Big Crank Pulley Nut Removal

[Shawn]

G'day all,



Ok, I know it is a 1-5/16", but with the engine out of the car, how do you lock the engine (without removing the sump) to get the thing undone. I'm looking to change a camshaft but at the same time do as little dis-assembly as possible.

Is it safe to jam something in against the flywheel throught the starter opening?

Any other experience based tips on camshaft swaps would be appreciated! I haven't done much Mog engine building, but I'm using my second spare engine (pictured) to practice. Even if I do someting stupid and break it, it won't be a train wreck.

Having said that, I don't plan on breaking it!

[Pyoor_Kate]

I think that's what it said to do in the Haynes manual; anyway that's what I did. Stuck a very large crow-bar into the ring-gear on the fly wheel and then proceeded to beat the living poo out of my giant adjustable spanner until it undid. I found it easier with two though, one to keep the crowbar in place - in my case I stuck it through the starter motor appature (which gave it something solid to lock against).

[KirstMin]

I've just swapped the cam on mine (2 weeks ago) and it was the first time I have had the engine out. Suffice to say I was stumped when it came to this part. I think that is due to the 75lbs torque and the fact that it tightens with use. I started off gently but ended up with a lump hammer on LONG spanner. I think this is known as 'shock treatment'!

Whatever the manual says, dont believe that a screwdriver will help keep the flywheel from moving! I didn't like the idea of jamming the cogs with anything whilst applying shock to the pully nut so we wrapped around the flywheel some of those thick, flat ties you use for keeping very heavy stuff strapped down (sorry no pick). So one person would hold that and the other bash the pully.

[bmcecosse]

Yes - shock treatment is the way. No point trying to hold the flywheel - just shock the spanner with a large lump hammer and rely on the engine inertia. Last one I did needed many very hard blows - but it came off in the end.

[Cam]

Engine inertia? But it just 'bounces' round! I have either used the starter method or jammed the flywheel. You can't rely on engine inertia for tightening up either!

[bmcecosse]

Believe me - inertia works ! Good hard smack on the spanner - yes it spins round - but eventually it comes loose. I don't attempt to tighten it that way - but then I rely on Loctite.

[Innovator]

I always lock the flywheel with a piece of square bar with a couple of holes in it. I bolt it to the flywheel using one or 2 of the clutch cover bolts and then to the back plate usinf one of the gearbox bell housing bolts.

If a socket and long bar doesnt get it off, then I will try a hammer. However the best method is a big impact wrench, either air or electric.

Alternatively a hammer and chisel will remove most tight nuts or bolts. It may sound destructive but often a very hard hit will loosen the fastner with very little damage.

John

[Shawn]

Thanks all,

I wound up locking the flywheel with a concrete star drill, and hitting my big 1-5/16 spanner with a big hammer. Took about three blows.

Tried the same method on the cam nut, but wound up using the "hammer and chisel" method, because the thin nut wouldn't hold the spanner cleanly.

...now to get the cam out...

[Packedup]

If you can't be bothered trying to wedge the crank (sump off) or lock the flywheel, then shocking does work. It can take a fair few heavy blows though, but then so can getting the thing loose with the crank held steady...

[Cam]

Believe me - inertia works ! Good hard smack on the spanner - yes it spins round - but eventually it comes loose.

Seems like you are making life difficult for youself there, but whatever floats your boat!

I don't attempt to tighten it that way - but then I rely on Loctite.

Well, you CAN'T tighten it that way! And I'd rely on a large spanner/socket/torque wrench rather than having it loose and using loctite!

[NZJLY]

Can't spell, and posted twice

[NZJLY]

And always remember to flatten the lock washer - otherwise it takes longer And when we have finihed, I have been using the starter handle to get it tight, then the lock washer. No problems so far, but I might have done that to the motor that blew up
John

PS: Nice engine stand

[bmcecosse]

I would rather not knacker the teeth on the flywheel! I can get it tight enough ok by wedging the flywheel - but it's too brutal (for me) when trying to get one off that hasn't been undone in 40 years!

[TeHoro]

Another approach....

I had to do this recently becaue I wanted to swap on a harmonic balancer pulley from a Mini. The engine was in the car and I found that the clutch wouldn't hold against a big spanner and length of pipe. I didn't fancy the starter approach so I used a different trick.

1. Remove 1 sparkplug.
2. turn engine so it is somewhere below tdc on that piston
3. Feed a length of (clean new) rope in through the sparkplug hole.
4. Turn crank so piston is pressing rope against the head

This was definitely firm enough to get the crank nut off, and works for tightening as well without messing around with crowbars.

I had some problems tightening the nut back up because the hex sits well inside the harmonic balancer part and the spanner didn't fit in there. I got it done in the end using a somewhat embarassing approach ( no one mention plumbers tools OK).

Trev.

[bigginger]

As if we would!

[Cam]

I have used the 'jamming of the flywheel' method many many times on different engines and it works great. I have never damaged a flywheel tooth doing it as the 'jamming' device is already in contact and the tooth is of sufficient thickness (and distance away from the crank centre) to spread the load. I would not like to use the 'rope trick' as you are effectively transmitting 70 odd foot pounds (dry) onto the small and big ends. I know this is probably ok but I just don't like the sound of it.

Besides which, the jamming of the ring gear is the method recommended in the manuals as well.

[bmcecosse]

Remember the ring gear is only held on the flywheel by friction !

[Cam]

...and a little corrosion!

Have you ever had one slip off/round?

[bmcecosse]

No - because I don't use it when trying to force the starter dog off!

[Cam]

Just wondered if you had had a bad experience with it which caused you to use a different method...