Diff.noise in my '98 AU1 XR6 VCT Auto - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

01-02-2001, 12:39

I've got an intermittent recurring clunking and chatering diff.(mostly in and out of 1-2 auto gears) with more recently diff. noise when turning and on corners. Its been back and forwards to Ford, who have changed the type of diff oil, replaced the drive shaft and last of all replaced the diff casing. The later worked pretty well for about 8,000k's but now the sounds are back with vengeance. The car is now also back to Ford but I'm not holding much faith in their expertise as 60K KM's later they still havnt fixed the problem! Hoping that someone out there may be able to share a similar experience in the AU range, and also perhaps knowledge of a solution that may help Ford get it right!

01-02-2001, 20:46

Sounds like limited slip diff to me needs re setting etc

01-04-2001, 20:44

Seems too many AU got this problem, Maybe its normal considering most of the AU have this problem.
I got used to it by turning the radio loud!
Whats that?? did you say something? :)

01-04-2001, 20:52

Seems too many AU got this problem, Maybe its normal considering most of the AU have this problem.
I got used to it by turning the radio loud!
Whats that?? did you say something? :)

01-04-2001, 21:36

Had the identical problem fixed this week at the 20,000 service for my 98 AU XR8. The tech I was talking to said the IRS diff has caused lots of problems, with some highway patrol cars having 5 or 6 replacements fitted. They put some kind of kit in & a additive in the oil and said if it started again they would probably replace the diff.

I'd be demanding a new one before you run out of warranty!

Hope this helps.
Doug Hall

jaffa · 01-06-2001, 12:37

This problem not isolated to AU series. I have 97'EL XR6 coming up to 39,000 KM and the diff is now making the same noises. Usually after 20 mins driving the diff clunks on trailing throttle eg when braking/slowing and is more noisy when turning but the noise goes away on slight cruise or accelerating.
I have just returned from trip to Melb. The diff was quiet all the time at expressway speeds but made noises at slower than 60km/hr eg turning into Hungry Jacks at Albury. It was so bad I thought it was going to dump it's guts there & then. I'll have to get it fixed soon. Priority this week.
Paul, you mention LSD may need resetting. Any recommendations? I don't think the local dealer would be up to it.
A pleasant surprise to get 10.5km/l (29.8m/gal in real terms):)

jaffa · 01-14-2001, 20:17

Hi everyone
Gary Dennison, Service Manager at Brad Garlick Ford suggested I change the diff oil first to see if it eliminates the clunking. So off I go to find some oil, 85-140w for LSD. I'm beginning to think this is some special oils. K-Mart & Big-W didn't have it. Brad Garlick Ford Spare Parts didn't have it. But Auto-One up the road had it. Must have liquid gold in it, $29.00 for 4 litres? Will keep you posted on results.

01-15-2001, 06:31

My intermittent thudding/ clunking diff. noise is back again. This is after the receiving the Ford diff. additive and new pinion seal which they assured me would get rid of this sound , however has only rectified the LSD scrapping/grinding noise.
The car is now back again with the Ford dealer under strict instructions 'to fix'.
Will keep this topic updated as to Ford's next remedy and subsequent results.

Jase_ELXR8 · 01-15-2001, 10:51

I had the same problem with mine, it sounded like something was broken. It only showed up at low speeds foot off the pedal or reversing slowly. It the cones in the diff over-running. My fix was to use a fully synthetic oil. I used the castrol synthetic diff oil. I got it from bursons it was $30 for 1 litre. Fixxed the problem straight away and it it hasn't made a noise since.

HSE2 · 01-15-2001, 11:03

Hi guys
New to this forum but know a little about the problems witht the IRS diffs. There are two problems. The first is described as a chatter and Ford have been trying to treat this by changing the oil spec. This oil spec has changed about four times. Series two or just before are now fitted with a sinter coated unit which is supposed to stop said noise. The second problem is a clunk or back lash problem especially on trailing trottle. A Melbourne supplier has been contracted to fix this but we won't see this improved refinement untill the next Falcon