Np231 slip yoke question -
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 > Models > Jeep Wrangler Forums > YJ Wrangler Technical Forum > Np231 slip yoke question

End of Summer Sale, 20% OFF!2007 - 2011 Jeep JK Long Arm Lift KitsIntroducing MONSTALINER™ UV Permanent DIY Roll On Bed Line

Unread 01-16-2014, 09:11 AM   #1
Registered User
1987 YJ Wrangler 
Join Date: Dec 2012
Location: inver grove heights, minnesota
Posts: 65
Np231 slip yoke question

Hey i have a 87 yj with an 88 np231 and found a sye on craigslist for cheap its out of a 2000 wrangler with a 231 j will this work in my np231? And i have the older style mechanical speedo will this still work with it because i know they switched to digital later on

I would support obama care if it covered my jeep too!
758879 is offline   Reply With Quote
Unread 01-16-2014, 09:34 AM   #2
Follow me
Anticanman's Avatar
1994 YJ Wrangler 
Join Date: Aug 2009
Location: Ripon, California
Posts: 19,230
Its one bolt to swap the speedos
Luck Favours The Prepared
Anticanman is offline   Reply With Quote
Unread 01-16-2014, 09:34 AM   #3
Wild Wheeler
jokerchief462's Avatar
1989 YJ Wrangler 
Join Date: Nov 2010
Location: Sin City, Nevada
Posts: 2,847
Your good my 89 is mechanical

Sent from underneath my Jeep
89YJ 2.5L TBI, AX-5, NP231 SYE, Ford 8.8, Yukon Grizzly, Tom Woods Shaft, 33" BFG T/As, 4" lift, Warn VR10000s.

AF Jeep Club Tail #184
jokerchief462 is offline   Reply With Quote
Unread 01-16-2014, 10:33 AM   #4
Registered User
1992 YJ Wrangler 
Join Date: Oct 2006
Location: Massachusetts
Posts: 2,715
A few things to look out for...
- Spline count. Your BA/10 tranny is a 21 spine output. Be sure the tcase you are considering is also a 21 spline.
- The front output yoke on the TJ tcase is for a CV (double cardan) driveshaft. Your YJ would have a single u-joint.
- The TJ tcase has an electric switch in the spot your YJ case has the vacuum switch for your front axle. Will need to deal with that if you still run the front axle disco with vacuum.
Baystate Jeepers
Deep Woods Extreme
New England 4 Wheelers
kloppk is offline   Reply With Quote

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