Jeep Creep: Off-Road Tech and Maintenance

Dec. 20, 2012 By Jim Brightly
Jeep Creek December 2012

In your Jeep Creep questions, please list your first and last names, your hometown, and your state/province/country, so that we can publish that information here. If you don’t provide this information, we may not be able to publish your question and answer. Don’t forget to be as complete as possible with the description of your Jeep and its problems, too. Send your questions to, Attn: Jeep Creep.

Previous Jeep Creep Columns
November 2012

October 2012

September 2012

One Jeep recall this month.

12V-527: Chrysler is recalling certain model year 2002 and 2003 Jeep Liberty vehicles manufactured January 9, 2001, through March 28, 2003, and 2002 through 2004 Jeep Grand Cherokee vehicles manufactured February 13, 2001, through May 23, 2003. A component in the air bag control module may fail causing the front airbags, side curtain airbags, and/or seatbelt pretensioners to deploy inadvertently while the vehicle is being operated. Inadvertent deployment of the airbags may increase the risk of injury and the possibility of a vehicle crash. Chrysler will notify owners, and dealers will install a supplemental jumper harness to the airbag control module, free of charge. The recall is expected to begin during January 2013. Owners may contact Chrysler at 800-247-9753.

T-Case Fluid
A friend was helping me change all the fluids in my 1985 CJ-7 and we didn’t have enough gear oil left to completely fill the Dana 300 transfer case, so he finished filling it with some 20W50 engine oil. I didn’t think it was right but he’s much more of a mechanic than I, so I didn’t argue but now I’m worried. He said it was the same thing and I haven’t noticed any difference in how it runs, sounds, or shifts. Should I change out the mixed lubricant or not?
Nate Withers
Mesquite, NV

Well, Nate, 90 weight gear oil and 20W50 motor oil both flow at about the same rate, but they differ greatly in the additives. Without going into great detail, I will say there are additives in gear oil that assists gears and bearings in living longer but would cause problems inside an engine. Luckily for you, a Dana 300 transfer case is not a stressful place for gear lube, so I’m sure nothing has been damaged thus far. However, I strongly recommend you replace the mixed fluid with a good quality gear oil before you go four wheeling again.

Shaken Not Stirred
I have a ‘99 Wrangler Sport with a 3-inch chassis lift and 1-inch body lift (tires are 33x12.5). Lately when I’m driving on road or street between 32 to 40 mph the front end will suddenly start shaking in such a violent way I have to immediately slam on the brakes and stop. All lug nuts are tight and getting underneath and visually checking I can see nothing wrong or disconnected or loose. Two years ago I had a heavy-duty steering shock absorber and heavy tie rod installed. I tried driving with all tires at 20 psi and also with 32 psi but saw no difference. What gives?
Bob Wick
Gold Canyon, AZ

You’ll need to do several things to rid yourself of what we call the “death wobble.” Take your Jeep to a good alignment shop and have it aligned and all the tires balanced. Make sure they examine the ball joints—this is what caused the DW in my JK—and have them tighten every component, nut, and bolt in the suspension and steering systems. You could do the tightening yourself, but you still need experts to perform the alignment, balancing, and examination. Each tiny little bit of misalignment or looseness can multiply with the larger tires and lifts into a major problem. Have the shop also check the condition of the Pitman arm, steering gear box (mounting and internally), and all tie rod ends (you may have to replace all the tie rod ends). And, if you happen to visit Kingman I can recommend a visit to Precision Auto.

Kickin’ It Up!
Got an old CJ-2a Jeep and I want to replace the Chevy 2.5 four banger with a V-8. Need more power for competition.

Paulo, I envy you but you do have a lot of work ahead of you. My first conversion—in the mid-60s—involved a 1946 CJ-2a and a Chevy 265-cid small block V-8, so I have some personal experience with this project. First of all, since it sounds like you’ve already competed with your flatty, I assume you’ve already upgraded the steering, brakes and clutch to accommodate the four holer, so I need not go into those details, right? You’ll have to change motor mounts and radiator; however, if you already have a large four-core cross-flow radiator, you may only need to match the inlet and outlets to the new engine. You’ll also have to cut out all the extra metal behind the grille to move the rad forward, and you may need to do some cutting and then resealing the firewall to accommodate the V-8’s distributor. But the bellhousing adapter and clutch linkage should still work. Take plenty of pictures, Paulo, and send them in, I’d like to see them and relive old times.

Cherokee Lift
Quite some time ago I read an article on here about the BOR 6-inch leaf spring kit for XJs but I can’t find where to buy them. What do you know about them or where can I get them?
Rob Maclin
Poplar Bluff, MO

BOR—Big Off-Road—was in Colorado but has since gone out of business without leaving any contact information, Rob. However, Skyjacker makes a 6-inch lift kit for the Cherokee XJ—see my article on it in the archives—as do several other off-road suspension manufacturers.

