Serpentine Belt idler (tensioner)

arrowrod · Post by **arrowrod** » 09 Jun 2011, 22:18

I just changed my timing belt.

Now I am looking to replace my serpentine belt. I am reading all about the "tensioner pulley".

My car (1999 S70) has a "tension pulley", but it appears to be mounted on a bracket with no adjustment. Am I all alone on this?

copandengr · Post by **copandengr** » 10 Jun 2011, 03:21

I have an 850, so I may be talking out of turn here. On every serpintine belt I have ever seen (and that is many different makes, not just Volvos) the serpintine belt is tensioned by a pulley that is spring loaded. That is to say the tension is determined by the spring on the tensioner pulley. There are no user adjustable settings. The only thing to do if there is a question about proper belt tension is to replace the entire pulley. There may be one exception and that is on some models the bearings can be replaced. Short of the bearing replacement there are no user adjustable settings for tension. These belts will last for a long time provided the tension set by the tensioner is within tolerance and the various accesories driven by the belt are in correct alignment. Check the belt for signs of wear (usually due to age). If there is cracking on the ribs of the belt or crazing from slipping, replace the belt after you have determined why the slippage happened and correcting that as well. The cracking on the ribs is from age. Always use a premium belt, preferably OEM. These belts are just too inexpensive even when purchased from a dealer to try to save a few bucks and then find yourself stranded somewhere.

The tensioner will have a square hole in it to fit a half inch drive bar or some other type of hole that is shaped for a tool of some kind to be placed into it. The pulley then can be moved in a dierction to release the tension where the belt can be removed and replaced. This is a very simple operation, well within the capabilities of a decent home mechanic. If you do not already have one, spend a few bucks for a shop manual that is available at any good auto parts store. This manual will be a great asset and will also prevent you from screwing something up that will end up costing you far more than the cost of the manual and a few tools.

Post by **Ozark Lee** » 10 Jun 2011, 07:04

Volvos are as described above except that a 1/2" drive is too small to release it, it is more like 3/4". Since I have 4 of these things I bought the tensioner tool from IPD - it is around $25.00. MIJ made a tool with plumbing stuff from the hardware store but I can't seem to find his post.

...Lee

arrowrod · Post by **arrowrod** » 10 Jun 2011, 10:22

There is no square hole on my 1999 S70 tensioner. It appears the "tensioner tool" with the 14mm wrench (hard to see the end, it may just be a hole that will fit over the bolt on the tensioner) on the end is the correct tool. You put the wrench end on the bolt head (of the tensioner pulley) and use the pulley on the power steering pump to lever the tension pulley to get clearance.

Cause I'm not going to wait for the tool, I'll build my own

I was able to see how the tensioner worked by using a piece of 1x2 wood, levering the tensioner from the power steering pulley.

arrowrod · Post by **arrowrod** » 10 Jun 2011, 11:05

OK, I took a 9/16 open end/box end wrench and mig welded it to a 1/4 square tubing to create the "tensioner tool"

Put the end wrench on the 14mm bolt holding the tensioner pulley, torqued the pully to give the serpentine belt room to put it on the pulley. Really easy.

What kind of disappoints me is this should have been easy to find on MVS or the web.

Onward...

Oh, I have found a wrecked 2000 s70 that might be for sale. In the words of Homer Simpson; "ummmm parts".

Post by **cn90** » 10 Jun 2011, 14:46

I thought 1999 uses this type of belt tensioner with Torx #60 Socket:

: 99belt.JPG (58.53 KiB) Viewed 15799 times

Post by **misha** » 10 Jun 2011, 15:33

Ozark Lee wrote:...MIJ made a tool with plumbing stuff from the hardware store but I can't seem to find his post.

I think that this is the picture of MiJ's home made serpentine belt tool:

: Serp%20Belt%20Removal%20Tool.jpg (153.53 KiB) Viewed 15795 times

db130 · Post by **db130** » 10 Jun 2011, 16:22

when i had to remove the serp belt to replace a dead alternator on my 2000 V70XC, i had to release the tension using a 14mm wrench as well. It's all about the 94-98 and 99-00 differences here, folks.

arrowrod · Post by **arrowrod** » 10 Jun 2011, 18:53

: tensioner tool.jpg (37.99 KiB) Viewed 15783 times

This tool is the one (if the attachment mechanism works). The hole on the end is a 14mm wrench.