Rear axle ratio identification problem
Thread Starter
TECH Resident
Joined: Jul 2009
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From: Bahrain
Rear axle ratio identification problem OK gents, here goes.
I have a 1994 LT1 F-body that has been sitting around for about 3.5 years now. Its previous owner informed me it had a 3.73 rear axle but I never got around to popping open the diff cover to check.
I am going to tear it apart for useable spares before I sell it for scrap metal, and I want to salvage the diff if it truly is a 3.73 to transfer onto my newly purchased 97 Camaro.
Having a look at some vids on the "spin wheel/count shaft turns" method, when I spin the passenger side wheel it rotates by itself and the driver side wheel remains stationary? I can rotate each wheel in opposite direction at the same time, and also when I rotate one the other won't spin opposite like it would an open diff. Confusing.
Also after performing the technique to identify the axle ratio, I came up with just 16 turns. According to this video I am supposed to multiply by 2 and then divide by 10, so in my case I might have a 3.23?
Or maybe its just slipping inside and thats why I cannot get an accurate reading?
I used to drive this car daily, and I know for a fact it has an LSD rear end. Did enough burn outs in it and both wheels spun together.
Help please
I have a 1994 LT1 F-body that has been sitting around for about 3.5 years now. Its previous owner informed me it had a 3.73 rear axle but I never got around to popping open the diff cover to check.
I am going to tear it apart for useable spares before I sell it for scrap metal, and I want to salvage the diff if it truly is a 3.73 to transfer onto my newly purchased 97 Camaro.
Having a look at some vids on the "spin wheel/count shaft turns" method, when I spin the passenger side wheel it rotates by itself and the driver side wheel remains stationary? I can rotate each wheel in opposite direction at the same time, and also when I rotate one the other won't spin opposite like it would an open diff. Confusing.
Also after performing the technique to identify the axle ratio, I came up with just 16 turns. According to this video
Or maybe its just slipping inside and thats why I cannot get an accurate reading?
I used to drive this car daily, and I know for a fact it has an LSD rear end. Did enough burn outs in it and both wheels spun together.
Help please
Teching In
Joined: Oct 2013
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I believe its however many times the pinion spins in relation to one rotation of the wheel is the gear ratio. As for the diff its possible its time for a rebuild, couldn't tell until you pull it apart and inspect the disks and shims
Thread Starter
TECH Resident
Joined: Jul 2009
Posts: 772
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From: Bahrain
Numbers stamped are 13:42 26019044 XXX. I believe this is an LS1 rear end swapped in.
But I remember the LT1 diffs had a spring pack. This has a geared setup? I will post pics.
Thread Starter
TECH Resident
Joined: Jul 2009
Posts: 772
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From: Bahrain
Thanks for the help buddy 
Just got one last question:-
Apart from having a better ratio than the 2.73 on my 97 Z28, would swapping out the Posi for a Torsen be an upgrade?
Is it possible to remove the Posi assembly inside the 97 axle housing and directly install the Torsen in its place, right into the 97 housing?
Or would I have to swap the whole axle assembly or just get a 3.73 ring and pinion for the Posi and call it a day?
Just got one last question:-
Apart from having a better ratio than the 2.73 on my 97 Z28, would swapping out the Posi for a Torsen be an upgrade?
Is it possible to remove the Posi assembly inside the 97 axle housing and directly install the Torsen in its place, right into the 97 housing?
Or would I have to swap the whole axle assembly or just get a 3.73 ring and pinion for the Posi and call it a day?
