Right intermediate shaft difference between 3.21 and 3.55 gears?

I found out the hard way recently that my 4 wheel drive didn't work. My regular mechanic said it was the passenger side intermediate shaft and C/V shaft (I had the driver's side replaced last year). That doesn't surprise me one bit as there was some slop in that joint; I just didn't think it was that bad.

Anyway, my mechanic's first option was to replace the whole diff. Yeah, that's not happening as I don't have a couple grand for a refurb unit. He told me he couldn't get just the intermediate shaft from his suppliers. He also told me the reason why is that he could only get the shaft for the 3.55 gears, and not the 3.21 gears, which is what my truck has.

After doing a bunch of reading, it seems like the intermediate shaft is the same regardless of which gearset the truck as. I'm looking for someone that might know this for sure one way or the other. After a couple of online chats with manufacturers, I'm just as confused. One says they're different, but they don't make the one I need, and another says it doesn't matter, it's the same for all.

Most of the parts listed online that specify gear ratio list 3.55, and some say 3.21/3.55 and one other that I can't remember right now. There are none that specifically reference the 3.21. So that's not really helpful.

So, does anyone know if the same intermediate shaft is used regardless of the gear ratio of the truck? I would greatly appreciate any insight anyone might be able to provide. Thank you!

It's the same. None of the usual parts stores list a different part depending on axle ratio. They show the same part, regardless of ratio.


This Canadian outfit makes units that have a pretty decent reputation.

The right side shaft only:


The kit with pretty much everything:


Oreilly auto part carries it as well. The left stub shaft:


And the expensive right side shaft:

The other cheap kits on Amazon should probably be avoided. Read through the reviews and you'll see what I mean.

Thanks Ken. I don't need the whole kit as the C/V shafts have been replaced and are under warranty. I'll replace the C/V shaft when I replace the intermediate shaft.

I think that maybe my mechanic just didn't want to tackle the project.

They also make little rubber boots that supposedly help. They won't keep the joint for 'wallowing out' over time, but they might help keep dirt and grime out of there to postpone wear.

It'll be a bit before I can get to this project. I just need it before hunting season!

tfoley95 said:

Thanks Ken. I don't need the whole kit as the C/V shafts have been replaced and are under warranty. I'll replace the C/V shaft when I replace the intermediate shaft.

I think that maybe my mechanic just didn't want to tackle the project.

They also make little rubber boots that supposedly help. They won't keep the joint for 'wallowing out' over time, but they might help keep dirt and grime out of there to postpone wear.

It'll be a bit before I can get to this project. I just need it before hunting season!

Click to expand...

OK. I tackled this project yesterday. It took most of the day, but I work slow and don't have a ton of tools at my disposal. I purchased the right side only kit that Ken referenced above from Premium Parts. It was a complete kit with the shaft, bearings, and seal, and they are good quality parts. I would recommend it. I also bought a new C/V shaft as well. The splined cup on the end of the C/V shaft was almost smooth it was so worn. If I hadn't replaced it, this whole project would've been for nothing.

Here are the general steps I followed. I referenced this video for the working on the shaft itself. https://www.youtube.com/watch?v=zem4U9dmn6M
It's not the greatest quality, but it gives a good idea of what's involved with removing the shaft from the housing.

I learned a few things during the process, so I'll share the info so someone else may benefit. I thought about making a video of the whole thing, but didn't want to embarrass myself!

Step 1: Put the front of the truck up on jack stands. SAFETY WARNING!! Support the truck in several locations and do NOT just rely on your lift jack! You'll be working right under the front cross member and A-arm. If the truck falls on you, you die! Maximum safety awareness here!

Step 2: Remove the tire.

Step 3: Separate the upper control arm from the ball joint and allow the steering knuckle to go to the side. I used a pickle fork to do so and damaged the ball joint boot, so I had to go pick up a replacement.

Step 4: Remove the C/V shaft. Once I removed the spindle nut, I was able to slide the C/V shaft off the intermediate shaft first (inside joint), and then remove it from the hub. There was just enough room to take it off.

Step 5: Unplug the wiring harness from the intermediate shaft housing. I used a pick to remove the red clip from the top side and a small screwdriver to wiggle the connector free. It was a pain.

