Bearing front wheel drum brake (Grimeca)

Paul Marx

Paul Marx

Hero member
Location
France
The front wheel bearings on my S are well and truly shot.
I took the wheel out. Heated up the left hand side and knocked out the bearing with ease. When it came to the speedo drive side, no amount of heat and knocking will move the bearing.
Please reassure me: the bearing does come out without the need to take of the speedo drive?

I've had to demolish the bearing taking out the inner race and the balls. Tomorrow, I'll try the bead of weld around the inside of the outer race, otherwise, I'll cut the outer race. Bearings are made from a very brittle steel. Cut a slit in a bearing and you can split it using a wedge such as the end of a screwdriver.

Paul
 
Be very careful of that old aluminium. If running a bead around the outer race is possible, couldn't you tack a cross piece in there to get a better surface to hit or press it out with the alloy heated.
 
Tippie said:
Be very careful of that old aluminium. If running a bead around the outer race is possible, couldn't you tack a cross piece in there to get a better surface to hit or press it out with the alloy heated.
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I'm being very careful. The balls and inner race are out so that leaves me the bead of weld or cutting it out. It's quite possible that the bearing heated up a bit initiating a sort of weld or by the looks of it, a DPO hit the alloy around the housing whilst putting it in since the alloy appears a bit peeled over around the edge of the bearing. I hope that the DPO wasn't me, I can't remember.

A bit of steel welded across the bearing would have been a idea but I did hit it quite hard from the inside and also used a bearing puller, with the alloy of the hub heated of of course.

Paul
 
Got it.
Not being very handy with a welder, I tried the Dremel with a cutting disc first. Cut a slot on both sides of the outer race left in there, keeping away from the alloy to relieve tension, then heat and wallop and out it came.
That bearing had obviously turned in its housing, it was well and truly buggered as was the one on the opposite side it turned out after cleaning.

I'd tanked up on Saturday before an outing of 200km on Sunday. I heard a noise from the front end setting off from the petrol station. I heard the noise again at slow speed setting out from our destination on Sunday and thought "wheel bearing" rather than fork or steering bearing.

The wheel is all cleaned up ready for the new bearings waiting in the freezer. Drum and shoes are wiped off with acetone.

Paul
 
If the bearing is a loose fit - as many are because they've been walloped out cold - then Loctite bearing fit is worth using.
 
Isn’t that the green 600 series stuff? Bearing annd Sleeve Retainer? And yes, I’ve found that a bit of lube will help entry……into most places.
 
Rob said:
If the bearing is a loose fit - as many are because they've been walloped out cold - then Loctite bearing fit is worth using.
Click to expand...
Yep, the stuff is on the shelf but I don't think the bearings will be a loose fit. The second one was rather the opposite.
I've used the stuff on swing arm bearings with great success.
Paul
 
All back in, but I'm not entirely satisfied. It'll do however.
Bearings straight from the freezer.
The brake plate side bearing went in normally. Heat and moderate walloping.
Speedo drive side, the one I needed to break up to get out was another matter. Heat and a lot of walloping.
Once it was in, it initially wouldn't turn. Too tight in its housing. I waited for the grease to warm up, it's a shielded pre greased bearing. Then it turned. Stiff, but it turns. It'll last a few thousand km.
Note to myself: next time, relieve the bearing housing on that side with a bit of wet and dry, and/or, use a C3 bearing.

The wheel's back in. Tomorrow, tighten it all up and out for a ride this weekend. Forecast is good and Corinne is out for the Lille braderie, Europe's biggest car boot type sale. Several square kilometres of it and up to two million people wandering about.

Paul
 
All done.
A drum front wheel is a lot more involved than one with discs. But then, it's not something I do every day. This S is my only drum front brake Laverda I have running.
Paul
 
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