Later WD21 LSD Differential Swap into an 1988

[Kyle94]

There has been some mixed stories that I've got and read. But here is my story and experience.

My 4.3 rear LSD differential started making popping sounds and jerking the truck around. So i began to expect the worst and started sourcing a new one out. After visiting a few junkyards, my friend David (Mister(Mr?)510) told me had one that was supposed to be an hg46 axle code. Turns out it was a HG43, whatever, no big deal to me

 

We tore mine apart and found this: Two cracked and one shattered belleville springs, and 5 teeth snapped off the spider gears.

 

So i left his house and next day tried to install the newer LSD rear differential carrier.... Except two bolt holes out of the 11 (my housing and old diff carrier were/are 9 bolt) sit over the cutout for the ring gear in the housing! :O Now what? I talked with David and a couple other friends and finally decided to just plug those two holes... SO, i decided to tap the two holes in the 3rd member flange that overlapped the ring gear cutout so i could stick some cut off bolts in there with silicone for "plugs" I ran across town to get a 12mx1.5 tap from my grandpa, and two 19mm head (yeah! wtf) bolts to cut off and use in the soon to be,freshly tapped holes. *sigh* (my frustration at this point) By the time we were done i would never recommend someone else doing it that has never done such a thing (i had my step dad, diesel mechanic for 20+ years, to help me) i silicone'd the holes, the threads on the bolts, and the back side of the bolts once they were screwed all the way in. Silicone'd the outer edge of the carrier and lifted it up in (78 lbs is not fun under a truck on the ground!) put it all together and viola! Works just fine, but definitely much more of a pain in the a$$ than i wanted it to be. Take my story as you will. But an 11 bolt differential from a later wd21 will NOT bolt right in. I will post a pic up tomorrow of it installed and the location of the plugs, plus the other two bolt holes that were not used. (yeah, scary, 7 bolts for the entire thing... )

Thanks for reading my clarification!

 

Mods feel free to move to a more appropriate location?

Edited December 31, 2012 by Precise1
requested

[Kyle94]

Mods For edit:

Davids Screen name is in fact Mr.510

 

 

And this pic added after "...ring gear in the housing!"

 

And i need this pic added right after "freshy tapped holes"

And ill have another pic or two of the installed product tomorrow... just forgot i had these pics.

Edited December 31, 2012 by Kyle94

[krmiller07]

After lookng at what you took out, I am surprised it rotated at all...what a mess !

Thanks for the post.

[ahardb0dy]

Just for future reference oem-surplus.com still has a few final drive assemblies available for $150 new surplus:

 

http://www.oem-surplus.com/nwp/pathfinder-3.htm

Edited December 31, 2012 by ahardb0dy

[Precise1]

If you wanted to plug the holes, why did you use RTV? JB Weld or similar would have been far better, and the best way would be to tap it 1/8-27 or 1/4-27 NPT and use an actual threaded plug. The 20+ year mechanic didn't point that out?

 

B

[Kyle94]

By the time the decision to tap the hole came about. I wasn't worried about getting an actual plug. I used whay we had. :-) which is what most people would do. Or what they had access to. I called my grandpa up for the tap. And went the the hardware store for the bolts. Had everything else...