DIY Alternator/Dynamo rebuild.

[nebuniram]

As per my previous post "Noisy Dynamo" I found out that the bearings were Loose/Dry on my F22D's dynamo causing the magnetic cap to vibrate and touch the Coil side of the dynamo making a chattering noise and eventually cause it to fail. The coil looks pretty stout so I doubt it would ever break unless it was completely rusted through. The wearable parts are the bearings themselves and thats what causes most of the Dynamo failiures. I believe in most cases just opening the case cleaning it out and replacing the bearings should take care of the issue.

1. Remove Dynamo and split case apart by removing the bolt from the rear of case and pounding out the shaft carefulley so you dont damage the threads on the screw. You wont believe how much dirt/grime/dust is in there

2. Remove bearings by pounding them out carefully.

3. Part number for the bearings is NSK 6201Z, about $2.50 each on the web. I ordered mine from VBX and got the 6201ZZ which superceeds the 6201z and is rated for 10000RPM's.

4. Replace bearings, put dynamo back together and install in tractor. Smile and be thankfull you didnt have to pay $300.00 for a new one

-Joe

 

[Egon]

Good show.

 

[YanmarFever]

How did you get those bearings out ?

I tried our hydraulic press without any luck, then I used a hammer with no luck.
This one was really rusty.

I wound up ordering one from Hoye tractor out of frustration !!

Im glad you did the fix yourself.

Ernie

 

[nebuniram]

Ernie,
I guess I was fortunate I used a 1/2" socket extension placed over the inner part of the bearing and just banged on it with a hunk of brass I had laying around . I was at work and those were the only tools we had in our cubicle . The top bearing thats on the coil assy came out really easy, its the one thats in the bottom on the case that is a pain and took some persuasion. I guess mine was not as rusty. Ernie, I also found out that Napa can send out the Dynamo for rebuild locally in portland to a place called Faulkners. I never got a chance to ask how much the cost would be. Just an FYI.

 

[YanmarFever]

Ernie,
I guess I was fortunate I used a 1/2" socket extension placed over the inner part of the bearing and just banged on it with a hunk of brass I had laying around . I was at work and those were the only tools we had in our cubicle . The top bearing thats on the coil assy came out really easy, its the one thats in the bottom on the case that is a pain and took some persuasion. I guess mine was not as rusty. Ernie, I also found out that Napa can send out the Dynamo for rebuild locally in portland to a place called Faulkners. I never got a chance to ask how much the cost would be. Just an FYI.

Thanks for the info !

 

[Jagmandave]

I've replaced alt bearings for years, it's pretty easy to do and the bearings are cheap and readily available at any good bearing house as well as NAPA and other parts sources. The good news is that that's all that was wrong with yours. Good job!

 

[John47]

Many years ago I used to overhaul electric motors from small fractionals to very large horsepower.
Many times bearings would be in blind housings. We had bearing pullers of various sizes to fit any sized bearings on the market. What they do is fit under the lip of the outer race of a bearing, or reversed on the outer lip of the inner race.
Those here in the trade should think about searching the tool houses for a set. They certainly make life easier!

 

[Jagmandave]

Theres a simple way to get a bearing out of a blind hole. Pack the hole full of grease put a drift that's pretty close to the size of the hole in and whack it, the grease will force the bearing right out of the hole........also works on pilot bearings in a crankshaft.............

 

[Mickey_Fx]

Theres a simple way to get a bearing out of a blind hole. Pack the hole full of grease put a drift that's pretty close to the size of the hole in and whack it, the grease will force the bearing right out of the hole........also works on pilot bearings in a crankshaft.............

Have done this myself in the past on pilot bearings. Sure makes what could be a tought job into a piece of cake.