How to lock engine while tightening/untightening things

kylemorley · Aug 26, 2015

What is the method of choice for locking the engine so it cannot turn while something like a crank pulley nut is being loosened or tightened? I know some rope down the spark plug hole has been suggested here but I have never had any luck getting the rope to go where it is supposed to on flatties.

Only other thing I can think of is pulling the starter and making a lock that jams the flywheel teeth but that seems like a lot of work.

Impact wrench will probably not work as the object to be removed has just a screw driver-type cross slot, in bad condition.

old · Aug 26, 2015

Why not just put it in the lowest gear and lock both brake pedals down and be done with it.

Ultradog MN · Aug 26, 2015

Agreed.
EZ

kylemorley · Aug 26, 2015

Don't work, The engine turns over and the tractor just inches forward. I even tried putting a couple of "C" clamps on the brakes pedals, to be sure they were held down absolutely tight, and they brakes still slip.

Dune Country · Aug 26, 2015

block the wheels or chain it to a pickup from the back

old · Aug 26, 2015

Then chain it to a tree it can only go so far before the chain stops it form moving and you can then tighten things up

souNdguy · Aug 26, 2015

Since you know something like rope in the cyl works, though you have a hard time getting 'rope' in there, have you tried liquid rope?

Ie, fill a cyl with oil...

NoNewParts · Aug 26, 2015

in gear, and wheel chocks..as many, and on as many tires as you need.(brakes? naw, torque multiplication and a strong arm...brakes are weak)
pound em in, or turn that bolt and it'll try to climb the chock.
..keep kicking the loose side one in.
I work on tri-cycle tractors a lot....absolutely no rear tire movement..both sides..is required..to stay alive lol.

ps a big ol T-handle lug wrench with the hubcap pryer end
in the screw slot and the other end dug in your gut hard...will make big worn slotted fasteners give up their fight.

Blue Jay · Aug 26, 2015

Use an impact driver. Works the same way as an impact gun but it has a screw driver bit and you strike it with a hammer. No need to lock up the engine.

Dean · Aug 26, 2015

That's because you need to put it in the HIGHEST gear.

Alternatively, remove a spark plug and feed a length of small rope into the cylinder.

The rope will interfere between the piston and cylinder head, locking the engine.

When finished simply pull the rope out.

Dean

Hobo,NC · Aug 26, 2015

A hammer and a chisel will break that slotted bolt loose BTDT and have more tools that the law allows (never meet a tool I did not like) ... If you have a air chisel the moe better..

Catch it near the end of the slot and bang on it...

Once you get that slotted head bolt loose find the injuneer that denizen it and shove it were the sun don't shine then make him eat his degree..

kylemorley · Aug 27, 2015

And the solution was ... air.

I remembered I had a fitting (actually just a spark plug anti fouler with a QD air hose nipple forced into it) for pressurizing the cylinder using shop air, I used to use for swapping valve springs without removing the head (on OHV engines, that is). Worked fine, with a sharp enough stop that I could get the bolt broke free.

Oh the bolt turned out to be a slot head machine screw with no flats on the head and some odd washers and spacers that don't appear in the parts book.

If I might say a word about some of the other methods mentioned here, involving chains, chokes,brakes. trees and pickup trucks, the problem I fran into is that the gearing on a tractor gives the engine such huge mechanical advantage that it is very hard to, by attempting to immobilize the wheels or tranny, stop them dead enough to undo a frozen fastener. There is alway an 1' or so of play left, which is often enough to cushion any force you apply to the wrench or socket, so you you cannot get enough torque to break it loose. If you can get a impact the driver on the fastener, fine, that is the best and easiest way, but if not, the compressed air method works pretty well.

Jock(OR) · Aug 27, 2015

I have used the PTO shaft to hold the crankshaft or turn it. I have an old PTO driveshaft yoke that
I put a bar through when doing this.

If you are trying to hold the crankshaft by blocking the wheels, put the transmission(s) in the
highest gear (including putting a Sherman in overdrive) to get the most favorable gear ratio.

It seems backwards, but it is harder to turn the crankshaft (and make the tractor move) when in the
highest gear. The lower the gear, the less torque needed at the crankshaft to move the tractor.

Hobo,NC · Aug 27, 2015

(quoted from post at 20:51:18 08/27/15) And the solution was ... air.

I remembered I had a fitting (actually just a spark plug anti fouler with a QD air hose nipple forced into it) for pressurizing the cylinder using shop air, I used to use for swapping valve springs without removing the head (on OHV engines, that is). Worked fine, with a sharp enough stop that I could get the bolt broke free.

Oh the bolt turned out to be a slot head machine screw with no flats on the head and some odd washers and spacers that don't appear in the parts book.

If I might say a word about some of the other methods mentioned here, involving chains, chokes,brakes. trees and pickup trucks, the problem I fran into is that the gearing on a tractor gives the engine such huge mechanical advantage that it is very hard to, by attempting to immobilize the wheels or tranny, stop them dead enough to undo a frozen fastener. There is alway an 1' or so of play left, which is often enough to cushion any force you apply to the wrench or socket, so you you cannot get enough torque to break it loose. If you can get a impact the driver on the fastener, fine, that is the best and easiest way, but if not, the compressed air method works pretty well.

TOH has are did have a nice replacement socket head bolt and washer set up to replace the original like you have...

How to lock engine while tightening/untightening things

kylemorley

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old

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Ultradog MN

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kylemorley

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Dune Country

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old

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souNdguy

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NoNewParts

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Blue Jay

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Dean

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Hobo,NC

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kylemorley

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Jock(OR)

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Hobo,NC

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