New XJ! Time for maintenance, advice much appreciated!

Hey all, just got myself a 98 XJ sport with a 5 speed (48000 miles), and am looking to do some maintenence to it within the coming weeks. Got some questions though.

1) What kind of fluid does the AX-15 take? If I'm not mistaken the manual lists the incorrect type, or so I've heard. Is 75w90 correct? If so, would you recommend running synthetic?

2) I'm gonna replace the plugs and wires, and am looking for some AWESOME wires. I've heard the name Magnecore thrown about a bit, any additional info would be great. Awesome wires with a lifetime warranty is even better, and I know they'll be pricey but I don't care, I want the best for my new baby. I'll probably run NGK since I've had great luck with them in my 92, and I've heard they make a new 4 prong plug like the Bosch +4? Any comments?

3) What type of grease would you recommend for the u-joints, ball joints, steering, etc etc. I normally just buy whatever, but this time around I want to use the best of the best. Any recommendations as far as brand/weight?

4) Going with Mobil1 synthetic this route. I'm used to changing my oil every 5000 miles (used to use Valvoline, but now am a Castrol fan, and always use high quality filters -> Mobil1 or K&N). What would ya recommend as far as oil change schedules with synthetics? 7500 miles? 10000 miles?

That's everything I can think of for now. I plan on servicing the engine oil, air filter, plugs, wires, cap, rotor, tranny, x-case, front and rear diffs, greasing everything, new radiator + coolant flush. Did I miss anything?

Thanks in advance everyone!

Answers

You've got yourself a nice toy so make sure and use it properly (scratched paint small dents and lots of time spent working on it) and these all should be from wheeling....
1) thats the right stuff some have run syn I did but cant give a long term report sold it to get another one but it was purring fine then...
2)I run msd wires lowest ohms per foot out there period (except for solid core which I dont recommend) and at 60-70 bucks not a bad price...I still have my first set from 5 years and 2 jeeps ago..Plugs real easy just plain old champions Ive tried all the rest they sucked (not everyone will agree with me here its all about preference)
3)Just a good moly lube is all Ive every needed just do them once every other oil change or if you live wheres its really wet every oil change...
4)Castrol full synth every 3000-3500 but here in AZ the heat and dryness really kills just about everthing including motor oil faster...You might be ok every 5000 but I dont (its not cheap though)
The rest tranny and xcase both atf (dextron or mercon 3 and you should be safe) the diffs 75-90 or is it 85-90? Ailing memory cant remember someone else will pipe up though
good luck
Welcome to jeepin and the best D&$##mn web site ever..
themud

98 XJ Sport - awesome !!!

IMHO and "stuff I've heard"

1) I have an auto - but a guy who knows Jeeps told me that if
the fluid looks good, regardless of type - don't change it. The
probability of introducing something foreign into a case is not
worth the risk. This idea may raise a host of opinion - but I trust
this guy a lot. If the color or smell is off - that's a different scenario.

2) no clue

3) I use the Valvoline Synthetic - little more expensive, but worth
every cent. Keep that baby greased (including needle fittings)!!!

4) I use the ole' standard Valvoline 10W-30. It's reasonably
priced and I don't feel weird about changing it more often -
which could be a good thing.

One last thing - keep the door hinges lubricated. A major design
flaw in the XJ are weak hinges. Talk to a guy who works in a body
shop - he'll tell ya. "An XJ will run until the doors fall off" *smirk*
I keep a WD40 in the garage and hit em all every week.


Good luck !

Try the Mopar Performance plug wires. Part number P4876436. From the dealer they should be about $46. Cut to fit and numbered. Look cool too with a blue/purple color.

Champion plugs # RC12LYC gapped at .035".

Nothing works better...I've tried a few different combo's with the 4.0 litre and this stuff has worked the best.

Thanks for the advice everyone.

I'm not new to the XJ world, I got a 92 that's mildly lifted and I wheel it every few months, but I've been longing for a 97+ with a 5 speed for awhile.

Just gave her the first wash and applied back to black on that sport trim that loves to fade to black, now she really shines.

I have a 98 4.0L 5 speed, Mobil-1 in the engine, tranny, transfer case, diffs. I also use Mobil-1 grease, found a basket of the Mobil-1 grease mispriced so I bought like a dozen plus tubes for something like $1.99 ea
As for using WD-40 on the hinges, only if you have a water problem with them, WD40=Water Displacement, formula 40, Boeing devleoped and used it for drying out aircraft wiring, any lube properties they put in it flashes off as soon as it drys. For the hinges I alternate between lubriplate moly spray lube and CLP Breakfree.
Don't forget a coolant flush and back flush as well as a new thermostat and pressure cap. I use the mopar coolant and distilled water and the prestone backflush kit along with the prestone 7 hour flush cleaner. I also use the OEM pressure caps and OEM thermostat and I use a gasket instead of RTV.
Get a big can of Anti-seize and whenever you pull a nut or bolt reassemble it with the Anti-seize, it will make you life much easier down the road.
I also stay with OEM cap, rotor and wires, Mopar makes a high performance wire set so you might want to look at that, I also run the stock champions.
I have 180,000mi on mine.
One other comment, I changed my AX-15's tranny oil and used Mobil-1 gear oil, according to Jeep and others thats a no-no, the oil you are supposed to use is GL-3, NOT GL-4 or GL-5 or GL-3/4/5, it has to do with the sulpher content, GL-3 has none and the others do, the sulpher is bad for the sintered bushings in the tranny. Spend the extra money and buy the correct lube from the dealer, it is expensive, $15 a quart or so, but better than having to rebuild a tranny.

