JK 2.8L Diesel Serpentine Belt Alignment

[MidnightMods]

Crowns are known to fail almost right away for the serpentine tensioner. I trailed 4 of them and all three failed with in 10,000. One failed in under 1500km...
If you have a crown in it now, then I have $50 bucks in my hand which I will give you if its not that. That is how conferdent I know its the tensioner, I have seen so many of them fail first hand and on every other engine I have seen them on.Not even ONE of them have I seen problem free last between services.. I have a new crown one here in a box you can have for $50. Its as useful as a door stop to me


On other notes tho. There was cheap belts from the uk floating around on ebay for a while which they sold a heap (have a few guys on the crd facebook page) buy them and every one of them failed. I was trying one out and it snapped around 20,000km.

going by those pictures, it looks like one of the pulleys round out. meaning its not a flat surface so it pushes the belt to one side. causing the wear of the end of the belt to rub on one of the walled pulleys(walled like the alternater is so the belt can't slide off) adding pressure to this wall will destroy the belt.

Check the pulleys for bearing damage and check the fan pulley

Take note just like your picture shows, which is hard to say with a bad picture, but look for uneven wear or uneven polished wear on the surfaces of the pulleys.

[DarrenR]

Originally Posted by samft

this just makes me happy to know the VM 2.8 will get to 300,000!
where in Aus are you?

Did you have any doubts Sam??? I'd hope so as your JK is prepped for that inevitable zombie apocalypse....

Yee have little faith..

Regards
Daz

[A2B]

Well, the stuff that has gone wrong.
Well I think the worst was my wipers failed and I needed to get a new TIPM. I must say they are not cheap but as it happened when the AUD and USD was on parity, I managed to get genuine extremely cheaper that the Australian dealers /sellers. Trying to find someone to install it was interesting. Jeep quoted me a minimum of 4 hours, whilst a secondary market Jeep guy did it with change out of $100
My Optima battery blew the lid, on exactly 2 years, luckily the $400 was covered by warranty, two weeks ago. I think this is my 4th battery. The oil pressure sensor failed the other day.
My alternator failed early in the piece (over 100,000kms), so about 2010 but at a time when the car was newish. I can't remember the price quoted but they were freakishly high but the cheapest options was out of two wrecks..one in Denmark and one in Italy. I had no luck finding someone to rewire.(not sure if they do now) but I still have it, incase they do... I went for the Italian one but they wouldn't ship to me. I had them ship to my cousin in Italy who in turn shipped to me for a total less than $200..It was a gamble but hey it worked. I have noticed that the prices of new ones are lower now but still not $200.
The weirdest one was a lever/switch failed in the transmission. Something that could be posted from Europe. Yet, it came to Australia via Singapore in 6-8 weeks.
On what may be considered a positive mechanical note but absolutely crazy and possibly lucky. I had the timing belt changed at 175000.
It doesn't surprise me with what you said about the Crown stuff but it was something I was not aware of and its here so.. sometimes you never know unless you give it a go.
Its weird cause the factory tensioner that had been there all the time from new, chewed up 2 belts and ended up with a crack in the support. I can't say how many kms I drove with 4 ribs and the crack in it, and the mechanic kept saying I had to change it. Whilst it ran on 4 ribs it was running in the normal grooves, closest to the alternator/power steering. The rounding may be from the fact that it has been driven many kms on 4 ribs.. I'll know better tomorrow and thank you for the heads up.

[samft]

Originally Posted by DarrenR

Did you have any doubts Sam??? I'd hope so as your JK is prepped for that inevitable zombie apocalypse....

Yee have little faith..

Regards
Daz

You never can be too prepared...

Nah, I hope I manage to get mine up to that sort of distance one day
Better quit work and do a few laps of the country!

[MidnightMods]

Most common fail point on the tensioner is due to the angle they work on, they bend in slightly and give uneven pressure on the belt in rare cases I have seen them wear bearings out because the angle they have been running on. Which would explain your problem as well. Just take a few hours to remove the fan shroud and take a good look at the angle of the wear on everything.
If it was your crank out of round, it would spit oil out of the front and rear seal and cause all sorts of problems.. none of which you have it seems

[A2B]

Same advice that my mechanic mate (not practicing) told me whilst we were in the paddock with only a torch for a tool on his work break. As I had it done by a mechanic, I thought I'd get him to recheck it, but only after I had the roadside look at it for a second opinion. The mechanic I use is generally good and fair in price but not a jeep / VM specialist but he does try to eliminate all possibilities of error before going for the $. We did not know the poor performance of the Crown stuff prior to this ( he still may not) as I have not seen him, but his decision on the crank pulley was part of him inspecting the pulley system. You may know if the crank pulley is a universal fit or one way only but he seemed to think there was a gain on alignment if he moved it around. I was after the part number to get ahead of myself, just in case it was a necessary change, as I had the part number of all the other pulleys / idlers and belt, not because it was giving any noticeable problems. He said the others did not seem to be a problem so he gave the rotation a go, as most people would think/hope a new part would be functional. I usually don't go for second tier products but I thought I'd give it a go. I go for your assessment of the tensioner and belt because they were the only step change and it was working ok before, but not perfectly but I will not find out until we try again. Thanks for your feedback.

[A2B]

For those that are interested.... The mechanic has changed the belt (Dayco) and rotated the crankshaft pulley. He was pretty confident that the pulley had been on reverse, as there were the telltale bolt marks and markings that were possibly used by a previous mechanic to assist in locating it, but as it was on the motor side it would have been pretty difficult to utilise. As the older tensioner required replacement, the issue with he crank pulley was not fully noticed until the tensioner was replaced, causing the belt to move across the pulleys.
He said that he noticed by rotating the crank pulley, the pulleys were more aligned, as the central plate where it bolts onto the crankshaft created a better alignment.
I have driven about 40 kms today and checked the location of the belt with respect to the power steering, the top idler and alternator when I have stopped, and it has remained in line, whilst the belt is still square on the crank pulley. I'm going to give it a longer run tomorrow, so I'm hoping to continue on the positive. Labour plus belt was $100..