Another chuffing noise
Discussion
Well a recon one is around £1200 but maybe all they do is polish the outside....
I've done OK on s/h gearboxes, which are far more complicated.
Regarding your suggestion of the propshaft I've never had a problem putting them back in upside down. The prop was last disturbed when I changed the gearbox around 7-8? months ago. And this noise wasn't evident then.
I had the rear up on axle stands the other day (to stress the bearings just the same, wheels on) and got it up to indicated 50mph but the noise didn't really appear. So it may be from the front but I'm struggling to work out why.
I've done OK on s/h gearboxes, which are far more complicated.
Regarding your suggestion of the propshaft I've never had a problem putting them back in upside down. The prop was last disturbed when I changed the gearbox around 7-8? months ago. And this noise wasn't evident then.
I had the rear up on axle stands the other day (to stress the bearings just the same, wheels on) and got it up to indicated 50mph but the noise didn't really appear. So it may be from the front but I'm struggling to work out why.
Never used them myself but might be worth a call...
https://www.google.co.uk/url?sa=t&rct=j&q=...
"Chuffing" at the front...Thats right isn't it...
Wheel bearing...Pad catching....Brake hose touching.....
https://www.google.co.uk/url?sa=t&rct=j&q=...
"Chuffing" at the front...Thats right isn't it...
Wheel bearing...Pad catching....Brake hose touching.....
Well the noise has slowly been getting worse, one extra piece of information is if I start zig-zagging along the road, the noise disappears on the zig to the left, but reappears straight on and/or zag to the right.
E.g. when exiting a roundabout, there's a temporary respite.
So I just jacked up the rear of the car again and also mainly jacked up the left rear so it was under compression, and running the rear wheels at about 40 mph the noise is evident, and seems to be coming from the diff (confirmed with jack handle on diff other end on ear).
So my money is on the left hand diff output bearing, and as the oil seal seems to be a bit weepy too, this is probably the area to attack.
Anyone know can it be replaced in situ or is it easier to drop the whole lot down to allow easy access - get brake caliper off etc?
E.g. when exiting a roundabout, there's a temporary respite.
So I just jacked up the rear of the car again and also mainly jacked up the left rear so it was under compression, and running the rear wheels at about 40 mph the noise is evident, and seems to be coming from the diff (confirmed with jack handle on diff other end on ear).
So my money is on the left hand diff output bearing, and as the oil seal seems to be a bit weepy too, this is probably the area to attack.
Anyone know can it be replaced in situ or is it easier to drop the whole lot down to allow easy access - get brake caliper off etc?
Well it turned out the top bracket has 4 bolts and the easiest was to get it off still attached.
I have stripped off the calipers, discs and side bearings and also had a look inside.
There isn't a definite "bad" side bearing, although the right hand one seems a bit stiffer to turn than the left one.
The side bearings are definitely leak-free.
The front bearing shows a bit or end float, and if I press on it while turning I get a noise from the diff internals, so I wonder if that's the problem, well it seems to be a problem anyway. As I recall the front bearing is the technically more difficult one to replace? It also leaks so the seal needs doing.
The crown wheel teeth look in good nick except for a small chip on the very corner of one, but it seems far away from where the pinion should engage so probably not an issue.
I have stripped off the calipers, discs and side bearings and also had a look inside.
There isn't a definite "bad" side bearing, although the right hand one seems a bit stiffer to turn than the left one.
The side bearings are definitely leak-free.
The front bearing shows a bit or end float, and if I press on it while turning I get a noise from the diff internals, so I wonder if that's the problem, well it seems to be a problem anyway. As I recall the front bearing is the technically more difficult one to replace? It also leaks so the seal needs doing.
The crown wheel teeth look in good nick except for a small chip on the very corner of one, but it seems far away from where the pinion should engage so probably not an issue.
Hi Adam - is it worth getting a diff specialist to check it over..
Found these guys
http://www.ajsengineering.com/Services.html
Found these guys
http://www.ajsengineering.com/Services.html
Edited by rev-erend on Wednesday 9th May 11:43
Looks like there are some DIY sites out there ..
http://buildraceparty.com/diy-tech-how-to-rebuild-...
Is yours an LSD.
Might be worth checking the plates too..
http://buildraceparty.com/diy-tech-how-to-rebuild-...
Is yours an LSD.
Might be worth checking the plates too..
Yeah LSD. Thanks for the pointer I found one about jag diffs a few months back too.
In my case the friction area doesn't need fiddling with that's all working OK. I think it's mainly the pinion bearing end float that needs sorting out, and front oil seal, and probably do the side bearings as these are only around £15 a pop.
I may take out the central workings so I can inspect the pinion drive gear.
In my case the friction area doesn't need fiddling with that's all working OK. I think it's mainly the pinion bearing end float that needs sorting out, and front oil seal, and probably do the side bearings as these are only around £15 a pop.
I may take out the central workings so I can inspect the pinion drive gear.
I just found this article:
http://bernardembden.com/xjs/diff/index.htm
which is excellent and may be my answer. Too bad I didn't realise the pinion end float was bad before dropping the diff.
I could have tried this a few days ago and given it a go and saved myself a big old job - hey ho you live and learn.
http://bernardembden.com/xjs/diff/index.htm
which is excellent and may be my answer. Too bad I didn't realise the pinion end float was bad before dropping the diff.
I could have tried this a few days ago and given it a go and saved myself a big old job - hey ho you live and learn.
More good reading material here:
http://dazecars.com/dazed/Diff.htm
e.g. the table here: http://dazecars.com/dazed/JaguarIRS2.html is very useful.
http://dazecars.com/dazed/Diff.htm
e.g. the table here: http://dazecars.com/dazed/JaguarIRS2.html is very useful.
This is a useful piece of advice if you're trying to diagnose things:
Bearing whine tends to be there from low speed all the way up and doesn't vary much as you ease on and off the pedal. Gear whine is at tooth contact frequency and is most prominent around 60-70mph (about 2000 Hertz). You can 'play' diff gear whine on the throttle and its sometimes more prominent on the overrun when the 'rear' sides of the teeth touch
Bearing whine tends to be there from low speed all the way up and doesn't vary much as you ease on and off the pedal. Gear whine is at tooth contact frequency and is most prominent around 60-70mph (about 2000 Hertz). You can 'play' diff gear whine on the throttle and its sometimes more prominent on the overrun when the 'rear' sides of the teeth touch
Hi Adam
Bite the bullet and take the diff to A1 Gearboxes in St Neots, they have rebuilt three LSD diffs out of wedges for me.
It didn't cost a lot, and it was a quick turn around three or four days.
Then refurb your rear brakes while the diff being done, then refit all at the same time.
Andy
Bite the bullet and take the diff to A1 Gearboxes in St Neots, they have rebuilt three LSD diffs out of wedges for me.
It didn't cost a lot, and it was a quick turn around three or four days.
Then refurb your rear brakes while the diff being done, then refit all at the same time.
Andy
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