October 22, 2018, 09:53 AM
banjoTransmission update
Hello all, just want to give an update on what I have found so far on my transmission
I went in and replaced all the bushings and the transmission case along with rebuilding the planets. Seemed to remove a lot of endplay, everything turns alot smoother.
The total endplay ended up at .013. It was probably in the .030-.04 when I build it, because I failed to take into account the pump gasket.
One thing I did find was I screwed up the clutch clearance on the forward drum. I found that in only had about .035 total clearance. How it didn't burn up all the clutches is beyond me. I speculate that at times the clutches were dragging more and it was trying to go to 1st and second gear at the same time. Definitely could explain what I felt in the car. It was definitely intermittent. I can only assume as things wore it caused this to get worse. New clearance is .095. I also went 7 to 5 clutches.
On the reverse clutch, I got a new piston so it eliminates some of the extra steels. I went from 6 to 5 clutches.
Definitely feel I got alot better handle on rebuilding a powerglide. First time I did it, I was in a hurry to make a race and definitely made some mistakes.
Has anyone ever tried one of these? I am going to try one to see if it helps maintain temp in the transmission.
la-210019240151&CATARGETID=230006180039217234&cadevice=m&gclid=Cj0KCQjw6rXeBRD3ARIsAD9ni9BSiJ8OlhrTPUFjjepgJHBvmXvaLX3iqiu12OSeO3ie7qtnl667p0UaAmybEALw_wcB" target="_blank">Oil thermostatThanks
October 22, 2018, 01:03 PM
banjoRegarding the high drum clearance, was looking at the powerglide manual and it shows for a stock setup, minimum clearance is .004 per friction, looks like I had the bare minimum for a stock setuo
Those of you that build transmissions, do you function check them with air? I still have the valve body off and I was cycling each clutch. Low and high gear turn like butter and I can turn the input shaft pretty easily by hand. When I engage reverse, it takes a good bit to turn. I put a set of voice grips on it and it turns smooth, just takes more force then low and high. Is this normal? Transmission is still hanging so not sure if it has anything to do with it. Thanks
October 22, 2018, 05:56 PM
790G T/DI bought adaptors for air testing, technical books and tools from Carl(RIP)@ TSR. I think they still sell them still. I air test everything that I can then follow up with pressure checks @ 1400 - 1500 rpm in the car.
October 26, 2018, 03:12 PM
banjoWell, got the transmission in the car, fire it. Reverse works, but slow to engage, 1st and second work great. I have the car on jack stands at this point. Put it in first and hit the button and slowly bring up the rpms. Wheels start to turn. Dam, reverse clutchs aren't holding. Check the fluid level, add a little fluid. Hit the button again and slowly bring up the rpms and the wheels start to turn. Let go of the button and the wheels don't start turning. Shift into high, and the wheels start turning. I have a pro brake, put it in reverse and the wheels start turning backwards without hitting the button. Crap shut it off. I have the transbrake valve with the spring on it. I hit the t-brake and I can't hear it. Wiring checks good.
Pull the transbrake solenoid off, and find that the valve is stuck. Dumb azz move #1, I put the original bent valve back in.
So I get the new valve and its moving smooth.
Get it back together, fire it up. Transbrake is still not holding.
I have two breathers on my transmission, and I had just put new lines on there and hadn't run them into an overflow. They are just laying across the top of the engine. This is about the point that I realize that fluid is flowing out of the lines all over my engine and floor.
Thinking crap, something is bad wrong with this thing. Going to have to come back out. So I got into my shop to get some cleaning supplies, and I look over and see the plate that goes between the rear support and the case.
So I put the plate back in there, and everything is happy.
So powerglide building tips, if you identify bad parts, ensure you get them out of your work area.
#2, don't forget the rear plate.
Plan is to race it tomorrow, hopefully all my headaches are behind me. Will update later.
thanks
October 26, 2018, 03:53 PM
chasracer
Yep - that plate is mighty important. If you ever decide to, I like the aftermarket support plate with the roller bearing in it. It eliminates that plate.
October 28, 2018, 11:52 AM
banjoI got to run it this weekend, and my issue is fixed!, 9 passes off the foot-brake, over 7 hours, the 60-330 moved .010. I actually pulled out a win the first time out with it. This is a new track for me at higher altitude then I usually race at, but it appears I picked up close to a 10th. In two weeks I will race at a track that I have more paper on and will be able to determine definitively.
October 28, 2018, 12:12 PM
Curly1Congratulations on the win and glad you resolved the issue.
October 28, 2018, 09:07 PM
BrktracerNice job, Bill! Congrats on your win and your success in rebuilding your own transmission. Well deserved win!