When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Rebuilding '90 GT OEM tensioner (PO mechanic didn't do it with timing belt change 4 months ago). Boot was totally gone. The tiny flat head bolt that goes into the idler shaft on the water pump was loose when I removed it. I have not recalled the bracket that runs from the top of the water pump to the idler on any of my other 928's with Laso pumps. After checking & cleaning the parts, I tightened the tiny bolt and now the tensioner pulley assembly will not move. If I back it off, it move freely. What am I doing wrong? Something defective? It is a GMB new pump (not my choice).
Polecat, you are not viewing the pix correctly. The picture is of the upper part of the WP. The tensioner is out of the car, flywheel locked at 45 degrees.
Polecat, you are not viewing the pix correctly. The picture is of the upper part of the WP. The tensioner is out of the car, flywheel locked at 45 degrees.
I always thought that bracket was just on to protect the tensioner pivot shaft from being bent while shipping and such as it does not even come on some pumps.
I always thought that bracket was just on to protect the tensioner pivot shaft from being bent while shipping and such as it does not even come on some pumps.
That's why I post the question. First I've seen it on a W/P. If there is another bolt, I don't have it.
On my 86.5 that bracket would probably interfere with installing the fan as it bolts to the front of the water pump in that position, although there appears to be a recess there.
That brace is only used on S4 and later cars so it is appropriate on your '90. Check that there is a spacer between the pivot arm and and the roller and a washer between the brace on the water pump and end of the pivot bolt. The pivot arm must have both bushings in the part that slips onto the pivot bolt and they both have to have their flange intact for the system to pivot correctly.
That brace is only used on S4 and later cars so it is appropriate on your '90. Check that there is a spacer between the pivot arm and and the roller and a washer between the brace on the water pump and end of the pivot bolt. The pivot arm must have both bushings in the part that slips onto the pivot bolt and they both have to have their flange intact for the system to pivot correctly.
Mike
I will check but I know there was no washer between the brace and end of pivot bolt. Will experiment with putting a washer between the prace and end of pivot bolt.
Take a look at the illustrations in PET. I was mistaken that all S4's came with the added brace from the water pump body to the pivot bolt. That was a mid year change in 1987 starting with engine numbers 81H00660 (M28.41) and 81H06736 (M28.42). IIRC there is a note in one of the Service Information books about the change and how to modify the timing belt cover to provide the necessary clearance for the brace.
Take a look at the illustrations in PET. I was mistaken that all S4's came with the added brace from the water pump body to the pivot bolt. That was a mid year change in 1987 starting with engine numbers 81H00660 (M28.41) and 81H06736 (M28.42). IIRC there is a note in one of the Service Information books about the change and how to modify the timing belt cover to provide the necessary clearance for the brace.
Mike
The PET for 1991 shows the brace with the W/P body but does not show the brace in the idler assembly. The #45 washer in the illustration of the idler is what I don't have.
The PET for 1991 shows the brace with the W/P body but does not show the brace in the idler assembly. The #45 washer in the illustration of the idler is what I don't have.
The PET is good at only showing the parts in one place. That brace is a stock part.
Check the washers and white plastic (nylon?) bushings. It may be the idler bearing that's not right. I'm sensing previous owner or previous mechanic blundering here. It's clamping up even without the #45 washer?
The PET is good at only showing the parts in one place. That brace is a stock part.
Check the washers and white plastic (nylon?) bushings. It may be the idler bearing that's not right. I'm sensing previous owner or previous mechanic blundering here. It's clamping up even without the #45 washer?
I have added two small washers that fit inside the bushing and same diameter as the shaft. Now all seems well. Tiny hex bolt is tight. No binding now.
05-27-2017, 10:07 PM
OEM Timing Belt Tensioner Question
). Boot was totally gone. The tiny flat head bolt that goes into the idler shaft on the water pump was loose when I removed it. I have not recalled the bracket that runs from the top of the water pump to the idler on any of my other 928's with Laso pumps. After checking & cleaning the parts, I tightened the tiny bolt and now the tensioner pulley assembly will not move. If I back it off, it move freely. What am I doing wrong? Something defective? It is a GMB new pump (not my choice). 
