Can anyone tell me how easy it is to fit a quaife LSD to a sierra 7" diff with push in drive shafts. I dont think it is too bad as quaife quote £35 to do it. But do you need any special tools? I'm up rating my tiger avon race car

Thanks

Steve

It is a straightforward but fiddly job. If you are using the same cwp, you don't touch the pinion and you have to make sure that the crown wheel goes back in exactly the same place. You do this by measuring the height of the pinion mounting flange on the new diff, once the bearings have been fitted. You adjust the height by adding or removing shims from behind the bearings.

This needs to be accurate to within a couple of thou so you will need an engineers height gauge and a surface plate. I wrote an article for PPC around April or May 2005 and I can let you have a copy if you really want it. £35 seems cheap when you take into account all the messing about of fitting and removing bearings and finding or making the right size shims.

It depends how dedicated a do-it-yourselfer you are

Graham Templeman

I'm sure lots of other people are going to ask this.


any chance of you emailing me as well?

I would appreciate this, as well.

Thanks,
Shaun

For £35 I would let Quaife do it! Thats a bargain.

me too, £35 is cheap for the hassle, very easy to trash the crownwheel an pinion if you don't know what you are doing!

Oh, come on Nat you know me. I'm bound to let quaiff do it, i just want to read how to do it!

shims????? If you're not moving the pinion the adjustment is via those big castellated adjusters! And it's p1ss easy. . . . Diff carrier bearing preload is 44 ft lbs from memory
To get the quaife ATB in you need to file a bit of metal off most diffs (some you don't). I can show a pic if anyone's interested.
cheers
Bob

I would appreciate seeing the pics, Bob. I live in Canada, so can't have Quaife do it for me, and will need as much info as possible when I get to that point.

Thanks,
Shaun

Whoops. I should have read the original post more carefully. I was talking about an axle and I had forgotten the adjuster collars on the Sierra diff. The aim is the same - to ensure that the crown wheel is in exactly the same relationship to the pinion that it was with the original diff. With the collars any movement is achieved by screwing one side in and the other out.

There is still the messing about with fitting the bearings which may or may not need a press to shove them on (some do, some don't) and £35 still looks like a right good price.

Graham T

Here you go. When you reassemble the crownwheel it's a bit of a puzzle to get it in the casing but it goes with the small chamfer indicated. Take up the bearing slack & move the crownwheel further into mesh until the backlash disappears. At this point you'll find that one point in the circumfrence is a tiny bit tighter than everywhere else (due to manuf. tolerances) - you adjust 'til this is just free. Preload the castle things to 40 ft lbss, recheck backlash & you're good to go. More pics at the end of
http://freespace.virgin.net/bob.carter/locost_build.htm
Having said all that there's not many miles on mine yet.....
If you file the casing you keep control of swarf & filings, if you grind it you'll have to REALLY carefully wash out the carrier before reassembly!
Bob
Rescued attachment diff.jpg

Thanks, Bob.

Shaun

Colin Chapman had a mismatched crown wheel and pinion in Lotus 7, ran it for 50 miles with the diff filled with metal polish.
Took it apart, replaced the bearings. proper meshing gears.