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Diff.noise in my '98 AU1 XR6 VCT Auto

4K views 23 replies 5 participants last post by  WBT56 
G
#1 ·
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!
 
G
#5 ·
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
 
#6 ·
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):)
 
#7 ·
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.
 
G
#8 ·
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.
 
#9 ·
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.
 
#10 ·
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
 
#12 ·
With all these diff noise you all been having I was wondering what king of transmission you are driving with.
Hard take offs with sudden release of gas does make the clunking sound on the auto. When you use the gears 2/3 and hold it there while you take the gas off it doesnt do it.
I'm saying that it may not be the diff, trans and diff probably not compatible.
The only diff problem I have is that clunk when driven hard, and that 4th gear whine.
 
#13 ·
XR Joe
no spy pics yet. Wheels done a brief article and rumoured that new ford will have the styling similar to the previous Audi A6 but larger. Engine specs.... well rumoured the V8 will get the 5.4 not the 4.6. Inline 6's will not change but there's no word on DOHC or SOHC.
 
#14 ·
I talk to people that work for Ford and as you all would know the employies have seen what the car looks like. There have also been clinics for a sellection of the public. I personally don't know but of the people that have seen the car they tell me that it looks sensational. As a guide the same person when he sighted the AU reckoned he would be looking for a new job as the car would not sell. He was right with at least 50% so I guess I will have to wait to see if his eye sight still works ok.
I do have some feelers in on the new V8 and hope to get an answer on these 5.4 VCT rumours soon
 
G
#16 ·
Ford have now replaced the diff in full, which according to the service guys comes complete with the latest syn. oil etc.
This has now definitely rectified the clunking/thudding/or backlash noise, and is a also a lot quieter.
Happy for the moment, but still won't be convinced until the diff. has done a few k's.
 
#17 ·
Hi guys
I am happy to confirm Jase_ELXR8 comments on Castrol synthetic diff oil. Castrol recommend SAF-XA for all LSD and transmissions for extreme high and low temps. Check out their site: www.castrol.com.au
After changing the diff oil to SAF-XA, no more clunking at low speeds. Just wonder how long it will last.
PS not many outlets carry SAF-XA but Repco in Auburn had it (in warehouse).
Regards
 
G
#19 ·
I have an AU II XR 6 VCT Auto which started clunking and grinding at 1500Km. The dealer said it was a loose roll bar, but I had to take it back next day with the same noise and they replaced the diff oil. The clunking and grinding went away but when turning there was a grinding sound at low speed. The dealer said the diff would have to be replaced, but Ford said they should replace the oil and pinion seal which they did. The only noise now is the occassional thump from the rear of the car when it changes gear. The dealer said this is normal with a LSD. The car also had to be returned several times for a scraping sound, which was found to be a problem with the hand brake - it was rubbing against something when the brakes got hot and it took the dealer 3 goes to find and fix this problem. My main beef though is the drivetrain noise between 60Km and 90km - it sounds like a front loader washing machine with a loose drive belt that is slipping slightly i.e there is a subtle whining noise, which the dealer says is normal. I have not driven other XR6's so I do not know if this is normal. I think Ford have a great product except for quality control and the drivetrain noise in the car. Its very frustrating dealing with the dealer when you know something is not right, but they say everything is normal. I'll never buy another Ford becasue of this.
 
#20 ·
macca, yes I agree Ford still hasnt mastered the quality control but thats, hopefully in time its gets better.
Its normal to have that whine. It think thats the AU 's forte. :) You'll live with it. If you cant sell it. My AU XR6 HP has little problem at all - you get the harsh thug in the diff when you back off too fast after heavy accelerating. Changing driving style solve this ie. keep your foot down!
By the way my car was the last batch of the 99 model before they started series 2 so I wouldnt know if they have made any changes to the diff oil they used as to previous makes.
Also I would like to point out that I dont really want to hear complain about not buying another ford. This is not the customer complaint centre.
If the last sentence offends you - sorry.
 
G
#21 ·
Macca, ye of little Ford faith, I've had my clunk/thud problem for 2 years yet I've managed to hang in there. I had a complete new diff (which includes all the latest syn. oils) and a new drive shaft put in 4,000K's ago which appears to have rectified the problem.
May I suggest that you go back to the dealer and INSIST on a new diff and perhaps driveshaft(s). Alternately ask for a refund.
You might also wish to have the dealer rattle off which current model vehicles/makes have as normal specifications 'thudding diff' coupled with LSD/IRS?!!!!
I'm glad that my local dealer hasn't remotely suggested this 'normal' new age auto refinement to me!
Alternately turn up the stereo!
 
#22 ·
I am like slow xr6 and changed my driving slightly to compensate for the slight back lash that can happen during gear changes. Fords week link is drive line refinement but they are working on it. I am sure the next model will be better and worthy of consideration!
 
G
#23 ·
This is along the same theme of problems with LSDs, but more of the diff losing it's 'limited slip' functionality.
The car is a 2001 AU2 XR6 VCT (with IRS) that's now got 36k on the clock.
Apart from some minor rattling and clunking at parking speeds (which went away a couple of weeks after they first appeared), the LSD was working great until about 11k, when it would allow one wheel to spin madly if it was on a poor surface.
The diff was replaced under warranty at about 14k, and again was fantastic - until about 23k, when it started slipping again, but not all the time. Seeing it was intermittent, I left it until the 30k service where it was reported.
It comes back with the comment "It's been checked and it's within the specifications, so it's OK".
Still not working as one wheel (either one, depending which one has the least grip) still spins madly. It goes back again with the same reply - the Break-off point is tested at 70Nm and the specifications say between 50 and 130Nm.
I've been told it's got the right oil in it by the dealer, but how do I know.

Has anybody had the same problems, and if so how was it fixed - permanently ?

Apart from that the car is great.
 
#24 ·
It is very common for the limited slip in these diffs to fail somewhere between 3000 and 12000km.The clunking noise is the cone assembly ratcheting when it has lost it's grip.Anyone with an old bottle of SAF-XA will see it was initially specified as open or spool diff and non-synchro transmission.Now it says LSD as well.The clunking goes because the oil over lubricates the cones and they slip more freely(less effective LSD).It is possible to rebuild these diffs successfully, but they must not be run on synthetic oil.
 
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