Crankshaft tool and Bearings


13 replies to this topic
  • SXP

Posted February 27, 2004 - 07:21 PM

#1

I just finished splitting my WR400 case in preparation for an Eric-Gorr to-be-installed 426 rod. The crank ships to him Monday. Many thanks to MAD_POTTER and NH_Kevin, and the many others who went there before (via the TT Search function) for their invaluable advise. While the split went fairly smoothly, I'm a little concerned about how I'll be able to pull the crank back thru the left case main bearing. The tool in the book probably cost $$$. Any advice on home made tools? I'm changing the main bearings so I expect an even tighter fit. BTW, why does the right case bearing simply slide off the crank, while the left is pressed? Are the bearings different, or is the diameter of the shaft different on the two ends?

I'll be changing out all the bearings while everything is open, so I'm wondering how folks feel about aftermarket bearings? Pro's, cons? Any good links to bearing shops? If I use a propane torch to heat the case up around the bearings, is there any risk of permanently warping the case?

Thanks.

  • Hick

Posted February 27, 2004 - 10:22 PM

#2

Any advice on home made tools? I'm changing the main bearings so I expect an even tighter fit.



This is an easy one, all you need is a universal steering wheel puller, or you can make one. I used a piece of angle iron, some 6mm all-thread (threaded rod), 2 6mm nuts, and the stock 12mm mag nut (or was it 14mm?) for the crank. There are two threaded 6mm holes on either side of the crank in the left case half, put there for the purpose of installing the crank. So you drill three holes in the angle iron, 2 6mm in diameter spaced to match the dimension of the holes in the case, and the third (12 or 14, I forget, probably 12...) in the center for the crank.

Cut the all-thread, install two pieces in the case w/ nuts on the ends, fit the angle iron over these and the crank end, and "suck" the crank into the bearing from the magneto side using the stock flywheel nut. About a two minute job, all told (but I have air tools).

I've not tried a universal steering wheel puller kit, but given how they operate I see no reason to believe they wouldn't work perfectly right out of the box (provided that the 6 mm metric requirement is met....)




BTW, why does the right case bearing simply slide off the crank, while the left is pressed? Are the bearings different, or is the diameter of the shaft different on the two ends?


Surely the crank is what is different since the bearings are standard-sized. If you reinstall a crank into its own bearing in my expereince no puller is needed.

:)

I'll be changing out all the bearings while everything is open, so I'm wondering how folks feel about aftermarket bearings?




I shopped around, but only very slightly (1 phone call), the savings in an aftermarket bearing in my case was minimal, and availability was questionable. Given that I needed many, many (many) other Yamaha parts I didn't see the point.







If I use a propane torch to heat the case up around the bearings, is there any risk of permanently warping the case?



I doubt it. Unless the cases are new also, the bearings won't be that difficult to get in. But I would want to use a press anyway, and freezing the bearings is probably as helpful as heating the cases, if not more so.


Hope this helps.

  • dubious

Posted February 28, 2004 - 07:26 AM

#3

Yup put the bearings and crank in the freezer, and put your cases in the oven.They fall right into place :)

  • SXP

Posted February 28, 2004 - 07:35 PM

#4

Thanks for the info on the tool - why didn't I thinks of it :)
When pressing out the bearings, can I lay the cases flat on the ground (on wood) and pound the bearings out, or do I need some kind of support directly on the casing around the bearings? The problem is that the area around some of the bearings is irregular so I cant get, for example, a slightly oversize PVC coupler in there to provide support to the case. Any ideas, especially as I don't have access to a press?

When reinstalling the bearings, how hot do I get the cases in the oven?

Thanks for all your help.

  • Hick

Posted February 29, 2004 - 03:07 PM

#5

I think heating the cases to 300 degrees would not be too extreme, but would be enough to work. I've never tried this method but it would seem safer than using a torch, which is what I did. Leave the bearings in the freezer for several hours and they should go into a 300 degree case w/out too much of a fight (unless it is a new case).

The face of the case will support the force needed to extract the bearing, but I don't know about using a hammer.

Anybody done this w/out a press?

  • SXP

Posted March 01, 2004 - 06:02 AM

#6

Thanks again.

Any quick way of getting the hardened thread lock compound out of all the bearing retainer bolt hole threads?

  • Hick

Posted March 01, 2004 - 07:31 AM

#7

Thanks again.

Any quick way of getting the hardened thread lock compound out of all the bearing retainer bolt hole threads?



Ooooh, I forgot about that, should've mentioned it.

About the only way those are going to come out is with an impact driver, the kind you hit w/ a hammer. As it was I buggered a few anyway and had to buy a few replacements. Heating them up will sometimes soften the loctite, or whatever Yamaha puts on there, but you are still going to need the impact driver in my experience.

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  • SXP

Posted March 01, 2004 - 09:53 AM

#8

Actually, I was referring to the hardened crap left in the bolt holes after you break the bolts free. I'm sure if I don't remove it, it's going to give me false readings when using the torque wrench during reinstallation.

  • Hick

Posted March 01, 2004 - 11:24 AM

#9

Oh, my bad.

If chasing the threads w/ a blind tap makes you queasy I'd suggest a really stiff wire bore brush.

  • SXP

Posted March 03, 2004 - 04:59 AM

#10

I got all the bearings out without too much trouble except for one. This one supports the Main shaft (with the pinion gears?) in the left case and has no opening on one end. It's the bearing that covers the business end of the clutch actuator rod in the engine.

Any ideas?

  • Hick

Posted March 03, 2004 - 08:08 AM

#11

Any ideas?



I know exactly which bearing you are referring to but I don't have any answers; when I did this job I also had to replace the cases so I didn't have to face this problem.

The only suggestion I can offer is the freezer/torch trick. The cases should heat up quicker than the bearing, especially if you keep the torch away from the cold bearing.

You may have to use a bearing puller.

  • SXP

Posted March 03, 2004 - 09:33 AM

#12

I received a PM from another lister who used a "slide hammer" with a hooked end. Off to Harbor Freight to see if I can pick one up.

Thanks for all your help - the end's in sight.

  • SXP

Posted March 04, 2004 - 08:19 PM

#13

The tool I needed is a "Blind Hole Bearing Puller". Found/rented it from Autozone and it took precisely all of one minute to remove that one tricky bearing. Pretty neat. The kit had 4 collets and I noticed between the four of them I could have pulled all 9 of the case bearings without the need for a press or any pounding with a hammer/risking damage to the case. The right size collet is slipped thru the inner race of the bearing and expanded using a flaring bolt that screws thru the middle of it. The "teeth" on the collet then expand out and grip the inner race. The collett is then attached to a slide hammer and after a couple of knocks the bearing pops out.

I had to deposit $150 bucks thru my credit card with Autozone while I used the tool and they refunded the entire amount when I returned it. I highly recommend this tool to anyone planning on removing bearings, especially that one blind hole bearing in the left case. And best of all, it's free!

  • Hick

Posted March 05, 2004 - 07:50 AM

#14

Cool, I forgot about their new tool rental policy.

Good tip, those bearing pullers do work well. :)




 
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