some basic newbie questions

Well, my new 87 XJ just passed state inspection and I am looking at some accessories. First, however, I am curious about the basics as I am new to 4wd vehicles. It has a bit over 265,000km on the clock and the friend who gave it to me said he had only used 4wd about 4-5 times in the snow when he was living in Winnipeg. He bought it off the original owner, a friend of his, with only 11,000km. the vehicle in question is an 1987 XJ Laredo, 5-speed with Command Track 4wd, tail mounted spair. It also has a dealer installed cruise and towing.

1. I have heard that 4wd systems need to be engaged to keep them lubed. Are there any possible problems with one that hasn't been used much? My plan at this time is to change all fluids run it a bit, and change again.

2. How can I identify what diff's and other 4wd bits it has?

3. The dealer mounted cruise control has not worked for years. Do any of the new kits work well? I plan to take it off and not replace it, if there aren't any good alternatives. I do make trips to visit family in Atlanta though, and after 1,200 miles cruise sounds good.

Thanks for any help,

Copperhead- New Hampshire, USA
1987 XJ Laredo, 4.0, stock

congrats on the new XJ...

1. IMO i think thats a bit of a myth.. but i'm sure there are some t/cases that require this.. but i could be wrong.. i'll refrain from anymore input on the chance of getting shot by the SPOBI police..
2. the front diff will only be a Dana model 30.... you said it's a command-trac model so that means NP-231 ( as long as you do not have a full time 4WD positiion).... here's a link for the rear axle ID..

http://www.highriders.ca/documents/axle_spotter_guide.htm

3. a little troubleshooting may get your cruise working, no idea about aftermarket but i see no reason why they wouldn't work well....

change every oil/fluid in the rig and enjoy your XJ
mike

4WD does not have to be 'engaged' to keep it lubed. That transfer case is or should be an NP231 part time which means don't engage 4wd on dry paved roads, it's not good for it. However if no one used it often I would crawl under there with some good oil and spray the heck out of the linkages, lubing them up good with say Mobil-1 spray lube to keep them loose.
Front diff should be dana 30 rear should be a Dana 35 though it could be a dana 44. You can get a printout of the original build sheet from the dealer, they just run the vin number and print it out.
As for the cruise control they generally die from two things, first is a vacum leak in the system, second is the 'head' unit that the spedo connects to, gears in there strip, new one last time I checked is around $60 or so aftermarket.
What I would do first is a complete fluids change, flush the cooling system, replace the thermostat, pressure cap and the belt if it needs it. Might even want to do the hoses if they look old.
I'd leave the tranny alone, no telling what mischief flushing that will cause. The two schools of thought are if you change the auto tranny fluid regular that there is no problem, if you have not done it regular then leave it alone. Depends on how much you want to gamble. My sons 89YJ was of unknown duration, we flushed and changed it with no problems other than a stripped tranny pan hole that we need to helicoil one day this month when we get time.

Once upon a time, in the days of closed steering knuckles with kingpins (unlike our open knuckles with ball joints) it was indeed important to run 4WD occasionally, or at least to engage the front hubs from time to time, because the upper kingpins were lubed from within by the grease thrown around by the axle U-joints. As others have pointed out, this is no longer an issue, but if you go for a long time without using 4WD the linkage will get stiff. Every once in a while, you can just get into the vehicle and without running the engine, shift in and out of 4WD about 20 times. The linkage will loosen up again.

For the cruise control, before you give up, make sure the little wires in the control stalk are intact. It's a common failure area. Also check the vacuum. The vacuum reservoir on cruise-equipped vehicles (at least for 87) has two chambers, one just for cruise, so even if everything else works, there still could be a vacuum problem in that system alone.

On my 87, after troubleshooting everything else, I found that a long-standing windshield leak had dripped on the cruise control module and eaten all the contacts off its circuit board. At that point, I gave up and tossed the whole thing.

If the cruise was dealer-installed, more than likely it's aftermarket and not factory. I run an Audiovox "OEM look-alike" cruise that I bought a number of years ago from the Sears auto catalog. This is in an 1988 and it's working as well as any factory unit of that vintage.

Sears doesn't sell it any longer, but J.C. Whitney sells a couple and I'm pretty certain one of theirs is the same thing.

It looks like the XJ is stock, with Dana 30 up front and a Dana 35 in the rear. The positions for drive modes are 2H, 4H, Neutral, and 4L, which I believe is Command Track (that’s what it looks like in the owner’s manual). I put a new belt and battery in, lubed the underside everything else looks good. Will try to do an oil change and radiator flush this weekend.

I haven’t had a chance to look at the Cruise control, but now have a good starting point to begin troubleshooting.

Overall impressions are good. It’s not as responsive as my wife’s 2wd 96XJ Sport, but I figure that is the difference between non-HO and more weight of the 4wd.

Thank’s again