Good advice from everyone else...

I run Castol Syntec and change it BY 3000 miles depending on what I've been doing with the Chief. Always the oil AND the filter. Synthetics are going to be your best bet no matter what brand you get.

As for the plugs, Champions are alright I guess but I run Bosch Platnum 4's and don't have any complaints other than their price. I used the cheapy junk from Discount Autopart for the cap, rotor, and wires when I rebuilt the engine- they seem to work OK for now.

I use synthetic grease for everything from the U-Joints to the door hinges. The Chief used to have some binding in the hinges so I second the importance of hitting the doors often.

I also have.....

I also have a '98 5-spd. Here is what i have determined through my profession, auto tech, and through ownership for two years:

RichP has most things correct, except for the trans lube. GL 3-5 is good for these trans's. Because the designation '3' is contained in the grouping it will not have the zinc additive thought to be disturbing to the synchros in the Jap made AX-15. Is too bad because i'd love nothing else but to fill it will something synthetic. I simply use the AZ $1.99/qt lube for that. Standard ATF for the xfer case. Not high stress enough to need to use anything else. Standard lube in the rear end unless it has a Trac-Lok like mine, then Mobile 1 with the factory friction modifyer because of the heat the clutches can generate. I still have the original wires. They have really short runs and are located on the other side of the exh- in other words do not see that serious of heat. Should last a loooong time. If you do want to replace your's, i'd use the factory plain stockers, again for the previous reasons...and good 'ole stocker Champions, side gap them if you want to modify something. Lube grease fittings often. I would not use WD-40 for door hinges, does not have properties for continuous use. Use what RichP said- something moly based would be great. I use Mobile 1 engine oil and M1-301 filter which has a larger capacity and generally used on Mustang GT's. It does have the necessary ck valve these 4.0's require. Because of the 7-qt capacity using this filter and if driving mainly highway, i might go 10,000 miles between services. If unusually hard use or stop and go, i will change it at 7 to 8k miles. With this i am considering several things.... Had not used a drop in that time period which tells me the oil control rings are in great shape and the sealing qualities of all the other components in the engine are up to par. Also, the oil is not that dark even after 10k miles- indicates there is not a lot of blow-by past the rings to where hydrocarbons are not overloading the capacity of the oil. Back in Va, some Jeepers had been doing oil analysis's to where most of them had found they could go 25k miles between services using Mobile 1. Not sure i want to go that long, but certantly is an indicator to me. There. Whew. kinda long-

Thanks for the additional advice everyone! I guess I'll go with the Mopar performance wires if the price is right (local dealership is a rip off, hopefully the one towards the city is a little better).

Don't worry, I don't even own a can of WD40, and like ya'll I tell everyone that it's water displacement-40, not lubrication-40.

And thanks for the clarification on the tranny oil. I'll definitely be throwing GL-3/4/5/whatever in there.

No, no 'whatever' about it. I've been lucky with the mobil-1 in there plus I'm not that tough on a stick. I've seen the Costal GL3/4/5 lube and I don't buy it, GL is not like SAE, GL3 was done for specific requirements, GL4 for different and GL5 for still different specs, GL4 and GL5 are pretty close to each other. Everything I have read and heard lead me to believe that they are NOT backward compatible or interchangeable in the AX15's. If you go to mobil.com and read their FAQ there is even special mention of it made pertaining to Jeep 5 speeds. Next tranny oil change, in a couple of weeks, I go back to the OEM stuff from the dealer. YMMV

Just to be on the safe side get the dealer stuff.....

I have seen stories of people who had BIG problems up to eaten synchros. The AX15 says GL3 then use GL3 or risk having to rebuild the tranny..... All of the aftermarket stuff that says GL3~5 seems to containt the "parts" that are corrosive to our brass synchros so even though I cringe, I cough up the extra $$ and buy the proper fluid. Carefull though: most dealerships will not know what you're tlaking about: you have to ask SPECIFICALLY for the AX15 tranny fluid (it's labeled as such when you get it)

Kejtar

If your dealer is a rip off buy it online, prices are not bad you just have to wait to get it and I hate waiting.

