc...)

Just a thought.

SgtDel
aka "Andy"

www.delbridge.net

1979 Big 10 383 stroker
1991 Blu 'Burb 3/4 ton 4x4

[79ChevyK20Guy]

I've actually been known to do that from time to time when I'm in a hurry so I'll keep an eye on it and see if this could be the problem, thanks for all of your advice we'll see how things work out

[alansres]

The TH-350 in a truck behind a torquey motor is a bit light, especially so in a truck with big tires & wheels.  You have very little give in your drive train, and the intermediate sprag is light, needs to be the performance part, all planetaries need to be in top shape, and the valve body should be done right.  You want to run line pressure low enough for some slippage.  One problem is the 2-3 shift, and the clutch drums need to have drain holes...  Also the trans case needs to be the truck 4 x 4 model, as the others are too light for a transfer case.  There is a lot of trick stuff to do far too much to mention, but all of it is necessary.  Most go to a TH400 because it is so strong that everything doesn't have to be perfect, and it is a natural for a truck since your driveline dynamics are so heavy anyway.  (The TH350 is better in a car since it is like a lighter flywheel, where the TH400 drums and planetaries are so heavy).   But the real deal is to beef a 700 R4 so that you not only have a great low gear so that you don't need a stall converter, you also have OD with 4WD and you also gain gas mileage.  Also, its yoke and splines are the same as the TH350, and it is only slightly longer.   That is what I went to.

Alansres