My Overdrive has left the chat….

[jpflat2a]

The Warn unit in my Jeep came with it in 1974.
Had a few repairs over the years, bearings etc.
But the same unit.

 

[duffer]

The Warn unit in my Jeep came with it in 1974.
Had a few repairs over the years, bearings etc.
But the same unit.

Same here. The same one I also purchased in 74. That said, the sbc now residing under the hood of the 3B should be good for 550+ ft-lbs------

 

[3b a runnin]

the sbc now residing under the hood of the 3B should be good for 550+ ft-lbs------

I love it

 

[Kaiserjeeps]

I have a Rogues Gallery of various pictures I took of overdrive failures.
I'll add yours to it and will be interested in your failure diagnosis.

Is there a link or a way to see these pictures? I have a saturn unit in my 69. I had an odd failure where the planetary gears wore into the shafts so much it started machining the windows open in the planetary housing they rode in. Got it all fixed but it made me wonder. I recently acquired a complete warn OD and thought maybe it might have better quality metal. Maybe someday I will get it installed. I have the 4:88 gears and the speed limitations with no OD are probably a good safety feature. Curious about those pictures... AL

 

[cj2atruck]

Time for an update after disassembly.

First, my assumption on an overdrive failure was not correct. Planetary looks good (except for the metal shavings), as does the OD gear.




Once I removed the OD, this is what I saw first.



Yup, the needle bearings on the intermediate shaft failed. I rebuilt my other Dana 18 twice, and the needle bearings failed twice, so I bought this one from Herm, and have now had another needle bearing failure.

I did an initial cleaning of all the parts in the parts washer to assess the damage, and it’s not pretty. This is the case at the intermediate shaft.




I’m not 100% positive, but I think this case would need to be welded and machined to be saved

I also have a couple of gear issues on the main shaft. This is the small gear. These could probably be saved.



This is the big gear. This could probably be saved as well.





The last time I was into the transfer case, I added this sealed bearing and retainer on the front side of the transfer case, so I doubt there is any contamination into the transmission.



The irony is that I have a complete kit to eliminate the needle bearings and replace them with taper bearings, but I was too lazy to pull the transfer case and install them before we left for southern Nevada. Post your thoughts on if this transfer case can be saved or if it’s time for a different case, this time with the taper bearings installed on the intermediate shaft.

Oh yes, on the Novak overdrive, I think I mentioned earlier that since I have the room with the 25.5” frame stretch, if I want an overdrive, I would convert to a 700r4 from Novak, as the turn key transmission is $3,000, as I have always felt the OD was a weak link…along with those stupid needle bearings.

 

[timsresort]

Wow, you are looking at starting over. Been there, done that. Except for the overdrive, amazingly, if it truly survived. Start with a 20 case, and just buy from Novak, save a lot of drama.

 

[colojeepguy]

complete kit to eliminate the needle bearings and replace them with taper bearings

I had very poor luck with that kit, bearings only lasted about 15k miles. I'm running Novak’s intermediate shaft now.

 

[47v6]

I had very poor luck with that kit, bearings only lasted about 15k miles. I'm running Novak’s intermediate shaft now.

I’m running that taper bearing kit. It seems to be ok for now, but I’m not sure it will last forever. The biggest was cut a bit oversized by the machinist and I used permanent locktite race retainer. No noises or explosions yet.

I used the Novak intermediate kit and it had visible wear in less that 10k miles. It’s the nature of the design I guess.

Buy a 20 case, new gears and start over. That looks sad.

 

[3b a runnin]

Buy a 20 case, new gears and start over. That looks sad.

X2

 

[Jw60]

I had very poor luck with that kit, bearings only lasted about 15k miles. I'm running Novak’s intermediate shaft now.

Who cut your gear? Jeff P has been doing something different with the shaft on his tapered bearing 5:1 gears on the 2a site.

 

[Norcal69]

This is way outside the box for many.... but you have the perfect rig to move beyond 1940's drive train technology.
A modern granny 5 speed connected to a D300 or Atlas transfer case.
TR4050 with 6:1 1st gear connected to a stock D300 at 2.62 is going to put you at 86:1 crawl ratio wise.
Plenty of crawl ratio with 33" tires.
The OD will be nice to have with your 5.38 gears.
Driver comfort will skyrocket with the quiet drive train and cooler operating temperatures.
Not to mention shifting a SM420 is similar to operating an old Yale or Clark forklift.

 

[colojeepguy]

Who cut your gear?

McRuff
That's another issue with the AA tapered bearing kit, finding someone to do the machining. I tried literally every machine shop in Colorado Springs, even shops that do prototype and areospace work. No one would touch it, they said it was too hard.

