Pulling that Pesky Main Shaft Bushing

[hodakamax]

Here's a quick and easy way to pull the main shaft bushing.

The only special tool you will need is a 1/2 – 13 standard tap (#1) and a few things from the hardware store.

Tap the bushing as shown (#2), about three turns will be all that is needed. You only want to tap about 1/2 the length of the bushing. Don't panic if it's not quite square, it will still work fine.

The puller is a standard coarse 1/2 inch bolt/nut/washer and a spacer – mine is a piece of conduit cut to about 5/8 inch (#3).

Screw the bolt into the bushing (hand tight) and tighten the nut until the bushing is removed (#4). You'll be surprised at how little effort is needed both tapping and pulling (#5).

Hope you find this useful.

Max
(Yes Bob, they're in the mail, really!)

[tudor8055]

Thats how we remove injector cups in diesel engines.

Mark Tudor

[Firehawkmph]

Max,
Did you ever try the trick with filling the bushing with grease and tapping the end of the main shaft into it using a non marring type hammer? Pops right out like magic. It's either in the manual or one of those tech tips on Paul's site. Can't remember where I read it, but it works great.
Mike Hawkins

[bchappy]

Max, you must be the kind of guy that lays awake at night figuring out how to best do things. This should have been in the service manual instead of the pack with grease and drive out with hydraulics that Mike mentioned. The old method didn't work real well if the bearing was worn a lot. Of course you didn't need any special tools for the old method.

[hodakamax]

Honestly, I've never tried the hydraulic method. I came up with this method years ago out of necessity. You have to admit that this method is more esthetically pleasing than grease, hammers and pliers! (lol). Also as far as 'special tools', the tap can be bought for less than the price of a new bushing. "What ever works" I say!

Maxie

[racerclam]

You can also tap the new bushing for better lubrication , done that for years for automotive trans pilot bushings .

Rich

[socalhodaka]

You can also tap the new bushing for better lubrication , done that for years for automotive trans pilot bushings .

Rich

Rich, can you give a little more detail? So tab the bushing with threads? then put the shaft in?

[bchappy]

I am jumping ahead of Rich's answer but it is bedtime. You can also drill an oil hole that can get a little more oil to the bushing.
These pictures are of a Super Combat case and the pictures above do not have an extended boss so it would not be so easy to drill the hole.

[dirtsquirt80]

Great Idea! I never saw that one before. thats why this is such a great forum your always learning something. thank's guy's!

[racerclam]

I have drilled the hole too. But the busgung had a tendency to turn abit closing of the hole !!!!! Now I use a needle bearing

Rich

[hodakamax]

While on this subject, it might be interesting to note that early on Hodaka offered a needle bearing kit for 90s with instructions on how to machine the cases to accept caged needle bearings on both the main and counter shafts. It was a modification done to my 90 racer at the time.

The first super rat (93) had this setup. The 93A went back to a bushing on the main shaft. Model 94 Wombats went back to a bushing on the counter shaft. There must have been some issue on the main shaft cage bearing, although I raced the early Super Rat and 90 for years with no problems.

By the way, you can save a 94 case when the counter shaft bushing has failed and eaten into the case (as I had to do on mine) by machining the hole to accept the early Super Rat caged bearing #931004.

Maxie

[hodakaguy]

Interesting. I thought all Super Rats had the needle bearing? I have never seen one without one (except if it is not a true Super Rat engine case).

[hodakamax]

I also thought all Super Rats had the needle bearing but the schematics on the SH site show the 93A back to a bushing.

Max

[hodakamax]

Hey hodakaguy--now you have me double checking--I have an original Super Rat owners hand book #939510A for beginning frame #B-53113 that also shows the bushing. I'm with you- I thought otherwise.

Maxie

[bchappy]

Another mystery. If the needle bearing was thought to be better, why did the Super Combat come out with a bushing? Of course, maybe like Maxie said, maybe there was some issues with the needle bearing.

[hodakamax]

And to continue our story the Super Combat went back to the caged needle countershaft bearing.

Max

[rlkarren]

Wow.. interesting... I also thought all Super Rats used the caged needle bearing. When trying to find a replacement left-half case, I'd run into a couple M-code motors that required a Main Shaft bushing... I thought that maybe they were "replacements". Maybe I'll I'll go find those cases again... hmm...

[bchappy]

Max, Now I am confused. The schematic of the Super Combat shows the bushing and not the caged needle bearing. And the pictures I posted yesterday are of my Super Combat. How about a little help here. Did the SCs have both kinds?

[racerclam]

You can tap the bushing in the case if your not too agressive , that could spin in the case , then you may have to deburr it since the tap could raise a bit of metal'
Have had replacement 98 cases that came with a needle bearing for the main shaft pilot , AND! they also came with a sleeve to press on to the pilot for a larger wear surface for a larger bearing. Pretty cool. That is how the 250s are they come with a sleeved pilot. It may be that it a harder material than the shaft it self. Remember that the actual surface that carries the load of a needle bearing is actually alot less than a bushing and that could have been an issue with pilot wear Thus the sleeve and larger bearing .

Rich

[hodakamax]

You're right Bill, the Super Combat had a bushing on the main shaft and a caged bearing on the countershaft. This is getting confusing! My last post was about the countershaft on the super not the main shaft.

Maxie

[hodakamax]

Thanks Rich--This all sounds very logical. Even if the sleeve was of equal hardness the sleeve would take all the wear and protect the mainshaft.

Max

[hodakamax]

More--the schematic on the SH site for the 250 SL shows the sleeve and lists it as "inner race". Mystery solved--good job Rich on pointing that out!

[taber hodaka]

The last super rat engines I worked on I couldn't figure out the bearing and bushing difference I was confused I either didn't know or forgot. The forum sure keeps us updated.------------Clarence

[hodakaguy]

I don't know how accurate the original manuals were. I remember looking at the Workshop manual and the super rat part of the manual shows a helical cut gear when a straight cut gear was really used. Maybe someone who has a super rat engine with a bushing can chime in? It is a small mystery.

[hodakaguy]

Max, Now I am confused. The schematic of the Super Combat shows the bushing and not the caged needle bearing. And the pictures I posted yesterday are of my Super Combat. How about a little help here. Did the SCs have both kinds?

Go here and this is the schematic I see:
http://www.hodaka-parts.com/97_B.asp
Part # 3 is it. All the super rat93s and 98s show the same thing.
This is what we are talking about, yes? or maybe another bearing/bushing?