I´m in the process of rebuilding the rear suspension of my GTA. The rear axle is disassembled now, at the beginning of the next week it will be media blasted and then powder coated.

I assume the right color will be semi gloss black. Can someone confirm this?

Thanks

 

Only the BW 9-bolt rears were painted. And gloss black was the color. All 10-bolts were unpainted, so they would turn that nice rust color.

 

Ok, thanks. So I will powdercoat the rear axle in gloss black!
Do you know if the panhard bar and the lower control arms have been painted in semi gloss black?

Thanks in advance.

 

Best of my knowledge gm did not paint anything under the car. Mayby someone else can add or confirm it.

 

This is a pic of the stock lower control arms. The rest of the color seems to be semi gloss black. But after 18 years I'm not sure...



As far as I can say the color is the original one, not repainted.

 

G92 and L98(B2L) cars finally got the Borg-Warner HD 7.75 inch four pinion rear end, produced by GM Holden's Limited of Australia (Firebird WS6 cars went to this unit in 1986). These units can be identified by their 9 bolt (rather than 10) differential cover that has a rubber plug. The Borg-Warner logo is also cast into the bottom of the differential case. This rear axle came with tapered rather than straight roller bearings and a cone-clutch rather than disc-clutch limited slip unit. These units came painted black from the factory while most others were bare metal.

Strait from the Tech Data on this site. Now I don't know what shade of black it was. My 9bolt looks like a semi gloss on my car the last time I was under there. Adam :-)

 

i have a borg warner rear end and when i opened the pumkin the and cleaning it up a bit i found that it was orange? was that done by a perivious owner or factory?

 

Done by BW

 

Actually, '85 T/A's got a 9 bolt if I'm not mistaken with the L69 T5 cars with 3.70's. At least the one under my GTA did, and the car had the RPO for the 3.70's.

Mine was a nice shade of rust with semi-black under the layer when I cleaned it up.

 

Yes, you could get the 9 bolt in 85, my 85 LB9 had one with a 2.77.

The tech data, as usual, is wrong. No gospel over there.

 

The 9 bolt in my 90 Iroc was gloss Black from the factory.

 

I have seen a bunch of very low mile T/A,formula an TT/A BW rears and they have all been semi gloss...

 

Here is mine, sticker still on it.



Not much to go on but who still has the sticker

Bonus:

Metal tag on left defines BW serial number with ratio.

8XV is the axle code that translates as 3:27 ratio with locking diff.
This code is also stamped on the passenger side axle tube.

Tag on right tells mechanic to use special lube only.

 

This unit had a 85 introduction year BTW

 

So sue me. That's what I get for trusting the tech data. lol. I got a friend that has a 9 bolt in his 85 t/a also. I'm not much into 3rd gen birds to begin with. I just know my maro's. Adam :-)

 

Ok, I've decided to do it in semi gloss black. Here is how it looks now:



Thank you all for your help!

 

wow, that looks sharp!

i'll have to paint mine before she goes under the knife.

 

I second that!


What did it take to clean it up?

 

Here's a detail pic of the axle:


It was media blasted, then a rust preventive layer was put on. The next step was powder coating with a following heating process to 220° CELCIUS.

 

very nice looks factory