Just a year ago I picked up this HT20 (2087-02) - it was my first Bolens. It got me hooked. It had been sitting in a barn for 7+ years after the original owner passed away. It took the usual stuff to get it up and running after sitting for so long - cleaning fuel system and carb kit, plugs, points and condenser and changing all the fluids. Since then it has been running great.
However, I've noticed a couple things over the last few months that need some attention. After it's thoroughly warmed up it sometimes misses here and there. Also, not every time, but if I have worked it hard the next time I go to use it there will be a drop or two of oil under her. The other day I pulled off the baffle over the #2 cylinder and sure enough, the bottom of the head was oily and dripping. Cylinder #2 needs a new head gasket. I checked the Kohler service manual and it said cleaning the head was a service item every 500 hours - and since I am betting cylinder #1 hasn't been serviced in the last 500 hours, I picked up two gaskets and I'll do them both.
I replaced the rear tires with Carlisle TruPowers last summer. I picked up a set of Carlisle ribs I want to put on the fronts. When I have the tires off the wheels I planned to clean them up too. I picked up some Rustoleum Canvas White. It looks to be a good match to the HT20. Anyone tried that brand and color to match that era of Bolens' white?
The third thing on the list has been worrisome to me. It's been psyching me out because I've read others posting about the PITA the job has been. I need to pull off and repair the drive shaft. Since I've had it there has been some vibration that has gradually gotten worse. I've got a lot of play in the U-joint on the hydro end of my drive shaft. Once I confirmed what it was I haven't used the tractor much at all - being concerned about wearing the hydro shaft. Sad.
Well, today I finally had some time to tackle it. From the get go, I was repeatedly shooting the crankshaft end with penetrating oil. After taking off the hood, fender and dash & steering column; I found I had just one set screw on the hydro end. The set screw was just to hold the fan and did not hold the drive shaft yoke onto the hydro shaft. The crankshaft end had the cross bolt, which was easy enough to pull out. At this point in time, I took a deep breath and said a little prayer. It looked to me like the thing had already gone through a drive shaft repair. There were what looked to be marks from hammer strikes on the yoke on the engine side. Instead of hitting the yoke directly I figured I would get a scrap block of wood, put it up to the yoke and hit the wood a bit. Then I got the idea to put the block up to the ears of the yoke and strike the wood, pushing the yoke towards the engine. It started to move! Within just a few back and forth 180 rotations of the yoke - and strikes, the shaft was off!
After getting the drive shaft off, I can see the damage that was starting to occur. The woodruff key on the hydro end was getting beat up. Also, the key groove in the hydro end yoke is no longer square but worn a bit. I'll need to get a new yoke on that end. The hydro shaft doesn't look bad or feel worn with my finger. I'll see if I can pick up or borrow some calipers to measure any wear that's happened. Anyone know the wear tolerances before the hydro shaft becomes an issue? I don't want to repair the drive shaft, get it all back together and still have vibrations. Also, there was no 1/4" key on the crankshaft. I looked for it. It wasn't there. The keyway was filled with kind of a sludge of dirt and penetrating oil, but no key. Could have this contributed to the u-joint failure on the other end?
So now my question is how important is the balancing of these drive shafts after a repair? If I have to put a new yoke on, does that mean I should have it balanced? I talked to my neighbor today who is a professional mechanic and he said he wouldn't bother to rebalance it - only rebalance if its a problem. I don't want to do the job twice if it does need balanced.
Any thoughts or sharing your experience on this would be appreciated. Thanks!
Edited by Clevis, April 02, 2017 - 02:05 AM.