I have a 93 Z28 with around 100k on it. When de-accelerating in 3-5th gear, a loud whine (almost like an airplane) can be heard from the rear when I left off the gas. If I disengage the gear it will go away. Im assuming its an issue with the rear end, and ive heard the stock rears arent that great. My question is...Do you think im correct with my diagnosis, and if so, should I get another rear end from another car, or have mine rebuilt with bigger gears.

 

yep its getting tired. check fluid level in the rear. if you can find a good low mile rearend go for it. not easy to find around here. most likely bearings letting you know there not happy.

 

Thats what I figured, Im going to drive it for as long as I can though, But junkyards around here are CROOKS and charge double for everything, and CL is a pain sometimes. Would it be wise to re-gear if i were to rebuild? And what other stronger axles from other cars will fit, I thought I heard about fords 9inch fitting?

 

i have a 9 inch in mine, they have to be modified to fit. cost for mine 3200 or so. you can get them cheaper from quick performance if you have tc and/or dont want to use abs if thats what you have. yep if your gona have new bearings put in you may wish to change the ring and pinion to like a 342 or 373 ratio. cost for changing gears should be minimal if bearing are changed anyways.

 

On a side note. The stock rears are adequate for a stock engine. Craby does not have a stock engine, and what he has would shred a stock rear in very short order. If your car is stock, and you have no plans to do more than the normal boltons, then your stock rear will work just fine.

If you are not able to find a good used rear, and I mean for a smokin' deal, I would personally just rebuild the one you have. Even a "guaranteed" used rear is still used. You won't be completely sure about the condition until you get it installed and drive it around a bit. New bearings and seals, and a rebuilt posi unit will do wonders for the rear end. About the only thing that is somewhat hard to do it setting the backlash. If it is set too tight or too loose, your rear end will make excess noise and the gears will not last as long.

If you do change the gear ratios, just know that it will affect how the car accelerates, cruising RPMs, and your mileage. Also, since you are working on the drivetrain anyway, may as well replace the u-joints as they are probably almost 20 years old now. Unless you have already replaced them.

 

Yeah im familiar with gears, I used to be big into offroad, jeeps mostly, but now im trying out this side of the fence. Im deff going with bolt-ons, and a cam but im hoping by the time I get that far ill have an LS. I guess ill just rebuild unless I find a deal