dana 20

I put a T90C in my 62 CJ-5 last summer. The 3.34-1 low helps a bit, but would still like some lower gears. After talking to Novak, they tell me that I can use a dana 20 case if I put In my dana 18 gears. Then I can use the 3.15-1 low gear set. Now what about the stud for the clutch belcrank? Does the dana 20 case have a provision for that? Can one be put on if not? After contacting different wrecking yards it seems the big hole dana 18s are scarce but the dana 20 is easy to find.

 

I know you just put in the T90 but I would look at a T18 or a SM420 swap instead to get the lower ratio.

 

Yes the large hole case has the boss but may or may not have the tapped hole in the boss.

 

I have to agree with the above. The cost of the low gear set alone is around $800+. If you can find a tranny for a reasonable price the swap is a great way to go. Just my $.02

 

If you're running the T-90C, I'd guess this is a F134 :hurrican:. As I'm sure you know, there's no easy 4-speed swap for this engine (other than the scarce OE T-98 :hurrican, so the T-90C, 3.15:1 gears and 5.38s may be your best option. That will give you a 57:1 crawl ratio, which I'd think would be sufficient for most people. Tire height will matter too...

Gotta love the Hurricane :hurrican: to keep it ... however, for that amount of money, there's an obvious alternative.

 

Here's a link for a 3.15:1 kit for a Model 18. However, I don't think it's enough of a change to warrant the expence and I personally don't do business with Advance Adapters. I had an experience with them that left a bad taste in my mouth.

 

The tera-low kit is a 28% reduction which is pretty decent, about like going from 3.73 gears to 4.88's.in the axles.

 

I had thought that the 3.15-1 kit would help a bit. I didnt really want a 4 speed, I like 3 speeds trannys. highway speeds are not an issue. I would be interested in hearing about posimotos bad experience with advance adapters, was it quality or a service problem?

 

Almost all the 20 cases have the boss for the pivot on them, as said, may need to be drilled and tapped though. Watch out for the fill plug location on the 20 case. Some have them on the back and some on the side like the 18. You want the one on the side. Reason is if you still have the transfer case mounted parking brake you won't be able to access the fill plug if on the back. Don't ask me how I know. I've installed quite a few of the Tera 3.15 kits and everyone I've spoken too about them has been real happy with the change..... Nickmil

 

Thanks nickmil! That info helps a lot. I always thought they should have been set up with lower gears from the factory.