Rearend Question
 

I got a full-locking rearend in my Malibu and driving around town sucks. My quesion is could I take my whole rearend (7.5 inch) out and place a Limited Slip Differential(12 bolt) in without a problem? Or do I have to get a whole new axle and housing set-up?

It depends on what's in there. You may just be able to replace a welded set of spiders or it could mean a complete guts replacement. If you don't have records and aren't in contact with the person who set it up you'll have to open it up.

Did someone before you have the car set up for drags?

just take the lokcer out and get a set of spiders and an open carrier....as long as she ain't lincoln locked / welded

The guy said he didn't welded but hes an ass so who knows, But if these spiders you talk about arn't to much money I could always go that route. When I bought the car it had a locker, so it only lockled when I punched it but I blew that to pieces so this guy put a full-lock in its place, I wasn;t thinking when I sent it off to him, but the part he put in only cost me 230 dollars. So I got like 600-700 dollars canadian to play with.

Thx for your help guys!


This part you mean?
http://store.summitracing.com/partde...5&autoview=sku

Pain Train,
I don't think the parts on that Summit Racing page are what you want. That looked like just the rack & pinion gear from the rear. What you want to investigate changing or replacing is the limited slip clutches/discs whatever.

Maybe something like this http://store.summitracing.com/partde...5&autoview=sku

or this http://store.summitracing.com/partde...5&autoview=sku

or simply an open diff version of the internals.

Wow those are expensive but the LSD one does that part go in with everything else or is that a full replacement of my old Diff?

Reason being I don;t have a 12 bolt rearend and the Detroit locker says 7.625, Mine is a 7.5 unless you can get them in different sizes?

I'm sure they are available at Summit for any rear you could have, I just quickly picked a couple examples of the type of part but most likely not the one you need.

I wouldn't exclude the option of finding a complete relatively newish rear in a junk yard and just changing the whole thing out.

well the junk yards here don't have much older cars like mine, I would hate rolling around in mud all day and probably not finding one, The plus side to new one is it should brake, just the install fee is gonna hurt!

You don't necessarily need the exact same rear end. As long as it is the same width it should just be a matter of changing spring perch locations, unless you're lucky enough to find one that matches perfectly. It may be a good oppurtunity to upgrade to a stronger rear or get one with a different gear ratio.

What size rearend would you recomend?

I was thinking of going for a 12bolt, guys at work want me to put a Ford 9 inch(but thats just stupid)

I'm thinking of that song "stick out your can momma, here come the garbage man" ...but I'm sure you didn't mean that rearend :crazy:


Sure, the 9" Ford would be virtually indestructible but I think the right GM rear would be too. I'm just not very conversational about domestic muscle parts other than my big can input above, so hopefully one of your local buds or somebody here will know.

Unfortunately, I'm not very well versed on chevy rear ends. And a 9 inch ford would probably work great, but they are getting hard to find in junkyards, impossible if they only deal in newer cars. I know the ford 8.5 is a popular swap for some offroad guys, and they have the advantage of coming with disk brakes if you grab it off a 95(?) or newer explorer, but I'm not sure if they come in a width that would be useful to you. There must be a couple chevy boards somewhere out there on the www that could give you better and more specific advice than I ever could.

Agreed on the Ford 9. Also, there are many versions to contend with. It may be overkill unless you have big ideas for the engine. Gears a great to setup though with the 3rd member out & easy on the bench and screws vs. shims.

guyondacouch, I think you mean the Ford 8.8. It's a good medium-duty swap for offroading. 95-2000 explorers have it stock with discs and 31 spline axles, so it's readily available. The only problem might be the perch positions, which I cut off for jeeps anyway. WMS width is 60". Gears may be 3.55, 3.73, or 4.10. LSD is stock with 3.73 and 4.10. Bolt pattern is 5 on 4.5 which means new wheels or adapters for a chevy.

There are other versions of the 8.8 available but they are often wider, use 28 spline, or goofy gearing.

Durp, yes I did mean the 8.8. I'm not sure where I came up with 8.5.

I might just stick with the my current diff and just get the LSD put in. I have already done the engine up, got 350+ HP out of a 400 c.i. SBC:D

That why I want something that isn't gonna brake when I take it to the track on the weekends.

The problem I got with my current setup is most of the time when I turn there is a clunk in the rearend, my mechanic said that its because the rearend it locked up to tight(I hope hes right) I'm just hoping the clunk isn't doing any damage to my axels, thats the last thing I need is to buy new axels. :o

I know a locked rear or very tight LSD will do weird things like clunk or make the rear take a little skip when turning sharply. That much is normal. For max acceleration and getting traction to both rear tires, you may want to reconsider keeping that locked rear unless it bothers you too much.

In the "old days" we sometimes cheated and locked the rears even when it was not allowed by the rules since it was an advantage at the drag strip.

If you're getting 350+ HP at the wheels then a 9" wouldn't be a bad idea. Especially if you plan on shaved or slicks. Really, if 350 is at all accurate (dyno?) I'm surprised your current diff has survived.

When does the clunk happen?

BTW, sounds like fun. :)

Well thats 3 people I have talked to and they all said its a normal noise, the only thing that is bothering me is people always think its broken when its not!


Wasn't dynoed the performance shop doesn't have one but they drove it hard for me and some how they came up with that number from RPMs and Speedo(beforethe speedo broke)

The clunk happens when I get half way through a turn, and now even some times when I'm just driving speed limit and let off the gas(that might be the tranny)

Oh and this thing is fun. :D

Well for now I'm going to take Badnicks addvice and stick with what I got untill got some more money to do the whole rearend axels and all! I gotta get my interior done now:D

Sounds to me like there is a detroit locker in there...A typical locking differential will clunk very loud and usually scares the $hit out of people when it bangs.. It should happen when you turn sharp corners..If you want to stop the clunking, do more of a coast around the corner and only come onto the gas when most of the corner is finished.

When force is applied to the locker thats when it locks up harder, there are big springs and pins in there that will allow the wheels to differentiate, but it results in a bang. So coasting through your corners will help that a lot.

This is the main reason I went with ARB air locking differentials in my Jeep TJ so that I don't have to worry about that.

If you want to take it out, just buy an open carrier with spider gears for it, have a gear shop swap the new ring gear on the new carrier, then sell the locker.

Humm I have been slowing down in the corners...maybe thats why it bangs so damn loud! But people here in Kingston don't know how to drive, so coasting corners never works out.