DrCharles
Full Access Member
Thanks for the link 
I see the one with the shock is even more expensive!
Rock Auto shows that Motorcraft BT-33 tensioner is for an earlier van, but 94-up F250. Obviously it fits because it's on there now... also it's $106 shipped.
I bought the enclosed non-shock version at O'Reilly for a whopping $92 since they had it... unfortunately the mounting bolt is a different style and length. The new one looks like it's supposed to have some kind of thrust washer or bearing under the head of the bolt, or at least a shoulder bolt to prevent clamping the two halves of the tensioner. And it's counterbored a good 3/4" into the front half, too.
My existing mounting bolt has a cone-shaped area under the head, and the opening in what I think is a thrust plate is also tapered to match it. So I took the new tensioner back.
Incidentally, that mounting bolt was grossly over-tightened, which was probably causing binding in the tensioner mechanism. It always seemed to take a lot of force to "spring" the tensioner when removing or installing the belt...
Anyhow - I was able to free up the thrust plate (thought it unscrewed, but it just goes round and round and is apparently staked in place). I gave it a good soaking with spray "Chain & Cable Fluid", dried the excess and put it back on the truck. That was an interesting exercise getting everything lined up properly including the top shock bolt. I finally got everything back on and immediately noticed that I did not have to lean on the breaker bar to get the tensioner all the way slack. Easier to get the belt over the alternator pulley, too.
When revving the engine and letting it decelerate abruptly, I can really see the tensioner move now... and best of all, no more chirp!
I'm not sure how long my temporary lube job will last, but at this point I suspect the bigger
problem was the gorilla who overtorqued the tensioner mounting bolt.
At least he didn't break it off in the bracket... anyway if the chirp comes back I'll spend the $106.
I see the one with the shock is even more expensive!Rock Auto shows that Motorcraft BT-33 tensioner is for an earlier van, but 94-up F250. Obviously it fits because it's on there now... also it's $106 shipped.
I bought the enclosed non-shock version at O'Reilly for a whopping $92 since they had it... unfortunately the mounting bolt is a different style and length. The new one looks like it's supposed to have some kind of thrust washer or bearing under the head of the bolt, or at least a shoulder bolt to prevent clamping the two halves of the tensioner. And it's counterbored a good 3/4" into the front half, too.
My existing mounting bolt has a cone-shaped area under the head, and the opening in what I think is a thrust plate is also tapered to match it. So I took the new tensioner back.
Incidentally, that mounting bolt was grossly over-tightened, which was probably causing binding in the tensioner mechanism. It always seemed to take a lot of force to "spring" the tensioner when removing or installing the belt...
Anyhow - I was able to free up the thrust plate (thought it unscrewed, but it just goes round and round and is apparently staked in place). I gave it a good soaking with spray "Chain & Cable Fluid", dried the excess and put it back on the truck. That was an interesting exercise getting everything lined up properly including the top shock bolt. I finally got everything back on and immediately noticed that I did not have to lean on the breaker bar to get the tensioner all the way slack. Easier to get the belt over the alternator pulley, too.
When revving the engine and letting it decelerate abruptly, I can really see the tensioner move now... and best of all, no more chirp!
I'm not sure how long my temporary lube job will last, but at this point I suspect the bigger
problem was the gorilla who overtorqued the tensioner mounting bolt.
At least he didn't break it off in the bracket... anyway if the chirp comes back I'll spend the $106.
