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Gt500 crank

Posted: Thu Mar 06, 2014 7:57 pm
by Jared51082
Does anybody know of a good shop that can rebuild a 76 gt500 crank? I'm located in the US.

Re: Gt500 crank

Posted: Thu Mar 06, 2014 9:34 pm
by jabcb
Bill Bune does a lot of crank for forum members.
http://www.billbune.com/services.html

Re: Gt500 crank

Posted: Fri Mar 07, 2014 7:39 am
by Jared51082
The crank is actually in ok shape. I mostly would just like to replace the seals and orings. It may be in need of one bearing on the right side but the others seem good. Where can I source the bearings if needed?

Re: Gt500 crank

Posted: Sat Mar 08, 2014 12:12 am
by oldjapanesebikes
Jared51082 wrote: It may be in need of one bearing on the right side but the others seem good. Where can I source the bearings if needed?
The only source I know of for new bearings made as per the original ones to fit T and GT 500s is Pete O'Dell - http://tr500.co.uk/index.htm" onclick="window.open(this.href);return false; 8)

Re: Gt500 crank

Posted: Sat Mar 08, 2014 12:15 pm
by Jared51082
I did get a quote from mr. Odell and he charges $135 to rebuild the crank and around $225 for each bearing (that's if I'm doing the monetary conversion correct). Are these good prices for the job? I know the parts are rare and expensive but to just get the crank 100% I'm probably looking at something like $800-$1000 if I had to guess.

Re: Gt500 crank

Posted: Sat Mar 08, 2014 12:56 pm
by dyrberg123
Hi, i have only heard good about Pete's crank bearings, and yes it is many $$$$ but the crank is vital, and if you cut corners you might end up with bigger costs. All the engines i have worked on, i always went all the way with the crank. It gives Peace in mind. Better to wait until you have the Money.

Re: Gt500 crank

Posted: Sat Mar 08, 2014 1:38 pm
by GT750Battleship
:up: Hi,the joys of restorations !! If I was concerned about the costs involved I would never have started in the first place :cry: Proper resto's go a lot deeper than a paint job & having a few bits chromed ? I gave up keeping records of what things cost years ago!now only keep a record of when I did the repair/replacement ! :?
Cheers,
Roger.

Re: Gt500 crank

Posted: Sat Mar 08, 2014 1:44 pm
by ConnerVT
Jared, I think you may be getting ahead of yourself.

First, have you disassembled your motor, and evaluated the condition of your crankshaft? Check that the three Main Bearings spin smoothly, and don't have obvious signs of deterioration/rust. Unless you are building up a competition engine, it is most likely that your bearings are good.

Next, check the condition of your connecting rods and large rod bearings. Rods in good condition, minimal side play in the rods (someone here knows the spec), free of corrosion, rotate smoothly? Again, these parts most likely can be reused.

The small end bearings are still available, and are not very expensive ($10/ea). Worth replacing during rebuild (along with the piston pins and circlips).

If the crank is in serviceable condition, a rebuild will likely be just a dis-assembly of the crankshaft, cleaning, and reassemble with new seals. Since you are in the USA, Bill Bune is a recommended rebuilder, $125+seals+shipping.

If your crankshaft is toasted (as the one on my '71 T500 was), you may be better off locating another motor with a serviceable crank. Or at least, with enough parts to make one crankshaft out of 2. I picked up a nicer motor than was originally on my bike for $300, and had a number of spare parts for the rebuild. I believe the T500 and GT500 crankshafts are the same, with the exception of the left side (Crankshaft, LH 12261-15001) which is different due to the electronic ignition vs. breaker points. (Again, others here would know better).

Re: Gt500 crank

Posted: Sat Mar 08, 2014 2:57 pm
by Pete O'Dell
incorrect i'm afraid, whilst t and gt cranks will both interchange in cases (although cases are different to) the crank are different in the balance and fitting a end from either crank on the other will cause severe vibration and bearing damage.

Re: Gt500 crank

Posted: Sat Mar 08, 2014 5:26 pm
by ConnerVT
Bummer. Thanks, Pete, for the info. I knew there was a physical difference on the one end (electric side). But wanted someone with experience to sound in, before stating as fact that they were interchangable.

Makes locating a second engine/crank a bit more trouble for the GT, I'm afraid. :(

Re: Gt500 crank

Posted: Sun Mar 09, 2014 7:52 pm
by Jared51082
Yes VT I have torn the motor down to just the cases. When I removed the cylinders one piston looked as tho it had no carbon build up at all like it had been running lean maybe. The motor is in verry good condition over all but when I got to the crank the right side was absolutely dry and slightly heat stained. As for the bearings the left and middle spin nice and smooth. The right bearing is kind of rough and spins free like an old roller skate wheel. I think everything else is in good condition and reusable.

The guy I bought it from is most likely the reason the for the problems on the right side. He had been trying to run it after it had been sitting for 15+ years with no prep like carb cleaning and making sure the oil lines were clear etc.

Re: Gt500 crank

Posted: Mon Mar 10, 2014 2:36 am
by Pete O'Dell
if the middle bearing spins smooth then the seals have gone

Re: Gt500 crank

Posted: Mon Mar 10, 2014 1:19 pm
by Jared51082
Well just so I don't confuse anyone on this issue I will try and explain better. Neither the left or center bearings will "spin free" but when rolled manually by hand they feel smooth. Left and center both have slight resistance where the right has none and will free spin multiple revolutions when rolled by hand.