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Welded Diff for Rally?

Posted by cmanreinhart 
NoCoast
Grant Hughes
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Re: Welded Diff for Rally?
October 02, 2015 01:34PM
What do they mean by 20% do you suppose?



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john vanlandingham
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Re: Welded Diff for Rally?
October 02, 2015 02:23PM
Quote
NoCoast
What do they mean by 20% do you suppose?

That there can be 80% difference in rate of rotation side to side.
(because they were set up that loose--not inherent design)

Directly from ZF literature in that bookshelf over there<-------



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Re: Welded Diff for Rally?
October 02, 2015 02:59PM
Quote
john vanlandingham
Quote
NoCoast
What do they mean by 20% do you suppose?

That there can be 80% difference in rate of rotation side to side.
(because they were set up that loose--not inherent design)

Directly from ZF literature in that bookshelf over there<-------

I thought he was trolling for an excuse as to why he was 80% less sideways than me. hot smiley

Dave
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NoCoast
Grant Hughes
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Re: Welded Diff for Rally?
October 03, 2015 01:24PM
Quote
john vanlandingham
Quote
NoCoast
What do they mean by 20% do you suppose?

That there can be 80% difference in rate of rotation side to side.
(because they were set up that loose--not inherent design)

Directly from ZF literature in that bookshelf over there<-------

80% difference in rate of rotation.
So let's say we have a 25" diameter tire and we are traveling at 45 MPH. That's 605 wheel revs per minute. The LSD is loose enough to allow a range of (121, 1089) or wheel speeds of 10 MPH to 80 MPH essentially. That seems pretty loose. That makes sense. Thanks John.

Dave - Not trolling, the stupid percentage numbers are annoying to me and always seemed like a sales tactic more than anything with never a good explanation that I could find.



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Pete
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Re: Welded Diff for Rally?
October 05, 2015 05:57PM
Welded diff allowed me to drive when I sheared another axle.

The axle that didn't shear looks like this:



That was with one (SCCA) rallycross on it... the splines were straight when I put it in...

New rearend has axles as thick at the splines as the old rear's axles are at the bearing (31 spline Ford vs. 26 spline Mazda). If I break those then I'll start a new hobby seeing if I can break crowbars in sand boxes. Or politely ask John Lane what he has in his Volvo.



Pete Remner
Cleveland, Ohio

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1978
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Edited 1 time(s). Last edit at 10/05/2015 05:58PM by Pete.
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john vanlandingham
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Re: Welded Diff for Rally?
October 05, 2015 07:28PM
Quote
Pete
Welded diff allowed me to drive when I sheared another axle.

The axle that didn't shear looks like this:



That was with one (SCCA) rallycross on it... the splines were straight when I put it in...

New rearend has axles as thick at the splines as the old rear's axles are at the bearing (31 spline Ford vs. 26 spline Mazda). If I break those then I'll start a new hobby seeing if I can break crowbars in sand boxes. Or politely ask John Lane what he has in his Volvo.

For us semi-furrin bastids who don't speak spline, any idea of the size in any common accepted mearuring system?
versts? pood? Li? mil?



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cmanreinhart
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Re: Welded Diff for Rally?
October 05, 2015 08:50PM
Would this kit work to rebuild a 1986.5-92 supra diff? http://m.ebay.com/itm/USA-Standard-Gear-ZK-T8-B-86-Toyota-8-Diff-Master-Overhaul-Kit-/171874713169?nav=SEARCH

Just wanted to verify before I break the bank.

-Thanks, Conner
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tdrrally
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Re: Welded Diff for Rally?
October 06, 2015 08:52AM
hey john isn't a versts about 2/3 of mile?



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john vanlandingham
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Re: Welded Diff for Rally?
October 06, 2015 09:19AM
Quote
tdrrally
hey john isn't a versts about 2/3 of mile?

Yeah..
and a li Chinese: 里, lǐ, or 市里, shìlǐ is about 1/3 mile
and a mil is 10km

we all know these old units.
But how many whats is a "spline"?



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czwalga
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Re: Welded Diff for Rally?
October 06, 2015 12:00PM
Quote
john vanlandingham
Quote
tdrrally
hey john isn't a versts about 2/3 of mile?

Yeah..
and a li Chinese: 里, lǐ, or 市里, shìlǐ is about 1/3 mile
and a mil is 10km

we all know these old units.
But how many whats is a "spline"?


John did you see my PM? Let me know.
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Robert Culbertson
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Re: Welded Diff for Rally?
October 06, 2015 12:44PM
Quote
cmanreinhart
Would this kit work to rebuild a 1986.5-92 supra diff? http://m.ebay.com/itm/USA-Standard-Gear-ZK-T8-B-86-Toyota-8-Diff-Master-Overhaul-Kit-/171874713169?nav=SEARCH

Just wanted to verify before I break the bank.

-Thanks, Conner

Conner, the few Supra diffs that I have used did not need a rebuild. They DO need to have the clutch packs shimmed correctly and stiffer springs installed.
Weir makes the diff kit to prelaod the clutch pack. Most have been using MaxGrip Kit #2: http://www.weirperformance.com/maxgriplsdkits.html

Very simple project to shim the clutch and preload it. Very simple.



Edited 1 time(s). Last edit at 10/06/2015 12:45PM by Robert Culbertson.
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Pete
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Re: Welded Diff for Rally?
October 06, 2015 01:37PM
Quote
john vanlandingham

But how many whats is a "spline"?

It's something that engages a shaft to something else, but that's not important right now.

According to sources, the ones that broke a bunch were 27mm at the spline end and 35mm at the bearing end. The new ones are (also according to Internet, since my bits are 2hr away) are ~33mm. So I was wrong by 2mm. Also apparently a "spline" can be the diameter in mm minus one or two-ish, in the ranges we are concerned with.

Wondering if I should have sprung for the 35s...



Pete Remner
Cleveland, Ohio

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1978
Silence is golden, but duct tape is silver.



Edited 1 time(s). Last edit at 10/06/2015 09:05PM by Pete.
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cmanreinhart
Conner Reinhart
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Re: Welded Diff for Rally?
October 18, 2015 02:14PM
How well does the stock supra diff lock up? I suspect its better than the BMW e36 LSD? Should I even bother picker up a shim kit from Weir Performance?

-Thanks, Conner
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Robert Culbertson
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Re: Welded Diff for Rally?
October 18, 2015 06:53PM
Quote
cmanreinhart
How well does the stock supra diff lock up? I suspect its better than the BMW e36 LSD? Should I even bother picker up a shim kit from Weir Performance?

-Thanks, Conner
It sucks, but it has potential. Bother... Yes.
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tdrrally
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Re: Welded Diff for Rally?
October 18, 2015 07:33PM
i know my toyota 7.5 lsd was worlds better than an e30 lsd



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first rule of cars: get what makes you happy, your the one paying for it!
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