2004 C-70 HPT T-belt TENSIONER adjustment

Dirtbag454 · Post by **Dirtbag454** » 12 Nov 2014, 23:59

Hello:
Just finished a t-belt, water pump, idler and TENSIONER replacement on my honey's 2004 C-70, and I fear that I may have not adjusted the TENSIONER correctly. (I'll stop with the all-caps on tensioner...just wanted to highlight that this is the point of this post.)

I have seen several posts that refer to the adjustment procedure on the temp sensing belt tensioner, and they talk about starting in the "2 o'clock position" or the "7 o'clock position" and moving the eccentric counter-clockwise until the indicator rests in the proper location for the current engine temperature. I understand the indicator position. What I don't understand is the starting position, and which engine it is applicable to. I also think I may have screwed up because I moved the eccentric clockwise to get the indicator in the correct position. I'm beginning to see that it can be moved in either direction (clockwise/counter-clockwise) and eventually that indicator will wind up where it is supposed to be, but is the belt tensioned correctly if it was rotated in the wrong direction? Could someone please shed some light on this? I was crowing about fixing her car, and now I am not so sure I want to let her drive it as I may have to pull the covers off and re-tension that belt, lest it jump time and cause all sorts of other problems.
I have searched this forum for an adjustment procedure specific to the 2.3 HPT engine in my wife's car, but the closest I have come is for an S-60, and I believe it was a non-turbo. In any event, the vvt pulley was on the forward (intake) cam, and my vvt pulley is on the rear (exhaust) cam. This might make a difference...I don't know because I can't find anything specific to this engine. I may not even be posting in the correct forum, as this one is for up to 2000 model year for this particular car. Since I could find no other forum for the ragtop, here is where I am.
here's a shot of two similar tensioners. Mine is on the left.

The same post I snaked that photo from had a video of the 2003 S-60 (non turbo) which clearly showed the tensioner being adjusted counter-clockwise, AND a Volvo technical bulletin which had a drawing of the adjuster, and gave printed instructions to move the eccentric CLOCKWISE. Perhaps you can see why I am confused. Any and all help will be greatly appreciated.
Dave
Well, crap. Just previewed the post, and the photo is too big to display. I pulled it off a post on this site too. Oh well.

Post by **cn90** » 13 Nov 2014, 11:10

Talking about the Vertical Tab...

Clockwise: is to tension the TB to remove slack.

CCW: is to release that tension a little bit, so the TB tension is correct.

Very simple concept but not explained well by Volvo repair manuals.

Post by **jimmy57** » 13 Nov 2014, 12:21

The indicator that moves as you tension belt should be between the "goalposts" at cool engine temp. If you look at tension on an engine a full operating temp the indicator will be to the right of the RH goalpost due to thermal expansion.

Just a note: Anyone with a 6 cylinder with mechanical tensioner as shown will move the allen wrench in the 6mm hex CCW to tension. 4's and 5's are CW and the 6's are CCW.

Dirtbag454 · Post by **Dirtbag454** » 13 Nov 2014, 16:43

Jimmy57 and cn90, thanks for your replies. Volvo seems to make this more confusing than it needs to be. Perhaps that is how those engineers justify their existence. There always seems to be exceptions to the rule, and I submit this video: https://www.youtube.com/watch?feature=player_embedded&v=IK_zH8g8Fow

The mechanic is replacing the same type of tensioner as I have, and on a 5 cylinder engine. He goes ccw to tension the belt. There seems to be no hard and fast rule, hence, my enduring confusion.

Post by **cn90** » 14 Nov 2014, 08:40

In the video above by the Volvo Tech from FCP:

Watch what tech says between 15:00-16:30 timing markings. It is a bit confusing when the "clock" is mentioned.

Note that there are 2 components to look at:
- The vertical tab that needs to be within the window when all done.
- The 6-mm Allen adjusting wheel, which moves in the opposite direction, i.e., when this moves CCW, the vertical tab moves CW.

In other words:
1. See BLUE arrows:
- First turn the 6-mm Allen adjusting wheel from 11 ---> 6 o'clock position.
- During this process, the vertical tab moves from 11 ---> 1 o'clock position.
- This basically over-tighten the TB a bit to remove any slack.

2. See RED arrows.
- Now turn the 6-mm Allen adjusting wheel from 6 ---> 7 o'clock position.
- During this process, the vertical tab moves from 1 ---> 12 o'clock position, now it is within the window.
- This basically release the TB tension a bit to get correct tension.

Side note: once you are done and have been driving for a while, the engine is HOT. When that happens, the metal expands, the belt also stretches etc. Since the tensioner is temp-dependent, it is designed to move the vertical tab in such a manner that the TB tension is adjusted to the current temp ---> correct tension no matter what temp is is.

Dirtbag454 · Post by **Dirtbag454** » 14 Nov 2014, 17:33

Thanks for the reply cn90. I got the job finished (went ccw, 11 to 6, back to 7. Post went right, past goalpost then left back to center). we're driving about 80 mi r/t to see the new XC-90 this evening. I expect the drive to be completely uneventful.