Instructions for changing viscous coupling ?

Hello, I was wondering if anyone had detailed instructions for changing the viscous in a 1995 np 249. I thought I could do it without a manual, I don't think so. I remember seeing a thread awhile back saying it could be changed without pulling the transfer case, Ithink XJ31 was the poster. But I cann't find the thread now. I feel a plate on the top of the tail extension, I wonder if the there is a snap ring under it? But even if I get the extension off I will need more instructions. Help please :)

I see alot of lookers but no replies, here is what I came up with on my own...

I'll try to talk you through it. It was a very easy repair, about 3-4 hours for a rookie. You pull the tail extension off the transfer case and the VC is pretty much right there. This is from memory so I may miss a detail.

First remove the driveshaft and the transmission crossmember (you can leave it bolted to the transmission), this will allow you to carefully lower the engine / trans assembly so you can access the top of the extension housing. Have someone lower it slowly while you look for any interference that would cause damage to the engine, etc. Block the assembly in this postion so it doesn't drop while you are working.

Next remove the speedometer ouput gear, it slides in to the tail extension housing.

Next remove the tail extension, the trick of this job is the snap ring that holds the extension housing to the bearing. It is accessed thru a rectangular plate on the top of the extension housing. The plate is held on with torx head flat head screws, use a mirror to get at the screws. Using the mirror and a pair of right angle snap ring pliers this ring has to be spread and the extension housing will pull right off.

A pair of flat nosed pliers would be ideal but I don't have and could not find any that were not straight. I used a pair of pliers for the snap rings with the holes in the ends, it took patience and luck. I was going to modify a pair of pliers if I could not get the job done.

You need a second pair of hands to hold the output shaft forward as to not pull it back so far as to have the bearing at the front end of the output shaft fall out, I had a helper hold a large screwdriver against the output shaft while I removed the housing. After the housing is off the the mating speedo gear, output support bearing, oil pump and VC are slid off. There are 2 snap rings, involved here and it pretty straight forward.

You may want to look inside the case at this time for any abnormalities with a mirror and light. Put the parts back on the same way they came off (duh) and seal the housing up with rtv.

As for the snap ring that is accessed thru the top hole, I cut a piece of wood to hold the ring spread while I put the housing back on, when in place I pulled the wood out.

I can email you pictures of the output shaft assembly if you would like let me know at [email protected] .

good luck

rick

well I wish I would have known earlier I would have dumbied up some pics for instructions, I have a spare 249 and get you the pics to do it step by step if you would like

like rmoore said this is a pretty easy job, the hardest part is getting the snap-ring apart for the extension housing.

if you would like the pics let me know

Joe
[email protected]

I have to put it back together then do the teardown, but I will start right away.

Wow where were you guys 2 weeks ago? ;)

CTCarpenter ... great link, I had not been to that forum, but I did spend quite a bit of time trying to find some instructions. I guesss my search methods were not working very well. I did put some pics together for another user that emailed me but the ones you listed are much better. I'll send him the link.

good luck everyone