01silvercoupe

After a hard 1st to 2nd shift, I'm having some really bad clunking/bucking from the rear when I start off in from a stop. Once I get up to speed it ok *** long as I don't press the gas to hard. Sound like a rear diff?

01silvercoupe

Ok, I got the car in the air and took the tires off just to get a good visual. Everything looks fine and no fluids are coming out. However, if I spin one rotor the other does not spin. Isn't the other side supposed to spin too? Maybe one of the outputs broke?

Sigforty

How bad is the clunk? When I had symptoms like you are describing it was because I sheared the cross pin in the differential into 3 pieces. The posi ate itself from the inside after that.

01silvercoupe

I would rate the clunk at "brutal". I limped it home but if I gave it more than 5% throttle, it would clunk so hard that is shook the car.

Bill Curlee

You either broke the cross shaft spider gear/s OR busted an output shaft.

You have to remove the differential either way... Here are some post for you to read and they will give you some ideas and may some upgrades on the cheep:

- C5, ragtopws6 , Upgrading your C5 rear with C6 Z06 guts, : http://forums.corvetteforum.com/c5-g...-z06-guts.html
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- C5, Its_Go_Time, Output Shaft Install - Left and Right: http://forums.corvetteforum.com/c5-t...post1573407966

- C5 Differential Seal replacement: http://forums.corvetteforum.com/c5-g...on-photos.html
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01silvercoupe

Awesome! Thanks again, Bill. I think you answer like 95% of my questions here Time to get to reading.

VGLNTE1

Yup...sounds like mine when it went. Clutch packs broke and a gear was stripped. Rpm is the best at rebuilding them. Stage 3 different for sure, and if you don't have it, a dts brace.

Bill Curlee

Another option for differential service is

RKT56.com

Rick Kim does EXELLENT work and will build the differential to any level that you want.

Excellent service

Once you get it out of the car, you will be able to diagnose it better

Bill

01silvercoupe

Got the differential apart today. Cross shaft is good but the spider gears are chewed up and the clutch preload springs were broken. Clutch packs and springs were so messed up I didnt even need a special tool to remove the cross shaft. Just pushed right out with my fingers. There were two pieces of preload spring left that made about 3/4 of a circle on the long shaft side and just on piece that was about 1/3 of a cirlce on the other. The discs are REALLY worn too. Should have had that changed a long time ago. I suspect the preload springs broke and started havoc with the spider gears.

One question though. The inside of the differential where all the spider gears and such are, the walls are a little marred in places. Would this affect anything on a rebuild?

Bill Curlee

Unless its a machine fit surface, I would say remove the burrs and fix the gears, clutches and springs. Make sure that you upgrade to C6 parts.

RPM sells a harder and better designed cross shaft. I also installed one of those:

New shaft on the left:

92GA

Might be time to upgrade the ring and pinion also.

Bill Curlee

Sometimes we take the C5 differential for granted. Its NOT a typical GM diferential. To replace the pinion carrier, the ring and pinion or any of the bearings, you have to have the rearend properly set up using the correct shims and set up tool that is required to do the job correctly.

Sometimes, the basic "fix whats wrong and move on" is whats necessary. Just didnt want the OP to think that just anyone can slap in a ring and pinion and move on.. Its NOT happening..

Bill

01silvercoupe

Yeah, just reading about changing the ring and pinion makes me sweat lol. So what is the best way to clean all the fluid off of the differential parts (Like any particular solvent).

Also, does anyone have part numbers for all of the differential internals. I found cluctch pack/spring part numbers but I don't know about spider gears or any other pieces that may need replacing?

Huge thanks for the help so far!!

Bill Curlee

Two places that I know will be able to help you out:

Gene Culley If its GM and available OEM, he will have it. Give him a call.

https://www.corvetteforum.com/forums...kend-sale.html

Rick Kim RKT56.com He can get any differential parts as he rebuilds differentials and transmissions.

01silvercoupe

Awesome, Thank!