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Used the 3 bolt case with original shims. Just swapped in a 4 bolt carrier and put the 4ws gear on it. Tolerances were "perfect" this way.
I am guessing that the case is the variable which requires diff. sized shims. Either way, it worked out just great.
I like my 4ws, especially on the freeway, and didn't want to get rid of it.
Could anyone point me to a website or give me a quick rundown of whats needed for the swap and the procedure? This has been rattling around in my head for a while and I'd REALLY like to know a bit more of what goes into the swap.
4 bolt diff
Left and right 4 bolt axles
4 bolt "Cups" or as the dealer calls them axle flanges.
1. It easiest if you take off the rear bar that hold up the diff (2 bolts right into the back of the diff) but it might be possible to leave it on.
2. Remove axles
4. Remove rear cover.
5. Remove the two bearing caps, one on each side, 4 bolts total
6. Pry the diff out.
7. press the rear pump drive gear off the 3 bolt diff and on to the 4 bolt diff. You may need to remove the bearing on that side of the diff to do this.
8. Put 4bolt diff into 3 bolt case with 3 bolt shims, as the case seems to be the variable and when my friend tried to use the shims from the 4 bolt case he spent a long time trying to get the diff back out.
9. Check the meshing of the gears, backlash ect.
10. reverse steps 4-1 and use 4 bolt axles and cups.
Since everyone talking about 3 bolt diff. How much one going to run me. Where it came off from. And you was saying 3 bolt is so cheap. You mean its not relieble, but have LSD, ums......how about converting to LSD instant of swap Diff. Would that work also.....
i just had this done. scott rebuilt the original diff in my car, and installed an lsd cartridge. he says since i'm not going racing, i dont need a 4 bolt, and he also recommended keeping the 4ws. the other day i had it up on the lift, and i can turn the rear wheel, and the other side turns the same way. really neat.
That's exactly right, but you forgot one thing. The 4WS Pump has to come out before you can take the differential carrier out, i believe.
I found it easiest to just completely unbolt the diff case from the rear crossmember and remove it, swapping carriers outside the car.
Wow. This is old.
I just did this not too long ago, on a different car. The 4ws pump does NOT have to come out. Here's how i did it, step by step.
A couple of prerequisites...
BUY NEW AXLE SEALS
Remove the 4 bolt differential from the case and inspect it thoroughly. Replace bearings if they show any signs of wear.
1. Jack up the car, put it on stands. Place the stands under the frame of the vehicle, not on the rear subframe.
2. Drain the rear differential
3. Remove both rear axles and 3 bolt cups.
4. Supporting the rear diff case, pull the 2 bolts that hold the diff case to the mustache brace.
5. Lower the rear diff case and pull the cover. Remove the mustache brace if it's still in the way.
6. Remove the caps on either side of the differential, drop the diff. KEEP EACH SIDE SHIM AND RACE WITH THE SIDE IT CAME FROM.
7. Remove the differential/ring gear/4ws drive gear assembly.
8. Remove the ring gear from the 3 bolt diff, and the 4 bolt diff. Put the 3 bolt ring gear onto 4 bolt diff. (use loctite)
9. Carefully press off both bearings from the 3 bolt diff. Don't damage them. Keep them marked so you know which side to put them on.
9. Carefully remove the drive gear and pin for the 4ws pump from the 3 bolt diff.
10. Remove the bearings from the 4 bolt diff.
11. Carefully press the 4ws drive gear, pin and bearings from the 3 bolt diff on the 4 bolt diff.
12. Install the diff with the shims and races you pulled out. Shims go with the case. (they're also a pain to re-install) Races go with their respective bearings.
I would recommend you check the ring/pinion engagement at this point, but the 3 i have done did not require any adjustment. On one of them, i replaced the bearings at the same time. The variable here appears to be the cast iron case, not so much the more precision machined differential carriers. If you're working with GOOD used parts, it should not be an issue. If everything lines up alright, put it all back together, fill it up, and enjoy your 4 bolt rear-end and 4ws combination.
13. Clean up the mating surfaces, polish/clean up your diff cover, and install it. Make sure you seal it up with some ultra grey.
14. Raise the diff and affix the mustache brace to it. (and the car if you removed it)
15. Install the 4 bolt axle cups and axles. Note: BE CAREFUL with the retaining circlips on the axles. I once buggered up one circlip by trying to force it in. It helps to put a little heavy grease on these circlips to hold them in place during installation.
Double check everything, make sure it's tight, fill the diff, get the car on the ground and take it for a test drive.