• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Got $$ to spend, help me!!!

LYKOS

NAXJA Forum User
Location
Bent Mountain Va
Ok, I finally sold my Harley and have some $$ to spend to get the XJ back to spec.

I imagine I will also, after posting this, become a red letter member. Been lurking long enough.

So anyway back to topic.

2001 XJ
141,000 miles, daily driver, only vehicle, on 31's, probably won't get any bigger any time soon, stock gearing, mall crawler, kayak carrier, love snow etc, not a rock crawler.

Recent replaced parts are an OE style radiator, water pump, tstat, and fan clutch and coolant temp sensor.


Current issues:

Trans is PUKING fluid from a vent or a seal when the engine gets above 215*.
Gauge goes from 220* to 250* about the same time. Drops back to normal very quickly and this only happens when on and off the gas or at the top of a long grade. Normal driving = no problems.

See why I've replaced all those cooling system parts?

Typical 01' heat soak issues.

Loss of power

NO oil in coolant nor coolant in oil, no fluctuations in oil pressure, other than the heat issue there is NO indication of the notorious cracked 0331 head. I know people love to preach about cracked 0331 heads. Here is my philosophy on it. Everything in my XJ is old. If anything CAUSED the head to crack it will CAUSE the new head to crack. So I need to exhaust all other problems and then replace the head and hopefully fix the problem before I get to that point.

Death wobble: I'm going to go ahead and rebuild the front end. Track bar (Probably the IRO) ZJ upgrade with new TREs. Ball joints, wheel hubs, U joints, shocks and UCA bushings) I'm debating on going ahead and getting a set of adjustable LCAs. (thoughts?)


So, after searching and searching and reading and reading this is what I've come up with and I'd like some opinions from those of you who have first hand experience. No offense, but I'd rather not read you repeating what you've read about. I can do that myself. Not being an a-hole, just saying...


The heat soak is a problem in higher mileage 01's because of the CA emissions precats. Since heat soak was not an issue in lower mileage it stands to reason that the precats are aging and need replaced. The rest of my exhaust is leaky and needs replaced anyway. So a new precat manifold, high flow cat and Magnaflo will be bought and installed. Basically replacing everything from the header back. With all CATALYTIC converters being replaced. (besides being a Jeeper I'm a tree hugger and do not advocate the removal of emissions equipment on modern vehicles.)
I'm hoping the exhaust will alleviate some of the power loss as well. If not, it needs replaced anyway.


I ordered a new Mopar temp sensor just to make sure my gauge is getting the right signal.

Speaking of sensors...

While the exhaust is out I want to go ahead and replace the O2 sensors. I know I have one bad upstream and one bad downstream.

Mopar is expensive and since NTK makes the part I will use their brand of replacement. What I cannot find are good NTK replacement part numbers. Any help?

transmission...

Ok, this is money I don't want to spend. My Harley wasn't worth THAT much,,,

I'm going to go ahead and instal a Hayden trans cooler and B and M trans temp gauge. It's just a good idea...

I'm transmission dumb and may take it to a shop to have it checked out. Right now, I live at the top of a mountain, when I get halfway up I look like the Batmobile with a smoke screen. It's annoying. The fluid looks good and it shifts well. I'm not getting rid of this Jeep so if a new tranny is needed I'll get one. But if any of you have had this problem and can help I'd love to hear it. or if you have good advice on finding a rebuilt transmission.


Future mods:

SYE
Front DS form a XJ to rear of mine.

I'm debating on selectable lockers or LSD's. I know selectables are the way to go but do I NEED them for trail riding, mud holes and snow?

4.10 gears

Winch: I'm the nitwit riding around in the snow and pulling people out. Ok, sometimes I need pulled out. I just like vehicles that don't get hopelessly stuck a lot.


Other than a bunch of nickle and dime stuff that's about it.

Ideas and advice on what I have planned?

How about something I've forgotten?

Basically this needs to stay streetable and as reliable as possible.


Thanks
 
Suggestions on where to buy the precats would be nice. Advance has Walker for about $230. I've heard Catco is good as well.
 
Yer lookin' for advice, more than anything else. That's why I moved the thread.

I don't know if they do pre-cats, but I've been using PFP cats for years with excellent results (and the price is right, I've usually gotten main cats from them for <$100. Again, don't know about precats tho - I usually work on older vehicles.) Figure PFP is worth checking, tho.

