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Author Topic:   Transmission/drive shaft?
ez2bcheesy
Dirt Roller

Total posts: 6
posted May 31, 2002 04:35 PM
How much play should I have between the rear of my transmission and the front yoke on the drive shaft. I've looked at several cars and the play in the driveshaft varies..Thanks in advance!!!

modified17
Dirt Roller

Total posts: 20
posted May 31, 2002 06:29 PM
You need just enough play so when your rear suspension works, the driveshaft and transmission doesn't bind. Take a floor jack and jack up each corner of the car independantly and check the slack. Make sure your getting the full travel of your springs or shocks to be sure. Sometimes I'll take the rear springs out and test on the minimum and maximum travel of the shocks. If it doesn't bind there, it shouldn't bind on the track.

awkwardjeff
Dirt Freak

Total posts: 390
posted June 01, 2002 09:36 AM
ez2bcheesy, The reason you see different distances from the tailshaft to the yoke is because yokes are different, if you use a jeep yoke which is a long one it bottoms out in the tranny different because of the splines inside the yoke. If you use the long yoke from afco the splines are different again........then the stock chevy one is a short yoke so that looks different again,....

I have 3 different driveshafts........and they all have different yokes.......the proper way to measure for driveshaft legnth is to install the yoke in the tranny./...completely bottom it out in the tranny...........then pull it back out 1 3/8 inch.........now measure the center to center..........that will give you the shaft legnth. NONE of my driveshafts bottom out when racing, or fall out..........but NONE look the same..............if you have less than 1 1/4 before bottoming out in the tranny you will bottom it and brake the tranny, or the shaft........if you have more than a 1 1/2 you will pull it out while racing and brake things..........

this is a very important measurement, set the car at proper ride hieghts and set pinion angle.......complete race ready BEFORE measuring drive shaft legnth.

Jeff

[This message has been edited by awkwardjeff (edited June 01, 2002).]

George Gilliland
Dirt Full Roller

Total posts: 39
posted June 01, 2002 09:38 AM
The amount of free play needed depends on how the rear suspension moves, if you have shocks and springs to absorb the torque reaction you will need about and inch. If you links are all solid you need about half of that. If you put a very thin layer of grease on it then you can inspect this after racing and see how much is used. If this binds you can distroy the rear seal and cause binding is the suspension.

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