Your Reading List

How to deal with a loose bearing race

Here’s a mechanic’s tip on how to make a loose bearing race fit snuggly into a housing

Whenever a bearing is replaced, the rule of thumb is replace the race it rides in as well. That ensures the new bearing will last a long time because it will wear properly as it turns in the mated surface provided by a new, matching race.

Bearing races are designed to have a friction fit inside a housing. The tolerance between their sides and the opening in the housings should be so tight that races are held firmly in place while the bearing turns freely inside them. All wear then occurs between the race and the bearing, protecting the larger housing.

Getting an old bearing race out of a housing is a simple process. Usually, a hammer and punch is all that is required. Firm strikes on the back side of the race will pop it out.

The replacement race is then driven into place with a hammer and a tool that ensures the force from the hammer blows is evenly distributed all around the race, squarely seating it.

But there are times when a replacement bearing race — even when it’s exactly the right replacement — just doesn’t fit snuggly enough in the housing. If a race is too loose and there isn’t enough friction to hold it tight, it could turn in place with the bearing and eventually damage the housing, which means a really expensive repair bill some time down the road.

However, there is a simple way to get that new race to stay in place, and all that’s required is a centre punch, hammer and some Loctite 660, which is designed just for jobs like this. Blue thread locker isn’t right for this job and probably won’t be an adequate replacement for the 660, unless the gap between the housing and new race is very small.

How-to

Here’s how to seat a loose race.

First, with the bearing race removed, take a centre-punch and peen (strike) the inside surface of the housing where the side of the race mates too. Do this around the entire circumference of the opening. As the point of the centre punch is pounded into the housing, it displaces some of the metal and pushes it up above the existing surface, creating bumps. What that does is effectively reduce the diameter of the opening in the housing, restoring a friction fit.

But that only restores a portion of the friction the race would have had if the tolerances were correct.

To help ensure the race remains in place, apply a film of Loctite 660. This compound can lock a component in place where there is a gap of up to 0.020 of an inch. There are other similar Loctite compounds available for this type of job. There is a chart on their website (loctite.com) to help you decide exactly which product best suits your particular application.

With the Loctite applied, use a driver to seat the race in the usual way, and allow adequate set up time for the compound. The combination of those two treatments should leave the bearing race secure and ready for work.

About the author

Machinery Editor

Scott Garvey is the machinery editor for Grainews.

Comments

explore

Stories from our other publications