clunky driveshaft?

[james dunk350i]

I have a 350i series one fhc, the bearngs are tight no bushes that obviously need replacing on the rear. Yet from the right hand side a keep getting a clunking noise! could it be a tired cv joint? any ideas would be much apprciated...

[jmorgan]

UJ? Jack up, usual with an axle stand and check for play. Probably a good idea to then jack the hub up to normalish hieght as the UJ can knock when the arm is fully down and wheel turned due to the angle.


Ps, could be the trailing arm bush?

>> Edited by jmorgan on Friday 20th August 09:01

[350matt]

Bear in mind that on these cars the drive shaft is part of the suspension, so has to work quite hard, jack the car up until the offending wheel is off the ground. Wiggle the wheel from top to bottom there may be a small amount of play about 2-3mm at the wheel rim is normal. there should be no play when wiggling side to side. If you've got more play than the few mm top to bottom then its likely you'll need to replace a UJ, which can be done at home with the aid of a vice, correctly sized sockets / press tools and a hammer
If its side to side then either a wheel bearing (a proper press needed for this one) or the wishbone bushes are shot or the long bolt holding everthing together is loose.

Matt

[leorest]

The first thing I'd check is the front anti-roll bar mounting bracket. I've broken/replaced a couple of these and haven't had time to up-rate them yet. I know it's the other end of the car but it's only two-seconds to check.

The driveshaft is highly stressed. Not only does it transmit power (V8) it has to provide breaking (inboard disks) and provide suspension (top link). So the UJs don't last long.

I have re-bushed my suspension and replaced UJs. The UJs (with regular greasing) have normally lasted 7000 miles (without any track days!). The last set lasted less than 2000 miles when the yoke cracked, probably due to worn bearing journals.

As others have suggested, when the chassis is on axle stands, move the road wheel up and down and look for movement between yokes either side of the UJ spider. Rotate the wheel so that one of the UJ bearings is at the top, check for play and then rotate the wheel through 90degrees and compare. If it is a UJ replace both on that side.

If you get fed up with replacing UJs on a regular basis then send both driveshafts to Martin Adams of Proptech Hartlebury and he will re-manufacture them into up-rated items for a very reasonable price.
NOTE Proptech probably made the original items for TVR and have all the drawings to make the up-rated items, as fitted to the more exotic later wedges, so these should be reliable for the application.

Leo

[james dunk350i]

cheers lads, I will be trying those out over the weekend.

[350zwelgje]

Broken rear spring/shock absorber gone perhaps? Worth a check anyway.
But agree that it is most likely to be one or more UJs.
Nuts fixing the drive shaft to the differential, if loose, could also be a possible source.

Rob