differential reinforcement

rsporsche

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so the question is, who is making these? Carl used to have them but they have been on back order for 1.5 years. i remember seeing pics from somebody here on the forum, but i haven't been able to find it.
 
We have them.
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Is the reinforcement where the diff bolts on to the car? Is this a true weak point? I just replaced my diff, is it worth taking off and adding reinforcement? Questions for the cognescenti
 

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Is the reinforcement where the diff bolts on to the car? Is this a true weak point? I just replaced my diff, is it worth taking off and adding reinforcement? Questions for the cognescenti

Yep, thats the right location.

Can't say that it is worth it for you in your car, but it is a point in e9's where cracks are frequent.


My car, being an automatic didn't have any. Probably driven gently?
As I am converting to M90, Lsd and 5sp manual, I still added some reinforcement
 
I've installed La Jolla's on both of my Coupes. Good idea if you are increasing torque with an engine transplant. If you are going to much higher torque, say 350-450 lbs it's a definitely needed upgrade. A couple of additional reinforcements are stitch welding the rear wheel wells, front and rear shock tower braces and structural braces under the rear seats that attach to the kick panel below the ashtray. Of course the diff reinforce is also needed. IIRC Coupe King used to make a diff reinforcement part but La Jolla's was better.
Regards, Jon
 
My two coupes didn’t have them and they are fine. Putting out 250hp then it would be wise to install them. And I think CK sold Carl’s part.
 
kinda my thought Chris. i might be just shy of 250, but its probably smart to do it when i drop the rear subframe to get rid of the 2800cs drums.
 
This is a well-known problem which was first dealt with by BMW with their own Repair parts. Carl Nelson, I believe he was one of the first to realize what was going on and buy a supply of the Repair parts for the United States. And then possibly it was Paul Cain that provided designs for continued productions here by Carl.
I eventually had a mechanical engineer that worked for me redesign for the third time what we felt was an even better product.
And yes, my first Coupe was a Csi and the rear sheet metal was Cracked to pieces and made it so I couldn’t drive the car until the entire underneath cracked section was repaired and welding a car upside down is really tough. It left a lasting impression and that’s why when Carl couldn’t find his supply I had them redesigned.
 
Yeah, I just made one based off the pics of the ones you can buy. Some metal, a few bends, some holes, a little welding and zinc rich primer..all good!
Yeah, the welding while laying on the floor with leather laying over me was a little…fun..:-/.
Here’s a pic of a test one out of thinner metal. I remade it out of thicker gauge and welded it in. Haven’t taken pics of that.
Also the flat piece that welds to the perpendicular beam, as well, but that’s not very exciting looking.
 

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