Your 2001 will likely have the AW4 four-speed auto - if you do, the 3.55 gearing complements it well (I wouldn't go past 3.73 or 4.10, unless you're wanting to go crawling. 3.55 is well-matched to the AW4 with up to 31" tyres in m experience, and 3.73 still should fit within the torque curve rather well.) If you've got the five-speed, stop using fifth until you can regear to 4.10:1 or so - the factory usually gave the 6-242 & five-speed manual 3.07:1 gearing, which is a horrible mismatch (with 31's, I picked up 3mpg when I stopped using fifth gear until I got up around 80-85mph!(

Where, generally, is the transmission leak? Possible sources:
- Vent tube atop case, just behind the bellhousing (external to it, so you can check it.) The rubber line may want replacing and it probably wouldn't hurt to pop the Nylon fitting loose (carefully!) and blow it out with some carburettor cleaner.)
- Big o-ring around front pump housing - you can't visually inspect it without dropping the transmission, tho.
- Input shaft seal (actually seals against torque converter snout.) Same problem.
- Output shaft seal (actually seals against tcase input shaft, but it's separate from the tcase input shaft seal.)

However, since both the AW4 automatic and the NP231 & NP242 transfer cases both use the same fluid (same spec - it's not a common fluid reservoir, you still have to drain & fill each separately,) know that if you're getting fluid at the tailend of the transmission it could be from the trans or transfer case. Both of those seals are relatively easy to replace. I'd probably flush the transmission as well - dump in a can of Berryman's B-12 Chemtool and run it for about three days' normal driving. Drain & drop the sump. Clean the sump, the magnet in the sump, and clean or replace the filter (it's usually a metal screen, cleaning is enough. The magnet will be "furry" if it hasn't been cleaned before, this is normal. It shouldn't get "furry" again unless something goes wrong, since everything is worn in.) Reinstall filter, reinstall sump (with gasket, I typically use cork and use it dry,) torque screws to spec (I believe it's 6-8 pound-feet or 72-96 pound-inches, but you can verify that in the tech section of my site. USE A TORQUE WRENCH and DO NOT OVERTORQUE - or you'll crush the gasket, and you'll have to replace it again!

(If you lose any sump screws, they're M6-1.0x15m/m or M6-1.0x20m/m, I'm not sure of the length. I tend to replace them with socket heads, they're easier to guide and work with under there. The size of the screws is probably also on my site.)

250* in the coolant is very technically overheating, and you may have wrecked your thermostat. Suggest you flush the system (it may be due, and can blow crud loose) then replace the thermostat and hoses AFTER you've done the flush and rinsed it all out! (Crud gets blown loose, and can remain in the hoses. Better to not put the new ones in until you've done the flush, I've found.) NB: Dumping in a bottle of Water Wetter (RedLine cooling additive) won't go at all amiss when you refresh your coolant, and it's often good for a 10-15* drop from elevated operating temperatures - JUST ONE BOTTLE. No, don't use more, OBD will notice and pitch a fit.

DW - Do you know how to check front end parts? I've detailed it here before, but it's been a couple of whiles. Let me know if you can't find it, but it can save you money on the "Shotgun" approach to fixing the problem (your rig is only 11 years old. Unless you've been flogging it hard, you shouldn't have worn out front end parts yet.)

Cracked #0331 heads? If the head has the TUPY foundry mark on it (probably be under the valve cover,) you're fine - you've got the revised head. If you have to replace the head, get a TUPY head (2002-up TJ and WJ w/6-242 will have it.) It's a direct drop-on, and it's been revised to address cracking. I have yet to get my grubby paws on any cracked 0331 heads, so I haven't sectioned the castings to see what's going on in there...

I've had good luck with Bosch HEGO sensors, as well as AC Delco (which are, I believe, reboxed Bosch anyhow.) TIP: Remove the HEGO sensor with the manifold warm-to-hot, it will be easier! Your new sensor should have never-seez (copper-based, usually) either in the box or on the threads already, USE IT. If you have to apply it, be careful to not get any on the sensor tip. Torque to 19 pound-feet on install, with never-seez (a regular 7/8" HEGO socket - extra-deep with a groove milled down one side to pass the wiring) should work, as should a 7/8" crowfoot wrench or open-end wrench (NB: Use a flare nut wrench for this, you'll want the extra grip.) Spec Life for an OBD-II HEGO runs 60-80Kmiles. I know you really don't want to hear this - but if you have to replace one, you may as well replace them all. The ones closer to the engine are more important, since they provide the feedback loop for fuel trim (the ones after the cats are just there to monitor catalyst efficiency, and don't have anything to do with fuel economy or efficiency.)

