Club Cobra - weak rear ends

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I have been looking at the new rolling chassis, And it seems to me that the rear ends used by some is dubious as to how they will hold up. One is using a BMW, one is using Toyota parts Ect. Any comments ? I have seen a number of failures in last few years .:confused:

It depends on how much torque you're putting through them. Some of these guys are running 302's and 351's with not much horsepower. Running through an open diff on street tires, it's hard to tear stuff up.

If I'm putting out any power at all, I'd feel a lot more comfortable with a nicely built 8.8" Ford or a 9" Ford if running a solid axle.

Why do people say that the E36 rear end is not strong?

The original 8.8 inch rear end in the mustang 5.o in 86 had what, 205 HP going to it on a 3200lb car? And ran as much as 240 or so from the factory with the same spline axles in later years. Most people out there are probably running this same rear end in there cobra's without failure.

BMW ran 260 HP on the same E36 diff on a 3600lb with more weight on the back end of the car back in the day. I would think they use the same engineering std's that Ford does for margin of safety.

Either rear end can fail if its put through lots of abuse. When it happens, you upgrade the parts!

Because there have been a couple guys on here that have broken them.

Sure, people break 8.8's and 9's, but it takes BIG power to do it....not 300-400 hp small blocks.

The Chicago area has several Everett-Morrison cars running C4 Corvette aluminum suspensions--seems to be quite a preponderonce of higher horsepower engines that are other that Ford engines

Jerry

Hey? I destroyed my indestructible 9" rear last year. The only salvagable parts were the main casing and the pinion yoke.

Roscoe

depends on the driver and HP or Tork applied

Bulletbrown, If a rear is setup to the CORRECT specs, with heavyduty axles, a rear support cover for the carrier caps to stay in location, NO SLICKS It should last 10-20K mile under all driving conditions. IF YOU ARE AN ANIMAL, it could last 3 burnouts. Wheel hop breaks rears faster that 500hp behind a 300 hp rated rearend. I don't have alot of info on BMW or Toyo rears, but the tork and HP rating, guessing would be in the 400HP and 400ft of tork. Jag rear is a 450/450 rated rear. I have upgraded it to 600/600 with cover,30 spline chromemoly shafts, harden spiders in the diff. A 8.8 rear with upgrades is good for 750/750 with the same upgrades. If drag racing with slicks, the rear would need a check after 25 runs for damage and backlash. You need to KEEP the back lash readings, Once out of spec, either rebuild or re adjust lash. You can put 1k hp behind any rearend, auto trans will soften the tork to the rear, a good clutch driver can do the same. It is about how hard you are on the car. With a BBF I would go with a 9" ford rear heavy duty with larger bearings and heavyduty pinion support housing. If you are going to be easy on the car the 8.8 with upgrades would be just fine and cheaper. Rick L.

Quote:

Originally Posted by Mark Brye

The original 8.8 inch rear end in the mustang 5.o in 86 had what, 205 HP going to it on a 3200lb car? And ran as much as 240 or so from the factory with the same spline axles in later years.

While true, I believe they are running the same in many PRO 5.0 classes where they are cranking over 600HP, easily. They do have to put 9"style axles to eliminate the weaker c-clip axles, but I think the 8.8 had shown some pretty good durability over the years in some extremely tough conditions. I'm not saying that the BMW is weaker, but I am willing to bet it has NO WHERE near the abuse testing that the 8.8 gets every weekend. How many runs can one make with a 600HP 6000rpm launch. It would be interesting.

Get a Ford 9" from Currie cut to size for your chassis. As long as you keep fluid in it (Roscoe...) it'll last longer than the rest of the car.

I've got more then 600HP going to the rear and haven't had a problem yet. People are just afraid of change.