RedToad

Recently got a 2005 GC, specifically to tow behind a motorhome. As luck would have it, it needed a new rear end -- $2,200 -- for one from a junk yard. (I'm told the electronic limited slip feature is what made it pricey.)

Got it all dressed up for towing -- towbar connection points in place of stock tow hooks, slaved the lights to the motorhome, added a 'surge brake' system that pumps the GC's brakes if the motorhome is slowing down in front of the Jeep. All very successful.

Pulled the rig from Seattle area to Lincoln, Nebraska. Now, each morning, upon startup, the first 200 yards sounds like something is grinding -- slightly subdued, not sharp metalic -- in the front end. (But not all listeners point to the same part of the car's floor.) It is a deep kind of grown, with an accompanying 'feel' through the steering wheel. This is not just initially after shifting 4WD system out of Neutral -- as required for flat towing. This is, I drove the Jeep 150 miles around Lincoln yesterday, parked next to the motorhome about 9:00pm, and when I pulled away this morning -- never going 4WD Neutral -- there was the noise.

Over the years, I have had a number of CV joints go bad in other cars. This doesn't sound like that, -- for a given speed, what might make four or five 'click-click' sounds from a failing CVJ, I get probably 15 to 20 quieter pulses, almost a buzz, -- but it does become more intense as I turn the front wheels. While the noise goes away after a couple hundred yards, it doesn't seem it could be 'cold' lubricant. Overnight low temp was 78 degrees, daily highs 98 degrees.

It gradually subsides within less than 1/4 mile. But it scares me. This is a long way from my garage!

Can I expect it to die while going 60 mph behind the motorhome on the way back to Seattle?

Any thoughts will be appreciated

dave1123

Sounds like you've got the Quadratrac II system and that CAN NOT be flat towed without destroying the system, even with the t/case in neutral. Those special electronic differentials are still spinning and wearing out the clutches.

RedToad

Thanks for the response, Dave. Jeep really did a number on us with the tranny and transfer case and differential mixes they allowed! I do have the Quadra Drive II, both per the emblems on the console, and the build sheet from Jeep, which does specify electronic limited slip diffs, fore and aft. And when it came to replacing the rear end with a piece of experienced hardware, it proved an uncommon feature to have the electronic limited slip. Ratcheted the cost of a used axle to right on 2 grand.

But the User Manual that came with my rig does offer an option for "Recreational Towing" specifying the Quadra Drive II. The Quadra Trac I, single speed (full time?) 4WD is clearly excluded from this, with a statement that this model has no Neutral option for the transfer case. And my car does have both Hi and Lo ranges, selectable via the lever next to the main shifter. But the discussion of Quadra Drive II calls for Transfer Case to be in Neutral, and the Automatic Transmission in Park. Which is the way we have been rolling, using a ball pen to trigger the TC setup for Neutral, and getting a confirmatory note on the dash display..

I took the rig to a Jeep dealer in Scotts Bluff, Nebraska today. They couldn't get it into their shop for at least two days, so I contented myself with talking to a tech who was on lunch break, and a service writer. I described to them the shuddering sensation, and the fact that it cannot be repeated after a few minutes of driving. And I offered the new data, that this morning, that "few minutes" was considerably longer than in the recent past. But, I had stayed at Chimney Rock last night, and the overnight temp was 41 degrees, compared to a low at Lincoln the last several nights before of 78 degrees.

While they stated plainly they were not guaranteeing anything, they said it could be a lack of "friction modifier" in the diff lubricant. And they sold me a 4 ounce bottle to pour into the diff, saying adding more cannot do additional harm... We'll see how it goes. Next stop Jackson Hole, where the overnight low is predicted to be around 25.