RyanPerrella

Being that i have the fan shroud off the car and have now gone 300+ miles on the new engine and belt. I thought now would be the perfect time to check the tension and adjust if necessary.

Originally I got the cover off and checked and it seemed to be within spec, half way in the window with one of Rogers Kempf tools. (Thanks again Roger, I'll have this back to you by the weekend.) After doing this i went beck under the car and finished up the clutch install and moved the crank a few revolutions while playing with the clutch. Well before putting the belt cover back on I checked tension again and this time found it to still be in the window but just barely and on the loose side. So i thought this was reasonable so i loosened the locking nut and adjusted the bolt in and out a bunch of times to where its now definately in the window but i am getting different readings all the time.

I check the tension, then wait and rotate the crank and belt about 90 degrees and check again and its still in the window but never the same. I think this has to so with some of the elasticity in the rotating assembly and that sometimes when cranking the cylinder pressure will rotate the crank anticlockwise a degree or two and figure this is partly contributing to my readings being off somewhat.

I guess what I am asking is that now i think i have it set nicely. Its always in the window and the locking nut is cinched against the tensioner housing now. But it goes from the halfway mark in the window to 1/4 or 3/4 (like you were reading a gas gauge)

Has anyone else experienced this before on a belt retension? When i installed the belt the engine was on the stand outside the car so access was much easier. Just curious if Bill B. or Roger or Dr. Bob if you guys have seen this as off the top of my head i must think you guys have 50 plus timing belt jobs between you all.

Thanks

PorKen

It should only be checked at TDC #1, AFAIK.

RyanPerrella

I checked it there once (ive checked it about 15 times) but why would that make a difference for belt tension?

PorKen

The pressure of the valve springs as the cams actuate them, stretches the belt.

Come to think of it, this may be why 32V show a little bit more tension, generally, than 16V?

It affects the valve timing, too. You can easily be off by 2° just from belt stretch, measured at different points on the rotation.

leperboy

The tension has to be measured at TDC#1. If you are rotating only 90 degrees between measurements the readings will be all over the place.

So, rotate 360 degrees between tests, and better yet would be 720 or 1080 between readings if you are adjusting the tension. Repeat, repeat, repeat until it reads consistently in the upper half of the Kempf tool at TDC #1.

Matt

RyanPerrella

YES YOUR RIGHT, thanks for pointing that out

I will try this again only at TDC #1

borland

Like many others here, you are not using the tool correctly.

Read the instructions that came with the tool or those in the WSM. There are no short cuts.

Adjust, rotate crank two turns.. back to TCD#1, check, repeat.

RyanPerrella

Yes your right, i should read the directions

RyanPerrella

Thanks Ken, Thanks Matt

I get nice repeatable readings now. Did it once, roated 720 deg got the same, I tightened the bolt and lock nut and measured again to get the same. Rotated another 720, got the same. Will do it twice more and put the cover back on and reassemble.

Thanks

RyanPerrella

Now I'm curious how many people tightened the belt after break in.

If you needed to tighten up the belt after break in, please let me know yay or nay. Also how much many flats or revolutions did you go on the bolt. I went 3-4 flat's or 1/2 to 2/3 a turn of the bolt.

Did you need to tighten, and if so by how many turns?

Bill Ball

"Break in"? Check tension at 2000-2500 miles, as prescribed by the maintenance schedule, then again at 30K miles and replace after 60K miles.

RyanPerrella

yes break in. The belt stretches, I imagine thats why they suggest you recheck the tension. A 2000 mile belt will most likely be a little longer then the same belt with 0 miles. Thus my term break in.

I am curious how many people tighten the belt at this check point and if so how many turns.

Bill Ball

I've always found the belt at 2K miles to be just a bit lower than initially. Maybe a half turn of the bolt brings it back to slightly over the middle of the window.

SeanR

On mine I initally put the tension at the end "tight" end of the window and when I went back in 1500 miles later it was sitting just shy of the tight end. Didn't mess with it after that.

For ****s/giggles I'm going back in to check it after 10k or in a month or so.

dr bob

+1

3 Flats at 1500 miles. No change then at 10k, almost two years later. At this rate I'll have 30-35k on it when it gets changed again at 5-6 year age-related limit.

Maybe if I put a little Armor-All on the belt it would last a bit longer...