Jeep Creep: YJ Oil Leaks, 37-inch Tires on a JK, XJ Engine Swap and more

Nov. 19, 2014 By Jim Brightly, KF7SCT

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 Jeep questions to [email protected], Attn: Jeep Creep.

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October 2014

September 2014

August 2014

Two Jeep recalls from NHTSA this Month
14V-530: Chrysler is recalling certain model year 2011 Dodge Durango and Jeep Grand Cherokee vehicles manufactured January 5, 2010, to July 20, 2011, and equipped with either a 3.6L or 5.7L engine. In the affected vehicles, the fuel pump relay inside the Totally Integrated Power Module (TIPM-7) may fail, causing the vehicle to stall without warning. A vehicle stall increases the risk of a crash. Chrysler will notify owners, and dealers will replace the fuel pump relay with one external to the TIPM, free of charge. The recall began October 31, 2014. Owners may contact Chrysler customer service at 800-853-1403. Chrysler’s number for this recall is P54.

14V-567: Chrysler is recalling certain model year 2008 Chrysler 300 vehicles manufactured May 31, 2007, to May 12, 2008, Dodge Magnum vehicles manufactured May 23, 2007, to May 12, 2008, Dodge Charger vehicles manufactured May 24, 2007, to May 12, 2008, Jeep Commander vehicles manufactured April 3, 2007, to May 12, 2008, and Jeep Grand Cherokee vehicles manufactured March 21, 2007, to May 12, 2008. In the affected vehicles, the ignition key may not return to the “ON” position after being rotated to the “START” position, instead sticking between the two positions. Potentially, while the vehicle is being driven, the ignition may inadvertently move through the “RUN” position to the “ACCESSORY” or “OFF” ignition position, turning off the engine. If the ignition stays between “START” and “ON” positions it could cause loss of certain electrical functions. If the ignition key inadvertently moves into the “OFF” or “ACCESSORY” position, the engine will turn off, which will then depower various key safety systems including but not limited to air bags, power steering, and power braking. Loss of functionality of these systems may increase the risk of crash and/or increase the risk of injury in the event of a crash. The remedy for this recall campaign is still under development. The manufacturer has not yet provided a notification schedule. Owners may contact Chrysler customer service at 800-853-1403. Chrysler’s number for this recall is P57.

Oil Spitting YJ
I bought a ‘90 Wrangler YJ. It was in OK condition but the motor needed help. I had the engine rebuilt and it ran great, it still runs great, with the exception that recently it started spitting oil out of the oil cap at acceleration. I’m guessing compression, but I’m no mechanic. Any suggestions?
Robert Reyes
Glendora, CA

Check your PCV valve and also check the crankcase pressure. A cylinder leak-down test would be the next step.

Wonky Wobble
When my ‘93 Grand Cherokee Ltd. 5.2-litre hits a pothole or bump at highway speeds the steering wheel shakes so violently I almost lose control. A mechanic visually inspected the tie rods and ball joints and said thumbs-up. The hydraulic steering damper was replaced last year. What are your thoughts on the problem and is this vehicle safe to drive?
M Glaab
Sarnia, Canada

I’d take it to a different mechanic. Obviously, something is worn or your steering would be tight. Check every component of the front suspension and steering—not just the steering components—for wear and tightness. It is also possible that the tires are out of balance, your shocks are worn out, or the stabilizer is worn out again.

JK Toughness?
I have a ’13 Jeep Wrangler Rubicon Unlimited with an automatic transmission and 34,000 miles on it. It’s both my daily driver and my weekend warrior, where I wheel in the Four Corners area. It has a Skyjacker 4-inch long-arm lift and 35-inch Goodyear DuraTrak tires. I’m thinking of going to larger tires—maybe 37s—and I’ve been reading in the off-road magazines that I need to upgrade to Dana 60 axles front and rear if I do that. Is this true? I thought the Dana 44s on the Rubicon are the ultimate? What do you think I should do if I decide to go with the larger tires?
Jason Meek
Farmington, NM

