Moparts Tech Archive
727 front clutch springsmdrglass
From: Mad River CA
Registered: Nov 1999
posted 07-03-2002 12:32 AM
I have a 727 trans i am building for a track only demon. 4000 stall and a griner reverse valve body. In the front clutch pack, which is better 9,11,or 13 springs and why. Thanks mdr ps 360 small block, 4.56 gear
The higher ratio band apply levers require more springs to balance the overlap
The trans has a 2.9 lever now and I was planning on leaving it. It came with the 9 springs but I have another clutch set with 11 springs. Just want to be sure before I put it all together. Thanks for the help. mdr
If you look over your Griner instructions, it says use all 15 springs if possible. I would try to use at least 12. Call Griner to make sure. The springs in the front clutch and the kickdown servo springs work together to provide the best 2-3 shift timing. Also, if you are using a High Pressure valvebody from Griner, it makes a difference. They make a Low & High Pressure unit. Look for an "L" or an "H" stamped on the valve casting. I would use a 3.8 band lever with that set-up. Also, you can use a 4.2, but not the 5.0. John
I am waiting on the vb from steve, so i better wait on the trans build till it gets here. He did not mention the lever change on the phone, but will check with him. Thanks John for the help. Jon
Which valve bodies(Full Manual) do you recommend to use for drag racing that apply the low gear band?
mdrglass - You can use the 2.9, but Bill told me the 3.8 lever is the best one to use in a 727 under 600 HP.
You can run as much HP as you want. You just have to be careful to do burnouts in 2nd and 3rd, and don't hit the throttle in 1st, let off, and get back on it. This will damage the rollers in the sprague. Even a bolt-in sprague cannot prevent roller damage. Just use common sense when driving with this VB. John
Say I jump on the gas and its a xxxx track, car goes towards the wall and you back off, should I get back on the throttle or feed it in slowly?
If you loose traction, you can let off and shift to 2nd when you get a chance. If you hit the gas again, the trans will free wheel until the rpm of the driveshaft matches the internal parts, then it will lock up. The rpm of the engine will rise until they match. This stresses the rollers.
The short spring, ~1.400" was used 1967+, and the long spring, ~1.600" was used from 1962-1966. Use the short spring. John
I have a TA RMVB and a 4.2 lever in a otherwise stock 727 transmission. On the 2nd to 3rd shift the engine will rev slightly before 3rd engages. How could I fix this problem? Thanks, Clay.
Try a kickdown band adjustment first. Snug the center screw in, then back off 1-1/2 turns. What kickdown servo do you have? The early solid servo with 2 springs, 1970 or earlier or the controlled load oil cushion servo 1971+? The best one to have is the early servo with 2 springs. Also, what was your high clutch clearance? If it's alot, it could cause problems. I would try the band adjustment first and see what happens. If the band does not change the problem, you'll probably have to go into the tranny. John
John, I don't know a lot about the transmission other than it was rebuilt before I got the car. I'll try that adjustment. Thank, Clay.
Griner also makes a rear band apply valve body in reverse manual and trans brake for the 727&904
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