Knocking from under the car???

[fullthrottlehyde]

Hi all,

So last week the Cerb developed a knock on the way back from the car club meet. It happens when changing gear so the revs drop or when on or off the power. It's not the exhaust, so I was thinking prop or diff is loose, or possibly engine mounts. She whent in for an mot today and I asked the guys to check the diff housing and prop bolts and they reckon they are secure, I'm hoping it's not a knackered diff. Has anyone else had this issue?

Cheers

Ben

[Steve_T]

Sounds like it might be worn diff bushes, not that unusual.

[fullthrottlehyde]

May be a silly question but would driving her with a slightly loose diff cause major issues, I'm meant to be attending a show reasonably close on Sunday.

[ukkid35]

It will drive you mad long before any possibility of causing damage.

[Luckyone]

I found I had to get the diff rebuilt after fitting new bushes, shortly followed by the gear box before all the knocking noises stopped. It seemed quite possible the hammering of the old worn bushes didn't do either any good, nor did doing a track day with it like that

That was a very long time ago, a twenty something year old driving a Cerb doesn't do the drive train much good

[Mr Cerbera]

Did you say knocking ???

[Ireland]

Probably either the rear diff mount bush or the rear diff mount bracket

If it's the bush then replace it with a new one

If it the bracket then it will probably be a crack in a weld or in one of the sides but either way it should should be repairable

Try to get under the car and get a nail bar (or similar) and see if you've got movement in the rear of the diff and if you have then this is the issue

I had the same recently and fixed it myself at home (I do have a pit in the garage which does help a lot with this kind of job) but access to the diff rear bracket is difficult