Page 1 of 1

limited slip diff

PostPosted: Tue Feb 17, 2009 5:39 pm
by atthelimit
Hi, help needed.

I' ve bought an atb LSD but have never had much to do with diffs before.

Can anyone point me to some good info/manual or have any tips for fitting and overhaul of diffs etc. Everything I have read says take it to a specialist. Backlash etc is not a thing for DIY. Is that correct? If so can anyone recommend services around the UK Leicetsre area.

Lots of questions, lots of answers needed!

Thanks

Kim

Re: limited slip diff

PostPosted: Tue Feb 17, 2009 8:51 pm
by john.p.clegg
Is it a quaife?

John :wink:

Re: limited slip diff

PostPosted: Tue Feb 17, 2009 9:28 pm
by bcmc33
It may be considered a smart-arse answer, but don't confuse a LSD (Limited Slip Differential) with an ATB (Automatic Torque Biasing) differential ? they are technically totally different things.

You will always know when an LSD operates because it comes in with a ?bump?, but the ATB is seamless and you?ve no way of knowing when it operates. Some may have opinions on which is ?best? ? but based on past experience of both in special production vehicles, I prefer the ATB. Quaife is the most famous for British competition use, but Torsen is the most widely used ? Mazda MX5 & Audi are uppermost in my mind when I say this.

If you think you have an ATB it is likely to be from Quaife, and if you don?t know how to assemble a diff, take it to Tony Thompson and he will do the necessary for you

Re: limited slip diff

PostPosted: Wed Feb 18, 2009 10:05 am
by atthelimit
Thanks Brian

It is a Quaife ATB. But apart from giving cash, (probably lots) to TT or the like I would really like to do it myself. I am reasonably bright, don't mind getting my hands dirty and willing to learn. So I was really just after some written info I could follow or something like so that I could dabble in this seemingly black art.

Thanks

kim

Re: limited slip diff

PostPosted: Wed Feb 18, 2009 10:30 am
by atthelimit
Re previous posts, if I can't do this myself does anyone have any idea what a reasonable price to pay for diff rebuild and install of ATB module?

Kim

Re: limited slip diff

PostPosted: Thu Feb 19, 2009 9:05 am
by Keith Scarfe
I have been in the diff a couple of times, infact one job was to install a Quaiffe ATB into a Ford diff unit just as you are doing. It was for my Westfield race car rather than the Lotus but the diff assembly is exactly the same (English Ford Timken). I am no mechanical expert but I found it relatively easy to do and would do it again if I had to. As long as you don't need to change anything within the LSD unit like pre-load, it is just the same as doing a normal diff overhaul. You simply bolt the LSD unit in place of the diff cage unit on the crown wheel. Bolts are the same torques are the same. Everything you need to know is in the Lotus workshop manual. In fact I actually used my Lotus manual as a guide for this. It has all the info on how to set up the diff, torques, backlash and mesh contacts. If you don't have one, you should be able to find it on t'internet or I have a pdf if you need. The only thing I probably wouldn't tackle, is if I wanted to open up the LSD unit and alter the settings in here. I would probably seek an expert for this. You can adjust how it locks up by shimming and playing with springs I believe, but when I got mine it was set for gentle application and I just put it in and tried it. Seemed just right for my car.
HTH. Keith.

Re: limited slip diff

PostPosted: Thu Feb 19, 2009 10:10 am
by atthelimit
Thanks keith,
You make it sound so simple, the current diff is running fine no whine or clonks etc so I will fit it along with TT output shafts and see where we are at.

Many thanks for your encouragement.

Kim