NCDON

This has happened to me twice in the last year both times in heavy rain when there are puddles in the street. Belt is tight, less then 6 months old.

Setting on the side of the road now hoping I did not overheat the head.


Ideas?

extrashaky

Did you use a belt tension gauge to make sure?

NCDON

In all honesty I did not use a tension gage, tightened the belt until no slippage or squeaking and then drove jeep for over 100 miles and retightened. From reading posts it seem many are successful tightening the 4.0 belt using this method.


Now that I have had the belt come off I am ordering a tension gage.

jordan96xj

Because it is so unusual that a belt would jump (if it was even close to the right tension), I'm actually wondering if you haven't been putting WAY too much tension on them. Such that they want to get off the belt path, especially under the added pressure of acceleration (did it happen when accelerating?) and as soon as the water lubricates any of the non-ridged pulleys, it is getting an opportunity to relieve the pressure by popping off.

My only other guess would be the possibility that you have some pulley in the belt path that is either damaged or a wrong part for the vehicle (rare, but I'm just speculating).

winginit

My guess would be alignment of the pulleys, or broken strands in the belt that makes it not want to track straight .

CR-Snow

Yeah I'd check everything on that belt path. When I first got my jeep the belt was way too loose, but it never jumped off. At least grab all the pulleys and give em a shake. Try to rule some things out

I would seriously doubt the belt is over tightened.

NCDON

I ordered a Gates 91132 Belt Tension Tester from amazon and found the belt to be tensioned to about 140 ft. lb. this reading is the belt tension after I pit it on in the rain on the side of the road, no idea what it was before it fell off.

The gage is fairly repeatable and I now have the belt tensioned to just over 180 ft. lb. (Spec is 180-200 ft. lb.) I did notice that my adjustment pulley now has only about 5 threads of adjustment left before the bully mount reaches the end of the threads.

I have been keeping an eye looking in my oil fill and cap for signs of coolant but so far no issues, I hope I will not have a cracked head.

Checking all pulleys I found they spin freely and do not have any sideways play so I am hoping all will be of and no more bely coming off during driving on flooded streets.

CR-Snow

Nice. Way to be thorough. Thanks for posting results.

DFlintstone

With the belt off feel everything for tight/wobbling. In alotta years with three jeeps, it's the idler bearing that goes first. Mine are different than yours, but I suspect one of the pulleys is not feeding the belt straight to the next pulley. Wet/dry, tight/ lose it shouldn't want/be tryen to get off.

Look real close with good light while it's running. Everything flat and square?

GronHog

Make sure to look closely at the A/C bracket pulley, if the belt is slightly out of the existing wear on the pulley, the pulley probably needs replacement. I had the same problem with my 99 also when the belt got wet.

Click-Click-Pull

I've only seen that once and it was a bad water pump. It would run fine for a couple days then kick the belt off. I put it back on and it ran fine for 10 min then kicked it off again. I re-checked the pulleys and everything looked and felt fine. then thought to check the water pump closer and it was seizing up, no noise no drips just bad. Not sure why water would change anything except being really bad timing for a break down... Good Luck