Limited slip diff.....

Limited slip diff.....

Author
Discussion

Poopaconk

Original Poster:

35 posts

228 months

Sunday 17th September 2017
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Hi,

Collected my brand new Caterham today and the limited slip diff is whining like an Irish Banshee.... It starts at around 50mph, is really loud at 60 to 65mh and the disappears into the background at around 70. The sound is there in other gears too and the same speeds. I've heard mild forms of this in other open diff (old now) Fords.

Is this something to be expected from a LSD?

anonymous-user

53 months

Sunday 17th September 2017
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The BMW diff? Mine clonks and chatters on light throttle but doesn't have a whine that sounds like you describe.


Spaceibiza

64 posts

109 months

Sunday 17th September 2017
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I have a 2016 car with the BMW LSD and mine does exactly what you are describing. 50 and 80 are the worst speeds for it, but 70 is silent! I asked the dealer about it and they said it's normal to do that.

Poopaconk

Original Poster:

35 posts

228 months

Sunday 17th September 2017
quotequote all
Thanks guys,

Mine does seem to clonk a little but not as much as I'd thought it would having heard the reputation, but then it's only done a few hundred miles.

But this whine is another story....

anonymous-user

53 months

Sunday 17th September 2017
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Is it definitely the diff? Which gearbox do you have? Does it do it regardless of which gear you're in?


Bing64

17 posts

80 months

Sunday 17th September 2017
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Poopaconk said:
Hi,

Collected my brand new Caterham today and the limited slip diff is whining like an Irish Banshee.... It starts at around 50mph, is really loud at 60 to 65mh and the disappears into the background at around 70. The sound is there in other gears too and the same speeds. I've heard mild forms of this in other open diff (old now) Fords.

Is this something to be expected from a LSD?
Same for me when I picked mine up. I had it checked out and did some research and it seems pretty standard. I have got use to the whine and clunks. Part of the character! That said if others think it's not then I am keen to hear what it said.

downsman

1,099 posts

155 months

Sunday 17th September 2017
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There seems to be a resonance at 50-60 mph that emphasizes whining noises whether Ford or BMW diff. I have the Ford and built my Seven in 2011. When finished I was surprised by the noise, and at the time people were saying it was a batch of Caterham remanufactured diffs that were the cause.

So, I purchased an old original Ford diff, had it rebuilt with new bearings by a well known expert and to be honest, the whine was exactly the same! Looking back, I believe the whining became a problem around the time Caterham swapped from the Arch chassis to their metric design, although I cannot prove this so it is just my opinion.

Some people with metric cars do say they have a quiet diff, so unless they are all deaf, there are probably other factors involved. A current Seven will not only have a different diff to mine, but most will have a Mazda box instead of a type 9, so the only common factor seems to be the chassis.........

My cure in the end was to wear 3M Optime 2 ear defenders! Ear plugs seemed to emphasize the whine and hide exhaust noise. The ear defenders do the opposite biggrin

Poopaconk

Original Poster:

35 posts

228 months

Sunday 17th September 2017
quotequote all
I've not checked but I assume it must be a Mazda 'box as its a new car. It's definitely the diff as its exactly the same noise as I've experienced previously.

Yes the noise is in more than one gears.

I've driven a number of open diff sevens, both old and newish, and non of them have whined anything like this, but never one with a LSD.

The chassis issue is an interesting thought....

tomwoodis

570 posts

183 months

Sunday 17th September 2017
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As a point of reference, I have a 2013 Duratec car with the S3 metric chassis and a 5 speed type 9 ford gearbox + BMW diff containing LSD which I built from new. Now done 3000 miles

I get quite a bit of chatter from the diff when I back off the power and some clonks coming on and off the power but mine doesn't whine like you describe. It's been pretty consistent thought the 3000 miles driven too.

I put friction modifier in the diff when it was new and the last change I did I used a diff oil that contained the friction modifier in it already so no need for seperate one. The friction modifier could be a red herring but have either of you with the whine dumped / sucked the oil out of your diff and refreshed it to see if that makes any difference?

Tom

tomwoodis

570 posts

183 months

Sunday 17th September 2017
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Sorry just re-read your post and can see you've a new car so forget the oil change bit.

I wonder if the Mazda box + BMW diff is noisier than the Type 9 + BMW diff combo.

sjl1

20 posts

82 months

Monday 18th September 2017
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Hello

I have a 2016 310r with the bmw lsd and mazda box and it is bl00dy noisy, in my case i think the gearbox rattles badly on the over run in 4th, sounds like an awful grinding noisy. I took it back to caterham and got TADTS. Also tried their demonstrator 310r which had similar noise levels. I am diagnosing its the box because the noise is loudest in 4th on overrun but it could be the lsd, dont know? Am planning to change gbox oil to redline mtl at some point to see if things improve, this seems a popular fix

Previously had a k series with type 9 gearbox and sierra diff which was much more civilised


bcr5784

7,102 posts

144 months

Monday 18th September 2017
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Which model are we talking about. I've tested both the current 360R and 420 R not too long ago, and while transmission refinement wasn't their strongest suit, neither was anything like as whiney as yours sounds to be.

anonymous-user

53 months

Tuesday 19th September 2017
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sjl1 said:
Hello

I have a 2016 310r with the bmw lsd and mazda box and it is bl00dy noisy, in my case i think the gearbox rattles badly on the over run in 4th, sounds like an awful grinding noisy. I took it back to caterham and got TADTS. Also tried their demonstrator 310r which had similar noise levels. I am diagnosing its the box because the noise is loudest in 4th on overrun but it could be the lsd, dont know? Am planning to change gbox oil to redline mtl at some point to see if things improve, this seems a popular fix

Previously had a k series with type 9 gearbox and sierra diff which was much more civilised

My diff chatter is most noticeable on easing of the throttle, going into overrun. Fully on or off throttle it's not bad. The higher the gear the more noticeable it is, at normal speeds, presumably because the torque changes are lower.

I have 6 speed and not aware of any undue noise from it. The indirect gears make a little noise compared with 6th but nothing you wouldn't expect. They don't rattle or grind.

Poopaconk

Original Poster:

35 posts

228 months

Tuesday 19th September 2017
quotequote all
bcr5784 said:
Which model are we talking about. I've tested both the current 360R and 420 R not too long ago, and while transmission refinement wasn't their strongest suit, neither was anything like as whiney as yours sounds to be.
It's a new 360R.

sjl1

20 posts

82 months

Tuesday 19th September 2017
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So thats mazda box and bmw lsd then

bcr5784

7,102 posts

144 months

Tuesday 19th September 2017
quotequote all
Poopaconk said:
It's a new 360R.
The ones I tested were at Bookatrack at Donington. If you are close I'd try to get a comparison there.

graemesmith

2 posts

82 months

Sunday 24th September 2017
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I've got a 2017 310S SV which I built. Open diff and Mazda 5 speed box. I get a whine between 65 and 70 but only in 5th gear. I initially thought it was the diff but that does not seem to be the case. Once the car gets good and warm the noise easies off a bit, either that or my hearing easies off!

Alternatively it could be the diff but I just can't hear it above the intake/exhaust noise when doing 70 in fourth. I've looked at various vids on youtube regarding Caterham diff noise and mine is nowhere as bad as most of those. If it is chassis related then maybe the SV is not as resonant?