Thinking about a DIY install of my 2.85 gears. I can get a fairly low mileage (150k) transfer case pretty cheap, so I can take my time. Looks like a job, but doable.

That thing's got a million bearings in it. Pricing out replacing them all ends up at about $300. <img src="/forums/images/graemlins/scared.gif" alt="" /> You think I can get by just replacing the oil seals and gaskets? Any advice?

My t-case has 220k+ miles and still works. I have only changed the output seals. But a completely rebuilt one would be better.

I've always been of the mind set that you replace what you can reach while you're in something. Ive spent more money than budgeted EVERY time, but I've never been sorry that I did when I didn't have to pull stuff apart to replace something I neglected the first time. It's up to you, but I'd probably go for the rebuild...

Where did you get gears? I'm jealous. I want to put 4 - 1 gears in my 231, but don't want to spend more money on the Raider until I get a drivable truck again... <img src="/forums/images/graemlins/rolleyes.gif" alt="" />

You're probably right, I should spend the bucks. It's just that that t-case seems to be rock solid--I don't think I've ever heard of one crapping out. I've got 220k on my original and I bet it could go another 200k. But it took me 4 hours today to pull the spare and it will probably take longer to put back in. Add the 40-80 hours estimated it will take to change the gears (newbie slowness), and I'd feel real stupid if I had to rebuid it in a couple of years anyway.



From the land of Vegemite, mate! Only took 5 months. Crikey!

Anyone can do a good job by replacing every part... The skill is evaluating used parts and making a good call to use or replace.

The bearings on the output shaft that drive the front axle get more trash ( bottom of the case) and are likely to be bad.

Clean and spin each bearing and see how it feels. When I did mine I replaced all the bearings that spun in 2WD and the two that were at the bottom of the case.

The counter shaft bearings were fine. My transfer case had 340,000 miles on it! I got my bearings through the dealer on the internet.

It's not that bad a job... At least compared to setting up diff gears and auto tranny rebuilds.

Have fun!

Kevin C

I've got two dead t-cases. Haven't cracked the first one open yet. Blew on the trail. Sounds like a bearing(s) and possibly a gear. IF you can get it into 4WD the t-case locks up and you can't move the vehicle at all. Can't get it into 4LO at all. Definitely some busted parts in there somewhere.

The other one won't stay in 4WD Lo anymore but otherwise seems OK.

They're not indestructable if you 'wheel a lot. Lockers and big tires put a lot of stress on a drive train - especially the t-case

Edward

Kevin makes a great point, and I would never encourage someone NOT to learn how to evaluate parts. However, it requires experience (usually under the eye of someone who already knows). Having troubleshot and repaired countless electrical motors, most of which ended up with bad bearings caused by heat issues, I can identify bad bearings. I don't know what bearings commonly go bad in transfer cases, though, and with a lack of guidance, I'd probably replace more than I should. The opportunity cost of having to r&r the t-case is greater than the monetary cost of a few bearings (for me, anyway).

Anyway, whatever you decide, keep us posted! I haven't had the guts, or need for that matter, to tear down a t-case to parade rest and put it back together. I did a SYE on the 231 and that's about as far as I've gone. Oh yeah, and post lots of pics! <img src="/forums/images/graemlins/kewl.gif" alt="" />

Pay close attention to spacer thickness selection. This controls bearing clearance, and thus bearing life. Otherwise the tcase is an easy build.

Thanks for the encouragement and tips, guys. I might have a few more questions before digging in to it and I'll post up some pictures when the time comes.

I decided to go for the full rebuild while installing the gears. I don't know the history of the spare case, plus I want to protect the investment in the gears.

Got a few questions.

1. How do I relieve the staked lock nut on the rear output drive shaft?

2. How do I stake the lock nut back on?

3. Should I get a new lock nut, or is it OK to restake the original?

4. Regarding rear output shaft reassembly, the FSM says to apply transmission oil to rotating and sliding parts prior to reassembly. Surely they mean transfer (gear) oil?

5. What is an equivalent to 3M ART part number 8660? This is used to seal the transfer case gaskets. I assume any gasket sealer would be OK. Should a substitute be the hardening or non-hardening variety?

6. What is an equivalent to 3M stud locking 4170? This is used on the cover bolts. Red or blue threadlocker? I'd sure like to use blue in case I have to take it apart again.

The following questions probably require guidance from someone who has actually rebuilt one of these transfer cases.

7. The FSM (1989 FSM page 21-161) has the following instructions. "(22) Measure protrusion A of the front output shaft rear bearing and recess B of the cover and calculate the clearance. If it is more than nominal, place a spacer at illustrated location. Standard value: 2 mm (0.078 in.)" I assume the intent is to prevent bearing lateral movement by having the recess support the bearing. So if the bearing protrudes, say, 4mm and the cover recess is 4mm then I don't need to install a spacer because the protrusion would fill the recess perfectly. But if A is 3.5mm and B is 4mm, then I should install the spacer, which from CAPS, appears to be 0.5 mm. If this is right, what is the "standard value: 2mm" supposed to mean? At first I thought "nominal" was the standard value, so if the difference between B and A was 2mm or greater, then install the spacer. But if the spacer is only 0.5mm, that would give the bearing 1.5mm to move, which sounds like too much. I guess I could measure the protrusion and recess dimensions when I disassemble the transfer case, and determine the intent if a spacer was or wasn't installed by the manufacturer.



8. Also from the same page of the FSM. "(26) Install the wave spring spacer (if necessary) on the rear of the bearing." What conditions make it necessary?

Once I have answers to these questions, I'm ready to place the order for the rebuild parts and start tearing stuff apart!