Gav
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| posted on 28/2/06 at 12:16 PM |
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3.92 LSD + 3.62 Open = 3.62 open LSD?
Slighty odd subject but im sure you get the idea!
i've got a 3.62 open diff and im hoping to acquire a 3.92 LSD with lobro shafts.
Ive seen somewhere that it is possible to exchange the crown wheel and pinion(?) to change the ratio but i guess what im asking is would it also be
possible to basically stick the LSD bits from the 3.92 into the 3.62 and still be able to use the open shafts?
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smart51
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| posted on 28/2/06 at 12:24 PM |
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The general consensus of opinion is this.
You are best to leave the pinion in the casting as it is trick to set it back up again. You can remove the differential gear and the viscous coupling
from one diff and fit it to the crown wheel, pinion and casting of another diff to give you a LSD of another ratio. You still have to use the lobro
shafts with an LSD. The reason is that there is no room for push in shafts as the viscous coupling is in the way.
Why not sell the two diffs you have and buy a 3.62 LSD. They are a common size. Most people who convert do so to get a lower ratio, not a higher
one.
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Mr G
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| posted on 28/2/06 at 12:31 PM |
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Is there any reason you want to keep the tripod shafts?
You could change the inner joints over to lobro so they fit onto the flanges on the lsd - Personally i'd pick up a 3.62 lsd seperately as it
will save all the work of an internals swap.
Cheers
G
Normal is getting dressed in clothes that you buy for work and driving through traffic in a
car that you are still paying for - in order to get to the job you need to pay for the clothes
and the car, and the house you leave vacant all day so you can afford to live in it.
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smart51
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| posted on 28/2/06 at 12:41 PM |
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tripod shafts / hubs / open diff = 10kg lighter than lobro shafts / hubs / LSD. The extra weight is split between heavier shafts / heavier ends to
the diff and hubs plus the weight of the viscous coupling.
10kg is worth about 0.1 seconds or a 1 metre lead from 0 to 60 or 0.2 seconds / 3.5 metre leadto 100. Worth it for a new build for racing but
perhaps not for a conversion for road use.
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Gav
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| posted on 28/2/06 at 01:00 PM |
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The main reason is because thats what i have and what i might be acquiring, so i was wondering what the options were rather than trying to source
lobro shafts and converting them for drum use.
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Mr G
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| posted on 28/2/06 at 01:18 PM |
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Ok well if thats what you've got and that's what you'll be getting then the main option is:
Create a 3.62 lsd with lobro flanges out of the pair of diffs you will have.
Then take the inner tripod joints off the driveshafts you already have and replace them with a lobro joint from the shafts you say you will be
getting.
Although you will need to check spline size and number as there seem to be slight discrepancys with some shafts.
Cheers
G
Normal is getting dressed in clothes that you buy for work and driving through traffic in a
car that you are still paying for - in order to get to the job you need to pay for the clothes
and the car, and the house you leave vacant all day so you can afford to live in it.
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Gav
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| posted on 28/2/06 at 01:20 PM |
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Thanks Mr G 
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NS Dev
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| posted on 28/2/06 at 01:29 PM |
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or just use the lobro setup which is stronger and in my opinion much nicer, and machine the CV cages (easy job) and get some light shafts made, (£160
a pair for beautifully made ones machined from billet)
That way for a few quid more you have a setup that's nearly as light and will outlast the rest of the car even with plenty of power going
through it)
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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Gav
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| posted on 28/2/06 at 01:50 PM |
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That may be an option for the future, right now I think ill leave the diff swapping alone as it seems quite a bit of hassle and concentrate on getting
the thing on the road 
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scotmac
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| posted on 2/3/06 at 02:35 AM |
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Where do you get the custom billet ones from? And, will they work w/ push-in joints....i know, that was not your point...but i have a ZF diff, which
ONLY works w/ push-in joints!!! 
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NS Dev
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| posted on 2/3/06 at 09:10 AM |
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Can't remember the phone number now but if you do a search for GB Engineering on this forum it will come up.
Give him (Geoff Berrisford) a call and tell him what you want, he should be able to do it.
Think there are a few on here that may have ordered from him recently?
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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NS Dev
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| posted on 2/3/06 at 09:12 AM |
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Link
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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Mr G
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| posted on 9/3/06 at 03:23 PM |
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MK machined up some shafts for billy with correct splines and circlip recesses to the length he specified for £70 a piece.
HTH
Cheers
G
Normal is getting dressed in clothes that you buy for work and driving through traffic in a
car that you are still paying for - in order to get to the job you need to pay for the clothes
and the car, and the house you leave vacant all day so you can afford to live in it.
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NS Dev
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| posted on 9/3/06 at 03:40 PM |
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Did they pass the job on though?
A lot use GB Eng to make em for them. The £70 a piece price was fixed for about 5 years, went up to £80 each last year.
Z Cars for example use GB Eng to make their steering racks, transmissions and driveshafts.
They are specialist automotive prototype engineers so are pretty well set up for that sort of thing, they do tooling for the big automotive
manufacturers.
The big plus is that because Geoff Berrisford races a grasser, he keeps prices pretty keen to clubbie motorsport types!
[Edited on 9/3/06 by NS Dev]
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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Mr G
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| posted on 9/3/06 at 04:04 PM |
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The MK i'm refering to is MK Engineering not Sportscars so I suspect they are their own or at least sub'd very locally if need be.
GB are 80 miles from Rotherham so if they did it would have to be a postage affair.
We spoke to a firm displaying shafts at westpoint but their name escapes me now - they gave a very hit and miss vague reply when questioned about
custom sierra items.
You still got that steel 8v sump btw? Let me know a price if you have
Cheers
G
Normal is getting dressed in clothes that you buy for work and driving through traffic in a
car that you are still paying for - in order to get to the job you need to pay for the clothes
and the car, and the house you leave vacant all day so you can afford to live in it.
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