I have an 88 Trans Am. I just pulled the rear end. It is a 10bolt Posi Rear Drum, The Casting Numbers Are-
GM N
22522878

Is there a website that i can use to Identify my rear end differential, and gears and such. someone please help me. thanks alot.

Erik

 

did you check the tech archive of this site?

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-Tas
'89 Formula WS-6

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Super GRK_Taz World
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EFI & Intake Options

 

I cant find any information on Casting number identification. I really would like to know. if anyone could help.
thanks alot

Erik

 

There is no magic in the casting. It's just a big dumb piece of cast iron. The same casting was used in all applications; it contains no useful information.

Take off the cover and look inside if you want to know anything about it. People post all the time about "what does this tag number decode to", it takes almost as long to type that on the Net as it does to actually pop the cover. It's so easy to change gears, and for that matter to change rear ends and move the tag over, that there is a significant chance that even the tag (the thing that actually carried the information when the car was new, as opposed to the casting #) is wrong anyway.

And look at it this way: if you haven't changed the fluid lately, then you need to anyway, and the only way to do that is to pull the cover.

The tech area on this site has a list of what gears came in various applictaions, i.e. by engine and trans combo, and so forth. As I said above though, that's no guarantee that you have what it says; only that your car came from Van Nuys that way.

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"So many Mustangs, so little time..."
ICON Motorsports

 

Or you could do this method.

Take the rear and jack it up. support on jackstands. put car in netural and put a mark on one of the tires that you can index with. Then spin the axle and count the amount of times you can spin the driveshaft for one revelution.

EXAMPLE
D=DR ROTATION
T=TIRE ROTATOIN
D=3.5
T=1.0
3.42:1 GEARS IN THE REAR END

 

There should be an axle code on the front passenger's side axle tube consisting of 3 digits then about 4 or five digits afterwards. Example, CBG 1121 E. Let me know what it is.



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92' Camaro RS 305 TBI
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Amen RB. Pulling the cover and actually looking is the most foolproof way to find out exactly what you've got! I'd rather pull the cover than spend half a day researching axle codes, plus you never know if someone has changed anything in the rear end unless you're the original owner of the car anyways.


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89RS w/350 TPI; 69RS/SS w/450 HP 350/Muncie 4-Speed "Too weird to live, too rare to die."

 

i have a 10 bolt rear end with disk brake i bought, but cant find out what it is GM 22522676 and the axel is 6HS C188 2
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GM N 22522676 an axel says 6HS C188 2

 

Welcome to TGO. Talk about pulling a thread back from the dead! Here's how to determinne what ratio the rear is if that's what you're looking for (jerk the diff cover and look): numbers are stamped on the ring and pinion:

41 : 15 = 2.73
41 : 14 = 2.93
40 : 13 = 3.08
42 : 13 = 3.23
41 : 12 = 3.42
41 : 11 = 3.73

JamesC

 

That's the nice thing about TGO forums, they keep a very old archive of messages unlike other forums.

Even axle codes don't mean much since a previous owner could have changed internal parts. All the codes tell you is what was originally inside the housing. The only way to know for sure of what's inside is to pull the cover and take a look.

There is no third gen 6HS axle code that I can find. Are you sure it isn't 6HB?

6HB = 1988-89 3.08 posi
C = Buffalo assembly plant
188 = Day of year (mid july)
2 = Night shift

 

I also have a rear end that i'm taking out of my 91 firebird to sell and i don't know what it is the axel code is 8HJ C 004 2 can anyone help me again please.

 

Can't find 8HJ in 91 but there is 8H3 in 91.

8H3 = 3.23 open carrier
C = Buffalo assembly plant
004 = Jan 4
2 = Night shift

Pull the cover and look what's inside it. It may not be original.

 

Will a 7.5 limited slip rear end gears 3.73 differential from a 83 monte carlo fit in a 88, 89 formula or iroc rear end

 

i have those same numbers on my diff on my 84 Camaro. hadn't checked the axle numbers yet, i didn'kt think they would be on that, where exactly are those numbers on the axle?

 

The numbers to determine the ratio can be seen in the following FAQ:

https://www.thirdgen.org/forums/tran...-10-bolts.html

JamesC

 

I have a rearend with the same casting numbers ,I was told it was a camaro, after searching I come up with nothing . The axle codes I have 6ET C191 or GET C191 anyone have an idea what this rear end is ?