gruffalo

Hi all

I discovered that the timing belt was running all the way to the front edge of the passenger side cam sprocket.


Drivers side is better.


But things are odd on the tensioner roller! The belt is probably 3-4mm off!

One can see from the rubber deposits that it has been running like this all the time, no recent event moved the belt.


What's going on? The engine has 2 years and 3000 miles on it since a full rebuild. Is something not assembled correctly maybe, during the rebuild? Where do I go from here?

MM

jeff jackson

Well...this begs the question be asked...IS the TB "installed" with the text "readable from the "front" of the car ??? OR...is the belt "biased-backwards" ? According to a recent thread, it has been established, that the correct orientation for the TB when installed is to have the text and numbers on the belt, "readable" from the front when looking at the engine . If the text is facing the engine...the belt is incorrectly installed, and the bias of the Kevlar cords in the belts construction, can cause the belt to "track outward" on the sprockets. So, you may have to hand crannk it over a bit till you can see the belt markings, but find out which way your belt was installed, apparently it matters. And NO....I"M NOT MAKING THIS UP.

gruffalo

Yeah! Check out the top pic, it even says "made in Italy"!?!?!? Must be a bad sign.

My belt is so far off, something has to be mis aligned, but I just can't see how this is possible? Off to the garage again.

mm

MGW-Fla

Great pics of something to keep an eye out for & great tip Jeff..... I know my mechanic just did a TB/WP for me since my level of expertise/courage is not to the point of tackling it myself. I know at the 1K retension, I will look at mine closely, especially the lettering! Hope yours is an easy fix & not something more serious. Keep us posted once you work it out.

928drvr86.5

I am wondering if your shoulder bolt that secures the tensioner arm to the waterpump is bent?

928drvr86.5

Is the belt rubbing on the backside of the tensioner arm as well? Can't really tell from the pics.

SMTCapeCod

Aint nuthin' wrong with Pirelli belts..
(edit: oops, now I see that it seems to say Dayco)

My '85 had the same problem. Ending up replacing the gear and all was well. Could've been worn from a prior belt-reversal, I suppose.

piccardo

I have seen this before on other cars and I would have a hard time believing that the timing belt would have that severe of a bias. It stands to reason that if that was the case it would track towards the block, and that doesn’t sound right either. Usually it’s the alignment of the tensioners or idlers that causes this. I would not be satisfied with just turning the belt. I would check all my pulleys and such with a laser or straight edge to make sure they are all straight.

chaadster

I was thinking exactly the same thing! I mean if that were the case, why don't they print directional arrows on the damn things. Maybe a "warning" sticker? Too much to expect for a potentially engine-destroying component?

AO

I'm with Ben on this. I would check the tensioning arm bolt. Big Dave's was severely bent and is probably what led to his TBF!

Glen McCartney

Most likely cause is the tensioner shoulder bolt is bent. That is what cause mine to track near the front of the cam gear on the passenger side, but was near middle on driver side. Mine was not quite dramatic as yours.

heinrich

Your belt is coming off the crnk wrong. Check the crank timing gear.

heinrich

Btw I've never heard of belt bias and I don't believe it

gruffalo

All right back from the garage.

More weird stuff is going on here. The tensioner arm is not going straight, probably another indicator of mis-alignment.



And the belt IS rubbing


And what's up with the timing arrow? It is also too far back, it should reach the lines on the pulley. With the cover on, it is hidden. Something wrong here too

gruffalo

which one is the sholder bolt?

I tried undoing this

and now it just spins. Does it go into the block? If so, it may have snapped right off.