Bang, clatter and whine.... TADTS! (The Difficult Differential)

[Dan R]

I have a 2012 R500sv which has done 3300 miles, with a Ford Diff which bangs, clatters and whines and sounds like you are driving over iron manhole covers.  A friend tested the preload on it and essentially there is well under 20ft/lb.  Is there a way of finding out what type of LSD is fitted and if this is the diff needing replacing or if it a peculiarity of what was fitted to the R500 at the time? 

[7 wonders of the world]

Dan,

Sadly you will have a Titan LSD inside he Ford final drive,

you might want to make a rather large coffee and have a read here:

https://www.lotus7.club/forum/techtalk/bmwtitan-lsd-viability

 

Worth speaking to Steve here about a proven solution 

https://www.tracsport.com/

 

[Phillip Meyer]

I had a new diff fitted to my 620s when I bought it from Caterham Cars (2015 reg) and even though it's new it is also really noisy alrho8gh mainly when I easy off the throttle rather than under acceleration.

[ScottR400D]

What kind of noise, Phillip?

Chattering of the CWP on lift off seems inevitable but generally you can drive around it. It's usually only at a point between on throttle and all the way off so if you avoid that spot....

Whining noises are usually the LSD though the gearbox can do that too. 

Clunking and grating noises when turning are the LSD. (Not to be confused with the sloppy driveline clunks)

If your LSD is a new Titan the noise may ease as it wears in and the preload falls. Then it stops working. Then it breaks. You'll soon know with a 620! 
 

[David_Long]

If it's a Sierra diff (and if it does have a titan LSD) then it will have sintered plates. As far as I understand it all Ford diffs were fitted with sintered plates, only the BMW were fitted with Carbon and after this date IIRC. Even with a low pre-load, it's likely to be in a serviceable condition, but if it is low and excessively noisy then an overhaul at Road and Race is probably a good idea. The Caterham Ford diffs of that period were not put together very well and will respond to a proper set-up (and not just the Titan bit).

[Benton]

According to Caterham a Sierra diff with Titan LSD should have a working preload between 16-20 ft/lb

[ScottR400D]

#6 Is there any reason why a Titan in a BMW housing would have a different preload to the same thing in a Ford housing? 

R and RT definitely deliver the BMW diff with a 45/50 ft lb preload and advise a rebuild once it gets to 20lb ft. I can't think why it would be different in a Ford diff.

 

[Benton]

Don't know, just quoting what I've been told 

[Phillip Meyer]

Exactly as you mention, clattering as I lift off the throttle and an almost grindy noise but as mentioned it is supposed to be new so I am not particularly worried, just surprised at the noise.

Also there is a whine that actually sounds like a siren or warning alarm at higher speeds. At first I constantly thought my indicators were on, it sounds a bit like a lorry's reverse warning tone.

[ScottR400D]

I don't think much can be done about the light chatter on gentle lift off other than drive around it which is mostly possible. 

The other noises don't sound right, especially the 'siren' (!) noise, I've never heard that!