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My Overdrive has left the chat….

Don't even think about salvaging that case or gears, all trash. I'll echo others time to modernize to 80's technology at least.
 
Rich M. said:
Don't even think about salvaging that case or gears, all trash. I'll echo others time to modernize to 80's technology at least.
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Agree, that case is toast. Some of the internals are salvageable, so I will keep it around for parts.

I pulled my old transfer case from the 2nd floor, and it looks like I rebuilt it after the second intermediate bearing failure, as the inside is spotless, bearings on the main shaft have new grease and everything feels tight. Heck, I even painted it and it’s never had oil after the rebuild. For some reason I decided to just buy a rebuilt one from Herm. I don’t remember the reason why, probably because I was concerned I was doing something wrong in my rebuild since this was my second needle bearings failure is a short period. Since I am now 0 for 3 with the needle bearings in two difference cases, I’m going to try the taper kit. Worst case, they last as long as the needle bearings.

One of the things I see too often is the never ending builds (not just Jeeps) that never get finished to the point of being enjoyed, and the project is eventually sold or parked. I realize folks think I should upgrade the transmission, transfer case and rear axle to more modern parts, but that’s a big project, further complicated by my conversion to coil springs and long arms late last year. Since it would take time to source parts, go through the new to me parts to ensure they are as expected, and then do all the fab work, this is a 8-12 month project. By using the rebuilt Dana 18 I already own along with the taper bearing kit I already own, at least I will be enjoying my Jeep while I source all the parts I need to do the conversion if I decide that is the direction I will be going.

Right now, I’m going to enjoy the jeep before the next project phase…or as long as the taper bearings last. Heck, I might even clean the overdrive and put it back in, haven’t decided yet.
 
cj2atruck said:
What was the sign that the bearing was failing? Was it as catastrophic as when the needle bearings fail?
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Certainly nothing g catastrophic like what happened to your case. When my T90 died and I did the T18 swap, I swapped all the tcase guts into a big bore D18 case. That's when I discovered that the bearings (which had been getting pretty noisy) were shot. I decided at that point to go with the Novak shsft and bearings.
 
I must not be doing something right, as I have never broken a transfer case. ;)

I have broken engines, transmissions, and axles, but never broken a transfer case.

I agree that gear box and the gears are scrap. Like you, I would take the path of least resistance and replace it with the parts you have on hand, so you can get back out on trail sooner.

Upgrades, if you decided to do that, are much better to prepare for while you still have an operable Jeep. You can still use the Jeep while you gather the parts, and make whatever other preparations needed for the upgrade, and delay it until you have time between planned trail rides.
 
nickmil said:
You mentioned using grease as assembly lube in the transfer case. That is death to these transfer cases. Use transmission assembly lube or petroleum jelly. It has a lower melting point than grease and will mix with the gear lube.
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I really like this stuff, it's super tacky & holds needle bearings in place very well.
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nickmil said:
You mentioned using grease as assembly lube in the transfer case. That is death to these transfer cases. Use transmission assembly lube or petroleum jelly. It has a lower melting point than grease and will mix with the gear lube.
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Interesting. I had never considered using grease on the needle bearings could be the problem, as I’ve used it for decades to stack needle bearings on various projects. Couldn’t hurt to try assembled lube the next time I need to deal with needle bearings.
 
cj2atruck said:
Interesting. I had never considered using grease on the needle bearings could be the problem, as I’ve used it for decades to stack needle bearings on various projects. Couldn’t hurt to try assembled lube the next time I need to deal with needle bearings.
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I used to to do this as well. Think about how long it takes for grease to dissolve in gear oil.. The assembly lube stuff is advertised to dissolve, so because Nick says so, and he has so much more experience with rebuilding this stuff, I have a tub of it for this kind of work. Its cheap anyway and works as good or better.
 
Amazon will have it here tomorrow for installation of the taper bearings and transfer case Tuesday or Wednesday. We got 5 inches of snow yesterday, and it needs to melt for the first test drive, so no big rush on getting the transfer case back in the jeep before mid week.
 
