Dana 18 Tapered Roller Bearing Upgrade.

Hey ya'll, long time not here but back in the saddle again. I just had my D18 Xfer case rebuilt by a very highly recommended individual and decided to do the tapered bearing this time. It came with Timken bearings which I've been highly suspect of for some time now. Low and behold, that S.O.B. is noisier than when I took it to him!! What the hell does one have to do to get quality parts anymore? :-(

 

Yeah mine isn't really any quieter with the roller bearings either.

 

But it should last much better than regular beerings.

 

Mine is a little quieter. Runs a bit cooler. But all the chatter is gone.

 

IMHO the biggest benefit is the longevity of the bearings, not the noise reduction. Mine is quieter, but maybe not much. Given the low quality of the available intermediate pins the tapered bearing conversion is a great idea. I was getting only a couple of seasons out of the roller style intermediate pins. Even the ones from Novak didn't seem to hold up that well.

 

Ok I have never heard of this tapered bearing kit for the Dana 18. Is it available for one's with the 1-1/4 shaft or just the early model Dana 18 cases?

Advanced Adapters lists them for 1 1/8" and 1 1/4". You have to select the "Configure and Add to Cart" option, then it let's you select the model/size.

DANA18-INT : Intermediate Gear Kit retro fits the Dana 18 With Tapered Roller Bearings for noise reduction & performance | Advance Adapters

 

I had mcruff (member here) cut my gearset for the conversion. If he is still willing to do it, he does excellent work.From an engineering standpoint, the original configuration for the roller/shaft is terrible. The design makes it easy to replace the intermediate shaft and simultaneously creates the situation where you have to replace it more often than you would like. I think that the majority of D18 t-case failures are related to galling of the intermediate shaft than any other thing excluding running the unit low on oil. The intermediate gearset is extremely hard and requires an experienced machinist with the proper equipment to do the work.

 

Novak also offers a specially hardened intermediate shafts in 1 1/4" and 1 1/8", from their website: "Our exclusive intermediate shafts are made here from case-hardened triple-alloy and are the strongest available."

Parts for the Dana Model 18 Transfer Case

 

Oh wow ok so you have to get the gear machined out. I think I'll just stick with the needle bearings right now.

 

Alot of the noise in a D18 comes from the spur gear design. the tapered roller bearings help with some of the noise, but it is not going to eliminate it completely. The tapered bearing design is a much more robust system the more evenly distributes the load applied to them compared to the standard roller bearings. Im waiting to get by gear back from the machine shop, and I'll be assembling mine.

 

I had Mcruff do mine too....I looked all over Colorado Springs and couldn't find a machine shop to do this, not even places that do prototype or aerospace work.

 

I tried the Novak shaft and it didn't hold up any better than the others I used. I got two seasons out of it and it started to loose the hardened surface. By the original design they are destined to fail. Just a matter of time.

 

Yep, only one real solution and that's the tapered roller bearings. And they do work very well and last. I'm sure they also cut the heat generated in the D18.

 

That's what happened to me the transfer case is louder than when it had needle bearings.

 

Wow, that's not good.

 

Some of the noise comes from the fact that the used gear wore a bit more on one edge of the teeth due to the previously worn bearings/shaft allowed the gear to "cock" slightly under load. A fresh intermediate gear with no wear is a bit quieter, and I suspect a worn gear will "bed" in and get less noisy with a couple thousand miles.
-Donny

 

Well here is the kicker I used a NOS surplus gear.

 

Maybe the gears that the intermediate is meshing with have wear. I think your excess noise will quiet down with some miles as the gears bed into each other. Also, have you rechecked the taper bearing pre-load since you have run it some? I found that mine needed to be snugged up a bit more after about 500 miles.
-Donny

 

I'm going to check it this weekend.

 

Mine is quieter now than when I first did it...I snugged up the adjustment after a few miles too (NOT easy once it's in the Jeep! )