It's getting late and I'm finally just about off to bed. Did I miss anything?

Installing an external transmission cooler is a good idea. Look for a kit with a "thermostatic bypass valve," and eliminate the OEM cooler circuit entirely. Your transmission will get up to operating temperature more quickly (hydraulic fluid likes SOME elevated temperature to function properly - 180-220*F is usually about right, with a preference for 190-195*F...) and it will cool more efficiently (since it's ejecting heat into ambient air instead of hot water - which is averaging about the same temperature as the oil you're trying to cool.)

Reports from the field on overhauled AW4s vary - I've heard lots of cases where they didn't work right afterwards. Me? I've overhauled three with good results - but they're far from the first slushboxen I've worked on. I don't recommend the AW4 for a "first slushbox overhaul," but it's simpler than many I've worked on.

Winch: If you can, go weigh your rig in "field trim" with full fluids. Double that. That's your minimum winch rating. A GOOD set of tow chains is also useful (look for a dedicated chain/wire rope house, you'll get better chains there even if you have to spend a bit more to do it. I figure the good hardened/toughened "Forged in the US" chains I got only cost me about 25-30% more than the Chinese crap at the hardware store, and I got a test card with the lengths of chain I bought! Used them several times for both pulling people out and for tying down heavy equipment - no trouble, no failure, no defect, no worries. I've only replaced the grab hooks once in the last fifteen years because dye-check was showing stress cracks.)

LSD: You've said snow, but I don't know the other conditions of how you drive. Know that if you use a clutch-based LSD, you're going to have to make sure you have friction modifier for the clutches mixed in with your gear oil - you'll probably have to buy it separately (Once upon a time, I had five rigs. Two of them had LSDs. I just mixed FM with all my gear oil - if I needed it, it was there. If I didn't need it, it didn't hurt anything. Yep - used it in the two manual transmissions I had as well.) Selectable lockers will involve drilling at least one port into the axle housing (either wiring or an air line or a mechanical cable,) something like a Lock-Rite or other lunchbox locker (essentially a mechanical clutch) has been known to chatter going around corners (perfectly normal, but can be irritating,) and a clutch-based locker requires FM. However, a clutch-based locker is also silent - but it's not a 100% locking coupling, either (the clutches can still slip, and do to some small extent. Thus, the friction modifier.)
 
LYCOS, what rear axle? I had a Truetrack gear driven limited slip in a D35.
It required no oil modifier and held up pretty well. I eventually broke an axle though
and upgraded to a D44.
 
5-90 THANKS!!!!

That's more than I had expected and I appreciate the effort!!

I had planned on the shotgun approach to the front end. I figured at 141,000 it would need a lot of parts. I've been hearing some clunking when I sit still and turn the steering wheel. Also there's been a lot of u-joint noise recently. For general purposes, and since I hate the idea of breaking down later, I was going to do hubs, u-joints and ball joints all at the same time. I'll look up your thread on checking front ends and go from there.
I don't offroad much, when I do I'm pretty tame. But I do drive it like a racecar on pavement.

I'm geared at 3.55 at the moment. I've noticed on the interstate that I have to be doing a fair speed to get the TC to lock up. More so than before the change to 31's.

I'm really looking at Detroit Trutracs. Gear driven, good reviews and 95% of my driving is on road, 3% playing in the snow and 2% other. It's hard for me to get past cost and complexity on the selectables and I don't want the bad manners of lunchbox lockers.


I'll check out the seals I can see that you mentioned on my AW4. If they look good I'm going to take it to a shop and let them drop the tranny and see what's up. All the leakage is on the front of the tranny, from up somewhere I can see. I can tell you it gets on the drivers coil spring but not the passenger. Never heard of that vsalve you mentioned on the tranny cooler. Is that like a thermostat?

I did flush the cooling system when I changed everything out. But I pulled the rad cap the other day and it was gunked up. I have a hard time with coolant disposal so this next flush will be at a shop too.

I've been data mining the net about o2 sensors on the Jeep and decided to buy NTK/NGK replacements. No, they are not cheap but yes, I did order all four. What idiot at Jeep thought four o2 sensors was a good idea anyway?


There's an exhaust vendor on another XJ site who is local so I'm going to call him up and see what he can do for me. Support an XJ site AND a local business. :) Double win.

Again, thanks for the help!!!
 
