Diff bushes

[jon.l]

This is on the '5 btw..

 

Issue 1 -

 

I seem to be getting a shuddering/vibration through the car at speed/when going over bumps in the road, as if the whole body is resonating side to side (think no suspension so the only absorption of vibration is done by through chassis). Think the way a wooden door moves when you slam it. As I type this I become more convinced this is down to the Bilstein suspension, but I'll carry on..

 

Issue 2 -

 

I get a similar feeling of vibration through the car when putting into first/reverse at low speed, accompanied by a 'clunking' metallic noise from the diff (as if it's taking up the slack, it's an LSD if that makes any difference). Now various searches have led me to believe this can be normal for a diff that requires oil, or one that is using the incorrect oil. The same searches have also led me to believe that the diff bushes could be worn.

 

I have purchased a pair of poly bush inserts for the diff but the work involved is making me consider other options. I know the car needs alignment as it is a lot more tail happy then I think it should be (again possibly partly due to the suspension, and tyres) and I'd rather not have the hassle of two trips to get this done. If I am replacing the suspension and tyres and getting an alignment I'd like to incorporate the diff bush replacement into this work as it will save me a return trip.

 

So far all I have done is set the gearbox lash, which seems to have made little difference.

 

Any spanner time will be covered by me, I'm not afraid to get my hands dirty but as we can all appreciate I'd rather not have to remove the rear diff if I can avoid it.

 

Advice welcomed

 

Jon

[Tony]

Issue 1: I agree

 

Issue 2: I have never replaced the diff bushings or seen a 5 that needs it, so i think you need to look else where, oil is an easy check/ fix.

[jon.l]

That's all I needed to know, thanks Tony

 

I'll do the oil at the weekend and see how I get on. Seems to be overlooked on 5's from experience.

 

As for the rattling, I'll have a look at the shock bushings and shocks themselves. Chances are after 130k miles they could probably do with replacing anyway, moreso with lowered springs on I bet.

 

Jon

[jon.l]

So I got stuck in earlier and drained the diff oil, and this was on the end of the drain plug (which I presume is magnetic)

 

 

 

 

 

Not sure what to make of that, but it all came off the drain plug before I fitted it and refilled the diff. In all honesty I can't say I've noticed any difference... still clunking

 

Also, whilst there I looked at the rear arms/shocks and bushes, and this is what the lower shock bushes look like

 

 

 

 

 

Though the bush isn't actually detached it's distorted and is sitting at an odd angle. I'd be willing to bet that there is metal on metal contact between the shock and the arm somewhere, which probably isn't helping.

 

Thoughts welcome

 

Jon

[Tony]

Metal on the drain plug looks about right, hence the magnet. I doubt if the shock is knocking but it's worth removing it and checking the condition of the core.