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G'day all! I'm having a few dramas replacing the bearings on my 100RS and hoping I can ellicit a few opinions as to possible courses of action!!
The mains were removed without drama and replacement seems straightfoward apart from the drilling of the new front bearing through its holder with two extra oilways (no problem!!!) Here is the drama!!
I have knocked out the retaining pin, which needs to be reinserted through the bearing holder and into the new bearing.
The pin is 4mm wide,15mm long and the bearing is about 2mm thick. I know I have to drill so as to ensure that the pin can go into the bearing but not through it,(drilling and reaming required) and that the surface of the pin is at least 1mm clear of the bearing surface.
ME 109 has discussed the process with me at length, but it's still causing sleeplessness!!!
Can I make a grub screw to secure the bearing? Make a new pin with some interference fit?
In knocking out the staked original pin, I have nothing left (alloy) to securely peen the pin into position!!! Locktight? Dob of ally weld?
Help!

The size of the pin hole diameter only needs to be increased a few thousanths of an inch to be the right size for a 5mm .90 tap hole. The threads can be removed from the end of a 5mm bolt, making it 4mm like the original pin to engage the bearing. The only other thing is to flatten out an area surrounding the hole for the bolt head to tighten down on.
Extra care must be taken sizing and fitting the end of the bolt/pin so it doesn't distort the bearing when you tighten it.

R90Steve wrote:The size of the pin hole diameter only needs to be increased a few thousanths of an inch to be the right size for a 5mm .90 tap hole. The threads can be removed from the end of a 5mm bolt, making it 4mm like the original pin to engage the bearing. The only other thing is to flatten out an area surrounding the hole for the bolt head to tighten down on.
Extra care must be taken sizing and fitting the end of the bolt/pin so it doesn't distort the bearing when you tighten it.

I have done exactly that to pin main bearings for years. It works well and never had a problem. Much simpler than the
factory method.

I'd red locktite that screw you two are talking about making, but maybe I'm just paranoid.

Major Softie wrote:I'd red locktite that screw you two are talking about making, but maybe I'm just paranoid.

I always used loctite on that screw. It's good to be paranoid about things like that.

If I thread the existing hole in the carrier to take a 5mm bolt........how do I ensure that the drilling in the bearing is central relative to the bolt? If it's not I run the risk of distorting the new bearing when I screw it in!!!! AARRRHH!

hools100RS wrote:If I thread the existing hole in the carrier to take a 5mm bolt........how do I ensure that the drilling in the bearing is central relative to the bolt? If it's not I run the risk of distorting the new bearing when I screw it in!!!! AARRRHH!

Maybe a protective plastic sleeve just under 4 mm diametre to go over the drill bit, with an internal diametre of 'about' 2.5mm.
That would allow for a good spot drilling to locate the larger drill bit.

Now, what about protecting the threads from the 4mm drill bit?

I think a drill press with a suitable vice would be rather handy.

Then again, how about a machine centre! It could drill 'dead centre' right between the eyes!

Here's an attachment of what I'm about to do!!! Wish me luck!!

I'm not familiar with 5x.9 metric bolts. The ones I've seen are 5x.8. Is there really a .9 or is that a typo?

Chuey

Chuey wrote:I'm not familiar with 5x.9 metric bolts. The ones I've seen are 5x.8. Is there really a .9 or is that a typo?

Chuey

There really is a 5X.9.