AA Intermediate Shaft

The shafts work great but finding someone who can machine the hardened gear can be the proverbial can of worms.  I believe Mcruff over on the Early CJ 5 site offers that service and Herm (the overdrive guy) would likely be able to refer you to someone for that.

Edited by duffer - 31 Mar. 2014 at 5:49pm

Is there anyone else who has tried the Advance Adapters tapered roller bearing conversion for the Model 18 transfer case intermediate gear? I'd like to hear more pros or cons to this conversion.

I bought the whole kit after trying to find someone locally to machine the gear for the bearing.....nobody around here would even talk about it.

The kit worked fine and was quieter than the one it replaced.....run cooler?....Don't know but I suppose it should. It was still in the Jeep and running quiet years later when I sold it.

I give it a thumbs up.

I'm having a tough time visualizing where the forward and rear thrust is going with the AA kit. Since the gears are helical the intermediate gear will push to the front when going forward, and push to the rear in reverse. Normally this thrust is on the front and rear thrust washers to the inside of the case. How does the AA kit handle this end thrust?

I see how the thrust is transferred from the bearings to the shaft, but what keeps the shaft from moving forward and rearward? Unfortunately I don't have the kit here so I'm going by the drawing in the AA instructions. Looks like the shaft can't move forward because it has a flange on the rear. So that would mean the forward thrust force of the intermediate gear is going against the rough casting surface of the rear of the case - instead of going to the machined surface on the inside of the front of the case.

I actually just did the machining and installed one of these kits a few days ago. Happy to answer any questions. 

What's the scoop on the copper tag?

oldtime wrote: Under extreme thrust the original design may prove superier. But under light load at higher Rpm’s the taper setup is superior.

I love a good AA meeting.

Hey Dave,

Have you installed the pan yet or can we see a straight on shot from the bottom to see the gaps between the bearings and the housing?

It seems to me that after preload is set, it would be a good Idea to measure the gaps between the inner races and the inner thrust washer surfaces, then make shims of equal thickness and install them... or at least on the inner side. This way the inner thrust is not all on the shaft and outside case wall.

I almost think a guy could just grind the AA bushings short so that they just support the shaft an don’t set preload, then make the proper width shims similar to the old thrust washers but make them so that they register the gear in the correct location on the front side and take up the space on the back side while also setting the correct preload. This way you can tighten up the nut so that it bottoms out on the case. Then you would have correct location, both sides of the case would share the load in either direction and the bolt would keep the case from spreading apart.