Front pulley crankshaft

[Matt Kirsch]

However, I would like to encourage the use of the threaded rod for reinstallation of the pully. Several times, at cubfests, I watched the front pulley installed by heating the pulley, then rushing to put it on, and ending up using an impact wrench for the final distance as the pulley cooled off. I'm sure this isn't really good for the crankshaft. Guess it really depends on how hot you get it, but then you risk damaging the new seal. Anyway, Raymond Durban's method is easy, does require some muscle, but if I can do it with my weenie arms, anyone can!

Well, the engine oil gets to AT LEAST 200F under normal operation, so a 200F pulley is not going to bother the seal one bit. That's why I'm quite specific about the temperature of the oven.

I'm also not sure how drawing the pulley on cold has any less potential for damaging the crank than drawing it on hot.

Worst thing you can do, though, is rush. That is all but guaranteed to end in a panic.

[Jim Becker]

. . . Well, the engine oil gets to AT LEAST 200F under normal operation, so a 200F pulley is not going to bother the seal one bit. . . .

200 is leaving a pretty wide margin. Buna-N (nitrile) is good for at least 250, neoprene 275, and Viton 400. These are working temperatures. Each should be able to stand much higher brief exposures before they start to melt or burn. You have to expect the pulley to loose quite a bit of heat by the time it is pushed on far enough to contact the seal.

[MattS]

"The seal installs from the backside?" That's news to me.

When I did the front seal on my 1953 Cub, I had to remove the BOLSTER, but not the front engine cover. Old seal popped right out the front. New seal tapped back in the front.

Also, I did not need a bolt to install the front engine pulley. All I needed was an oven. Put the pulley in at 200F/90C for at least an hour. Have a wood block and hammer handy by the front of the tractor. Get your oven mitts. Take the hot pulley from the oven, run out to the shop, and slide it on to the crankshaft. If it doesn't go all the way on, take the wood block and use it to tap the pulley the rest of the way on.

The hard part was getting the pulley OFF.

I must apologize...I was confusing two tasks (front seal replacement on the cub AND the Super A, which DOES install from the backside)...you are correct, the front seal replacement on a cub does not require removal of the front engine cover. SORRY.

However, I would like to encourage the use of the threaded rod for reinstallation of the pully. Several times, at cubfests, I watched the front pulley installed by heating the pulley, then rushing to put it on, and ending up using an impact wrench for the final distance as the pulley cooled off. I'm sure this isn't really good for the crankshaft. Guess it really depends on how hot you get it, but then you risk damaging the new seal. Anyway, Raymond Durban's method is easy, does require some muscle, but if I can do it with my weenie arms, anyone can!

Something else that might be mentioned is the possible need for a "Wear Sleeve" or "Speedi Sleeve" in case there is an excessively deep groove worn on the pulley shaft. TM Tractors, a forum sponsor with link below, carries them, but they may also be available from auto parts stores.
http://www.tmtractor.com/new/en/472fp.htm

P.S. Thanks to Glen who also pointed this out to me!

No problem, now I would have the solution if I bought a Super A

That means that with the threaded rod you didn't heat up the pulley ?

Yes I have to check that

[Dale Finch]

No heat...a bit of antisieze on the theads as well as between washers. That's it.

[MattS]

Ok, that's good to know

[MattS]

Thanks for your answer.

So the bolt we need to use to remove the pulley is a 1/2 -13 x 6in Grade 8 bolt but what does the grade 8 mean (we have not the same designation in France )


Last question : to install the pulley, I think it's better to use a threated rod 1/2-13 ? I think the bolt will be to short.

Hi everyone,

It's been a long time since the last message I have planned to make this work in the few next days. I just want to come back with the topic from the threaded rod, should it be a 1/2-13 UNC or a 1/2-13 UNF rod

Thanks,
Matt

[Bob McCarty]

There is no 1/2-13 UNF. UNC stands for unified national coarse (coarse thread), whereas UNF stands for unified national fine (fine thread). 1/2-13 is a coarse thread, 1/2-20 is a fine thread. I'm not very familiar with metric, but 1/2-13 means 13 threads per inch, 1/2-20 means 20 threads per inch. Hope that helps.

[MattS]

There is no 1/2-13 UNF. UNC stands for unified national coarse (coarse thread), whereas UNF stands for unified national fine (fine thread). 1/2-13 is a coarse thread, 1/2-20 is a fine thread. I'm not very familiar with metric, but 1/2-13 means 13 threads per inch, 1/2-20 means 20 threads per inch. Hope that helps.

Thanks for you answer