Tensioner pulley problem

AndrewCRD · **Joined:** Mon Dec 22, 2014 12:45 pm **Posts:** 50

So ive been hearing this squeaking sound from the front of the car. I know its not the alternator, i also changed one of the static pulleys. However i am faced with a weird issue now. The tensioner pulley seems to cause the belt to slip off. The belt doesnt stay on the middle of the pulley but slips forward about 3/4's of the way off ... almost falling off. When this happens, whatever pump is on the bottom left(facing the engine) the belt comes out of the grooves and sits with 1 groove off the pulley. Right now i am in a sort of a research mode, the car starts and runs but i try not to have it run as im affraid it will completely fall off and break something worse. I have verified that the belt is on properly on all the gears, i pull the tensioner forward and set the belt properly ... inspect it etc. As soon as i start the engine it slips off as described.

I am going to wait for monday and see if i can get a replacement tensioner arm + pulley ... i dont have any other ideas.

Any ideas what could cause the belt to slip off ? Alternator has been changed recently thats all.

Andrei

PS. Also one of the pumps ... top left pulley has a play in it and some squeak. Anyone know what that pump is ?

flash7210 · **Posted:** Sun Nov 27, 2016 4:24 pm

Yes. You need a new tensioner.
Once you get the tensioner replaced you can diagnose other belt/pulley probleme.

Bottom left (passenger side) pulley is the power steering pump. The pulley will have to be removed to get to the tensioner.
Top left is the viscous heater.

WWDiesel · **Posted:** Sun Nov 27, 2016 4:47 pm

If tensioner pulley is worn out, it is highly probable that the alternator overrun pulley is bad also and needs replacing as well. A bad alternator overrun pulley will cause the tensioner pulley to bounce excessively thus wearing it out! :roll:

papaindigo · **Posted:** Sun Nov 27, 2016 5:15 pm

He said alternator had been done recently so the pulley should be ok assuming of course that the alternator has the correct decoupler pulley. I suspect the original alternator decoupler pulley went bad which likely caused the tensioner to go bad and lean which is why belt tries to come off.

FYI the viscous heater bearing can be replaced but I'd wait on that and see what happens with new tensioner. FYI if tension and pulleys are ok the tensioner should barely twitch at idle.

PS is serp belt new or relatively new? If not replace.

AndrewCRD · **Joined:** Mon Dec 22, 2014 12:45 pm **Posts:** 50

ill clarify ... i changed the alternator without diagnosing the voltage

luckily it wasnt extremely costly but still unnecessary. I figured the squeaking was the alternator and overcomfidently changed it.
When i asked at the dealer for a new tensioner and pulley they just gave me a pulley so in realizing they gave me the wrong thing i also changed the pulley under the alternator not the one in front of the alternator.

I can get another pulley to change the one in front of the alternator as well.

What i have done after realizng the alternator was NOT the problem is removed the seprpentine belt and spun the various pulleys to see which sound bad. The viscous heater one has a sound in it also it seems to have some play. But until i posted this i didnt know what that was.

When i bought the pulley from the dealership i also ordered a belt, i did NOT install the belt because i just didnt want it worn in case the pulley didnt do the job. At this point im thinking of using the old belt until i can get it running ok and then ill throw in the new one.

GordnadoCRD · **Posted:** Mon Nov 28, 2016 9:14 am

Should you need to replace the viscous heater bearing, here is the bearing information.

Koyo DAC355222RR9D is the original bearing
VXB 35BD5222 is sold by Amazon for about 25 bucks, and specs say it has double row round ball rollers, same as original
Santech MT2149 is sold by AutoZone for about half that, and is identical size. Santech product info says they use single row tapered rollers though. I decided to try it anyway. I ordered on ebay from this guy - http://www.ebay.com/itm/400863173220?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT Incredibly nice guy, I accidentally gave the wrong shipping address, and when it was returned, he contacted me for the right address and shipped it again without charging double postage. (no local autozone)

This bearing is unique to this clutch, and is not the same as the AC clutch bearing. Parts houses swear it won't fit this vehicle though because they look it up under AC pulley clutch bearing which is MT2024.

Edit: I could not find a part listing for this bearing alone, from Mopar. Both Mopar and VMMotori offered only the complete unit, at much higher cost. Koyo is a bearing brand I'm familiar with and have great respect for, but I could not find a source. VXB, Santech, Air Global, etc are brands I have no history with, so I have no idea about their durability. The Santech bearing I installed fits properly and operates smoothly with no problems, but is still new.

Word of caution: Be very careful that you DO NOT LOSE the large "Jesus Clip" internal snap ring. We had one heck of a time finding a proper replacement after mine flew away.

AndrewCRD · **Joined:** Mon Dec 22, 2014 12:45 pm **Posts:** 50

So i just got off the phone with a few parts places and the dealer is willing to sell me a belt tensioner for 400 beaver pelts( or canadian dollars)... WOW

By the way, thank you very much about the info on the viscous part, i tried to find replacements for it and it is even more elusive than other parts. On the other side it sounds like good news since i might be able to just replace the bearing in the thing as opposed to the whole thing.

Andrei

flash7210 · **Posted:** Mon Nov 28, 2016 10:21 am

Have you tried IDparts.com ?
http://www.idparts.com/liberty-crd-serpentine-belt-tensioner-oem-5072440aab-p-2826.html

GordnadoCRD · **Posted:** Mon Nov 28, 2016 10:54 am

Regarding the Viscous Heater, I believe Mopar refers to it as a Supplemental Coolant Heater. As long as the bearing has not completely self-destructed taking the magnet and clutch with it, a simple bearing replacement works fine.

If you are interested in why it's there, this link may help explain, under section Denso Heats Up Diesels
https://www.sae.org/automag/techbriefs/07-2001/techb3.htm

If you live in an area with nighttime temperatures below 50F for most of the year, it may help with defrosting when you leave for work in the morning.
If this is not an issue and you wish to increase mileage, it can be unplugged when not needed, or, removed entirely if never needed, as Flash and Mountainman (and probably others) have done in other threads.

AndrewCRD · **Joined:** Mon Dec 22, 2014 12:45 pm **Posts:** 50

The main issue i have is that i am not sure what is messing up my serpentine belt. Since the viscous heater pulley is what im feeling is the problem ... i wiggled it and it has a bit of play ... i dont want to buy the belt tensioner and have it be messed up again by something else.

I guess it could also be the AC compressor (which i saw for 800$ :O ), i tried to move that wheel when the belt was off and see if its got any play and while its hard to properly grip it it didnt feel like it. I can only assume its the viscous heater that is messing up the belt.

GordnadoCRD · **Posted:** Mon Nov 28, 2016 4:41 pm

That may be possible, but there is no way to reliably check if other pulleys are causing failure, until you replace the belt tensioner that you already know to be bad.

While any of these other pulleys needing replacement won't immediately cause a new tensioner to fail, having the new tensioner on will allow you to see if any are bad enough to cause improper tracking.

Generally if they do not make noise, or have any axial play when you try to rock them by hand while the belt is off, they probably don't need replacement at this time. I replaced that bearing on mine because it made a dry sounding hissing when I spun the pulley and had about .050" movement when I applied rocking force at the edge of the pulley.

Also, the AC clutch pulley bearing, while being a different size, is separately replaceable from the whole pulley. That one can be looked up by application at any parts house.

Tensioner pulley problem

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