 

[colojeepguy]

This is way outside the box for many.... but you have the perfect rig to move beyond 1940's drive train technology.
A modern granny 5 speed connected to a D300 or Atlas transfer case.
TR4050 with 6:1 1st gear connected to a stock D300 at 2.62 is going to put you at 86:1 crawl ratio wise.
Plenty of crawl ratio with 33" tires.
The OD will be nice to have with your 5.38 gears.
Driver comfort will skyrocket with the quiet drive train and cooler operating temperatures.
Not to mention shifting a SM420 is similar to operating an old Yale or Clark forklift.

I hate to say it but I agree with this. I think a Warn/Saturn OD is the single best mod you can do to a short wheelbase early CJ. I love the gear ratio combos available with my T18/OD/D18 combo, and having 4 shifters is cool But it's heavy, shifts like crap, difficult to get sealed and noisy. If I had a longer wheelbase I'd seriously consider a more modern trans/tcase.

 

[FinoCJ]

McRuff
That's another issue with the AA tapered bearing kit, finding someone to do the machining. I tried literally every machine shop in Colorado Springs, even shops that do prototype and areospace work. No one would touch it, they said it was too hard.

Is Sal at vintage jeeper doing such work these days? ....looks like you can buy machined gear from him:

https://vintagejeeper.com/product-search/ols/products/dana-18-tapered-bearing-complete-kit

 

[FinoCJ]

As Kyle said....with long wheelbase and 'stock' long gone, I see no reason to run a D18/OD combo.

 

[colojeepguy]

Is Sal at vintage jeeper doing such work these days? ....looks like you can buy machined gear from him:

https://vintagejeeper.com/product-search/ols/products/dana-18-tapered-bearing-complete-kit

Thats pretty cool. But I wonder if that's a stock gear or a reproduction of questionable quality?

 

[cj2atruck]

Thanks for all the great input. My last two intermediate shafts were from Novak, and neither lasted 5,000 miles, with the last one lasting less than a year of occasional trail use. I bought a rebuilt transfer case from Herm because I was concerned I was doing something wrong on my rebuild, but turns out Herm’s rebuild didn’t last any longer than my first rebuild. If the taper bearings get me 15,000 miles of trail use, that will be almost 4 times the life of my last two Novak intermediate shafts and the transfer case from Herm.

Updating the transmission, transfer case and rear end may be in the future, but it is a pretty significant redesign/rebuild of a lot of the jeep that already works (I like the SM420 and v6), so a last resort if the taper bearings fail quickly.

Has anyone had the taper bearings fail on gears that were cut correctly? If so, was the failure as catastrophic as needle bearing failures? How did you know the taper bearings were failing, what was the signal? This needle bearing failure destroyed the case on this Dana 18.

I have a spare Dana 18 and the taper bearing kit, so it’s the easiest path to get the 47 back on the trail quickly. My only questions now is the taper bearings shaft size and the shaft size in my previous Dana 18, which I will confirm today. I think they are both the same 1 1/8”, but if not, I’ll be back to the drawing board trying to get the 47 ready for the Moab trip in May and Rubicon in June.

I like the overdrive, and have run them on jeeps dating back to my 1971 in the early 1980’s, but I see the overdrive as an unnecessary potential failure point for a rig that will see primarily trail use.

 

[colojeepguy]

Has anyone had the taper bearings fail on gears that were cut correctly?

Me (I'm assuming the job was done correctly)

see the overdrive as an unnecessary potential failure point for a rig that will see primarily trail use.

I use OD more on the trail than I do on the street. It's great to have that "just right" gear.

 

[FinoCJ]

My last two intermediate shafts were from Novak, and neither lasted 5,000 miles, with the last one lasting less than a year of occasional trail use. I bought a rebuilt transfer case from Herm because I was concerned I was doing something wrong on my rebuild, but turns out Herm’s rebuild didn’t last any longer than my first rebuild

I seem to recall a few years ago there was a lot of discussion about the intermediate shaft thrust washers from various suppliers was not correct, and @1967 CJ5A also was finding a lot of issue with wear on various gears and trying to find a quality set of gears....and of course there is concern over quality of reproduction.....

Thats pretty cool. But I wonder if that's a stock gear or a reproduction of questionable quality?

Not sure....maybe @Sal Consalvo could give some details.....sure if anyone wanted details, he'd be happy to chat

 

[cj2atruck]

Me (I'm assuming the job was done correctly)


I use OD more on the trail than I do on the street. It's great to have that "just right" gear.

What was the sign that the bearing was failing? Was it as catastrophic as when the needle bearings fail?