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Newer LSD in an older gearbox?

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Old 10-10-2022, 01:35 AM
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swehedman
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Default Newer LSD in an older gearbox?

Hi! So im doing a manual conversion on my -81 eur S this winter. I have most parts incl an -82 5-speed without LSD. But i do want LSD…

I have found an complete -85 LSD diff from a 4 speed AT with housing for a wery good price.

I know i can use an LSD from an AT but will a -85 LSD fit an -82 gearbox?

thanks!

Last edited by swehedman; 10-10-2022 at 01:37 AM.
Old 10-10-2022, 05:02 AM
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The Forgotten On
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It won't fit. You need a 78-82 LSD. After 83 it changed and isn't compatible with they early boxes.
Old 10-10-2022, 06:01 AM
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thank you. I read someware that the major difference was placement of the Speedometer magnet and maby i could use a later diff lid to get around that?

Originally Posted by The Forgotten On
It won't fit. You need a 78-82 LSD. After 83 it changed and isn't compatible with they early boxes.
Old 10-10-2022, 05:32 PM
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Originally Posted by swehedman
thank you. I read someware that the major difference was placement of the Speedometer magnet and maby i could use a later diff lid to get around that?
No, the offset of the ring gear is different, requiring a different differential or a spacer between the ring gear and the differential and longer bolts.
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Old 10-11-2022, 02:24 AM
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Originally Posted by GregBBRD
No, the offset of the ring gear is different, requiring a different differential or a spacer between the ring gear and the differential and longer bolts.
thsnk you Greg. So if i understand you. It can be mounted in the 82 gearbox but i would need to fabricate a spacer? My plan was to move my old ringgear over so that would be a match to the pinion gear in the old box.

do you know how thick the spacer have to be?
Old 10-11-2022, 02:37 AM
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Originally Posted by swehedman
thsnk you Greg. So if i understand you. It can be mounted in the 82 gearbox but i would need to fabricate a spacer? My plan was to move my old ringgear over so that would be a match to the pinion gear in the old box.

do you know how thick the spacer have to be?
Of course you have to use your original ring gear with your original pinion. They are an inseparable pair, from their creation to their last day. You loose one...and the other is scrap metal.

Sorry, it's been too many years, for me to recall the details about what thickness spacer is needed.
Trade your '85 limited slip for the correct limited slip.
Way easier.
Old 10-11-2022, 02:55 AM
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Thanks again Greg! If i could find a early LSD or even a G28.10 or later gearbox for a resonable price i would but it. Problem is the market here in Sweden is super small and even extending my search to central europé has not given any results yet.

Originally Posted by GregBBRD
Of course you have to use your original ring gear with your original pinion. They are an inseparable pair, from their creation to their last day. You loose one...and the other is scrap metal.

Sorry, it's been too many years, for me to recall the details about what thickness spacer is needed.
Trade your '85 limited slip for the correct limited slip.
Way easier.
Old 10-22-2022, 11:18 AM
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Originally Posted by The Forgotten On
It won't fit. You need a 78-82 LSD. After 83 it changed and isn't compatible with they early boxes.
Will the later style LSD fit a G28.07 gearbox. Its still not the Borg Werner but its later then -83.
Old 10-22-2022, 10:49 PM
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Originally Posted by swehedman
Will the later style LSD fit a G28.07 gearbox. Its still not the Borg Werner but its later then -83.
I'm not sure....
If it didn't cost so much for you in shipping, I'd just trade you your later limited slip for the correct one you need.
I've got many of each and one or the other doesn't make much difference to me.
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Old 10-23-2022, 07:41 AM
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Originally Posted by GregBBRD
I'm not sure....
If it didn't cost so much for you in shipping, I'd just trade you your later limited slip for the correct one you need.
I've got many of each and one or the other doesn't make much difference to me.
wow Greg! Thats wery nice of you! If you are seriouse that might acctually be an option. I think shipping isnt the worst part. VAT and customs usually is the killer. But for a swap i dont think i would need to pay those fees. I will contact u via PM.
Old 10-23-2022, 01:43 PM
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strange question... we did just the opposite , placing a old LSD in a newer gearbox.....to have best of both .
Old 10-23-2022, 04:02 PM
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Originally Posted by belgiumbarry
strange question... we did just the opposite , placing a old LSD in a newer gearbox.....to have best of both .
yes. That would be ideal. But that would only be possible if i had a pre 85 LSD and a post 85 gearbox but i have the opposite…

These parts are not that easy to find anymore at least not in europe.
Old 10-23-2022, 08:51 PM
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Originally Posted by swehedman
wow Greg! Thats wery nice of you! If you are seriouse that might acctually be an option. I think shipping isnt the worst part. VAT and customs usually is the killer. But for a swap i dont think i would need to pay those fees. I will contact u via PM.
I won't see my PM's until tomorrow, but if you can figure it out, it's fine with me to swap, as I said.
Old 10-24-2022, 02:36 AM
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Originally Posted by belgiumbarry
strange question... we did just the opposite , placing a old LSD in a newer gearbox.....to have best of both .
Easiest way to do this is to get an 83-84 LSD. It has the early style LSD build with the later offset. So it fits any 85-95 box as well last I knew.

But those ones are pretty rare now. So they are worth real $$$.
Old 10-24-2022, 02:58 AM
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Originally Posted by The Forgotten On
Easiest way to do this is to get an 83-84 LSD. It has the early style LSD build with the later offset. So it fits any 85-95 box as well last I knew.

But those ones are pretty rare now. So they are worth real $$$.
so the offset charged in 83 but the internats in the LSD chenged in 85? Does this aply to both manual and automatic gearboxes?

if this is the case then a 85 LSD would have the correct offset for a -83 G28.07 manual box, yes?

Last edited by swehedman; 10-24-2022 at 04:03 AM.


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