I second the MSD wires, there is no better wire.Ohms resistance per foot of wire is the technical measurement you should be comparing.Most racing motor heads use them also.I seriously doubt any wire you get from a dealer will even come close to MSD resistance.You might also consider their coil upgrade,definately an improvement over weak stock coil.

SyCo said:

Don't worry, I don't even own a can of WD40, and like ya'll I tell everyone that it's water displacement-40, not lubrication-40.

Click to expand...

Sunday morning sermon (IMHO)

I've always believed that keeping mositure out of hinges,
bearing surfaces, or any other features requiring lubrication,
is the first line of defense against corosion. Moisture causes
corosion, and corosion is one of the main degradation factors for
the compromise of bearing surfaces such as hinges.

Here's a test: Open your door and inspect the hinge. If you see
ANY coroision what-so-ever (that brown stuff called rust) -
someone has not done a good job of keeping water OUT of the
hinge. Regardless of the "lubricant" you use, or how much you
goop in there - the presense of moisture will no doubt eventually
distroy the hinge or the surrounding weld structure. Soon the
door will not close properly - then eventually fall off. (OK maybe
the door falling off is a little poetic license.......)

Obviously WD-40 alone will not mitigate the entire problem of
lubrication an automotive hinge. However, it was originally
designed to co-exist with (or will not degrade the performance
of) other lubricants such as silicone or moly based greases (I
prefer silicone spray by preference only).

Anyway - assuming you're already using a decent grease in your
door hinges - I would still recommend "de-watering" XJ door
hinges with WD-40 on a regular, if not weekly, basis.

Like I said - my auto-body friend has done literally hundreds
of cob-jobs re-attaching doors to XJ's, while the engines purr
flawlessly in the background.

???? I don't think I ever lubricated my hinge..... it looks that when it was made they put so much in there to last a lifetime, plus I don't think that I ever heard of falling off doors.... I heard of doors that were removed on purpose but that's about it.

Kejtar

Well, there are door problems, the door problem is really prevalent on the 2 doors models, same size hinges, heavier/longer doors, increased leverage. Actually that is kind of true on all the two doors that have longer doors to allow better access to the rear seats. I generally lube mine every tuneup when I go from bumper to bumper draining, cleaning, pumping and spraying everything. I spray my shift linkage with Mobil-1 spray, top off my transfer case and allow the seeping TC rear seal to keep most other things under there coated LOL..
I do have a needle attachment for the grease gun for doing hinges and other small things that have the needle sized hole in them but I always seem to forget it when I'm doing it. It's been sitting in my tool box, in its new plastic wrapping for about 4 years now...

Mr.Creosote said:

Try the Mopar Performance plug wires. Part number P4876436. From the dealer they should be about $46. Cut to fit and numbered. Look cool too with a blue/purple color.

Champion plugs # RC12LYC gapped at .035".

Nothing works better...I've tried a few different combo's with the 4.0 litre and this stuff has worked the best.

Click to expand...

I agree on the plugs most of the people that try to run the newest "hot" plugs and wires end up with mis-fires and check engin lights.
Also Flush the cooling system, seems like all the newer 4.0s have a lot of casting sand lift in the water jackets this affects the cooling of the engin. You may also (if its very dirty)want to clean the throtle body and AIS motors plunger, and change the fuel filter.

Kejtar - Southern California - now there's your problem.

Perfect weather 365 days a year. No wonder your door hinges
look like new......*smirk*

In New Hampshire the combination of salt, gravel, and lots of
snow and ice do quite a job.

perfect weather 365 days a year?????? Honestly people have a WRONG idea about our weather. Granted we have way nicer weather then New Hampshire, BUT when the rain season starts (believe it... we have a rain season) there is a lot of water around here. Also those that live closer to the beach have a lot of salt damage due to the air from the ocean (I've seen it, and it looks interesting when the roof of a car is rusted over but the rest is fine).

In regards to the plugs, I run the Bosch 4+ and I'm really happy with them. They seem to burn nice and clean (looked at them not too long ago and they looked nice) and the XJ seems to have a bit more of oomph to it when it moves (but then also it was new plugs vs old plugs so that makes it hard to say...)

Kejtar

Champions, and more....

There is a big problem in the auto industry when using Bosch Platinum plugs, or other aftermarket platinums but to a lesser degree. Seems they cause misfires that on some of the later OBD II vehicles sets ck engine 'misfire' codes. If a certain plug actually causes increased misfire problems then i consider it a lesser plug. Perhaps the plug's resistance is not particularly compatible with many systems out there, but whatever the reason i do not want to use it.

As far as MSD wires, i am aware of the less resistance, but the ignition systems today are designed with stock wire resistances in mind. To mess with that parameter you might be causing problems. Is fine to experiment, but if the stock system is working perfectly, ie., no misfires, then that is as good as it gets. I know is boring to go stock, but spend the $$ elsewhere.