Cascade Crew

jchaussee · Member Joined: 14 Nov 2010 Posts: 1318 Location: renton

So last night I picked up a rear from a 4th gen ta for the extremly low price of free. It only has 16k. the only thing is I do not lnow how to determine year, gear ratio, or posi. I have it stripped Down, cleaned and cover plate off. Every answer on how to id it on the Web tells me to look at rpo codes or vin. that onfo is nlt avail, so how do id tbis tbing? I am hoping it will be enougj of an lmlrovement over mine that it.will be worth the swap

fiveoformula · Posted: Wed May 08, 2013 8:02 am Post subject:

You can count the teeth on the ring gear, and divide by the number of teeth on the pinion then you have your gear ratio.
Also are you running 4th gen wheels? if not third gen offset wheels will stick out a few inches more on each side.

Alphius · Posted: Wed May 08, 2013 8:17 am Post subject:

You can count the teeth on the gears or a lot of times you will be able to find a marking on the ring gear like "41:11" which is just a tooth count. In my example, you can divide the numbers and find out that this would be a 3.73 rear end.

Here's what my rear wheels looked like with thirdgen offset wheels on a 4thgen rearend.

As far as posi, check these pics out:

Open differential. Only has spider gears and the locking pin.

Auburn limited slip. Has springs and plates. Can wear out.

Torsen limited slip. Has spiral gears. Can't wear out. Used in 99-02 LS1 F-bodies.

jchaussee · Member Joined: 14 Nov 2010 Posts: 1318 Location: renton

I am going to have to run different wheels anuways I thonk because tbe discs look to be too big to fit my 15s. He also gave me a delta cam, bjt doesnt have tje cam card so.I have to take it somewhere to get the info. He has an el Camino tthat just did a 9.7 134 mmph qt mile. 427 all motor

jchaussee · Member Joined: 14 Nov 2010 Posts: 1318 Location: renton

Says torsen inside but doesnt look like pic

jchaussee · Member Joined: 14 Nov 2010 Posts: 1318 Location: renton

I think it is the torsen. 3.23. So kt shuod be an upgrade to my 3.23 drum rear?

fiveoformula · Posted: Wed May 08, 2013 8:54 am Post subject:

99-02 Fbodies? what did the early 4th gens use?

fiveoformula · Posted: Wed May 08, 2013 9:51 am Post subject:

You'll get a decent posi and disc brakes, those are good upgrades. Id like to have something better than the worn auburn that I have. Sure you dont want to sell it? lol

Alphius · Posted: Wed May 08, 2013 9:59 am Post subject:

93-98 F-bodies used an Auburn, same as thirdgens. Some very early '99 MY cars used Auburns as well, although almost all were Torsen by then.
Jeremiah, can you post pictures? If so, I can identify what it is.
1. Picture of carrier same as ones I took above showing the inside.
2. Picture of brake caliper.
3. Picture of entire axle.

Here's another few questions that will help ID it:
1. Measure the brake rotor. Is it 11" or 12"?
2. Is there a sensor in the pumpkin measuring a straight cut gear that wraps around the outside of the carrier?
3. Are there two separate brake lines not connected to each other or are there two brake lines merging together at a junction block to go to the car?

RSFreak · Posted: Wed May 08, 2013 10:06 am Post subject:

He'll also have to add a prop valve for the drum to disk swap, right?

Alphius · Posted: Wed May 08, 2013 10:13 am Post subject:

jchaussee · Member Joined: 14 Nov 2010 Posts: 1318 Location: renton

I cant upload pics from tbia phone, but he said from 99 Trans am. Has a electeical plig on each brake. inside on case rhst all thr little gears are,in says,torsen. The huge gear,has a bunch of numbets. One strand sajd 1340 which divided to 3.23

Alphius · Posted: Wed May 08, 2013 2:01 pm Post subject:

Sounds like a traction control rear end from an auto LS1 car with a Torsen to me.

jchaussee · Member Joined: 14 Nov 2010 Posts: 1318 Location: renton

Is thst good thrn?

Alphius · Posted: Wed May 08, 2013 2:54 pm Post subject:

It is what it is. It's better than some but worse than others.
Is it worth it to you to swap out for 3.23, posi, disc brake? Or sell it for a profit to somebody like fiveoformula... Laughing

jchaussee · Member Joined: 14 Nov 2010 Posts: 1318 Location: renton

Ya. Now I have a non posi 3.23 drum. I couldnt sell even if I didnt want it. Dide gave it to me because he said I would use it befote he evrr would.

jchaussee · Member Joined: 14 Nov 2010 Posts: 1318 Location: renton

But basicallybi have a rear swap, gas tank swap, head swap, cam swap, door swp, decklid and spoilet swap and numerourus things to install beforw my wife gives birth kn Dec

Alphius · Posted: Wed May 08, 2013 4:23 pm Post subject:

That sounds like a couple weekends of hard work to me. Very Happy

jchaussee · Member Joined: 14 Nov 2010 Posts: 1318 Location: renton

Itll take me monthes

aaron_sK · Posted: Wed May 08, 2013 8:21 pm Post subject:

Tank and rear swap are basically the same job and can easily be done in less than a day.

Decklid and spoiler swap are also the same job and take a couple hours.

Door swap is easy, just use a floor jack and a drinking buddy to hold it.

Head swap takes a day if you're lazy and drink while you do it.

So yeah, a weekend of work. Cool