Series 3 & 4 Powerlok revisited-again

I did a search here and found some information. But maybe there's more. I just sold a Powerlok from a D27 that had 5.38 gears. The guy who bought it wasn't sure of his ratio, but he told me his CJ was a '67 original V6 Dauntless with a D27A. It turns out that he has 3.73 gears and apparently the carrier doesn't work because the ring gear is 3/16" approx. to close to the pinion. I was under the impression that the 3.73 carrier would accomodate the 5.38 R&P. Also, and this is pretty strange, he claims that the original carrier that he took out had no shims behind the bearings on either side. I suppose that's possible, but highly unlikely. I don't see how you could get the proper backlash and preload without shims. Any ideas out there?

 

There are a few pics in the Photo Archive, here's a link to one showing the differences:
http://www.earlycj5.com/gallery2/v/picBank/album/MVC-003F.JPG.html

I believe John A. Shows submitted the pics, so maybe he can help.

Jim

 

Yep he's right about the difference. I actually took pictures of mine to show people. A power lock that was installed in a gear ratio of 5.38 will not work in a 3 series set up. I'm not sure about the shims. It seems like mine did in fact have the shims.

 

"A power lock that was installed in a gear ratio of 5.38 will not work in a 3 series set up."

So the question becomes, is a 3.73 ratio a 3 series. Acording to an earlier post by nickmil it's a 4 series. Unless I misunderstood it. Once again Jeepconfusion reigns supreme!

 

In a 27 3.73 is a 3 series as John Shows has shown us. That means it fits 3.73 to 2.54 gears. However, in a 30, 3.73 is a 4 series. I think in an earlier post I screwed up and confused the two . A thousand lashes with a wet noodle do I deserve .
John proved it without a doubt when a 4 series 27 Powerlock was sent to him by mistake thinking 3.73 was 4 series in a 27. It didn't work for him as the pics he kindly posted show. 3 series Powerlocks for a 27 are pretty rare and hard to come by so if you come across one, snag it quick. Sorry for any confusion I may have caused. Nickmil.

 

Nick should know since he's in the business, but I actually went through the experience. I bought a power lock for a 4 series gear (R&P)and tried to install it in my D27A with 3.73:1 gears and it just wouldn't work. Take a look at the album under "Axles" and you'll see what I'm talking about. I set my open dif on a table next to the Power Lock and the mounting surface for the ring gear on the power lock is about 1/4" to 3/16" higher (or farther towards the pass side) than on the open dif. I believe if it were the other way around....if I were installing a 3 series power lock with a 4 series R&P then the mounting surface would be lower (or farther to the pass side) then I could use a spacer between the Ring gear and the Power lock that would center things up.

 

The FSM says that to go from 3.73 or higher ratios to 3.54 or lower ratios you need to change carriers. This includes the Powerlok. I guess it's subject to interpretation and obviously, from your experience, the manual is wrong. The FSM also states that "there are no traction aiding devices available for the Model 27 axle". Obviously that's wrong or we wouldn't be having this discussion.