Eaton LSD

XR4Ti / Sierra / Sierra Cosworth Discussions - Questions, problem resolution, general talk, technical tips and modifications.
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DSPXR4ti
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Eaton LSD

Post by DSPXR4ti » Fri Mar 23, 2007 9:13 pm

Hello All,

Does any one know if they make an Eaton LSD for the stock 7.5 with no Mods to the case, the rules say I can use any LSD just can't MAKE it fit if you know what I mean, if any one has any info on this please let me know.

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xrattiracer
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Post by xrattiracer » Fri Mar 23, 2007 9:50 pm

so far as i know the only 100% drop in replacement would be the cossie unit.
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Post by DSPXR4ti » Fri Mar 23, 2007 10:14 pm

Well,

Let me ask this, has anyone check into this, I mean Chevy, BMW, Jag, MZB, Toyota, Mazda, Nissan all make a 7.5 26 spline, I was just checking to see if any one else has looked into this and if anyone can point me in the right direction would be great.

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Post by RatFink » Fri Mar 23, 2007 10:36 pm

I have herd of people using the chevy 7.5 LSD. I'm not sure of the details though. Good luck!

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Post by whitelx » Sat Mar 24, 2007 12:00 am

I believe there might be some info over on turboford.org about fitting the 26-spline GM 7.5" diff into the Merkur case. I know you'll have to shave a small amount off the ring gear holes for the bolts and I believe you'll have to grind on the inside of the case a little.

I am going to put a GM diff in my XR once I get it on the road. I'd like to get a torsen-type diff. I think Detroit makes one.

some links
http://www.turboford.net/cgi-bin/ultima ... 014#000000
http://www.turboford.net/cgi-bin/ultima ... 314#000006
Last edited by whitelx on Sat Mar 24, 2007 12:10 am, edited 1 time in total.
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Post by DPDISXR4Ti » Sat Mar 24, 2007 12:03 am

The GM 7.5 is 26-spline, and has been used, but it's absolutely not plug-n-play. It wasn't designed to fit after all, so some fabrication is involved. I don't believe any grinding on the case is required however, if that's all you need to be concerned about. The stock GM LSD usually is an Eaton however, though I'm not sure why you're specifically looking for that. :?

Of course the other alternative is to use a complete stock LSD from a Euro Sierra or Scorpio. The 7.5 version is the same identical case, so how's anyone gonna know it wasn't the one that came with the car?

The Quaife will of course fit in the stock 7.5 case, but some grinding is required on the inside. Do you really think someone is going to ask you to tear the diff down?
Brad

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Post by DSPXR4ti » Sat Mar 24, 2007 12:36 am

Well, let me put it this way, a year or two back a corvette way missing some tirm in the T-tops and was DQ for that event, plus I would like to beat them with no extras.

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Post by worked_xr » Sat Mar 24, 2007 12:40 am

Actually, I think there is only one actual "plug and play" diff that will work, and it's not all that common... something like a 4wd Sapphire Cosworth diff I think.

Anyway, wait for John V. to chime in... he's got a solution that is darn near as cheap as it can get.

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Post by anglin » Sat Mar 24, 2007 1:30 am

worked_xr wrote:Actually, I think there is only one actual "plug and play" diff that will work, and it's not all that common... something like a 4wd Sapphire Cosworth diff I think.
The Scorpio Cosworth diff will bolt in with no thought as well.

If we can keep this thread focused on the GM diff swap we can FAQ-ify it. We can cover the Euro Ford bolt-in diffs elsewhere.

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Post by John Brennan » Sat Mar 24, 2007 2:43 pm

The focus of the thread appears to be on a diff swap that will be "invisible," with the Eaton diff guts raised as a possible candidate. Of course, if you really want to "beat them with no extras" then you'll be running the pegleg. If you want to cheat creatively, then I think Brad's response sums it up best. The only LSD diffs that look and fit the same wll be the bespoke Euro items, bearing in mind that the Cossie diffs have a larger bolt pattern for the axle shafts.
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Post by DSPXR4ti » Sat Mar 24, 2007 5:15 pm

John, Here is the problem with the SP rules, there are major parts of the car you you can NOT change, like the DIff, so something like the larger bolt pattern for the axle shafts would be one of them, I have hear that there are some of you with T5's in your car and if you were to run in the SP class, the rules do say you can use a T5 BUT! you have to find a T5 with the same gear ratio as the stock car transmission 3.36,1.81,1.26,1.00,.88 and the trans would have to weight the same as stock, again I will say, spend your money in the right places.

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Post by John Brennan » Sat Mar 24, 2007 6:25 pm

Right, so if you were to use an Euro LSD that appeared stock, you might get away with it, especially if you didn't "lay rubber." :wink:

And if they did call you on it, just play dumb and then sell it... to me! :)
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Post by whitelx » Sat Mar 24, 2007 7:10 pm

brncapri wrote:John, Here is the problem with the SP rules, there are major parts of the car you you can NOT change, like the DIff, so something like the larger bolt pattern for the axle shafts would be one of them, I have hear that there are some of you with T5's in your car and if you were to run in the SP class, the rules do say you can use a T5 BUT! you have to find a T5 with the same gear ratio as the stock car transmission 3.36,1.81,1.26,1.00,.88 and the trans would have to weight the same as stock, again I will say, spend your money in the right places.

Ben DSP XR4ti
does the class allow for updating or back dating?
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Post by Maurice S » Sat Mar 24, 2007 7:32 pm

How bout that "Phantom Grip" deal...Back when I asked about it, it seemed to be ok..especially for road racing and auto X, not so much for drag racing... I think it's an easy installation...Russ at Rapido sells em.
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Post by DSPXR4ti » Sat Mar 24, 2007 8:29 pm

And if they did call you on it, just play dumb and then sell it... to me! :)[/quote]
John, about playing dumb, the SCCA will not buy that and if you drove 3600 mile round trip and all the money for the trip would you want to chance that.
Are far as updateing and back dateing, they have to be a US base car, sold in the USA but LSD are open you just can't Mod your case to make it fit.

Ben DSP XR4ti

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