Timing Belt Tension...Again...

[mstephenson]

I bought this car some time ago and am getting it cross country worthy. Changing the timing belt was on the list.
http://vwdiesel.net/forum/index.php/topic,36988.msg346445.html#msg346445

So, now I have questions:

1. I did not put the new belt on completely straight the first time. The advice was it would straighten itself out. It did not. After re-straightening it stays put, but it wore a little on the edges. Do I need to worry?

2. Is the timing belt too tight? The 64K$ question I know. Science and Art converging into one universal question for VW humanity.

I found a thread with a video of a gasser with a belt too tight, but none of a diesel with the older tensioner. There are recommendations as to what "time" the tension tool should be pointed (10a-11a) when tightening bolt. I just don't have a good go-by since this is my first time with this exercise. I have uploaded two videos to show you the results thus far.

The first is of me twisting the belt and moving it up and down. FYI, I am a woman with a little above woman hand strength.
https://youtu.be/s73oOVG-8FQ

The second is the car running. I apologize for the vibrations. The purpose is to document the sounds. Specifically, the whine. Is there a whine? Or is it my imagination?
https://youtu.be/qDUE_EdPPPI

My fear is over-tightening and thus bearing wear. I have learned a lot, but dropping a motor and rebuilding sometime in the future is really not how I want to spend my fun-time.

Engine: 1Y TD / 1.9D block (with squirters) and Garrett T3 from 1.6td
Temp 70degF
Continental Belt

Thank you, -m

[fatmobile]

I usually gauge my belt tension by starting it up and watching the belt.
 This is for a 1.6 but might work for yours.
 
 I rev it up and watch the belt between the crank and tensioner.
 If it vibrates too much I tension it a little more.
Some vibration is allowed but I don't want it coming close to hitting the cover.

Usually vibrates most around 2500 RPM.

[mstephenson]

So, the question asked is not quite right. The incorrect question is if it is too tight. And the correct question and working direction is what is just tight enough. The exercise should start from slop and slap to tighten until that slop and slap is almost removed. whine removed. all at/around the 2500rpm range.

I do not expect this thread to be definitive, but rather a more narrowed "guide" for the novices working through the process. Too tight and too loose is an expensive lesson without the input of experienced IDI owners.

Any comments/corrections/modifications for the above synopsis?

Thanks, -m

[ORCoaster]

What I saw when I watched you grabbing the belt is that on the third grab you have about a 30-degree twist going from the initial position.  The correct amount is a 45-degree twist so I would say you have it just a tad tight.  Loosen the tensioner just a tiny little bit with all the locking pins in place and the cam pulley free to turn on the cam itself. 

As for the frayed edges of the belt, don't worry so much about them now that you have it tracking properly.

The whine should go away if you loosen the belt.  It looks like you put a new tensioner on, is that correct?

[mstephenson]

Yes, new tensioner.

After explaining your methodology and adjusting my perspective of what timing belt success is, I planned on loosening things up a little more.

Thank you for your help. I frequently feel isolated geographically and socially with my choice of project. Texas is big on diesels as long as they come in 3/4 and 1 ton wrapping. I rely mostly on this forum and the manuals and to a lesser extent from European forums and of course the vortex. But I need the garage space for other projects and a reliable (fun) daily driver. So, the mk2 has to be dealt with.

I have a friend whose Mazda has been at the dealership going on two months waiting for parts. It's nice to tell folks that parts supply has not been an issue for this car. Costs have risen some, but not parts availability. That is nice.

Thank you, -m

[ORCoaster]

You are most welcome and keep wrenching on it.  I toyed with my 81 Caddy over the weekend after I took it for a drive and was losing coolant.  I replaced the water pump the weekend prior and didn't get one clamp totally tight. 

Stopped three different times to add coolant.  Twice more than what I thought I should have needed.  Whenever I drain some of the coolant it never seems to get totally full until I drive it for a while and some air in the system finally leaves and the reservoir drops its level accordingly.

[fatmobile]

So, the question asked is not quite right. The incorrect question is if it is too tight. And the correct question and working direction is what is just tight enough. The exercise should start from slop and slap to tighten until that slop and slap is almost removed. whine removed. all at/around the 2500rpm range.

I do not expect this thread to be definitive, but rather a more narrowed "guide" for the novices working through the process. Too tight and too loose is an expensive lesson without the input of experienced IDI owners.

Any comments/corrections/modifications for the above synopsis?

Thanks, -m

Sounds right to me.

[libbydiesel]

If using a tensioner wrench, proper tension is just a wee bit tighter than where the belt will push the tensioner back to when you are applying almost zero pressure to the wrench.  If you can actually feel the tension of the belt pressing back against the wrench, then it is too tight.