928drvr86.5

is that plunger that holds tension on the arm really as bent as it looks in these pictures? The plunger actually looks like it's in backwards, I.E. the rounded end with the ground wire in towards the tensioner when it should be out against the arm.

928drvr86.5

ok, to me it seems the plunger on the tensioner is in backwards and is pushing the arm at an angle (towards the block). , ruining the plastic bushings for the shoulder bolt and possibly bending the bolt itself.

928drvr86.5

The shoulder bolt is the upper one that passes through the upper roller, it mounts the arm to the pump and allows it to pivot it's OK that the bolt on the lower one turns, if I remember correctly it's just a bolt and nut with a spacer washer.

j.kenzie@sbcglobal.net

In last picture the other bolt is the shoulder bolt. The bolt you spun has a nut on the other side; you can tighten when you have the tensioner arm off so no problem there at least.
Dave McK.

Big Dave

Yes, THIS one is the bolt that attaches the tensioner arm to the block. It was bent on my car when my belt failure happened.

Park it until you fix it. Seriously.

Big Dave

Here's what my bolt looked like:



For more info...LOOK HERE

gruffalo

Yes. Relly bad, perhaps more than it looks like in the pictures.

heinrich

Then you have the wrong tensioner / arm combo!!!

Imo000

Make sure you check the 2 small plastic bushings on the shoulder bolt too. In my case the bolt was fine but the bushings were worn. This threw out the alignment of the bent and slowly pushed the belt off the sprockets. Also, the tensioner “push rod” looks really out of alignment. If should be running parallel to the front of the motor and not on an angle like in your picture. This could be because, either the shoulder bolt is bent or the shoulder bolt bushings are worn out. One other thing, the tensioner roller bearing might be a bit worn to.

I hope this helps!

Bill Ball

The belt running forward on the passenger side but more true on the drive side is characteristic of tensioner arm misalignment, either from bent shoulder bolt, a spacer on the wrong side of the roller or the wrong arm. A later tensioner with an early arm would be off like this, but it does not look like you have a later tensioner. Garth knows the tensioner - tensioner arm MY differences stuff better than anyone. He'll chime in soon hopefully.

Garth S

Hey MM,
Two things come to mind that contribute to this. Worn pivot bolt bushings/ bent pivot bolt has been mentioned, and is a bad combo ( pivot bolt is the top one in the carrier arm that allows the tensioner to 'pivot' the big roller into the TB to add tension).
Another possibility is that the circlip is not in the axles groove on the back side of the tensioner roller: this circlip locates the correct depth of the tensioner roller shaft in the carrier arm. If it is absent for whatever reason the roller axle has no face to allow the lower bolt to apply clamping force between the shaft/axle and carrier arm .... then the roller will migrate inwards as in the pics.
The apparent poorly aligned piston rod between the tensioner body and carrier arm can be caused by several things - it will be apparent when you pull it off ....

gruffalo

I took a day off work to get the car on the road, today. But it looks like I'll be pulling the whole belt/tensioner assembly.

I guess I have to drop the PS pump and the alternator, undo the dreaded crank nut, and pull off the pulleys. And take it from there.

Thanks for all the input guys!

Crap, why didn't I do this in the winter? I should be driving, not wrenching by now...

928drvr86.5

I take back my statement about the plunger (push rod) being backwards, I didn't realize there were differences in tensioners between model years. From a diagram on another thread it looks like both ends of the push rod are the same.

jeff jackson

The timing marks do NOT reach the marks on the pulley...It looks funny, because the pulley that drives the AC belt is not on the damper, but that is correct. As for the tensioner arm, there is a thick washer that goes on the inside the pulley between the pulley and the block, and the condition of the bushings inside the tensioner arm are very important. These are what the shoulder bolt "rides in"...These guys are right...the shoulder bolt, for $12 "should be replaced when parts are gathered for the TB-WP service job. And ...make sure you check the PET, or the numerous TB service resources available to make sure all the parts are properly installed. Washers, cupped or not, need to be present where they are supposed to be or the whole tracking alignment will be off. As for the Belt Bias issue...I did NOT bring this up, but it HAS been confirmed. Bill Ball referenced in an earlier thread a Porsche Technical Service Bulletin specifically pertaining to this issue, and another Rennlister, who deals with Timing Belts, and their construction, basically explained the whole Kevlar reinforcement thread bias issue in this same thread. It makes sense if you can find and read this post...Sorry, I don't have a link to it.

heinrich

Yes. I agree. Looks like a severely bent shoulder bolt rather than the wrong tensioner.