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BF225A54 - Timing Belt Tension Instructions Question

W

wildebeest

Contributing Member
Starting a new thread on this issue. This is probably a stupid question, but I'm having difficulty understanding the Shop Manual's timing belt tension procedure at 3-23.

"Rotate the crankshaft pulley counterclockwise by six teeth of the timing belt driven pulley gear, then return the crankshaft pulley clockwise by three teeth of the timing belt driven pulley gear. If the crankshaft pulley was turned more than three teeth of the timing belt driven pulley gear, turn the crankshaft pulley clockwise to bring the No. 1 piston at its compression stroke, then repeat the belt tension adjustment procedure explained above. Be sure that the spark plugs are installed properly."

How do I count the number of teeth I'm turning the crankshaft pulley? I can't see the teeth and TDC mark on the timing belt driven pulley gear because it's underneath the crankshaft pulley. If I look at the teeth underneath the crankshaft pulley from the back of the engine (in between the idler pulley and tensioner pulley), what do I use as reference to count the number of teeth it has rotated?
 
I just did this a few weeks ago and ran into the same issue. I ball parked it from the first image on 3-23 using the reference lines. Found my timing belt a little loose. 600 hrs. Hope that helps.
 
Nothing at all wrong with your question. That's just a poorly written set of instructions! I don't have any experience doing this but just chiming in to provide a little moral support.

Sheesh! You'd think that mess of a paragraph was written by ME!

Good luck!
 
I'll tryand make simple.On the cover over the cam shaft sproket there is a rubber grommet covering a window. Remove it and while turning the crank in a clockwise direction, look for number one, clearly marked with green paint. Turn back 3 teeth from the mark, then clockwise again until dead on the mark. Release the tensioner bolt and allow the spring tension alone to adjust the pulley, do not assist it or you will over tension the belt which will cause it to be noisy and shred rubber. Retighten the tensioner lock bolt, job done. Tge whole idea is to ensure all the slack in the belt is on the tensioner pulley side, it's that simple. Hope this helps.
 
Thanks, all.

I was confusing the Timing Belt Driven Pulley Gear with the Timing Belt Drive Pulley Gear. The Drive pulley gear is underneath the crankshaft pulley where I can't see it, but the Driven Pulley Gears are the camshaft gears, which are readily visible if you remove the covers (or use the little window as iang noted). I removed the cover because I was pretty sure I had caused it to jump teeth when originally trying to tension this improperly (but fortunately I hadn't). I've now done this counting teeth on the crankshaft gears (the "Timing Belt Driven Pulley Gears) and I'm in spec after doing the procedure--barely. I'm right at around 3/8 inches of play between the right camshaft gear and idler when doing the tension check procedure (reverse 5 teeth), which is within the .38" specification. This still seems pretty loose, but I guess it's okay since it's in spec. I did notice some wear on one of the teeth of the belt, so I guess I also need to get a new belt soon too.
 
The belts do run fairly loose, I have found these belts are good for1000 hrs provide all pulleys remain in good condition. There is no recommended service interval in the OEM manual
 
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