Glass Getrag Diff pictures - thank you Germany

**somethingclever** · 08-31-2015, 03:38 PM

Since this site (and any forum) is only as good and steady as those who contribute to it, (and I enjoy having a local site), I figured I should make a short thread instead of sitting back and complaining how slow it is.

So for those at the rental back in June I made 10 passes and broke the diff on the 11th.

Didn't surprise me that much since they are a known weak link.

The 1st Gen (04-07) CTS V has an aluminum rear diff housing and is an IRS setup.

I showed up to the rental on my crappy (I'm really cheap) Chinese produced mud and snow tires with fresh urethane bushings all over the IRS and diff (thanks to TTK for his help) and with a newer tune from Amswell. (Thanks Rick) Since alot of guys break these diffs on drag radials and wheel hop, i gave myself a 30% risk of failure.

Bushing upgrade pics:

Well, that theory proved wrong.

Pass #10 was my best with a 12.78@110 on a 1.95 60'. I was mildly happy with that but felt I should muster a 1.8x 60' as credit to my Chinese tire producing brethren. After a lengthy track cleanup (DSM?) I was more aggressive with the launch which produced some wheel spin and then subsequent failure.

End result was that the case simply wasn't strong enough to handle the sudden torque applied as I pedaled the car and it caught traction on the glued surface.....the pinion gear got shot out the top of the case. (actually pretty impressive)

Onto the carnage pics:

Also proceeded to mess up the rear CV joint in the driveshaft - of course another junk Getrag non-serviceable part.

My 6 yr old daughter helper:

Anyway got all that buttoned back up here just recently as I spent the last two months working on an outside french drain in all my free time. Glad to have the drain done and car back on the road.

Only tracks it will see again will have turns and require the use of it's 4 piston 14" brakes on all four corners.

Who knows....I may even spring for some Japanese or American tires this spring.

**SlowSix** · 08-31-2015, 03:47 PM

holy shit. That blows.

**Dan B.** · 08-31-2015, 03:48 PM

JB Weld and a couple zip ties will fix that.

Nice work.

**Stangman701** · 08-31-2015, 04:03 PM

Nice work John. Glad you were able to get it back on the road. Too bad we didn't get to line up the CTS-V and STI at the rental. Both went 12.7's @ 110, would have been a good race!

**PaxtonShelby** · 08-31-2015, 04:52 PM

That was some Bob-like carnage right there!

Glad you got got it back together.

**Ares** · 08-31-2015, 05:03 PM

RPM induced carnage. I approve

**Martin0660** · 08-31-2015, 05:14 PM

It died with honor ....

**torqueboxer** · 08-31-2015, 06:40 PM

8.8 swap?

**PaxtonShelby** · 08-31-2015, 06:47 PM

I think John said that's a pricey mod on the V?

**torqueboxer** · 08-31-2015, 06:51 PM

A blown up getrag diff gotta be expensive too lol

**somethingclever** · 08-31-2015, 08:20 PM

8.8 swap would cost 4200 with a 1 piece driveshaft. These cars are only worth 15-17k ish so 1/3 the value on a diff doesn't make sense. I picked up the used getrag unit for $200.

I could prob do it for 3k if I built my own diff and kept the factory driveshaft.

I have 500 total in this repair for the parts, shipping and fluids.