Ok guys i got lucky yesterday and got a Borg Warner rearend out of a firebird. To my knowlege from the camaro technical database there where only 74 of these rearends made. They only came 3 different gear ratios, 2.77,3.45, and 3.27. How could i find out what gear ratio it is with out taking the pan off and i could figure it out if i had a list of what firebirds this rearend came in. HELP!

 

if you can get to the firebird you can look in the center console and look at the codes for the build sheet(GU5 is a 3.23 posi) as for the others i cant tell you

 

The only way to know for sure is to take the cover off. You can count the turns of the wheel relative to a turn of the drive shaft and you can look for a tag on the rear cover stating the ratio (if all original).

There are some very rare factory 3.70/3.73 ratios and 3.08 ratios, but most were 2.77, 3.27 and some 3.45.

Diff Solutions has brand new 9 bolt ratios of 3.23, 3.45, 3.73, 3.91 and 4.10 available along with new posi units and other stuff www.9bolt.com

Miles
Diff Solutions
www.9bolt.com

 

See this is my problem......the rearend has already been pulled....and the car is gone...... i mean i know i got a good rearend i just hope its not to high geared......i know its posi and..... does anyone know anything about the borg warner rearends......why did they only come in certian cars?......whats so special or different about them......i know one difference is they offord a 3.27 gear and the regular posi didnt.....but other than that i have no clue......and is there any way i can trace the numbers on the rearend to find out excactly what car it came out of?.......anyhelp would be appreciated.....thanks guys....

 

when i go to count the gear ratio what do i need to divide by to get the fina gear ratio.......someone who could explain excactly what to do would be helpful.....i used to know what to do but i forgot.

oh it has the factory tag but the barcode type sticker thats on the cover is faded to where its unreadable......thanks again...

 

First of all, there were more then your number of BW 9-bolts made and installed in 3rd Gen Cars. Now for your question, the most accurate way is to pull the cover and check the stamped gear ratio on the Dr Gear. At this time you should be servicing this rear with fluid change,visual inspection for damage or any defects.

1) 2:77 ratio standard on 350 cars
2) 3:27 ratio a option on 350 cars with RPO G92
3) 3:45 ratio a option on 305 5sps with G92

I would do a lot of work on this rear before installation. My opinion. Good luck on your find.

 

How many of them where actually put in them?

 

The totals could be researched on the volume of BW 9-bolts used on 82 to 89 Camaro/Firebirds but who cares. It would be in the Hundreds of Thousands would be my guess. Alot more then the previous quoted number.

 

To determine the ratio by counting teeth, divide the number of teeth on the ring gear by the number of teeth on the pinion gear.

The 9 bolt is much stronger than the 10 bolt, but also costs more. All the info you need on a 9 bolt is at www.9bolt.com

Miles

 

Ok thats what i thought.....we checked it its 2.77......now i need a set of gears....thats to high for me....thanks miles....

 

look up the rpo code on the rear end that will tell you what type of gear is in it!!!

 

Yes it would if the RPO code was stamped on the axle housing.

 

I hate to be the one who points this out to you but if you have 277's it's not as easy as just buying new gears to get a different ratio.First 277's use a series 2 posi and to go to lower gears you will need a series 3 carrier which are EXPENSIVE + gears and install kit+finding someone with enough experience that you'ed trust to put it all together and paying them for the work.
I've ran into this problem myself. and the money for parts adds up quick.You could find someone with a series 3 posi and factory 345's but good luck,most that have them won't ship and if they will you're back to getting a install kit and finding someone with enough experience you would trust to set your rear up.
Sorry to vent but I'm currently going thru this too.

By the way anybody want to buy a 9 bolt with 277's?

 

if i was you i would just look for a 12 bolt rear end or if you dont need your rear end to hold up to a great ammount of hp get a 10 bolt

 

Thanks a lot for the feedback guys......i guess i'll stick to the high gears for now and try to find a 10 bolt posi later....yeah i check onthe series 3 carrier and everything else that i need to go with it and its way to expensive for my blood......appreciate all the help
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