Ariel Owners Motorcycle Club

Just fitted the new key.....its as "snug as a bug in a rug" compared to the old. I would say about .0005" clearance as opposed to considerbale play in the old...probably in excess of 0.002". It also definitely showed signs of fretting on the shaft portion of the key. I'm hoping, as per Mark's experience, goes a long way to tightening things up.

Cam

Hi All
The Henkel site runs a comparison engine between different Loctite products.....I have more confidence in this than some of the chat rooms that pop up! Looks like 648 is the appropriate option, given the interference fit.

Link below;

https://www.henkel-adhesives.com/br/en/ ... e_648.html

Cam

Should there be any discernible clearance between a Woodruff key and the crankshaft? I've not removed the connecting gears on mine yet, but every other engine I have worked on has had very tight Woodruff keys. They have needed to be driven out of place and on rebuilding with new ones, they needed to be tapped in.

Hi Allan
It's not an interference, but pretty snug. Roger Gwynn advised the tolerance is between 0 and .002", so on that basis I would appear to be in a good place. As above, the original key had about 0.002 to 0.003" , and had signs of fretting on the shaft portion.

Cam

Ahh, I see. It sounds like yours is fine now.

camstevens wrote:Hi All
The Henkel site runs a comparison engine between different Loctite products.....I have more confidence in this than some of the chat rooms that pop up! Looks like 648 is the appropriate option, given the interference fit.

648 is what I settled on for the VH
I made a call to Loctite tech support about the various specs - albeit 4 years ago, and I've not checked the specs since.
At June 2017:
Loctite 648 - should be OK, new formulation is slightly better performer, but at 200C performance goes off a cliff
Loctite 6300 - thinner than 648 but not as strong (648 is 30%-50% stronger), but less heat degradation (NB no toleration of oil on surfaces)
Loctite 620 - higher temp but thicker to apply so likely to get pushed out of the surfaces

SG

When this problem appeared on my 4G, shortly after the rebuild, I put the gears back on with Loctite 620. Getting on for 3000 miles later, the problem is still solved - but I don't tow a double adult sidecar around with the bike!

Hi Simes
I think I used 620 loctite .

Cam,
As for the new woodruff key - I had to press it into the shaft as there was no discernible play . ( Also using a press helped ensure it was straight and unlikely to shift / ride up as the coupling was pressed on.)
- Another check - engage the woodruff key separately on the coupling before reassembly in case there is play there instead.

Good luck
Mark

Hi Mark
Actually, my woodruff key is a tighter fit than I thought (interference) as I hadn't pressed it all the way to the base of the shaft slot. However, there is about 0.002" play in the gear slot. The loctite is really designed for curved mating surfaces, so not sure if it would help to "pack out" the gear slot.
Apparently 0.002" play is within alowable tolerance, but I do have 0.002" shim, but I'm not sure if it would be practical to use.

Cam

camstevens wrote:
Apparently 0.002" play is within allowable tolerance, but I do have 0.002" shim, but I'm not sure if it would be practical to use.

Cam

Hello Cam,
Do you mean it is not a practical proposition to try and fit the shim, or that you feel it would be of no practical benefit?

Allan.