j20 transmission and transfer case - JeepForum.com
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > j20 transmission and transfer case

Ledlight bar light locks @ oconee off road 706 534 9955Don't forget the Jeep Forum discount, 10% off!The Original 3/8" Ruffstuff Diff Cover!

Unread 12-14-2009, 04:27 PM   #1
Registered User
1981 CJ7 
Join Date: Nov 2008
Location: Illinois
Posts: 30
j20 transmission and transfer case

I will soon be looking at a 4 speed tranny out of a j20 year unknown. My question is what tranny is this? I'm sure it probably isn't an sr4 or t4. He also has a transfer case. He says they are heavy duty. with this possible combo work behind my 1981 258? I am just wanting some info before i go look.



jruff is offline   Reply With Quote
Unread 12-14-2009, 04:35 PM   #2
Hybrid Jeep
Registered User
1976 CJ5 
Join Date: Aug 2007
Location: Monument, CO
Posts: 1,013
It's probably a T18. If it is the T18 (it is) the input shaft will be too long.. you can get a short shaft kit from Part's Mike to have this work in your CJ. This is a common upgrade and I have a short shaft T18 out of a FSJ myself.
Hybrid Jeep is offline   Reply With Quote
Unread 12-14-2009, 08:19 PM   #3
Registered User
1977 CJ5 
Join Date: Nov 2004
Location: Southeast PA
Posts: 1,198
J20 should be a T18. Transfer case, if aluminum (np208), is nothing to brag about. Could be a Dana 20 if the truck is a 70's model, still nothing to brag about. The late J20 T18's are quite odd, as they are a Ford in the back(31spl, ~7" extension housing) and Jeep up front (odd mounting pattern, long input) and they also have no pto cover, it's cast into the case (Yes, I have confirmed this personally). Earlier 80's FSJ T18's are the same spline as the Dana 300, but came with a NP208, which isn't anything great. Either way, if it's an 80's model, with the long rear extension housing, it's almost better to start with a Ford T18 for a swap into a CJ.
1977 Cj5, 258, T-18, 2.46:1 Dana 20, 2.5" BDS lift, OBA, 38.5's. Chevy 60 frt, 14b Rear, Full hydro, 102"wb, full DOM cage.
No_Bs is offline   Reply With Quote
Unread 12-15-2009, 05:36 AM   #4
Cool as Ice...
PavementPounder's Avatar
Join Date: Dec 2006
Location: Birmingham, Michigan
Posts: 2,652
The 208 is actually a nice, strong transfer case with 32-spline outputs, bigger planetaries, and a wider chain than a 231. It is also shorter and of course has the factory fixed rear output that other 208's don't.

The comments above about the "Ford" style configuration of it are correct. You don't want the 31-spline version. Like No Bs suggested, The later 80's T-18 isn't a good setup to start with.

In the event it is a T-177, it will accept your Dana 300 and work well as long as you don't have an input shaft issue.
This is how NAXJA Midwest Chapter elected officials like to treat their resident users and former multi-year supporters.

<--- Click "Classifieds" under my avatar to see all my parts (mostly CJ & XJ) currently for sale on JeepForum!
PavementPounder is offline   Reply With Quote
Unread 12-15-2009, 06:11 AM   #5
Registered User
2003 TJ Wrangler 
Join Date: Nov 2005
Location: Palm Harbor, Fl.
Posts: 556
I used t-18 out of a 81 FSJ in my cj-7. The short shaft, and the adapter to fit the dana 300 came to over 700.00. I can,t remember if the t-case was a 208, but it was a driver side drop. I didn,t know much about jeeps at the time, and was told by the seller that this combo would bolt right into my cj. After all was said and done, my jeep is on the road( 360/t-18/dana 300) and that guy is out of business.
Andy5150 is offline   Reply With Quote
Unread 12-17-2009, 04:46 AM   #6
Registered User
1981 CJ7 
Join Date: Nov 2008
Location: Illinois
Posts: 30
Sounds like i need to pass on this one. Thanks for all the advise!!
jruff is offline   Reply With Quote
Thread Tools

Suggested Threads

Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.