Noisy Diff Following refurb

Noisy Diff Following refurb

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Discussion

SILICONEKIDOBHP

14,997 posts

230 months

Thursday 24th July 2014
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Sardonicus said:
uriosity really Daz scratchchin how did you diagnosis a faulty LSD was it lighting up only one tyre in a straight line? who told you it was knackered?
I was told if you get the car in the air ,get your mate to hold on wheel solid the other should have tension ,if it spins freely without any tension the lsd is shot .

900T-R

20,404 posts

256 months

Thursday 24th July 2014
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By the drift angles my car reached trying to get up an icy slope until I ran out of road width, I could tell my LSD was in full working order even after 140,000 miles...

carsy

3,018 posts

164 months

Thursday 24th July 2014
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SILICONEKIDOBHP said:
I was told if you get the car in the air ,get your mate to hold on wheel solid the other should have tension ,if it spins freely without any tension the lsd is shot .
If i do that with mine Daz, i also have, surprisingly, very little resistance. However if i spin the wheels it always leaves two black lines on the road which tells me its working fine.

Sardonicus

18,928 posts

220 months

Thursday 24th July 2014
quotequote all
SILICONEKIDOBHP said:
I was told if you get the car in the air ,get your mate to hold on wheel solid the other should have tension ,if it spins freely without any tension the lsd is shot .
Really confused who was stopping the prop-shaft turning then while you carried this test out? rolleyes Carsy's bench test is more telling hehe anyway I cant be here jibber jabbing I have a gearbox to remove rolleyes





Edited by Sardonicus on Thursday 24th July 12:41

TVR Beaver

2,867 posts

179 months

Thursday 24th July 2014
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Your right in what you say about the running wearing a pattern on the crown wheel and pinion.. if they have been run with ‘almost’ not clearance, this is where they are bedded in (shiny area on the gears)… now they have been pulled apart a bit, they are running maybe on the edges of the existing wear pattern... also new bearing will re-position them slightly...

I’ve blued up a few diffs to get them running right and the drive through the correct places on the gear wheels when under load…. I think however the advice they gave you is good.. run it for a bit and it should now wear into its new position.

The noise will be coming from the fact that the gear teeth are not exactly the right shape where they are contacting due to previous wear.. this will bed-in over a few hundred miles and should stop the noise….

Good luck.. hope it works wink

nigelj77

Original Poster:

196 posts

128 months

Thursday 24th July 2014
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TVR Beaver, thanks for the info, I would hope that it was inspected with engineers blue like you suggest, thats what I would have done had I had the bottle to pull it apart but hearing how hard the bearings can be to remove I left it to the experts.

I suppose how long it takes to bed back in will depend how long it's run with the wrong backlash.

I was on holiday at the time the diff was dont so my mate made the decission to reassemble the diff with the same gears after talking to John, I still dont know what my decision would have been, the diff was fairly quiet before so I think I'd have assumed it would be the same when it wnet back together.

At least the sun is out so I'm enjoying running it back in and worst case it's £8-900 to put it right as I look out the office window I forgive it all the money it costs me....

spend

12,581 posts

250 months

Thursday 24th July 2014
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nigelj77 said:
...I had the bottle to pull it apart but hearing how hard the bearings can be to remove I left it to the experts.....
FYI specifically for GKN diffs.. The outer bearings come out easily as long as you know how to release a circlip and screw them out evenly. The inner bearings the same, its only making up something to 'spread' the casing thats a bit off-putting I'd guess but its only a case of making up a couple of brackets and then a big nut+bolt to jack them apart?

Probably more concerning IMHO are a lot of old PH threads advising cranking up the nut as tight as possible which I can only visualize would increase the float in addition to the normal wear ~ opposite of your situation where it's had no float though.

BillC99

348 posts

159 months

Friday 25th July 2014
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What oil did you put in ? was it recommended by the guy who rebuilt the diff? You can't just put anything in.
Also be very wary of anyone telling you it is the "same spec"- be aware viscosity is NOT a spec!

NZ fan

310 posts

133 months

Friday 25th July 2014
quotequote all
Sardonicus said:
SILICONEKIDOBHP said:
I was told if you get the car in the air ,get your mate to hold on wheel solid the other should have tension ,if it spins freely without any tension the lsd is shot .
Really confused who was stopping the prop-shaft turning then while you carried this test out? rolleyes Carsy's bench test is more telling hehe anyway I cant be here jibber jabbing I have a gearbox to remove rolleyes





Edited by Sardonicus on Thursday 24th July 12:41
Tell me more, with all the diffs I have seen if you stopped one wheel from turning and also stopped the prop-shaft from turning you shouldn't be able to turn the other wheel at all. Do these diffs have some sort of slip mechanism that should allow some rotation when doing this test? My diff behaves exactly as Carsy explained and I always gathered it locked under power rather than a preloaded type which if one wheel is held and the other rotated there will be tension but still possible to rotate. I am genuinely curious about the internals of my diff (95 5l chim...GKN?) so if anyone knows I would love to know.
Apologies to the o.p. for hijacking his thread. Cheers.

