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GT550 crank right outer bearing & oil seal

Posted: Sun Dec 02, 2018 5:56 pm
by jabcb
Rats! Am working the the GT550 cafe build.

We were assembling the motor today & found out that the right outer bearing is on backwards.
This bearing has a groove for the C-ring that laterally positions the crank. The parts diagram is also wrong. Presumably the shop assembled it as show in the diagram.

How difficult is it for us to flip the bearing around? (Am weighing the tradeoff of fixing it ourselves vs. the delay of having the shop do it.)
Will the oil seal be damaged in the process of removing the bearing?

Re: GT550 crank right outer bearing & oil seal

Posted: Tue Dec 04, 2018 6:59 am
by dollydog
hi jab, you'll definitely need a bearing puller - those bearings are on TIGHT. you need the type that tucks in behind the bearing, not a 3 leg. i bought one of these kits years ago, and although it's a bit of a pain to set up, it was well worth the money. the 2 black bits at the top of the photo are the sort to use :D
cheers, dd.
https://www.ebay.co.uk/itm/Hub-Bearing- ... rk:33:pf:0" onclick="window.open(this.href);return false;

Re: GT550 crank right outer bearing & oil seal

Posted: Tue Dec 04, 2018 7:38 am
by jabcb
Thanks for the info.

Using a tool like that likely will damage the oil seal. Also not sure how to get the bearing off without damaging it. So I’ll order a new seal and have the shop do the fix.

Re: GT550 crank right outer bearing & oil seal

Posted: Tue Dec 04, 2018 8:41 pm
by Cliff56
Yes, c clip groove is on the inside!

Re: GT550 crank right outer bearing & oil seal

Posted: Sun Jan 06, 2019 3:06 pm
by jabcb
Quadruple double rats!

Got the crank back from the shop with the bearing oriented correctly. Tried installing the crank & it doesn’t turn!
Compared the dimensions to the specs per service bulletin Specification-7, and the 5 listed dimensions are out of spec.

Don't know what's up. The shop previously rebuilt a few cranks for me & they were fine.

Re: GT550 crank right outer bearing & oil seal

Posted: Sun Jan 06, 2019 3:55 pm
by karl pa
That stinks :(
I have my 550 crank and lower case at the shop now, they like having the lower case and installing crank in it. Hopefully won't have issues.

Re: GT550 crank right outer bearing & oil seal

Posted: Sun Jan 06, 2019 4:41 pm
by jabcb
When he flipped the bearing to orient it correctly, he also flipped the drive gear so that is now wrong.
The error for each of the 5 measurements is small but they add up. Combine those errors with the gear on backwards & the crank can’t turn.
But even if it could turn correctly, the points cam can’t engage the locating pin on the drive gear.

I wish I had thought of giving them the lower case half. This is my first triple build & I didn’t know.
You should be ok. If the crank turns, then you don’t have the problems I’m dealing with.

Re: GT550 crank right outer bearing & oil seal

Posted: Mon Jan 07, 2019 3:42 pm
by Splant
What's happening ,are the flywheel s catching the crankcase? Are you taking it back with the lower crankcase?

Re: GT550 crank right outer bearing & oil seal

Posted: Mon Jan 07, 2019 7:04 pm
by jabcb
Right flywheel of the left cylinder rubs and the drive gear rubs.

I’m undecided on what to do. I ordered new crank seals today to replace any of the new seal that gets damaged if they have to pull the crank apart.

I’m considering two choices:
1) send the crank & new seals to Bill Bune
2) Give the shop another chance. This time they would get the crank, new seals, Specification-7, pics of a correct crank, and the lower case

Re: GT550 crank right outer bearing & oil seal

Posted: Thu Jan 24, 2019 5:55 am
by jabcb
Ended up sending the crank to Bill Bune.

Re: GT550 crank right outer bearing & oil seal

Posted: Thu Mar 07, 2019 7:17 pm
by jabcb
Got the crank back yesterday. Fit perfectly. :D

Re: GT550 crank right outer bearing & oil seal

Posted: Fri Mar 08, 2019 4:58 am
by daxman
Any recompense from the first shop?

Re: GT550 crank right outer bearing & oil seal

Posted: Fri Mar 08, 2019 7:20 am
by jabcb
The local shop rebuilt the crank for the GT250 cafe build & did a bunch of top ends. All of the prior work was fine.
Had I given the shop the lower crankcase half + the service bulletin with the specs, this crank probably would have been fine too.

I’m not going to try to get any $$$ back. There are very few places that work on vintage bikes. I’m not going to poison the well.
The local shop has a pretty low hourly rate. He has a good reputation & knows he screwed up. I see it as lesson learned for him.

Re: GT550 crank right outer bearing & oil seal

Posted: Fri Mar 08, 2019 9:45 am
by daxman
jabcb wrote:The local shop rebuilt the crank for the GT250 cafe build & did a bunch of top ends. All of the prior work was fine.
Had I given the shop the lower crankcase half + the service bulletin with the specs, this crank probably would have been fine too.

I’m not going to try to get any $$$ back. There are very few places that work on vintage bikes. I’m not going to poison the well.
The local shop has a pretty low hourly rate. He has a good reputation & knows he screwed up. I see it as lesson learned for him.
Fair enough - we all make mistakes,. Good of you to take it on the chin.