X2 on not using grease for assembly lube.

It will prevent the gear oil from getting where it needs to be, and if you used grease for that on the previous gear boxes it probably contributed to the failures.
 
I used engine assembly lube for my outer needle bearings and a dummy shaft.

Two things to consider:
1. This is not a pressurized passageway. It isn't even like a transmission where the gear mesh pumps a little oil to the needle bearings between input and main shaft.

2. With overdrive and 5.38 gears that bearing is moving a lot faster than anything in the transmission or wheel assembly. The only thing spinning faster is the output shaft and pinions which use tapered roller bearings that get a lot more oil to them.
 
It seems to me the obvious solution is to get another 18 and dont rebuild it. Dont open it up just bolt it in and call it done. Dont even change the oil.
 
jeep2003 said:
It seems to me the obvious solution is to get another 18 and dont rebuild it. Dont open it up just bolt it in and call it done. Dont even change the oil.
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yes, I’m going to start looking for a Dana 18 so I have a spare. Except for the needle bearings, I think I remember reading that the Dana 18 with 1 1/8” shaft is considered pretty strong, with Novak noting that these have been used behind big blocks. Should be able to handle my little v6 power.

I was reading about oils, and I have been using the GL-5 oil that apparently does not play well with brass. This time I’ll be using GL-4 this time. Don’t know if it will matter, but…
 
cj2atruck said:
yes, I’m going to start looking for a Dana 18 so I have a spare. Except for the needle bearings, I think I remember reading that the Dana 18 with 1 1/8” shaft is considered pretty strong, with Novak noting that these have been used behind big blocks. Should be able to handle my little v6 power.

I was reading about oils, and I have been using the GL-5 oil that apparently does not play well with brass. This time I’ll be using GL-4 this time. Don’t know if it will matter, but…
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GL-5 attacks brass and bronze parts. It’s fine in D25-44 axles.
 
It sounds like you figured out the recipe for a longer lasting D18, but I was wondering if the transfer case out of a Mahindra Roxor might bolt up and have any potential improvements. Just thinking out loud mostly.
 
cj2atruck said:
yes, I’m going to start looking for a Dana 18 so I have a spare. Except for the needle bearings, I think I remember reading that the Dana 18 with 1 1/8” shaft is considered pretty strong, with Novak noting that these have been used behind big blocks. Should be able to handle my little v6 power.

I was reading about oils, and I have been using the GL-5 oil that apparently does not play well with brass. This time I’ll be using GL-4 this time. Don’t know if it will matter, but…
Click to expand...
The 29 tooth input 1/4” times intermediate is a little stronger and the loose needle bearings on the intermediate distributes the load better. The 26’tooth input 1 1/8” intermediate uses caged bearings with fewer bearings.

I’ve had to literally cut the guts out of transmissions and transfer cases that were seized or burned up that still had grease in the passage ways. I’ve covered this subject many times in the past. Probably need to use the wayback machine if you want to bother reading the threads.
 
nickmil said:
The 29 tooth input 1/4” times intermediate is a little stronger and the loose needle bearings on the intermediate distributes the load better. The 26’tooth input 1 1/8” intermediate uses caged bearings with fewer bearings.

I’ve had to literally cut the guts out of transmissions and transfer cases that were seized or burned up that still had grease in the passage ways. I’ve covered this subject many times in the past. Probably need to use the wayback machine if you want to bother reading the threads.
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Well, I’m abandoning the needle bearings this time and using taper bearings. Can’t be any worse than my experience with the needle bearings.

The Mahindra transfer case is an interesting idea, wonder if it would bolt right up…

If the taper bearings fail quickly, I’ll probably start looking for all the components to switch to a small block Chevy, 700r4, transfer case with a passenger side drop and a D44 rear that is centered. Might be best to find a 1973–1991 square body that is running and driving so I have everything I need with one purchase. Hope I don’t have to go that route, but it would be a fun build.
 
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