Sardonicus

18,928 posts

220 months

Friday 25th July 2014
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NZ fan said:
Tell me more, with all the diffs I have seen if you stopped one wheel from turning and also stopped the prop-shaft from turning you shouldn't be able to turn the other wheel at all.
Correct wink but I was answering Daz and he wasn't doing this rolleyes

SILICONEKID345HP

14,997 posts

230 months

Friday 25th July 2014
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Sardonicus said:
Correct wink but I was answering Daz and he wasn't doing this rolleyes
Just tested the BTR, with one wheel on the ground ,hand brake off you can spin the wheel but there is alot of tension . The GKN had non .

Edited by SILICONEKID345HP on Friday 25th July 22:16

wuckfitracing

990 posts

142 months

Saturday 26th July 2014
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Daz your original GKN also had a rather telling clunk when doing this, which was the main clue as to it being knackered.

nigelj77

Original Poster:

196 posts

128 months

Monday 25th August 2014
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Update on my noisy diff following it being refurbished, I'm now 350 miles through the 1000 that many sources have suggested should settle it down.

So far the diff isn't quietening down, this weekend I've done about 130 miles in the car and after a long run the diff seems to sound even worse than normally, I'm wondering if the temperature is thinning the oil and therefore there's no cushioning effect between the gears.

Opinions would be appreciated on whether after 350 it should be settling down at all, as I say at the moment if anything I think it's sounding worse.

The gentleman who did the diff refurb is currently on holiday but back next week so I'm planning to also speak to him to see what he thinks is going on.

Cheers.

SILICONEKID345HP

14,997 posts

230 months

Monday 25th August 2014
quotequote all
Sardonicus said:
uriosity really Daz scratchchin how did you diagnosis a faulty LSD was it lighting up only one tyre in a straight line? who told you it was knackered?
Well i was told by the "specialists" .They put the car in the air ,got his mate to hold one wheel solid while the other guy turned it ,there should be some tension ..Am i correct ?

If its wrong i have a perfectly good GKN diff sitting on the garage floor .

Tell you the truth i hate the BTR 3.45 diff ,it`s to low geared .


Pupp

12,206 posts

271 months

Monday 25th August 2014
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SILICONEKID345HP said:
Sardonicus said:
uriosity really Daz scratchchin how did you diagnosis a faulty LSD was it lighting up only one tyre in a straight line? who told you it was knackered?
If its wrong i have a perfectly good GKN diff sitting on the garage floor .

Tell you the truth i hate the BTR 3.45 diff ,it`s to low geared .
You could always swap it for this one - no mention of that being faulty...

Alexdaredevils

5,697 posts

178 months

Monday 25th August 2014
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Pupp said:
SILICONEKID345HP said:
Sardonicus said:
uriosity really Daz scratchchin how did you diagnosis a faulty LSD was it lighting up only one tyre in a straight line? who told you it was knackered?
If its wrong i have a perfectly good GKN diff sitting on the garage floor .

Tell you the truth i hate the BTR 3.45 diff ,it`s to low geared .
You could always swap it for this one - no mention of that being faulty...
That is Daz's diff!

SILICONEKID345HP

14,997 posts

230 months

Monday 25th August 2014
quotequote all
Pupp said:
You could always swap it for this one - no mention of that being faulty...
That`s a bargain .. that famous breaker up north wants that for the transducer pickup .

Its in working order ..The clunk was down to the wrong gearbox mounts fitted ..sitting to low .




Edited by SILICONEKID345HP on Monday 25th August 21:28

rigga

8,727 posts

200 months

Monday 25th August 2014
quotequote all
SILICONEKID345HP said:
That`s a bargain .. that famous breaker up north wants that for the transducer pickup .

Its in working order ..The clunk was down to the wrong gearbox mounts fitted ..sitting to low .




Edited by SILICONEKID345HP on Monday 25th August 21:28
Hang on, didnt you say you thought it was knackered so changed it to a btr?

Alexdaredevils

5,697 posts

178 months

Monday 25th August 2014
quotequote all
Busted

Sardonicus

18,928 posts

220 months

Monday 25th August 2014
quotequote all
Alexdaredevils said:
Busted
laugh No pun intended then Alex? bow