No Four
I have a 1990 XJ with an auto transmission. The other day I went off road at a local beach and got stuck in the sand. I noticed that it wasn’t engaging in 4-wheel-drive; the back tires kept spinning and digging deeper. The indicator lights weren’t going on either (4L, 4H). Someone pulled me out and when I got home I checked under the vehicle and noticed that a line was disconnected on the front axle. Would this be the vacuum line that engages the Jeep into 4-wheel-drive? It is on the passenger side of the axle near the tire. I haven’t reconnected anything yet. I wanted to make sure what I was playing with first. How do you check if it’s the solenoid? Do you tap it like a stuck starter? I checked out the lines at lunch today and found two wires going into a plastic piece. But where it connects to the axle there is only one connecting point. I tried the one sticking out further and nothing happened. I then switched it to the shorter side and it engaged, but the only indicator light that came on was the “Part Time” light, nothing came on in 4L. Any input on where the longer side connection goes? As you can tell, I’m a newbie, but you explain well.
Aloha – Eric Nakaguma
Honolulu, Hawaii

Make sure you clean out all of the sand first so nothing gets gummed up. If everything doesn’t begin working again when you reconnect the hose, check the solenoid. It may be stuck. That happened on a Suburban I once owned while I was “deep” in a Baja California dry sandy riverbed for the Baja 1000. I’d suggest you buy a new solenoid and install it, even if your 4WD begins working again, and keep the old one as a spare. You need to “exercise” the 4WD around once a month to keep it operating, and by exercise, I mean you have to activate 4WD just to make sure everything’s moving okay. After you reconnect the hose, put it in 4WD low range on a soft surface and watch the front tires. If they have power, it’s okay. If they don’t, pull out the solenoid and watch it while activating the controls. If it doesn’t move, it needs to be replaced. Eric, it is vacuum-operated by a switch. The pod on the axle has two or three lines on it; one to pull it to disengage, the other to engage. I think it’s time for you to take it to a Jeep dealership to make sure everything is connected correctly.

Eco Filter
When I was having my Jeep serviced at Oil Can Henry’s recently, they replaced the air filter. It had only been in for about 6,000 miles—I have my Jeep serviced every 3,000 miles—but I do live in the desert and do a lot of dusty trails. When I asked them why they changed it, they told me the new filter would improve my gas mileage. I did some Internet searches and a few sites said that it would improve mpg and others said it made no difference. Do you have any idea which is which?
Dennis Wolf
Tucson, AZ

Hey, Dennis, many recent tests pretty much mirror what you found in your ‘Net searches. Fuel economy is not affected at all by a slightly restricted filter and a small amount when the filter is pretty well plugged to the point where a performance degradation is noticeable. Some tests do indicate that carbureted engines are more affected than electronic fuel injected engines, and the larger the engine (more air flow) the more it is affected. That being said—and me being old-school—I prefer a clean air filter to a dirty one.

I’ve got a V6 ‘89 Jeep Cherokee Laredo with an automatic and 266,000 miles on her. I want to service the tranny (fluid, filter and gasket only). What is the correct fluid to use? The fluid is not burnt now and I have no shifting problems other than it occasionally slips out of overdrive at low speeds. Also would an additive such as Lucas be beneficial? I checked the dipstick and the fluid type is not printed on it.
Robert Torres
Mobile, AL

First of all, Robert, it’s an inline 4.0L six, not a V6, and congrats on getting that many miles on the clock. The correct type of fluid is Dextron 2 or 3 for the 1989 Jeep automatic transmission. I also strongly suggest that you order the appropriate shop manual for your Jeep from 4-Wheel Parts; it’ll answer all your questions. With that many miles on it, I’m sure your Cherokee would benefit from any extended mileage ATF and/or additive.

YJ V8?
I have a ‘92 Jeep YJ with its stock four cylinder engine. And I have a ‘97 Suburban with a 5.7L V-8. I would like to swap the engine and as much of the Suburban’s drivetrain as possible. Can I do this and still be smog and street legal, are there any good shops in SoCal to contact?
Ken Nolan
Anaheim, CA

I once did the same type of conversion in Colorado where I didn’t have the California smog cops looking over my shoulder. I pulled a ’76 Suburban’s 400-cid engine and TH350 tranny out and placed them in my ’82 CJ7 (see photo). I can’t ever sell it in California but I’m sure enjoying it in Arizona! I think you should do the same thing with your pair of vehicles, Ken. Pull the engine, transmission, and wiring harness, then you can sell the Sub to a junkyard. And you’re in luck, there are 4-Wheel Parts shops all over SoCal—their headquarters is in Compton—including one in Santa Ana. If they can’t do the conversion for you, they can point you in the right direction. Tip: while consulting Advance Adapters for the transmission/transfer case adapter, you might also consider replacing your OEM T-case with an Atlas two- or three-speed transfer case.

As usual, each month, I’m shouting out a huge THANK YOU to Paul Schupp at Rock Lizard 4x4 in Kingman, Arizona, for his invaluable assistance in answering many of the Jeep Creep questions.

Previous Jeep Creep Columns
November 2012

October 2012

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