ball drive

[tongham runfold]

am using ball drive on my Marder but only get about 120 hours use out of drive cups. Have been using the little springs in the cups which keep the tension on the shafts but also mean they are loading up in the same place everytime. Would leaving out springs give me more life out of cups?

 

[Mike1970]

I've never seen little tension spring in an FG ball drive system as they use a little rubber disc as a cushion. 120 Hrs on any car is a chunk of run time and things will wear. For the rubbers, I just use an old bicycle inner tube and cut discs out of that.

There is also the possibility that your car isn't adjusted correctly. Take off your rear shocks, hold your wishbone level and the should be 5mm to 10mm movement on the shaft.

To get the desired 3 degree to in, screw your forward turnbuckles in untill they're a thread or 3 off the plastic rod end/wishbone (make sure it's equal on both sides) then adjust your toe in on the rear most turnbuckle. You may need to give the front ones half a turn or so to get the required movement on the shaft.

You can also alternat where the shaft sits - move it round one every so often.

 

[tongham runfold]

I use the Elcon ball drive set http://www.elcon-models.com/products/baja/18529balldrivesystemxl with the XL wishbones http://www.elcon-models.com/products/baja/18557lowerwishbonelrxl
The shafts move about 3mm each way on the springs and are held in roughly the same place all the time (all my old cups are worn in exactly the same place) I change the balls fairly regularly (usually 'cos i lose them when i take it apart) Will try rubber discs then, see if they last longer with a bit more play

 

[Mike1970]

Most of what I've said about the wishbone and stuff isn't relevant to the set up you have. I'd say about 5mm max when the wishbone is level, make shure the shaft won't pop out on full droop.

 

[weeman]

120hrs seems like alot of run time ..i think that is great if mines lasted that long