peening layshaft bearing

mcns · Apr 29, 2010

I will be putting in the stronger layshaft bearing this weekend, and will be using green loctite(the strongest they make according to their salesman).

My question is that I was also considering peening the bearing in 3 or 4 spots with a center punch. Does anybody out there think that this is a good idea or not and if so how far away from the bearing should it be done?

thanks

swooshdave · Apr 29, 2010

post58604.html#p58613

You had the loose layshaft bearing. I'd probably just Loctite it and let it be. You don't necessarily need the strongest Loctite, just one that is meant to take up any clearance.

From what I understand the layshaft bearing isn't under the most tremendous load.

tpeever · Apr 29, 2010

mcns said:
I will be putting in the stronger layshaft bearing this weekend, and will be using green loctite(the strongest they make according to their salesman).

My question is that I was also considering peening the bearing in 3 or 4 spots with a center punch. Does anybody out there think that this is a good idea or not and if so how far away from the bearing should it be done?

thanks

When I disassembled a 75 Moto Guzzi 850T gearbox this past winter I was surprised to find that all the bearings in the cases had been peened in. Generally in 3 locations 120 degrees to each other about 3 mm from the outer race of the bearing around the periphery of the bearing. I assume this was done at the factory as I am pretty sure the gearbox had never been apart. I have never seen this on a British bike which makes me wonder why it would be necessary. Peening seems an incredibly crude technique to keep a bearing seated. It would seem to me that other techniques like Loctite are preferable if you ever plan on getting the bearings back out without damaging the cases. When I have replaced bearings in Nortons and related bikes with AMC gearboxes, I have frozen the bearings and heated up the cases on my gas BBQ. They have all dropped in as sweet as can be and seated very tightly without any assistance from Loctite or a punch.

swooshdave · Apr 29, 2010

tpeever said:
mcns said:

I will be putting in the stronger layshaft bearing this weekend, and will be using green loctite(the strongest they make according to their salesman).

My question is that I was also considering peening the bearing in 3 or 4 spots with a center punch. Does anybody out there think that this is a good idea or not and if so how far away from the bearing should it be done?

thanks

Click to expand...

When I disassembled a 75 Moto Guzzi 850T gearbox this past winter I was surprised to find that all the bearings in the cases had been peened in. Generally in 3 locations 120 degrees to each other about 3 mm from the outer race of the bearing around the periphery of the bearing. I assume this was done at the factory as I am pretty sure the gearbox had never been apart. I have never seen this on a British bike which makes me wonder why it would be necessary. Peening seems an incredibly crude technique to keep a bearing seated. It would seem to me that other techniques like Loctite are preferable if you ever plan on getting the bearings back out without damaging the cases. When I have replaced bearings in Nortons and related bikes with AMC gearboxes, I have frozen the bearings and heated up the cases on my gas BBQ. They have all dropped in as sweet as can be and seated very tightly without any assistance from Loctite or a punch.

If you saw his previous post he mentioned that he believes the bearing is loose. I assume that mcns has had the box apart and checked the bearing fit. He just mentioned that the kickstart shaft was moving despite loctite on the outer race.

In that case I can see where staking might be an option.

No idea why the Moto Guzzi was staked, my guess is that they got enough bearings with varying tolerances on the outer race to need it.

BrianK · Apr 30, 2010

FWIW, I faced a similar issue with the carrier bearing (u-joint rides in this in the swingarm) on an old Guzzi. The u-joint is supposed to be an interference fit into the bearing, but the u-joint slid in and out of the bearing too easily and there were signs of slippage on the part of the u-joint that rides in the bearing.

I ended up peening it with a punch a few dozen times and then coating with Loctite 609 before installation.

All seems well so far.

YMMV. Good luck.

tpeever · Apr 30, 2010

BrianK said:
FWIW, I faced a similar issue with the carrier bearing (u-joint rides in this in the swingarm) on an old Guzzi. Supposed to be an interference fit, but it slid in and out too easily and there were signs of slippage on the part of the u-joint that rides in the bearing.

I ended up peening it with a punch a few dozen times and then coating with Loctite 609 before installation.

All seems well so far.

YMMV. Good luck.

Interesting! I will be re-installing my driveshaft carrier bearing shortly so we'll see how it goes. It was pretty hard to get out so hopefully the new one will stay put on it's own. I have been thinking about how to install this bearing as I won't be able to do my usual routine of heating the race with a propane torch and dropping in a frozen bearing. I don't want to ruin my nice new powdercoating job on the swingarm!

Here's a shot of a few of my Guzzi gearbox case complete with factory staking job!

BrianK · Apr 30, 2010

To be clear, I didn't remove the carrier bearing (those, as I understand it and I guess you've found out, are a total PITA to get out - don't think you'll have to worry about peening that one!). I was referring to the u-joint itself - it is supposed to be an interference fit into the ID of the carrier bearing, but wasn't. So I peened the part of the u-joint that slides into the bearing, then applied the green loctite.

PS - I see now that I worded my previous message poorly, so I've edited that for clarity.

tpeever · Apr 30, 2010

BrianK said:
To be clear, I didn't remove the carrier bearing (those, as I understand it and I guess you've found out, are a total PITA to get out - don't think you'll have to worry about peening that one!). I was referring to the u-joint itself - it is supposed to be an interference fit into the ID of the carrier bearing, but wasn't. So I peened the part of the u-joint that slides into the bearing, then applied the green loctite.

PS - I see now that I worded my previous message poorly, so I've edited that for clarity.

Gotcha! I haven't checked the fit of the U-joint in the new bearing yet. Better do that.

The carrier bearing was difficult to get out but not impossible. I might have heated up the swingarm first. Can't remember. Did you replace your U-joint? I was debating about it. My bike has 30K on it and the U-joint seems solid so I am re-using it.

I guess we'd better get back onto Commando content or we might get banned from the site! Shaft drives not welcome here!

swooshdave · May 1, 2010

tpeever said:
BrianK said:

To be clear, I didn't remove the carrier bearing (those, as I understand it and I guess you've found out, are a total PITA to get out - don't think you'll have to worry about peening that one!). I was referring to the u-joint itself - it is supposed to be an interference fit into the ID of the carrier bearing, but wasn't. So I peened the part of the u-joint that slides into the bearing, then applied the green loctite.

PS - I see now that I worded my previous message poorly, so I've edited that for clarity.

Click to expand...

Gotcha! I haven't checked the fit of the U-joint in the new bearing yet. Better do that.

The carrier bearing was difficult to get out but not impossible. I might have heated up the swingarm first. Can't remember. Did you replace your U-joint? I was debating about it. My bike has 30K on it and the U-joint seems solid so I am re-using it.

I guess we'd better get back onto Commando content or we might get banned from the site! Shaft drives not welcome here!

Welcome in Other, not hijacking a Commando thread.

peening layshaft bearing

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