Has anyone removed the rear diff....

[KJL]

I am looking to upgrade my rear gears to 4.1 and possibly the flywheel to a lighter weight aluminum unit. I don't have a lift but have done this work on my 1972 vette up on jack stands. Is it possible to do this with a C4? I know the transmission is a lot heavier than my TKO5 speed.

[We Gone]

Yes, you can remove the complete batwing assembly or just the pumpkin.

[RussMcB]

KJL, send me a heads up when you think you'll tackle it. I'll come over and lend a hand if you'd like and if I'm free.

I almost tackled that job (rear gear change) a few months ago, researched it a little bit, but didn't follow through (I've since changed my mind about changing gears). Soon on my to-do list is to replace my rear leaf spring, so I'll probably be removing some of the same bolts as you.

[KJL]

Hey Russ, haha, just sent you a PM. Thanks for the info. Thinking about doing doing a gear change... although I have rebuilt a rear diff before, likely send to Marc H. for the rebuild.

Not sure what I want to do with the 92. Nice stock car but damn, this is the last year I need to worry about emissions... can do what ever I want.....

[KJL]

Hey Steve-
It has been awhile, I hope all is well with you. I just finished most of the upgrade to my 72 but having some tuning issues. The car has been sitting at the builders garage since Jan 1st. No sooner do I get done messing with one, I get the urge to work on another. I fixed all the little things that were wrong with the 92, third brake light, head light gears, bad rear audio amps (I am now an expert at replacing the caps myself). , tightened the oil pan bolts...man were they lose... no more leak, new radiator overflow tank and chased down some vacuum leaks and flow master exhaust (thanks to you) now she is almost as good as new.

[ZRXMAX]

Changing the rear spring is easy and can be done in a half hour or less. Changing the rear end will take some time and is rather awkward without the right tools and support.

I do mine on the garage floor and use a floor jack fitted with a lifting bracket I made for the diff. I take the batwing and all for the simple fact I don't like dealing gear lube until the unit is on the bench. :)

Getting a set of Beam Plates from Bill B will make reinstalling the unit a bit easier.

I also suggest you support the transmission where it is at and remove the C beam so the shifter boot stays intact and in place so you don't have to re seal it later.

[KJL]

If I take all that off, wouldn't that be a good time to change out the flywheel? Don't know what is involved with that. I assume the exhaust must be removed from the cats back? Has anyone rebuilt the rear diff themselves? I did for my 72, I recall needing some hefty tools for torquing the pinion nut etc.

[We Gone]

Good to hear from ya, hope all is well. Flowmaster my not be the best flowing exhaust but I think it is one of the best sounding. I put mine on the 93 when I changed to Corsa on the 91. Keep in touch.

[XfireZ51]

I am looking to upgrade my rear gears to 4.1 and possibly the flywheel to a lighter weight aluminum unit. I don't have a lift but have done this work on my 1972 vette up on jack stands. Is it possible to do this with a C4? I know the transmission is a lot heavier than my TKO5 speed.

I've dropped both trans and diff from my C4's. The diff is easier than the trans because of the weight and the space.

[KJL]

Thinking that if I am going to drop the diff, upgrade beam plates. I may as well do the clutch and upgrade the flywheel while I am at it. I just know how heavy my TKO 600 was. All I used was a Harbor Freight scissors jack laying on my back.

[KJL]

I love those Flowmasters. Marc H. says swapping to that system was good for a 15HP gain over stock 92 system. I think some porting and a chip is all that car will need and still look stock. I may attempt porting it myself. I recall finding a detailed article somewhere regarding how to do it. Most expensive part will be finding the correct diameter ball gauges.

[XfireZ51]

Thinking that if I am going to drop the diff, upgrade beam plates. I may as well do the clutch and upgrade the flywheel while I am at it. I just know how heavy my TKO 600 was. All I used was a Harbor Freight scissors jack laying on my back.

Harbor Freight has a fairly inexpensive trans jack. I bought mine for about $45.

[KJL]

45? Damn... the cheapest trans jack that they have on sale is about 120.00 Just a scissors type mechancial which I already own. I purchased the next level up, it is an 800lb hydraulic. based on how far you have to angle the engine/trans to get the shift to clear, the trans jack needs to also have the ability to match that angle as close as possible. The cheap 400lb scissors has very limited angle capability but is very useful when you need a jack with a large platform, like for engine support that you would not want to trust to hydraulics.

[rkreigh]

with the weight of the trans supported you can pretty ez shim it up to be the right angle.

I had a 95 with headers and flowmaster and it sounded fantastic.

still one of the best sounding exh.

close in 2nd place but better flowing is the B&B

I have one for sale for $600 complete with cats if anyone needs it.

got it from someone "demodding" the car back to stock.