I have a vibration issue with my auto TJ wagon.

It has 170,000km on it, and I've done most of those kms. The auto trans was rebuilt late last year.

I recently had the driveshafts replaced, as there was too much movement in them.
Since getting them replaced, I've been experiencing some vibrations coming through the chassis between 40 and 60km/h when accelerating.
The vibration is speed-related and not rev-related.

Interestingly, sometimes the vibration occurs badly, while other times it is almost negligible (ie, after cornering, the behaviour changes as the alignment changes).
Some experimentation confirms this appears to be related to the alignment of the left vs right driveshafts, as gentle acceleration between 40-60km/h around a long bend (freeway entry ramp) causes the vibration to come and go.

My mechanic has swapped out the driveshafts with some new replacements - with no change in behaviour.

Any thoughts or ideas?

The next step is to replace the transmission mount, and see if that makes any difference.

Ball joints!

170,000 km of dirt & bumpy country roads, or smooth bitumen?

In my case lower control arm bushes

Sure sounds like a ball joint problem but if 2 sets of replacements hasnt fixed it then perhaps its not. I had a similar issue but it was at much higher speeds. It felt like small corrugations in the road. It disappeared when I replaced the shafts and joints.

Ball joints!

170,000 km of dirt & bumpy country roads, or smooth bitumen?

Mostly smooth bitumen.


Sure sounds like a ball joint problem but if 2 sets of replacements hasnt fixed it then perhaps its not. I had a similar issue but it was at much higher speeds. It felt like small corrugations in the road. It disappeared when I replaced the shafts and joints.

Drive shafts and inner and outer CV joints have been replaced, and haven't resolved the issue yet.

Ball joints, lower control arm bushes, wheel bearings.

A lot of suspension places offer a $29 one hundred point suspension check.

If you tell them the symptoms they will hoist the car and be able to pin point the cause during the safety check.

Then just tell them you will think about their exorbitant quote, and take it back to your local mechanic and get him to replace the parts.

Jack the car and grab the wheel at 3 and 9 o'clock and shake vigorously. Any movement whatsoever is a sure sign your wheel bearings are shot.

Ball joints, lower control arm bushes, wheel bearings.

I wouldn't expect lower control arm bushes to only cause vibration at 40-60 km/h - but wheel bearings are worth checking.

Mounts ......

Mounts ......

Yup - getting the transmission mount replaced atm, and will see how much difference it makes.

Driver's side mount is a polyurethane mount (http://martybugs.net/magna/mount.cgi) that I had cast quite a few years ago - the other top mount appears to be in good condition.

Replacing the (new) driveshaft with yet another new driveshaft (including inner and outer CV joints) resolved most of the vibration.
One of the lower mounts was also replaced, as it was starting to tear apart, and may have exaggerated the vibration somewhat - but it looks like the driveshaft was the primary culprit.