Rear end swap question

I assume a 1992 Caprice wagon rear end will fall right into a 1996 Caprice wagon. Am i correct?
The 92 has a 3.23 posi, the 96 is posi but higher ratio so I'm wondering what else will need to be addressed?
Thanks in advance. Steve

PCM will have to be re-calibrated to reflect the new gear ratio.

Tom C.

It is probably easiest to remove the e-brake cables at the e-brake actuating arm in the brake accuating assembly, and use your original brake cables. There are clips that hold the cables where they exit the backing plate, and you can remove them by squeezing the fingers that lock them in place. Removing the backing plates requires you to remove the axles.

If you decide to use the e-brake cables from the donor, there is a splice about half way between the axle and pedal. It can be dissassembled by bending the tang in the center, and removing the end. I cut the cable on the donor, in front of the splice, for quick removal purposes. You would also have to dissassemble the adjuster at the cable split to remove it from the car, and readjust it in you installation.

Depending on how many miles the 3.23 rear has on it, will determine whether you swap/replace axles. The driver's side axle usually has less wear on it, and is recommeded for junkyard pulls. You could use both of your driver's side axles. Putting new bearings and seals in is not a bad idea either. If you are going to pull the axles, you have to remove the spider gear shaft. The bolt that holds it in, is sometimes difficult to remove. Heat will be your friend. It is a lot easier to work on the axle housing once you have it out of the car.

The entire housing probably weighs in the neighborhood of 160-180 lbs. Put a wheeled dolly under it before lowering it. You will be much happier.

^^^ +1 on the dolly. I dropped a 9c1 rear into the dirt and had to kick it out from under the car with my feet. With three people (one on the diff), they are easy to move. Two can do it, but it's alot of grunting.

I used an enging hoist to lift mine up and backed the wagon into it then dropped it into the cargo area.

Will reclaibrating take care of speedo correction or is there a drive gear in the trans? Isn't there somewhere you can send unit
for upgrade calibration? Thanks Steve

Prior to 94 you have to change the gearing in the VSS. 94 and after, have programming in the computer to modulate the pulse rate for different gearing. It does require that you change it for the engine and transmission to work together properly. You also have to change tire size in the computer if you go to a larger or smaller diameter tire.

Fred Kiehl wrote:

Prior to 94 you have to change the gearing in the VSS. 94 and after, have programming in the computer to modulate the pulse rate for different gearing. It does require that you change it for the engine and transmission to work together properly. You also have to change tire size in the computer if you go to a larger or smaller diameter tire.

How about the ABS Fred? Is that the same?

So, I need to list all my mods and send computer out to be reprogrammed?
Who does this? Any idea on cost? Thanks Steve

I believe the ABS is the same. The yellow connectors are extremely fragile, so either be careful, or you will be buying pigtails, and splicing. You can't have major tire diameter differences from front to rear, or it will cause the ABS to show a faulty signal. There is a thread on ISSF about the tire size issue.

For what it would cost you to send it out, you can get a hand held programmer for the computer. It will allow you to set basic functions, like the gear ratio, tire size, etc.

Yes BUT, I'm a computer moron. Steve

I swapped in a 3.23 posi in place of the 2.56 open in my Fatwoody at Fred's old shop. Bolted right in. ABS worked fine.

A 96 will most likely be a mail-order tune for you as the guys like me that have the software that could do it, are cheap and only have the inexpensive OBD-I software for the 94-5's...

Aparently I'm high, mine is a 94 not a 96. I mistyped in the start of this post. DUH. Steve

....or REALLY cheap like me and put an OBDI from a 95 into a 96...

Krzdimond wrote:

....or REALLY cheap like me and put an OBDI from a 95 into a 96...

That works? No issues of any kind?

no issues after 2 1/2 years. You just need to reprogram the PCM to match what you have.

like the crank position sensor, extry oxygen sensors, etc.?

No, deleted those. My second O2 sensors have been deleted even with the OBDII.

From what I understand, the CPS is used as a computer function, not a mechanical one. The car ran fine without it in 95, it'll run fine in a 96, the CPS just sits there doing nothing now.

Interesting. For some reason, I thought going to OBD1 was more involved than swapping in a 94/95 PCM. Good to know.