LYCOS, what rear axle? I had a Truetrack gear driven limited slip in a D35.
It required no oil modifier and held up pretty well. I eventually broke an axle though
and upgraded to a D44.

I have a 8.25 Corp. Detroit offers the Trutrac for my rear end. What sort of driving did you do with the Trutrac and how did it act? Any problems? If your axle broke before the carrier it's obviously strong, yes?
 
You might consider swapping in a ford 8.8, they can be had with 4.10 gears , limited slip, and disc brakes for 200 or so, less than the cost of a new gearset for the rear
 
5-90 THANKS!!!!

That's more than I had expected and I appreciate the effort!!

I had planned on the shotgun approach to the front end. I figured at 141,000 it would need a lot of parts. I've been hearing some clunking when I sit still and turn the steering wheel. Also there's been a lot of u-joint noise recently. For general purposes, and since I hate the idea of breaking down later, I was going to do hubs, u-joints and ball joints all at the same time. I'll look up your thread on checking front ends and go from there.
I don't offroad much, when I do I'm pretty tame. But I do drive it like a racecar on pavement.

I know what you mean about pushing it - I blew through four transmissions in my 88 (Peugeot BA-10/5) before I scored an AX-15. And I was specifically trying to not push it too hard...

Consistent failures - stripped first and second gears on the countershaft. Got to do a more comprehensive FA on the third one I blew up, and found out much of what the problem is with the wretched things.

I'm geared at 3.55 at the moment. I've noticed on the interstate that I have to be doing a fair speed to get the TC to lock up. More so than before the change to 31's.

The AW4 is electronically shifted. This means you can make a full manual control setup, a "manumatic" setup (shift it manually or let the TCU do it,) or just put in an override switch for TCC lockup. All of the information you need is here on the board, check it out.

I'm really looking at Detroit Trutracs. Gear driven, good reviews and 95% of my driving is on road, 3% playing in the snow and 2% other. It's hard for me to get past cost and complexity on the selectables and I don't want the bad manners of lunchbox lockers.

Had a Lock-Rite, put it in my wife's rig. Her only complaint was the noise - as I said, it can chatter a bit on turns. Not noticeable in the straight, but she loved it when the Wx turned foul (I put it in hers because I wanted her to have every advantage. Had to teach her how to drive with an LSD, but she picked it up very quickly, and the brief learnin' saved her more than a few roads incidents afterward.)

I'll check out the seals I can see that you mentioned on my AW4. If they look good I'm going to take it to a shop and let them drop the tranny and see what's up. All the leakage is on the front of the tranny, from up somewhere I can see. I can tell you it gets on the drivers coil spring but not the passenger. Never heard of that vsalve you mentioned on the tranny cooler. Is that like a thermostat?

It is exactly a thermostat. Below specified temperature, the fluid bypasses the cooler and get routed back into the transmission directly. When the fluid gets hot enough, it opens up and routes fluid to the cooler. It shifts flow back and forth whenever it needs to. I think B&M came up with the idea for the thing, shortly before they sold out (I used to deal with B&M quite a bit - but that was a good 20 years ago.)

I did flush the cooling system when I changed everything out. But I pulled the rad cap the other day and it was gunked up. I have a hard time with coolant disposal so this next flush will be at a shop too.

Most shops that do radiator work (around here, anyhow) will accept used coolant. The shop I take it to actually has a truck come around and recycle it for them on-site - filter it, crack out the old additives & contaminants, refresh the additives, and they've got bulk storage for the new stuff. Easier for them to restock, easier for the truck because it doesn't have to really haul around anything in bulk. Check shops in your area as well.

I've been data mining the net about o2 sensors on the Jeep and decided to buy NTK/NGK replacements. No, they are not cheap but yes, I did order all four. What idiot at Jeep thought four o2 sensors was a good idea anyway?

Not Jeep - SAE. It's part of the OBD-II spec, if you have more than, I believe, five cylinders, they get split into banks and monitored before/after the cat (the "five cylinder' thing is largely due to Audi using inline five-cylinder engines.)

There's an exhaust vendor on another XJ site who is local so I'm going to call him up and see what he can do for me. Support an XJ site AND a local business. :) Double win.

Again, thanks for the help!!!

Better all around - I prefer supporting local businesses, and my favourite counterman has been working at a "mom-and-pop" as long as I've known him (I've worked the "big corporate" parts houses, I admit, but I needed the job more than I needed to be picky about it. Small businesses are almost invariably better to deal with.)
 
Back
Top