Here Kitty, Kitty
I have an '04 Wrangler with a 4.0L. The catalytic converter went out at 50,000 miles and the factory replaced it under warranty. What could have caused the converter to go bad? Could driving the Jeep through deep water have done it? Also, they put the old O2 sensors back in the new exhaust. You said in the August '06 issue that the O2 sensor should be changed every 4th oil change. I have four of them in my exhaust! How do I know if any of them are bad or are going bad? I don't think the dealership ever diagnosed why the cat went bad. They just replaced it without telling me why. Those O2 sensors are expensive, so which one should I replace; the last one in the exhaust, the first one, or all of them?Jesse PfisterCitrus Heights, California
For starters, I never said you should change the O2 sensor at any scheduled interval. Our Associate Editor Pete Trasborg wrote that in his article "The Invisible Gremlins" in the August '06 issue of Jp. I don't agree that the O2 sensors should be replaced every "third or fourth oil change." I have no trouble leaving them in until they go bad, which is usually well in excess of 120,000 miles, if at all. Don't go swapping them. You shouldn't need to.
There can be any number of factors that could have caused your converter to go out, but if your deep water crossing preceded your cat failure then I'd say there's a good chance that's what caused it. When you are working your Jeep hard on the trail the cat can get pretty hot. Quickly dousing the outside of it with cold water will cause the steel casing to contract, but the catalyst brick inside will still be near red hot. The contracting steel could conceivably cause the catalyst material to break its bond to the converter case. Chunks of the catalyst could then break off and plug up the unit. This is the exception rather than the norm. I've dunked a few catalytic converter-equipped Jeeps through deep water with no issues. However, the scenario is still plausible.
I wouldn't worry about it and I certainly wouldn't waste a couple hundred bucks changing your O2 sensors out. Sorry I can't give you a concrete reason why your cat failed, but I hope I've set your mind at rest to some degree.Shimmy Jimmy
I have a '99 Wrangler Sahara with 33s. Please list the top two or three steering stabilizers.GCVia e-mail
They're all very similar. Unless it's worn out, there's little wrong with the factory steering stabilizer that comes on the vehicle. You really don't want a gas-pressurized stabilizer like some companies offer. The gas charge can push the steering linkage causing wander and actually increasing tire wear.
Go for a regular Rancho, Pro Comp ES3000, or other cellulose (non-charged) unit. The shock shouldn't extend by itself after you compress it. Currie Enterprises (currieenterprises.com) has a nice one, or you can go to 4 Wheel Drive Hardware (4wd.com) or Quadratec (quadratec.com) to shop several different types. Any stabilizer on those sites will be fine for your use and should all perform similarly.
Chop Swap Shop
I am a subscriber and my '88 Wrangler's frame is rusted big-time. I am looking at a '92 Wrangler 4.0L. How much can I swap between the two? Are the frames, motor mounts, and bodies all the same? What about the leaf springs? Any input will help! My '88 has only 43k miles on it. Jim ManningPeotone, Illinois
With the exception of the engine wiring harness and in-tank fuel pump on the '92 most everything should interchange. Go ahead and do your swapping. Your biggest troubles will come from getting the rusty bolts from your '88 off to do the swap.
Tranny Terrors
I would like to put an AMC 360 and TF727 combo in my '77 CJ-7 and keep the Dana 20 T-case. The CJ currently has a manual transmission and I have two full-size donor vehicles. One is a '79 with a 304, TH400, and Quadra-Trac and the other is a '83 with a 360 and TF727. I would consider using the whole drivetrain of either, except the rear output of the Quadra-Trac is offset and the front output shaft of the '83 is on the driver-side. Is this going to be relatively simple or is it easier to use a Dana 300 T-case combo?Michael BixCarinda, Iowa
Here's The Truncated Answer:
TH400: The TH400 with the Quadra-Trac uses a 10-spline output shaft that can only be coupled to the Quadra-Trac. If you want to keep your Dana 20, use Advance Adapters PN 50-1300 or PN 50-0500 to mate the Dana 20 to the TH400. They are both similar, but the PN 50-0500 is a direct copy of the factory adapter and is a little longer, so you'll have a longer rear driveshaft if you use the PN 50-1300.
TF727: If it's got a factory New Process transfer-case you can unbolt it and put either a Jeep Dana 300 or a Dodge NP208 from a '81-'86 1/2-ton pickup or Ramcharger. Either of these T-cases have the same 23-spline input shaft and 6-bolt pattern as the '83's T-case (although you should verify it's a 23-spline round pattern before buying anything). The Dodge NP208 will have a fixed rear yoke for a longer driveshaft than an '87-'93 Dodge NP241 with a slip yoke driveshaft.
As for strength, the TF727 and TH400 are nearly identical, but the TH400 has a larger pan kick-out on the passenger-side that can present driveshaft interference issues when used with a passenger-side drop front axle.
Got a tech question you're just itching to get answered? Send it on in to Jp magazine, Your Jeep, 6420 Wilshire Blvd., Los Angeles, CA 90048, or e-mail christian.hazel@jpmagazine.com.