Far be it from me, Jason, to argue with the print magazines, but I’ve seen seven years of experience with a JK Rubi Unlimited, so I take exception to that statement. I feel the OEM Dana 44 axle tubes are adequate on a two-door Rubicon for up to 35-inch tires if it’s driven like you own it (and have to repair it!). However, as I did on mine, for an Unlimited four-door JK, I’d suggest you upgrade to a Dynatrac (http://www.dynatrac.com/) ProRock 44 front axle housing with RCV lifetime axles (which is what I used) and 4.88:1 or 5.38:1 gears. I don’t think a Dana 60 housing is needed unless you’re moving up to 40-inch tires or larger (the weight alone would be determent). Other than changing out the gears in the rear OEM Dana 44 to match the front, leave it alone. The Dynatrac’s housing’s axle tubes are approximately ½-inch thicker (larger in diameter) than OEM tubes, the pumpkin tilt to accommodate the lift is built in, and the ball joints are much beefier as well. You may also want to upgrade the driveshafts if you spend a lot of time on the rocks, because the OEM rear shaft is quite prone to rock damage. This setup should easily accommodate 37-inch tires if you’re not competing in King of the Hammers (because I’m not known for a light right foot and it has worked quite well for me). PS: You’ll find articles on changing out the front differential and driveshafts in the archives here on ORC.

Four-Banging TJ
I’m working on a ‘97 Jeep CJ8 with a 4-cylinder engine. I started out thinking the fuel pump went out, but came to find out that was not it. So now I’m thinking it’s the crank sensor. It has no power to the pump, but has power to the gauge to show fuel level. And it has no spark. Would the crank sensor cause this? What are your thoughts?
Brad Bradford

First of all, Brad, Jeep quit making CJ8s (Scramblers) in 1986 (along with CJ7s). What you have—if in fact, it is a 1997—is a TJ (1997 ~ 2006). You may have lost a PCM fuse or a relay is not powering up. Check all fuses with a test light or multi-meter for continuity. If continuity in those circuits is okay, look at and/or test all the relays in the system, starting with the PCM relay.

Height-Challenged YJ
I want to install 35-inch tires on my ’90 Wrangler. What kind of lift do I need on it for tire clearance? And what gears would you recommend with the taller tires?
John Stafford
Carlsbad, NM

First thing you have to understand, John, is that you’ll have to do some body modifications unless you want to go super high—which I wouldn’t recommend. Several suspension manufacturers make 6-inch lifts for the YJ with its wider front leaf springs (wider than the previous CJ models, and front and rear springs are the same length). I suggest going with a 6-inch lift and a 1- or 2-inch body lift, plus modifying the fender openings. And don’t forget to address the bump stops so the tires don’t come up too far and start modifying your Jeep’s body all on their own. If you do a lot of rock crawling, I also suggest using springs with a military wrap and boomerang shackles, which I used on my CJ7 (it has YJ front spring hangers in order to use the wider springs). With a Dana 30 up front, I wouldn’t go deeper on the gears than 4.56:1, and I’d also suggest to replace the rear Dana 35 with a Dana 44. With 35-inch tires, the Dana 35 could give up at the worst possible time.

XJ Engine Swap
Do you have any information or advice on doing a swap for an ‘86 Jeep Cherokee that is powered...haha...by a dying 2.8L four-cylinder engine? I think I can pick up a used engine from a ‘94 Camaro pretty cheap from the junkyard out of a wrecked one.
Jonathon Jackson
Grand Junction, CO

I’m not sure if you’re talking about a V8 or V6 out of the Camaro, but I’m assuming you mean a 4.3L V6. Either way, use the engine, computer, and transmission. You’ll love it! Advance Adapters can provide you with everything you’ll need for the swap, including technical information and advice.

Tranny Trade-Out
I would like to replace the transmission in my 1991 YJ Jeep Wrangler. Would the AX 15 be best? Where can I buy one? How much do you think it would cost? Also, could I swap out to a better transmission like a NV 3500 or NV 3550? How much modification would be required? What would be the benefits?
Mike Donovan
Phoenix, AZ

Since the NV3550 (five-speed manual), manufactured by New Venture, was used in 2000 & 2001 in SE models with 4.0L I6 engines, very little modification will be needed. You can either find the parts in a junkyard or at Advance Adapters.

I have a request of all the readers out there. Send us your questions. For some reason the questions have fallen off, and I know we haven’t answered all your Jeep technical questions. There are no dumb questions; only unasked questions. Send them in and try to stump us.
—Jim Brightly

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.

Send your Jeep questions to [email protected], Attn: Jeep Creep.

Previous Jeep Creep Column
October 2014

September 2014

August 2014


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