Small modifications

Adrian Harris · Post by **Adrian Harris** » Fri Feb 06, 2009 6:38 pm

I've been stripping down my 222 and found some problems with the motor mount and components.

One of the bearings hadn't seated fully so the screw on the end of the lay shaft had required some packing to secure it. I decided to remove both the bearings and try and rectify this, not realising the bearings had been glued in place. Long story short, I ended up damaging one of them, so bought some replacement ones from Ebay.

I successfully removed the small ridge which was preventing the bearing from seating properly but then found that when I tightened down the screw on the end of the lay shaft, the whole shaft seized. This turned out to be due to a difference in the size of the inner ring on the new bearings as opposed to the old.

The old bearing is on the left, new one on the right. The difference is minimal but still enough to cause the inner ring to bind. Something to watch out for if you ever replace the bearings.

To overcome this, I opened up the hole in the motor support to 13mm, so that there is clearance for the new bearings.

This picture also shows the witness marks caused by the centre diff rubbing on the motor support. Has anyone else noticed this on a running 222

I'm hoping this was just an alignment problem and easy to rectify when I start the rebuild.

Adrian.

Ad Wouterse · Post by **Ad Wouterse** » Sat Feb 07, 2009 9:37 pm

Hi Adrian,

As far as I can see on the picture you just damaged the steel seal from the old bearing. With a small knife you can try to remove this seal, working from the inner ring. If the bearing rotates freely after the seal has been removed, you can use it again. Just mount the now unsealed side of the bearing facing inwards.
Basically all ball bearings are manufactured to the same international standards. So bearing 608-2Z from brand A should be identical to that of brand B. Unfortunately bearings manufactured in China tend to be made to wider tolerances, which may lead to a deviating fit or clearance.

You may want to check if the lay shaft is fully straight. It may show a slight wobbling, which may cause it to seize.

Adrian Harris · Post by **Adrian Harris** » Sat Feb 07, 2009 11:14 pm

Ad,

The bearing has rough spots now, though this may be due to the damaged seal catching inside.

Given the price of new bearings, I decided to go with new ones.

What did surprise me was that it was possible to cause them to bind just by tightening down the end cap.

This may be due to their country of origin but hopefully this modification will prevent any further issues.

Time will tell ...

Adrian.