I have an LSD 3.62 and am going to be using a CBR1000 engine which has pretty low gearing.

Can i butcher a 3.14 or 3.38 diff and use the bits i have from my 7.5 inch LSD to make a 3.14 or 3.38 LSD?

I hope the answer to this is YES

the answer is YES! but it might not be a DIY job i believe it was jimgiblett who said he had had his fiddled with, he had a company do it for him, around £200.

EDIT! oops, it might not be possible with a 7.5 inch LSD thingy...

[Edited on 18/8/04 by JoelP]

i lied! he said it cost £80:

http://www.locostbuilders.co.uk/viewthread.php?tid=12766

You sure it's a 7.5" lsd? I think the 7.5" lsd's are 3.64 and the 3.62 lsd's are all 7" from sierras/4x4s. If you've got a 7.5" lsd and want to put bits of it in a 7", and 7.5" bits are bigger there might be problems. I dont thiiiiiiink it should matter cos I expect the centres are the same size for 7" and 7.5" diffs and just the crown wheel diameter and the cases are different.

You will want to put the lsd centre in your 3.14/3.38 rather than put the 3.14/3.38 crown wheel and pinion in the lsd. That way you avoid having to set up the crownwheel and pinion shims/pinion torque etc etc. You will need to use the flanges from the lsd too but they will go right in the 3.14/3.38 once the lsd centre is in there.

Hope that helps,

Liam

thoroughly confised now!

this is what i have/will have in working order.

1 x LSD 7.5 inch 3.62 ratio.

I want to find a 3.38 or 3.14 non

Once i have found such a beast can the 2 be put together in the 7.5 inch casing to give me a better ratio LSD?

Also does anyone know a place where i can get this sort of work undertaken because its out of my remit im afraid!

Liam, not sure if the LSD is 3.64 or 3.62 - not much difference really i just assumed it to be 3.62. (dont actually have it yet, but its on the way!)

[Edited on 19/8/04 by colmaccoll]

i u2u'd jimgiblett about contact details for road&race, if he gets back to me i will post the details.

Col

I might not have been clear earlier... you dont want to put the two together in the lsd case - you want to put the two together in the non lsd case. The 3.14/3.38 crownwheel and pinion are nicely set up in the non lsd case with the correct shims etc etc - they just need an lsd centre. If you put all the bits in the lsd case you have to set up the crownwheel and pinion in there which is a load more, and harder work, whoever does it.

Besides - I'm assuming the 3.14/3.38 will be a 7" diff in which case the crownwheel/pinion will be too small for the 7.5" case anyway. Or maybe you're getting a 7.5" non lsd?

Done in the above way it shouldn't be too hard for the d.i.y.er - but £80 don't sound too bad either.

Liam

Thanks for the clarification liam, i guess i will be on the look out for a 3.14 / 3.38 diff now then

quote:

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Originally posted by Liam
I might not have been clear earlier... you dont want to put the two together in the lsd case - you want to put the two together in the non lsd case.

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The diff case has no influence on the driveshafts you have to use - it's all defined by what diff centre you use. An lsd centre must be used with lsd drive flanges. You'll see why when you start taking diffs apart - the lsd needs unequal length input flanges which only come with lsd's, because the diff mechanism is set to one side to allow room for the viscous coupling.

Any non-lsd can use either push in shafts or bolt on flanges, but they must be equal length bolt on flanges from a non-lsd. There are no push in driveshafts with unequal length diff input splines, so no lsd can ever use the push in shafts.

Liam

[Edited on 23/8/04 by Liam]