My diff just exploded...
My diff just exploded...
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Discussion

jamesc_1729

Original Poster:

470 posts

213 months

Saturday 22nd June 2013
quotequote all

Enjoying the cerb after having a new exhaust fitted yesterday.

I was coming off a roundabout onto a dual-carriageway slip road, booted it and heard a bang. From then on when in gear and applying power there is a speed related grinding/whirring sound. When out of gear or with the clutch down it is silent.

What have I done and what's the most cost effective way to fix? I have a pit so I could have a go at removing the diff to get it refurbed by someone. I think it's very hard to remove diff though?

I had read that diffs were weak on cerberas - since it's such a generic part have people replaced the oem part with a modern one?

Tanguero

4,535 posts

225 months

Saturday 22nd June 2013
quotequote all
Sounds like it may be a driveshaft rather than the diff its self. They usually go long before the diff. If you can reach up underneath and try wiggling the driveshafts it will be fairly obvious if that is the problem.

PoleDriver

29,348 posts

218 months

Saturday 22nd June 2013
quotequote all
Sounds like the same that happened to mine, it was the brackets and bolts. Fitted heavy duty bracets and had the diff heli-coiled and has been fine since!

FUBAR

17,065 posts

262 months

Saturday 22nd June 2013
quotequote all
Tanguero said:
Sounds like it may be a driveshaft rather than the diff its self. They usually go long before the diff. If you can reach up underneath and try wiggling the driveshafts it will be fairly obvious if that is the problem.
I concur with my learned friend. Same sound and symptom as when my driveshaft went launching it at The Pod years back

jamesc_1729

Original Poster:

470 posts

213 months

Saturday 22nd June 2013
quotequote all
Will have a look at some point and update - do you mean the propshaft or one of the two driveshafts? I.e where should I be looking?

FUBAR

17,065 posts

262 months

Saturday 22nd June 2013
quotequote all
jamesc_1729 said:
r one of the two driveshafts?
yes

ridds

8,366 posts

268 months

Saturday 22nd June 2013
quotequote all
Don't assume diff.

Clutch down quietness would suggest gearbox input shaft to me.

We're you in 3rd gear by any chance?

jamesc_1729

Original Poster:

470 posts

213 months

Saturday 22nd June 2013
quotequote all
I think I was in third gear actually. Driveshafts feel solid and not loose.

Vee8ight

734 posts

163 months

Saturday 22nd June 2013
quotequote all
jamesc_1729 said:
Enjoying the cerb after having a new exhaust fitted yesterday.

I was coming off a roundabout onto a dual-carriageway slip road, booted it and heard a bang. From then on when in gear and applying power there is a speed related grinding/whirring sound. When out of gear or with the clutch down it is silent.

What have I done and what's the most cost effective way to fix? I have a pit so I could have a go at removing the diff to get it refurbed by someone. I think it's very hard to remove diff though?

I had read that diffs were weak on cerberas - since it's such a generic part have people replaced the oem part with a modern one?
Out of gear with clutch down or either or?
Clutch down is clutch related problem
Out of gear and clutch down is likely to be input shaft or gears.
If you are still moving, with no noise when clutch or neutral, it isn't the diff or the driveshafts as it would still be noisy

ridds

8,366 posts

268 months

Saturday 22nd June 2013
quotequote all
I'll put my money on third gear popping.

Vee8ight

734 posts

163 months

Saturday 22nd June 2013
quotequote all
ridds said:
I'll put my money on third gear popping.
It does sound like it, a lot more than diff related

jamesc_1729

Original Poster:

470 posts

213 months

Saturday 22nd June 2013
quotequote all
Reading around the subject I think you are probably right. The noise sounded like it was coming from the back of the car but a red herring I guess.

Options I guess are to remove gearbox and rebuild or replace with another.

Guessing if I can get this sorted for less than £1000 I will be lucky. Joys of cerbera ownership!

Vee8ight

734 posts

163 months

Saturday 22nd June 2013
quotequote all
jamesc_1729 said:
Reading around the subject I think you are probably right. The noise sounded like it was coming from the back of the car but a red herring I guess.

Options I guess are to remove gearbox and rebuild or replace with another.

Guessing if I can get this sorted for less than £1000 I will be lucky. Joys of cerbera ownership!
There is an easy way to check, get it jacked up, or on a ramp. Try different combinations of clutch/gear/prop moving and you will find what the cuprit is

Brummmie

5,284 posts

245 months

Sunday 23rd June 2013
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My guess is Driveshaft, simply get someone to look underneath when you let the clutch in and see if the driveshaft spins, if it does that is your dead one.
I have done 4 or 5 of them including the Racefailed ones.
Dave Mac ones have been great and are warranted for life!

jamesc_1729

Original Poster:

470 posts

213 months

Sunday 23rd June 2013
quotequote all
I've just been out and driven it up and down the road:

With the engine running/revving and the gearbox in neutral there is no problem (so cant be input shaft?)
As I drive their is a grinding noise which is there in any gear.
Dipping the clutch makes it go away
The noise is definitely defintiely coming from behind me, from the diff area (so not gearbox?)
I can get under the car and there is no play in either driveshaft.

I can see the logic in what people are saying ref: clutch and driveshafts always moving , but maybe the diff has gone in a way that only manifests itself under load?

Vee8ight

734 posts

163 months

Sunday 23rd June 2013
quotequote all
jamesc_1729 said:
I've just been out and driven it up and down the road:

With the engine running/revving and the gearbox in neutral there is no problem (so cant be input shaft?)
As I drive their is a grinding noise which is there in any gear.
Dipping the clutch makes it go away
The noise is definitely defintiely coming from behind me, from the diff area (so not gearbox?)
I can get under the car and there is no play in either driveshaft.

I can see the logic in what people are saying ref: clutch and driveshafts always moving , but maybe the diff has gone in a way that only manifests itself under load?
Is the noise only under load, then? Sounds like bearings to me, gearbox maybe or diff

GT6k

946 posts

186 months

Sunday 23rd June 2013
quotequote all
On the grounds that you are going to have to remove the gearbox or diff I would start by disconnecting the propshaft then the driveshafts and see what you can feel. Quite often all the bits are kept in place by other loads so it is difficult to tell under the car what is broken.

ridds

8,366 posts

268 months

Sunday 23rd June 2013
quotequote all
Does it doing when accelerating and decelerating?

Possibly diff output CV joint touching the chassis? It's odd that it's there under load but then gone when de-clutched.

PoleDriver

29,348 posts

218 months

Sunday 23rd June 2013
quotequote all
ridds said:
Does it doing when accelerating and decelerating?

Possibly diff output CV joint touching the chassis? It's odd that it's there under load but then gone when de-clutched.
When my diff bracket went it was exactly the opposite!

jamesc_1729

Original Poster:

470 posts

213 months

Tuesday 25th June 2013
quotequote all

And the answer is......

At the back of the diff there are two bolt holes, on my car currently one of these has a sheared thread in it, and the other one is empty. So basically my diff and rear bracket have parted company, causing the two output driveshaft joints to be resting on the chassis.

Hopefully a quick fix for me to remove exhaust and diff, remove sheared thread from diff and then reassemble.