Drive backlash

[chriswilliams]

I have noticed a 'clunk' when I apply the drive and I think its 'backlash' or looseness in the drive train.

Its not in the drive shafts (there is no looseness in any of the joints) so it must be in the gearbox.

I did a measurement: I jacked up one side front, put the car in gear and then rotated the wheel back and forwards (the other wheel on the ground can't turn).

With a ruler on the top of the tire I can see that the backlash is about 35mm.

Has anyone else done this measurement and how does it compare with my 35mm?

Thanks,

Chris.

[alfadave]

Could the front engine mounting be torn?
Someone on here has a DIY fix for it.

[chriswilliams]

Unfortunately not.

The engine was not moving whilst doing this test.

Chris.

[Pedrokat36]

Although you say no movement in the driveshaft joints.... my sprint had a similar clunk between gear changes particularly noticeable in first and second. Mine turned out to be wear in the inner CV's. I just wish I could find new outers now.... new inners on 40 Yr old shafts made the world of difference.
I think there is an amount of slop in the diff as standard, if I get time later I will Jack my car up and try your test .
Cheers
Peter

[Pedrokat36]

So I Jacked my sprint up, for another job and had a look.... slightly different test but very similar to yours.... both front wheels in air.... gearbox in first, if I spin one wheel there is say 15 to 20mm play before other wheel starts to rotate in opposite direction....eg... back lash in diff.
Hopefully this is of use.
I should mention my gearbox has no issues, infact it's a replacement I fitted last winter and it's been good as gold for a year, infact it was like night and day compared to original.
Cheers
Peter