71nova

My 1990 Iroc z 5.7 has a borg warner 9 bolt is this normal for the year.

JamesC

iTrader: (5)

Welcome to TGO.

Supposedly dropped in 89. Check the following for some general info about your 90:

https://www.thirdgen.org/1990-chevy-camaro

JamesC

71nova

Thanks that's what I,ve been reading but I just bought a 1990 iroc and it has a 9bolt and I believe the metal tag on the rear says 3.27 car has 80,000 miles 4 wheel discs.

JamesC

iTrader: (5)

Are the rear calipers single-piston alum (PBR's)? That would make the rear end 89+. If the calipers are Delco-Moraine single-piston, then the rear is from an earlier model. You can see the PBR's in my Car Details below.

JamesC

jv9999

iTrader: (1)

Even though they switched for the '90 model year, I'm sure they used any remaining 9 bolt inventory. You should change the gear oil every 30-40K in the 9 bolt. The cone wear pollutes it quickly.

71nova

My calipers look like the PBRs in the picture. The car was built in September or August. It looks like its all original. I am the second owner. I paid 1200 for the car 50 dollars in parts to get it inspected. ran 14.2 at 97.79 mph quarter mile. I'm figuring it was left over inventory from 1989.

jv9999

iTrader: (1)

Damn good for a $1200 car! Congrats.

71nova

I bought it in July. The original red on red car was dirty it had sat for 4 or more years under a tree and the inside was filthy. I bought it without driving it. The front brakes were stuck. The battery was dead and it would only run for a short time off of a jump. Towed it home, replaced the front brake hoses and calipers, battery, belt, and endlinks to pass inspection. I washed the outside took the interior apart and cleaned it.The paint is faded and the clearcoat is coming off. The interior cleaned up really good no tears except the dashpad.Took it to the track to see how it ran had some wheelspin issues and only 3 passes. I need to check the gearing in my rear or my tach because the car does not shift until the tach is buried above 7000 and the car is still pulling. What kind of gear oil for Borg Warner 9 bolt? I'm pretty happy with the price. Original owner was a mechanic, car in stock form for now nothing missing.

jv9999

iTrader: (1)

Good deal! regular 80/90 GL5 gear oil. I use Mobil1, but it doesn't really matter as long as it's a brand name. You might need some posi additive if it chatters in corners, but they usually don't and it will cause you to lose some grip on the clutch cones.

RPOL98

my '90 also came with the BW 9-bolt. it's a 5.7L.

Red87SC

i pulled a BW 9-bolt out of an 82 trans am in the junkyard.

Come to find out its an Austrailian rear end built for Holden.

I havnt searched yet but im going to be looking for a set of 3.73's for it... wish me luck lol

JamesC

iTrader: (5)

Must have been transplanted since, IIRC, 85 was the first year for the BW.

JamesC