Broken Rear Diff Mount

[God666]

Just got my car back from the dealer after having the rear diff mount replaced. Noticed a lot of clunking from the diff (not the traditional diff clunk, that was fixed by replacing the half shafts some months ago). Found that particularly when reversing, the diff would get a bit of a shudder when riding the clutch. Threw the car on the hoist, engaged the handbrake and watched the diff move around as the clutch was partially released. A quick look at the rear diff mount showed cracks in the rubber, quite obvious if you look closely. See picture attached, (sorry about the crap quality, camera wouldn't focus so close). You can see the rubber pulling away from the ferrule in the centre of the rubber mount, photo doesn't show the cracks in the rubber.

Note that mount is offset, the bolt head is not meant to be in the centre of the hole. See the attached page from the wksp manual for an indication of where to look.

The entire diff cradle has to be dropped to replace this mount, so it is not a small job.

Browsing through the forums, I have seen about four or five posts from members that have had similar over the years. I am only running just over 250 rwkw and I do a lot of towing however, I suspect this problem may be a bit wider spread in modded Ts and people are attributing the clunk to the diff or half shafts and not to the diff mount itself. My dealer initially denied the fault existed until I insisted that he be shown the diff shuddering the the obvious movement of the diff under load.

If you have a modded T, it is probably worth crawling under the car and having a look (actually, crawling under the car is probably not going to give you enough room to see properly).

[Ninka]

Good advice, thanks.

I wil lift my 'T' and have a look.

I guess with the higher power our modded 'T's" are putting out, all suspension and engine/diff/geargox mounts are worth checking every now and then.

I just found 2 bolts missing from where the front anti roll bar bracket is fixed to the chassis

See here

[mickq]

I have the honour of being the first person in the world to break the diff mount, on my Mk1 about 2-3 years ago.

Took them a while to work it out, as it hadnt happened before.

My symptoms were a squeaking more than a clunk.

It was a big job, as from memory the rear wheels come off, and a lot of the rear suspension setup.

I didnt need a modded T to do it either....but perhaps getting it airborne and landing hard at 140 may have helped...

[sdrew]

Unsure if this waws something they had to do to my T at its last service. When I called up to check about its progress they informed me that there was a diff seal that had given way and that there was actually low oil in the diff. They kept the car overnight as they had to remove the complete diff etc to replace it.

[mickq]

Unsure if this waws something they had to do to my T at its last service.  When I called up to check about its progress they informed me that there was a diff seal that had given way and that there was actually low oil in the diff.  They kept the car overnight as they had to remove the complete diff etc to replace it.

<{POST_SNAPBACK}>

DIFFerent issue (pun intended....)

Yours is an oil type seal that went, leading to a loss of oil from inside the diff.

The one above is related to the mounting of the diff.

[ENVY-T]

I too have had the diff cradle replaced! It was as 666 described it. When I put it into reverse I would get a shudder, and this was with an auto.

All better now. The bush was ferked and had cracks all over it.

[800STA]

Just got my car back from the dealer after having the rear diff mount replaced.    Noticed a lot of clunking from the diff (not the traditional diff clunk, that was fixed by replacing the half shafts some months ago).  Found that particularly when reversing, the diff would get a bit of a shudder when riding the clutch.  Threw the car on the hoist, engaged the handbrake and watched the diff move around as the clutch was partially released.  A quick look at the rear diff mount showed cracks in the rubber, quite obvious if you look closely.  See picture attached, (sorry about the crap quality, camera wouldn't focus so close).  You can see the rubber pulling away from the ferrule in the centre of the rubber mount, photo doesn't show the cracks in the rubber.

Note that mount is offset, the bolt head is not meant to be in the centre of the hole.  See the attached page from the wksp manual for an indication of where to look.

The entire diff cradle has to be dropped to replace this mount, so it is not a small job.

Browsing through the forums, I have seen about four or five posts from members that have had similar over the years.  I am only running just over 250 rwkw and I do a lot of towing however, I suspect this problem may be a bit wider spread in modded Ts and people are attributing the clunk to the diff or half shafts and not to the diff mount itself.    My dealer initially denied the fault existed until I insisted that he be shown the diff shuddering the the obvious movement of the diff under load.

If you have a modded T, it is probably worth crawling under the car and having a look (actually, crawling under the car is probably not going to give you enough room to see properly).

<{POST_SNAPBACK}>

I reckon check it EVEN if you don't have a modded T.....

My Bf is yet to be Edited, however it had a vibration from the rear diff area when I picked it up & thought it might have been a rear uni... I was told at 14,000 odd km that it was this bush was "Flogged out" and yes the whole rear suspension clip has to be dropped to replace it..... My question is If this was noticeable from NEW (every standstill start from the showroom) then why wasn't it picked up?

[God666]

I doubt whether the bush would have been flogged out at new, I suspect the rubber is not quite up to the task however, I am surprised yours flogged out at 14000 km.

The diff has two large mounts either side at the front and the rear seems to be a large bolt into the back face of the diff that fits in through the rubber bush. Under high load, this rear one is going to be under quite a bit of stress. When it is flogged out, you could easily mistake the symptoms for driveline clunk (I have had both now and they are very similar symptoms). The flogged out bush is more of a shudder when riding the clutch however, it did bang a lot with the same symptoms as my worn cv joints.