A mob of high school students got hold of my Cub!

[Super A]

Last week at Boss's fest I picked up a Cub transmission I bought from him last fall. My small engines class pulled the tractor in on Tuesday and after about 90 minutes here's what it looked like!

They cleaned and flushed the new transmission and started getting it bolted back up but the bell caught them.
They will replace differential seals and start putting things back together on Monday. It's been a fun project so far, students have really enjoyed it.

I think some of the old transmission might be salvageable. It ran low on oil, which of course is my fault. But the inboard end of the PTO shaft and the shifter looks really good; it never would stay in gear unless you removed the little stop that bolts to the trans. cover. Looks like the end of the main drive shaft may be the issue thought I haven't taken out the shifter lever yet.

Al

[randallc]

That is great getting students involved. Maybe some of it will stick with them.

[Ole90633]

The first thing I noticed in the picture, put my heart in my throat !!!

The concrete blocks being used, as seen in the picture, are NOT designed to carry the load on their faces !
They will collapse end-to-end at a moments notice and allow the machinery to fall, injuring/killing someone !

Concrete blocks will bear immense load when the cores are VERTICAL, not horizontal. Even then, a wooden base the length and width of the load bearing surface of the cores should be used to support the jack. The mortar surfaces are less than true flat and the wood evens out the load bearing surface, preventing stress risers on any high or low points; exactly as mortar does in masonry.

I cannot believe that in a teaching environment, there are not specific jack stands for supporting machinery.

Safety is constantly emphasized in the forum (i.e. wedge the front axle [did you?], pull from the drawbar, etc.) and rightly so ! Those concrete blocks have no place whatsoever in the shop... only wood blocking. Teach the students good mechanical practices and SAFETY !!!

[Super A]

I figured there would be comments about the cinderblocks.

They were not holding the full weight of the tractor, soon as the tires left the floor the jack stand went under it. They were also turned 90deg. with boards over the top to carry the weight evenly across the cores. The students hadn't removed them completely when I snapped the pic; I hadn't taken any prior to because I was watching their every move.....

We had a long safety discussion before the activity began. Including wedging the front end, which I did myself to make sure it was right. I don't fool around when it comes to safety in my classes. I tell my kids I am expendable but they are not!

Al

[Ole90633]

Just a few more things in the interest of SAFETY:

Over a long career in aviation and heavy equipment maintenance, I learned a lot of valuable lessons.

Early in my wrench-turning life, I was fortunate to have a Master Mechanic show me how to do things correctly, teach me tricks of the trade (welding nuts on broken studs to remove them, freeing stuck parts with a "squirt" of penetrant and a "bump" of the raw hide hammer daily, shortcuts can kill you, know when to walk away from a situation, wear a hat when under a machine, keep your tools clean and organized, etc.). They became thoroughly ingrained and in the few times I abandoned them, I was either lucky to get away with it or got bitten by them.

That skill set, acquired over half a century, has been passed down to my daughter as well as many other up and coming students. I don't have all the answers, just a few of them: you get an opportunity to learn everyday.

Seeing the picture in the first post set off several alarm bells for me with no intention of personal malice.

As you have read, concrete blocks, known as "cinder blocks" (made with coal ash & cinders and extremely failure prone), "cement blocks" (cement is an ingredient in concrete), are an accident waiting to happen. Concrete blocks belong only in the construction of the shop; throw them out please.

Expanding the picture, I thought the front axle was wedged to the bolster but, only presumed so as it was hard to see. Sure, the front wheels are blocked and might not roll; why not flatten the front tires also, just to where the rims nearly touch the floor? You ever tried to push a Cub with flat tires? A little bit more of a Safety factor!

The SINGLE adjustable 'jack-stand' appears to be fully extended, yet not tall enough, so additional blocks were placed under it to fill the gap. The jack-stand probably has (considering arm x weight = moment) 5,000 ft lbs resting upon it while itself is not being secured to the machine. One accidental bump...

A small portion of the monies that would be spent to defend a wrongful injury/death lawsuit, could easily supply the shop with dozens of 6" x 6" x 12" and 10" x 10" x 24" hardwood blocks, to block and brace the equipment. A "Field Trip" to a professional heavy equipment maintenance facility will show how it is done Safely. Even better, visit an aircraft maintenance facility.

Those simple wooden blocks would also prevent the recurring nightmare of a disabled or fatally injured student in those that could have made a difference.

In the interest of Professional Training and Safety Compliance...

Don