Rattling or knocking generator

wilfreeman · Post by **wilfreeman** » Thu Aug 02, 2012 12:10 am

OK, here's one of the things that I am determined to fix while I'm off this week. A couple of months ago I heard (what I thought was) a rod knock. My heart sank! After listening around by putting a wooden dowel up to my ear and onto different parts of the engine, I found that the sound was coming from the generator. I thought it was vibrating on the motor mount, so I finally got around to buying some shorter belts to raise it up otd the mount a couple of weeks ago. That didnt fix it.

While I was off last week, I ended up wedging piece of scrap wood between the generator and the oil fill tube - that stopped it!

Now, before I go tearing it all apart, has anyone run into this problem before? The rubber bushings were replaced before I put the engine back in last year. They felt like they were a little soft to be supporting that heavy generator, but figured the dealer would send me the correct parts, so in they went.

Any thoughts?

skyjeep50 · Post by **skyjeep50** » Thu Aug 02, 2012 2:04 am

The generator bearings may be going bad. Loosen the belts and spin the generator by hand - you should be able to feel if the bearing is rotating smoothly or not. Some models have a oil fill cap behind the pully and require periodic oiling. Others have a sealed bearing. I have one of each on my '38 and 'A1. You can buy generator rebuild kits w/bearings, brushes, etc. - sometimes available on Ebay or check the military jeep parts suppliers. See the "Downloads" section of this website for manuals.

wilfreeman · Post by **wilfreeman** » Thu Aug 02, 2012 2:20 am

Thanks, I will check that first. It could be making the noise only when the tension from the belts is on the bearing - when the back of the generator is pushed out, it could be loosening the belts enough to stop the bearings from making noise.

RICKG · Post by **RICKG** » Fri Aug 03, 2012 10:31 am

Matt, if you get a chance to pull the genny (i know it's a pita)
check the bolt holes on genny front and rear mount flanges. If one
or more is oblong or "wallered out" it'll allow that heavy genny
to vibrate. Mine made a lot of noise before we machined the worn rear mt and installed a light bushing in place to remove the slop. My 2c..

wilfreeman · Post by **wilfreeman** » Fri Aug 03, 2012 4:22 pm

Thanks Rick - I'll check that on Sunday. I haven't had a chance to start working on the Jeep yet, because I have been putting brakes on the car hauler I am going to be using to take her to the rally in October.