Brand New Member with a ? about MCI-9 Tensioner

Scott & Heather · August 17, 2011, 03:56:08 PM

Quote from: bevans6 on August 17, 2011, 03:41:27 PM
The cradle is in the right place based on the fixed swing-up hold down bolt shown in the upper left hand photo. That bolt is on a hinge, it swings up and bolts down the sliding cradle, and the fact that it has engaged means the cradle is in the right spot. I bet the pulley on the mitre box is bent, or the tension is too high. which pulley seems to want to make the belt jump? The lower pulley is a huge cast piece, it won't bend it will break.
Brian

Brian, I might have confused the issue by posting photos of my own coach...which of course does not have a problem. I only posted the photos to help someone point Brett to the proper place to check his engine cradle. Sorry...

bevans6 · August 17, 2011, 04:39:26 PM

Well, he knows what to look for now anyway~

Busted Knuckle · August 17, 2011, 10:48:58 PM

Quote from: bevans6 on August 17, 2011, 03:41:27 PM
The cradle is in the right place based on the fixed swing-up hold down bolt shown in the upper left hand photo. That bolt is on a hinge, it swings up and bolts down the sliding cradle, and the fact that it has engaged means the cradle is in the right spot. I bet the pulley on the mitre box is bent, or the tension is too high.

which pulley seems to want to make the belt jump? The lower pulley is a huge cast piece, it won't bend it will break.

Brian

While you are most correct about those hinged bolts and that if the were engaged one would think that it was all good.

However my friend Steve found out the hard way that this is not necessarily true. At the time the engine was put in they were properly aligned as was the rest of the cradle. But for what ever reason after owning and driving the bus for several yrs they loosened up and the eng/trans & cradle worked their way back creating the same symptoms as we have here.

It took us a while for us (Steve in S. TX and me in TN over the phone/internet) to figure out that just because the hinged bolts were still in the slots did not mean all was well and it had in fact moved back and the bolts were in a bind.

Now having not seen said coach we are actually talking about I have no idea if that is really exactly what is going on here.

BK

brett · August 20, 2011, 02:09:22 AM

yeah, the top pulley is the one that makes the belt want to jump off. i havent gotten to take video yet. not sure if that's coming or not, but i noticed that on that part the WM-279-E1, I forget the exact part number but I noticed for one, its facing the wrong way, so the bottom is facing you when you open the back hatch, but when i looked on the other side, the Front of Bus side, to see if there was a bolt i could either tighten or loosen, there wasn't that shiny bolt. it was missing. so i'm thinking this could be the problem, but do i just put any old bolt thats threads fit or do i buy it specially say from the mci parts boutique? or this might not be the problem, actually, that top pulley being bent sounds very likely as well... thanks for helping me get my hands dirty dag nabbit

Busted Knuckle · August 20, 2011, 03:28:30 AM

need pictures to fully understand what your talking about.

BK

bevans6 · August 20, 2011, 04:01:10 AM

It's just a 1/4" bolt with a jam nut, around an inch long, that adds preload to the spring that the air diaphragm pushes against to regulate. If the bolt is gone, then the regulator is not going to work well at all. But for the life of me I can't remember if you raise the pressure by putting the bolt in further or lower the pressure by putting the bolt in further. In other words I don't know if not having the bolt in sets it at maximum or minimum pressure! I would try to get a new one if you can, I got both a new one and a repair kit from Luke at US Coach.

Brian

thomasinnv · August 20, 2011, 09:43:47 AM

I do believe no bolt would be minimum pressure. You turn the bolt in to raise the pressure. Put a gauge on it and check the pressure before doing anything else.

brett · August 22, 2011, 02:02:32 PM

Quote from: bevans6 on August 20, 2011, 04:01:10 AM
I would try to get a new one if you can, I got both a new one and a repair kit from Luke at US Coach.

Brian

Wow, I used to live right off Cross Keys in Berlin, NJ and never even knew of him. Now that I'm in Colorado I could really use him! Ha, ain't that a bitch! I'll be picking one of those bolts up today! Thank you!