I may have located a 4th gen rear axle in my area. The seller says it's out of a '98 Z28 with about 50k miles on it. Thinking of swapping it into my IROC to A) save me from using spacers with my Z06 rears, and B) save me from having to pull the axles to install the C5 conversion brackets on my existing drum brake rear.
Is there anything i should look for in particular? Obviously, i'll spin it to make sure it's posi and to make sure there's no slop in the pumpkin. Is there anything else i should check? Also, how direct of a swap is this modification? Does it basically bolt right back up the same as the original, drive shaft and all?
Also, what would the gear ratio be on this rear end?
Thanks in advance....

 

Direct swap. Everything bolts up. Check the following link for info that you may find helpful:

https://www.thirdgen.org/forums/tran...-10-bolts.html

JamesC

 

I remember seeing a picture on here of a 4th gen rear in a 3rd gen that showed how much further the rear tires stuck out. Does anyone have that picture?

 

Check post #8 in the following link:

https://www.thirdgen.org/forums/tran...-question.html

JamesC

 

being out of a z28, it will either have 2.73's or 3.23's (if it was out of an auto car), or 3.42's if it came out of a 6 speed car.

rear is a direct bolt it. only thing you need to figure out will be the e-brake cables.

 

Uh.. that post is incorrect. The rear ends are ~1.5 inches longer at either end. The stock wheels will set out a little bit further than they will with the stock rear (about 1.5" per side...). Otherwise, how would the 4th gen offset wheels fit without spacers? Check my CarDomain (click my signature picture) there is a picture of my car with the 4th gen rear and stock wheels on page 1 or 2.

 

Stock 15in RS rims with 235/65/15 tires. Rear is from a 1995 Trans Am

 

Man, that's a nice shade of blue methinks!

 

Medium maui blue, ive never seen another one in person, and only seen one picture of one. Thanks man i love the color.

 

Thanks guys, i knew you would all come through for me. Going to look at the rear end tonight, so we'll see what shape it's in. I'll bolt up my Z06 rears and see how the clearance is if i do buy it. Even if it's only 1.5" wider on either side, that still saves me from having to run such a large spacer in the rear.

 

Picked up that rear end last night. Needs to be cleaned up, but otherwise is in very good shape. Thinking of sandblasting as much as i can, just b/c of all the nooks and crannies that are involved. Are there areas i should tape off well to keep out any small particles? Will get that painted and ready to go in, then remove the stock rear end and drop the fuel tank while everything's outta the way. Now that it's close, i'll be able to chronicle the progress better with pics. May start a rebuild thread.

 

This shows my bird and where the 15" stock axle sat, and where the 4th gen (2000 Camaro with PBRs) axle with 3rd gen 16"s ended up.



Just make sure you don't get any sand into the axle itself (in pumpkin or axle shafts), tape it off liberally and you'll be fine. People have also Por-15ed their axles with great results.

Also the e-brake cable isn't that much of a hurdle as long as your willing to fabricate a bracket or use one from a fourth gen and weld it to the body. The rest is bolting up relatively. I even used the 4th gen equalizer after bracing it with some steel and still used the stock '88 ebrake cable and handle and all. Good luck!

 

"Spinning" it didn't do you any good - only way to know it's posi for sure is to look inside. Gears as well - only real way to know is to look inside.

I have a 305 block under the porch - I could say it was a 350, and 99% of people wouldn't know the difference without taking a head off and measuring.

 

Tell me if i'm wrong, but on a posi rear end when you jack the car up and spin one side, the other will spin in the same direction. With an open diff, they'll spin in opposite directions.
Is the standard block storage location under a porch? All these years, i've been keeping mine on an engine stand in the garage.

 

If the limited slip is shot, it'll act just like an open.

JamesC

 

My open spins only the wheel you turn, it's weird.

Jon

 

All I know is, many a fellow TGO brother has been very upset assuming anything was posi with the 'spinning wheel' method.

Well, if you read the fine print in the rule book:

"Under penalty of law, any and all Chevrolet 305ci blocks removed from any vehicle at any time shall be properly disposed of in the following manner:

A maximum of 10 feet of chain rated at minimum for a working load limit of 20 lbs. shall be attached to the block in such a manner that said chain will not come off, and said block must then be lowered off the side of any floating vessel large enough to safely port said block, and that such disposal MUST be done in waters with a minimum depth of 100 feet.

If such a floating vessel or body of water is not available for the above disposal method, a person(s) may hide such block under a porch, in the back corner of a garage or storage building, or under a house until such time as the means may be attained for the above disposal method, provided that said block is completely out of sight, especially from women, children, or innocent animals.

AT NO TIME may any Chevrolet 305ci block be adhered in any manner to any engine stand or other device intended for the storage of any respectable engine or motor. This is a serious offense punishable by death!"


Since you are a brother of TGO, I won't turn you in for desicrating the sanctity of an engine stand with something as obscene and repulsive as a 305 block. We'll just call it a "lessoned learned". But you better not let anyone else know!

 

Well, thanks for not turning me in. Hopefully i have a couple guys coming this weekend to take it off my hands. I think he said something about jamming it into a VW Beetle. In the mean time, i'll make sure they follow the proper "storage" proceedures.

 

Bugs make for an excellent storage facility for 305s. Don't need a 350, in a 1200 lb car!

V8 Bug video link

 

Oooo, that does look fun. Goes to show what a good horsepower to weight ratio will do for you huh?

 

not sure about a 98, but I have a rear axle from a 2000 with the zexel locker and it does not behave this way. the zexel is not the clutch back type you may be acustomed to. only locks up on torque demand from a slipping wheel.

 

Here is my 86 with a differential from a 95 camaro z28. It has the stock 15x7 z28 rims on it with 235/60/15 tires...