Transmission help

[landarts]

I finally finished up my long build enough to drive it . The build was over a eight year period. Before I tore the truck down it was a daily driver that ran well and had no mechanical issues, 350 v8 motor with a TH350 transmission. It would from time to time have a small drip or two of transmission fluid as well as engine oil. When I finally got it back together and on the road it leaks transmission oil about 18" x 18" puddle.

Here are the items I noticed after the first drive out of the neighborhood. The truck would not shift out of first gear. Went back home and drained all the transmission fluid and replaced the oil, filter, modulator, also replaced the vacuum line. The truck now shifts into all gears but it shifts really late. It has to get to high rpm's before it will shift. For example where it used to shift around 20 mph now has to go to 35 mph with high rpm's.

So the two problems with the TH350 are it is shifting late and is leaking badly. Does this need to be rebuilt? Is this something a first timer can do? Please advise, and thanks in advance.

[rjs53]

If its the same trans and has been sitting for years, the governor may be sticking. Pull it out and check the springs and weights, see if their gummed up.

[landarts]

Thanks, it is the same transmission that has been sitting over 8 years. I will pull the governor and give it a good cleaning.

[OldBlue70C10]

Sometimes the seals will harden when they sit for a long time as well. It may need taking apart and freshening up. You might try some Lucas stop slip, or something like that, and see if the seals will soften back up?

[landarts]

Sunday I was able to pull the governor and give it a good cleaning. When I first pulled it out it seemed like the piston inside was not moving up and down freely. So I removed the small pin that holds on the gear at top and cleaned everything real good with brake cleaner and it seemed to help with the piston moving up and down freely. Put it back together and went for a test drive.

The truck shifted the same, it shifted the first time at about 35 mph and the second shift at about 50 mph. When I had the governor out I also inspected the rubber connection at the manifold as well going into the modulator. All rubber was brand new and over the fittings properly. The modulator is also brand new, I do remember the guy at the NAPA counter saying that the modulator was an adjustable type. I guess that will be the last thing I try before looking at a new transmission.

Any other thoughts?

[Super Dude]

Yes most aftermarket modulators are adjustable. Remove vacuum hose. Look inside tube where hose goes. If there is a provision for a small flat screwdriver, then its adjustable. Turn the adjuster clockwise for earlier shifts and counterclockwise for later shifts.