Cummins QSB 5.9 water pump belt idler.

[driver0606]

Hello,
In the late summer I posted regarding a leaking Sherwood raw water pump. There were a number of useful replies and I have now replaced pump shafts together with the latest seals on both engines. The age old lesson relearned was that just a few ours after one pump started leaking, the other engine started to do the same thing.
When doing the work I noticed a slight amount of "rock" in the drive belt idler pulley bearings. This is the older version drive belt system. They are both the same and bearings are smooth and quiet. The play is only about half to one millimetre at the pulley outer edges, but does not seem quite right. Are they standard ball bearings?
This may be one for Latestarter and any comments would be appreciated.

 

[Latestarter1]

So you have the older arrangement with V belt using adjustable idler pulley and it is the bearing in the idler which appears to have some play correct?

Never had idler bearing fail but always a first time and this is a potentially engine disabling failure so worth checking out.

Give me your engine serial# and I will see what part explosion tells me. IF bearing is replaceable will be plain old Imperial race.

 

[driver0606]

Hello again Latestarter1, nice to hear from you,

Yes, it is the bearing in the idler. The engine numbers are 46548901 and 46549242. I did not know if slight play in a single ball race is normal. The result is that it is possible to pull and push the outer rim of the attached pulley in and out for about half to one mm. i.e. at right angles to the line of the belt.