[1995-V6-3.4]

Just came across this thread to read up on rear ends, and after reading everything, I share the same question as Joe. Will all of this work for a manual transmission, or are there differences that I would need to look out for? I'm dead set on a posi unit for my 3.8, but since everything here was listed for an auto I just want to make sure I'm not going to spend unnecessary money on something that won't work well with my car. I want to make sure I have all my bases covered so that the swap goes as good as it can.

I know nothing about this stuff but are gears universal? There's a guy on Craigslist selling 3.73 gear, pinion and shims for 50 bucks. It came out of a 8.8 Ford rear end. I figure 50 bucks is reasonable enough to pick 'em up if so.

 

[Injuneer]

No. You need a ring and pinion set specifically for a GM 7.5/7.625" 10-bolt rear axle. Gears are difficult to install and set up correctly. Get it the least bit wrong and they will howl like a wounded banshee. Used gears are even harder to set up, because they will have developed a wear pattern.

A new gear set will run about $200. Install kit is $80-125. Labor to install $250-350.

Does your car have a limited slip differential (optional on the V6's, standard on the V8's)? Without a limited slip diff, as soon as one wheel loses traction, you'll just sit still spinning the one wheel. A limited slip diff (often called a "posi") will prevent a single wheel from spinning when it loses traction, using clutches or a gear system to hold the two axles together and drive both wheels. Look for code G80 on your service parts tag - in the glove box or on the end of the driver's side door.

 

[Yusuf]

Question: Can a manual transmission Firebird be tuned?

 

[Injuneer]

Welcome to Firebird Nation !

Yes, you can tune the computer (PCM) in a manual transmission car, just like you can tune the computer in an automatic transmission car. I'm not aware of any hand-held tuners for the 3.8L V6 (there may be some), but I kow there are mail order tuners that will do the work. Maybe a 3.8L V6 owner can help with regard to hand-held units.

Helpful suggestion - Start a new thread for your questions. Tacking a question about "tuning" onto a pinned thread about rear axle modifications isn't likely to get a lot of responses.

 

[1995-V6-3.4]

No. You need a ring and pinion set specifically for a GM 7.5/7.625" 10-bolt rear axle. Gears are difficult to install and set up correctly. Get it the least bit wrong and they will howl like a wounded banshee. Used gears are even harder to set up, because they will have developed a wear pattern.

A new gear set will run about $200. Install kit is $80-125. Labor to install $250-350.

Does your car have a limited slip differential (optional on the V6's, standard on the V8's)? Without a limited slip diff, as soon as one wheel loses traction, you'll just sit still spinning the one wheel. A limited slip diff (often called a "posi") will prevent a single wheel from spinning when it loses traction, using clutches or a gear system to hold the two axles together and drive both wheels. Look for code G80 on your service parts tag - in the glove box or on the end of the driver's side door.

I'll check it out. Thanks for the info as always, Injuneer!

 

[RedMissMurder]

Thanks for sharing I was thinking of changing gears on my 3.4 but wasn't really sure if that much money would be worth it I'm glad to hear that's what I need and its worth it. Thanks for sharing your experience and knowledge

 

[RedMissMurder]

how much top speed did it kill though?

 

[berzerkshadow]

where could i find all of these parts? I'm looking to upgrade my rear end to 3.73 i have a 98 automatic 3800 v6 firebird what all would i need and where could i get it?

 

[Injuneer]

where could i find all of these parts? I'm looking to upgrade my rear end to 3.73 i have a 98 automatic 3800 v6 firebird what all would i need and where could i get it?

Does your car currently have a limited slip differential? That will determine whether you need:

With limited slip:
-ring and pinion
-install kit
-install/setup labor

Without limited slip:
-limited slip carrier
-ring and pinion
-install kit
-install/setup labor

With either, you need the PCM (computer) tuned for the new rear axle ratio.

If your car has a limited slip from the factory, it will have RPO code G80 on the service parts tag in the glove box.