itsdaveonline

After reading alot, it seems the rear ends give out alot on these cars. What's the part which gives out? Or is it the wheel hop which messes things up?

I have a '06 with upgraded creative steel axles, does that help to keep my rear end from blowing up?

bmylez

iTrader: (3)

Lazy/cheap GM engineering is the reason. '06 rears are decently strong, just don't let it hop a lot.

itsdaveonline

I mean is there a specific weak point which can be beefed up? Just saying the whole rear end is junk doesn't really give me much info.

bmylez

iTrader: (3)

Unless you can redesign the entire case, no, nothing to beef up.

Fweasel

iTrader: (6)

See, you know more than you think.

Poly cradle, trailing arm, and diff bushings, upgraded axles, a 3rd or 4th gen diff, and an intelligent right foot is about as far as you can go before you pull then entire thing and go 8.8" or 9".

rand49er

Wheelhop causes stresses in the diff case that exceed its strength.

Even eliminating WH will not 100% protect the diff if you do too many burnouts, but it will help.

As mentioned, going 8.8"/9" seems to be the only real "cure."

DMM

Shitty German engineering is the root cause. American made diffs don't do that, not under OE power anyhow.

Blackberrysvt

so longbars or a form of them are not offerec for the our car im taking it.

heavymetals

iTrader: (3)

Blame the GM bean counters.

If you do the work and look at the GETRAG specifications for the diff, it is underrated for the torque the LS motors are capable of.

The big reason why they got away with it is no one died, or the # that died wasn't big enough, unlike the ignition switches.

Update:

Looks like all the tech specs on the GETRAG 645 have been removed from their website.

The CTS-V FAQ's just lists an old link that doesn't work.


I will search my old HD's as I think I downloaded the specs at one time.

Creative Steel

CORRECTION:
If the axles are plugged in to a Getrag diff.....they aren't from us. We only sell axles for the 8.8 swap.

True: GM could've picked a different diff from the Getrag catalog that would have stood up to the LS engines, but would have cost more.

odthetruth

iTrader: (4)

You could bulletproof the case, and then spend your time snapping stock axles every run. You could bulletproof the axles, and snap the case at the ears.

You'd need a full swap to be able to hop and NOT break anything.

isis

iTrader: (1)

The cool part is that such a short thread has such complete info. The case is weak. The axles are weak. The engine is not. Solutions are available but band-aids stink.

4doortypels

iTrader: (39)

Tc performance makes a nice steel girdle. If i were on my oem and money was tight... i will say cradle bushings for me had the largest improvement

MN_V

iTrader: (5)

Have hopped bad quite a few times when it was wet out- get off the gas, and learn what causes it on your car. In my '06 it's only a problem if I were to try to do a standing burn out or too much gas when wet out.

If you don't hop it, you're probably fine long term. 115k now on my stock diff. I wouldn't replace stuff if you're not abusing it.

MN_V

iTrader: (5)

Have hopped bad quite a few times when it was wet out- get off the gas, and learn what causes it on your car. In my '06 it's only a problem if I were to try to do a standing burn out or too much gas when wet out.

If you don't hop it, you're probably fine long term. 115k now on my stock diff. I wouldn't replace stuff if you're not abusing it.

88BlackZ-51

I am able to buy a diff out of a t-bird for a good price. what else do i need from u guys to complete the swap?

Sssnake

With stock power maybe. Mine was getting bad prior to the EForce. After it went in a hurry. Less than a half dozen burnouts but a ton of aggressive driving. Keep in mind this is all on a gen IV rear.

LAYGO

iTrader: (10)

I'm going to go out on a limb here & say . . . physics.

isis

iTrader: (1)

There's a whole thread here called DIY 8.8 conversion or something with all those details.

Edit, here ha go:
https://ls1tech.com/forums/cadillac-cts-v/1592297-diy-ford-8-8-into-v1-build-thread.html

bmylez

iTrader: (3)

Ok, so you broke a gen 4. I'm having a debate with someone who will remain unnamed for now who claims that NOBODY has broken a 4th gen diff...I think I've counted at least 2 people and that's without really searching yet.