mmmm Slow=good

So how much if any alterations did you have to do to the case? What year model 20 did you use?

 

Its a 72 Dana 20. There was quite a bit of grinding required to clear the new gears. It is not just the ridge that the instructions tell you to remove. A good small hand held grinder is a must. A dremal will not do the trick.

 

Excellent! Greatly appreciated.

 

Here is the comparison I made.

Stock= T-18A w/ stock Dana 20 and 4.56 gears.
Tera Low = T-18A, Dana 20 with Tera-Low and 4.56 gears.



And this is what the gears are:

Stock

1 low 58.502976
2 low/1 hi 28.8192
3 low/2 hi 15.643992
4 low/3 high 9.2568
4 High 4.56

Terra Low

1 low 90.78048
2 low 44.38476
1 high 28.8192
3 low 24.27516
4 low/2 hi 14.0904
3 high 7.7064
4 high 4.56

 

Novak has a short shaft kit for the T-18A wide ratio (6.32 1st) no kit for the T-18B 4.02 1st. Kit number is T18-ISK price? Don't know.

Duh checked out the link lots of good info and parts avail there. Bookmarked it.

 

How does the 4.02:1 transmission relate to the topic?

I believe the 4.02:1 1st (close ratio) T-18 was only available in the 71-75 (76?) CJ and Commando vehicles. The input shaft from those transmissions is a little longer than from the Ford T-18, since an adapter plate was used to mate the CR T-18 to the T-15 bellhousing.

You can get a 4.02:1 T-19 from a Ford truck - that should have the short shaft. Novak has an adapter for the T-19.

 

I picked up a wide ratio T-18A (6.32:1 1st gear) that came from a '77 J10 but the input shaft is WAY too long. As I learn more about adapting this tranny to my stock '75 CJ5 (304CID w/ T15 tranny), it appears that I need a '76 - 86 CJ bellhousing along with the clutch fork. Plus a '76 - '79 clutch plate.

I realize this a little off topic but noticed Hudsonhawk also has a T-18A and thought he might know where to get the parts to make it fit into my '75.

 

My T-18a came out of a 78 J-series truck. You can use the bell housing from a t-150 or 1-176 tranny. Both will have to be drilled for one bolt. Tap the hole and run a long bolt through it from the inside. then use a washer and nut on the outside to mount the tranny.

I used the stock clutch plate from my 72 w/a throw-out bearing and clutch fork to match the bell housing. 1000 miles and the clutch is working great. Make sure you get the special pilot bearing. I also used the '72 flywheel on the '83 258 as that engine did not have a flywheel when I picked it up.

 

I'll be putting the 3.15 kit in the D18 in the 5.
That with 5.38s it should crawl well.

 

I've been doing a bit of research on the subject; off the top of my head, anyone feel free to correct me if I am wrong on anything,
:The 76 up bell housing is approx 1 in shorter then earlier bell housing (this could be good for rear driveshaft length as 4 spd is longer then 3 spd) earlier bell housing doesn't appear to have enough "meat" for the 4 spd bolt pattern.
:input shaft could be sent to Moser Engineering to be shortened/ remachined, about $80-90. You need to send a sample shaft for length, diam,splinecount etc. (this could be from a 3 spd that fits clutch/bellhousing.)
:You need to be aware of the bearing retainer also, offhand I don't know what type the J-10 tranny has. A regular cj retainer could be swapped in or maybe the J-10 retainer shortened. Be aware that you need t/o brg travel rearward towards tranny. This is area you need to watch.
:You could also buy and swap in new input shaft/retainer etc.
Anyone feel free to add or correct anything I have stated, You need to do some of your own research, use these suggestions as starting point. Be sure and post what you discover along the way. I do not intend to hijack, just add to. Good luck.

 

Thanks for all the info. I think I now know what I need... now to find it all at a decent price. Once I get it all together I'll post all the variables in a new thread so others attempting this will have options at their fingertips.

Thanks again,
Bryan