Okay, so I had posted before about my problem, tranny is not shifting back to 1st when stopping/starting, i.e. if I am at a red light, when I hit the gas, I am starting in 2nd almost every time. The 2-3 shift works fine and the 3-2 shift seems to be okay. So, I got a standard service done the other day: drop the pan, new filter, top off fluid. I had waited too long to do this, 40K-60k, but I was hoping for the best. Well, no difference, still starting in 2nd. It will manually go into 1st just fine. Here is another thing I discovered the other day. If I am at a red light and I drop the shifter into 1st, then back to Drive, when the light turns green, I start in 1st and my 1-2 and 2-3 shifts occur as they are supposed to. So, did I just wait too long for a fluid change and I need a rebuild or is it something else?
Zach, Common problem, here is what happens. The valve in the governor is likely sticking. If some of the crud from the pan gets into the governor valve, it causes it to stick and not exhaust pressure from the shift valves. The 1-2 valve remains open and you start out in 2nd. Shifting into low, manually puts the valve in 1st and it stays there until it shifts to 2nd again. Cleaning the governor may help, but sometimes does not solve the problem permanently. In rare situations, the governor bore in the case actually wears and there is too much clearance between the governor and the case. This causes oil to go past the governor and keep the valves open. This doesn't happen often, but can be a cause. When I rebuild a TH400 governor, I will put a tiny spring in the end of the valve to make sure the valve will not remain open. If your problem continues, I can rework a governor for you (or do yours) and install the spring. Hopefully the deep freeze will break and I can take a look at it for you. Feel free to stop by or send me a PM. Take Care, Mark
Thanks for the replies guys. Thank you for the offer Mark, I may take you up on that. Looking at my Chassic book, it seems pretty easy to get to the governor. Do I just take the cover off and spray carb cleaner (or something else?) in there or do I take out the governor and then spray it down?
Take the governor out. Grasp the gear end and hold it up so you can look into the passages in the shaft. Move the weights in and out. You should see a valve inside the passages moving up and down as the weights move.
Zach, Yes, exactly what Dwayne said. Get the solvent in there and hold the weights in and shake the governor up and down. The valve should move freely. The pour trans oil into the governor. The governor is easy to get to and is held in by 4 bolts. However, if you have the original trans gasket on the cover, it may fall apart when you take it off. I would suggest you go to a trans shop and try to get a new gasket. You could make one from gasket paper if necessary. DO NOT use RTV silcone!! My opinion on this stuff is that any excess can fall into the trans and cause more problems. Some guys have luck with it, but I don't trust it. My take is that it is too slippery and will cause leaks as well. Take the time to find the proper gasket. Hope this gives you some options. Mark
