TB Tension at 1500 miles
#1
Three Wheelin'
Thread Starter
TB Tension at 1500 miles
Minor question, but curious what the panel thinks:
Running very well and I did TB/WP about 1500 miles ago.
Gates belt and rebuilt stock tensioner.
I rebuilt the stock tensioner mostly because as a rookie I wanted to learn the original system, and also I was too impatient to wait for a Porken tensioner at the time.
As TB went on I had tensioned to about center of my Kempf tool.
I had expected the need to re-tension belt by 1000 miles for street car.
At 1500 miles I checked tension and same reading on Kempf tool.
So question becomes will I develop laxity in the belt, if I have not by now?
What's the story?
Running very well and I did TB/WP about 1500 miles ago.
Gates belt and rebuilt stock tensioner.
I rebuilt the stock tensioner mostly because as a rookie I wanted to learn the original system, and also I was too impatient to wait for a Porken tensioner at the time.
As TB went on I had tensioned to about center of my Kempf tool.
I had expected the need to re-tension belt by 1000 miles for street car.
At 1500 miles I checked tension and same reading on Kempf tool.
So question becomes will I develop laxity in the belt, if I have not by now?
What's the story?
#2
Rennlist Member
Join Date: Oct 2005
Location: Gatineau, Québec, Canada
Posts: 5,166
Received 1,288 Likes
on
489 Posts
I don't have much experience with the stock tensioner, but I would say that if everything's good (good tension and no warning) you're good to go.
I think that some put the tension on the higher side with the Kempf tool but...
I think that some put the tension on the higher side with the Kempf tool but...
#5
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
'No Change' is a good thing. In fact, I'd be more concerend if there was any significant adjustment needed; That would be a sign that something had moved, at least to me. Modern aramid-reinforced belts generally don't do much initial stretching any more. The technology has improved a lot since the first 928 WSM was written. Of course, there are still recent experiences reported with the Conti belts stretching, and there is always the possibility that something does move in the system, so I wouldn't ignore the 1500 mile tension check exercise completely.
I did a quick visual inspection a week after I did the timing belt recently, and found I'd left a couple distributor rotor screws loose on the passenger side. So I got to do another round of fastener-checking to see what else I might have missed. Point is that the belt tension recheck is a good opportunity for another work quality inspection. Oh, the telltale on the not-yet-secure rotor screws? I add QC 'torqued' marks on fasteners on every major project. Those two screws lacked the yellow (for this project) marks that indicate they were secure and checked.
I did a quick visual inspection a week after I did the timing belt recently, and found I'd left a couple distributor rotor screws loose on the passenger side. So I got to do another round of fastener-checking to see what else I might have missed. Point is that the belt tension recheck is a good opportunity for another work quality inspection. Oh, the telltale on the not-yet-secure rotor screws? I add QC 'torqued' marks on fasteners on every major project. Those two screws lacked the yellow (for this project) marks that indicate they were secure and checked.
#6
Rennlist Member
I am in the early stages of the TB and WP job, and I noticed prior to the job my belt was not tracking properly and wobbling about an eight of an inch on the cam gears. Outside of following the detailed adjustment procedure, what should I be looking out for to ensure proper tracking?
#7
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
You are replacing the bushings on the arm, and the pin it rides on if you are replacing the water pump. so wobble in the arm should not be an issue. After that, the belt rides only on gears (crank, oil pump cams) plus the water pump drive pulley. It the belt moves much, it would be interesting to try to relate the movement to some reference in the rotation (every engine rotation, every cam gear rotation, every belt revolution) to narrow down a cause.
Belt manufacturers and the WSM both offer strict guidance to not pry or hammer on the belt to get it into place. Yet I've watched "pro" wrenches use prybars, screwdrivers and hammers routinely to get the belt into place. Huh??? Damaging the cords by any of these methods causes the belt to have uneven tension side to side, and will cause the belt to track funny. If you can't get the belt onto the gears with finger pressure only, step back, figure out why, fix it, and try again.
Belt manufacturers and the WSM both offer strict guidance to not pry or hammer on the belt to get it into place. Yet I've watched "pro" wrenches use prybars, screwdrivers and hammers routinely to get the belt into place. Huh??? Damaging the cords by any of these methods causes the belt to have uneven tension side to side, and will cause the belt to track funny. If you can't get the belt onto the gears with finger pressure only, step back, figure out why, fix it, and try again.