Yamaha G1 Crankshaft Bearing and Seal Replacement Sequence

Cisgww

Member
I need to know/confirm the proper crankshaft bearing and seal replacement sequence.

My cart is a 1981 G1-A2, code #J10. My service manual 1st published December 1981 is for 1982 G1-A3, code #J24.

On page 3-11 I find this:
3. Bearing and oil seal installation
a. Install bearings with their manufacturer's marks or numbers facing outward. They should be visible when installed.
b. Install oil seals with their manufacturer's marks also facing outward.
c. Always thoroughly lubricate bearings and oil seals with the specified lubricant before installing them on the crankshaft.
On page 3-12 I find this:
3-3. ASSEMBLY AND ADJUSTMENT
A. Bottom End
1. Fitting the crankshaft assembly.
a. Lightly grease the crankcase seal lips.
b. Carefully install the crankshaft (left half) into the crankcase (left half).
c. Install the crankshaft setting tool.
d. Place the crank at TDC, and hold the crankshaft assembly with your hand.
e. Using an off-set wrench, tighten the setting bolt nut so that the crankshaft is fitted in position.

So it appear that I install the bearings and seals first into case and then pull the crankshaft into them second?

If so, I should ignore the suggestions of heating the bearing in oil so they expand to enable an easy install onto the crankshaft and then draw the crank with bearings into the crankcase.

Am I correct on understanding the process?
 

Cisgww

Member
Also, I have a Tusk splitter/puller, borrowed from a friend. That said, neither of the two adapters will thread onto the fan end of crank (both too small), nor will the flywheel nut fit inside the puller without rounding down the hex pattern.

I need to get another nut and grind it down to fit. What is the size of the threads on the end of the crankshaft...diameter and thread pitch? Any other ideas?
 

Cisgww

Member
On 1981 G1, what is the size of the threads on the end of the crankshaft...diameter and thread pitch?

I have a Tusk splitter/puller, borrowed from a friend. None of the adapters will thread onto the fan end of crank, nor will the flywheel nut fit inside the puller without rounding down the hex pattern. I need to get another nut and grind it down to fit inside the puller..

Any other ideas?
 

Cisgww

Member
On 1981 G1, what is the size of the threads on the end of the crankshaft...diameter and thread pitch?

I have a Tusk splitter/puller, borrowed from a friend. None of the adapters will thread onto the fan end of crank, nor will the flywheel nut fit inside the puller without rounding down the hex pattern. I need to get another nut and grind it down to fit inside the puller..

Any other ideas?
Found it!
Need a flywheel nut for the crankshaft? Size is M16-1.0. Go to any auto parts store and have them pull this Dorman spindle nut #615-082. Bought 2 for under $5 with tax.D1D7D491-D6C6-478F-BC3F-CA04F5D9205B.jpeg
 
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