Step 6: Remove the intermediate shaft housing. There are 4 bolts securing it to the differential, and 2 (different sized) bolts securing it to the motor mount. Have plenty of ratchet extensions handy, because you'll need 'em! It's difficult to get to the upper 2 bolts securing it to the differential. I sprayed a little WD-40 in the joint before I started, and it came apart fairly easily. Do not force this. These housings are both aluminum and can break if too much force is applied. That will ruin your day!! (i broke an Envoy doing this once).

Step 7: Remove the actuator off the housing by removing 4 bolts and pulling it free. Remove the gear from the end of the shaft and set aside. You'll need it later.

Step 8: Remove the circ clip from inside the housing where the actuator came out (see above video) and then the shaft should come right out with a couple of taps. Don't let it fall, and save the circ clip.

Step 9: Remove the needle bearing from the small end of the housing. This was probably the most difficult part of the project for me. I didn't have a long enough punch to tap it out. After a few attempts with various implements, and lots of cussing and a trip to the parts store, I ended up using a Dremel and cutting it out with a small cutoff wheel. If you go this route, be very careful to not cut too deep and into the aluminum housing. The bearing is hard steel compared to the soft aluminum.

Step 10: Tap in the new needle bearing into the housing using an appropriate sized socket. Once it was in place, I packed some fresh gear into the needles.

Step 11: On the new shaft, tap on the large roller bearing. I installed it with a larger chisel type implement that had a wide end. I worked my way around the bearing, tapping slowly until it was in place, making sure to only have the chisel touch the inner race. Once it was seated, the circ clip was installed. The circ clip will need to be removed from the old shaft and installed on the new one. Add grease to the roller bearing.

Step 12: Tap the small needle bearing into the cup end of the shaft. Use the appropriate sized socket to do so. Add grease to the needle bearing.

Step 13: Reinsert the shaft into the housing. It should tap back into place easily. Now reinstall the circ clip moved in step 8. Give the shaft a spin. It should spin nice and smooth.

Step 14: Install the large rubber seal on the small end of the housing. Now install the metal 'cap'. It should tap down until it's just below the lip of the housing. Tap both in slowly as to not damage them.

Step 15: Now install the rubber O ring on the small end of the shaft, and then the C clip.

Step 16: Add the gear removed earlier on the large end of the shaft and reinstall the actuator. Make sure the fork slides over the groove on the gear. I added some grease to the geared end of the shaft before I installed the gear. I also added a bit of RTV to the actuator housing to make sure it was sealed well.

Step 17: Now the completed housing assembly is ready to go back on the differential. I used a little RTV so no water/mud/salt would get into the joint between the housing the differential. Do not overtighten these bolts. They are easy to strip because the differential is aluminum.

Step 18: Plug the wiring harness in and make sure to insert the clip.

Step 19: Feed the C/V shaft from the inside of the control arm, and into the hub first. There should be enough room to insert the cup onto the intermediate shaft. This will require some 'finesse'. I made a trip to the plumbing store and bought an 1 1/2" rubber reducer. After some trimming, I installed it on the cup end of the C/V shaft. Once the steering knuckle is reconnected to the ball joint (next step), I slid the reducer toward the housing and then tightened up the hose clamp. I then ran a bead of RTV between it and the metal cap. Hopefully this will help to keep mud and grime out of the joint. Time will tell.

Step 20: Reconnect the upper control arm. This is tricky with one person, but I figured out a large C clamp is helpful here.

Step 21. Install the hub nut and tighten fully. I find a pry bar between a couple of the lug bolts helps to keep the hub from spinning while tightening.

Step 22. Install tire and tighten lug nuts.

Step 23: Take the truck for a ride and listen for strange noises etc. For me, the whole truck rode smoother, and there was no grinding noise at low speeds. Also, recently there had been a loud banging noise at highways speeds. This went away as well. If everything is copasetic with your ride, project complete!

Obligatory disclaimer: Use these steps and advice at your own risk. I am just a DIY-er that didn't want to spend a pile of cash on the repair. No implied warranty, etc etc..

See pictures for worn C/V shaft splined cup, new C/V shaft, new C/V shaft inserted into the housing, and a closeup of RTV bead (not super pretty).