551 clutch issue

[wh22366 7]

My 551 had a brandy new H60 Tecumseh bolted to the frame when I got it but it had never been hooked up or run. It then sat for 25 years in a dry basement. I've gotten it running but now have a clutch issue. I've adjusted the clutch, brake rod and clutch finger by the ops manual, made sure all pulleys align, but cannot put it in gear with the engine running. The trans pulley turns so easily it just never stops even though the belt is loose with the idler disengaged - or even removed! The belt looks new and is correct (WH #1569). 551 pictures I seen on this site show the idler pulley and trans pulley about the same diameter. My idler is 3" and and the trans pulley 4". The belt guard fits well.

What am I missing? The trans pulley would have to be stopped to put it in gear and that ain't happenin.

[stevasaurus 22,725]

OK...here we go. First, the belt guard needs to be installed to make shifting possible. Second, the belt guard guides need to be in place. (they guide the slack in the belt when you push in the clutch). Third, if the pulleys themselves are hanging onto the belt, if the belt is the right length, clean them with mineral spirits so the belt can slip on those pulleys. Fourth, the belt is wrong and may need another inch or two.. That is about all it can be...there really is no adjustment for the clutch...all you are doing is putting the pedal at a different height. Let us know what you find.

[wh22366 7]

Thanks, young man. I have had the guard installed and greased the skids, but there doesn't seem to be enough slack to "guide", so I suspect you're right about the belt length. It was the right one for the original tractor, but might not be for the engine transplant/pulley sizes I have now.

[stevasaurus 22,725]

Understood...I do not know for sure how you would adjust for the belt. If I was to guess...take off the guard...take a piece of string around the pulleys...(once with the clutch depressed and once with the clutch out.) and maybe split the difference. You will have to let me know if that works.

:)

[Coadster32 793]

I agree with Steve, not much else to fix exept for belt tension/slack. The rod adjustment just changes the brake/clutch timing.

As far as adjusting the belt, couldn't you just slide the motor slightly forward/backward for finer adjustment?

[buckrancher 2,679]

#1569 belt is 28.95" long

[wh22366 7]

Well, I tried a 30" belt (green one in the pics) and it works sorta OK as there is more than enough slack for the clutch finger and guard to guide away from the drive pulley. The downside is that the idler arm is bottomed out on the trans case and the belt is a little loose when the clutch is let out - the guard will eat the belt eventually. The other picture shows the black 29" WH belt installed - you can see that things are a bit tight and even with the clutch depressed there's too much friction. I thought that the replacement Tecumseh (H60 75482U) might be dimensionally different, crankshaft centerline to frame, etc. but the blind hole in the case that accepts the forward guard stud is right on the money. As I couldn't buy a 4L belt locally in anything but 1" increments, trying a 29.5" belt is out.

Moving the engine back slightly (1/4" or so) by elongating the frame mount slots might give the 29" belt enough slack to operate correctly, but I'll need to modify the location of the front mount hole in the guard to match. It might be worth trying. If I can't locate a 29.5"belt, I thought I might try is to find a 3" pulley for the transmission!

Thank you all for the ideas! I'll show you the final result at some point.

[Coadster32 793]

I have ran my 551 without a belt guard for a period of time as well. What I have done, that worked well, is make a small l shaped bracket, and stuck it behind the idler pully. When the clutch is engaged (it's highest point), it doesn't interfeer with the belt. When pressed, it interfeers with the belt, and gives it the slack it needs. I made it so low profile, that I still have it under the belt guard that is in place now. Your're right about having to modify the belt guard if you move the motor forward. Looking at the picture, it looks like the green belt is tool long.

[hcminis 1,556]

Had this same problem. Only I couldn't even get the 1569 belt on the tractor.

[stevasaurus 22,725]

Had this same problem. Only I couldn't even get the 1569 belt on the tractor.

Great pictures...did those guides work for you...and would you have a picture of this with the clutch depressed???? :)

[hcminis 1,556]

This is a short video of it in action

[wh22366 7]

I've ordered a Gates Truflex 8400-2295 (29.5") and will try that. I like hcminis's guides as they're a small enough wire diameter to ride inside the guard, although I may not need them if this new belt works. Don't know what I'd do if I had a hard problem!

[Callen 64]

Think I would try turning that guide over, getting it close to the engine pulley. there isn't anything to guide out there when the pedal is pushed. Moving it closer to the pulley will push the belt out of the engine pulley when it is running with the tension removed.

[wh22366 7]

Got the 29.5" belt and installed it this afternoon. It's tight enough to keep the idler arm working against the spring and has enough slack (where the 29" did not) to allow guides to do their work of letting the drive pulley spin free. Speaking of guides, Cullen's comment made me take a look at the clutch finger and darned if he wasn't right about flipping the stock finger over. If I had looked at the wear on the finger and seen where it hit the inside of the guard over the years, I'd have tried that. Thanks Cullen! The new belt won't stop with just the finger repositioned, but with the guard in place to, it all works slick. Again the shiney wear pattern on the inside bottom of the guard shows me that the factory designed the guard to be the (other) belt guide for the belt.

I want to thank all of you who commented in this thread - you all helped in some way, even if it was to make me think!

[wh22366 7]

That's thanks Callen!