Alternator bearings

[37chief]

My JD 401 more than likely has the same alternator bearings since it was new. Going on over 40 years old, I am wondering if I should replace the bearings? My 05 F 150 alternator has the same bearing with over 100 thousand miles, and is still spinning, with many more hours on it than my JD. Any one replace their alternator bearings as a maintenance item, or wait until the bearings freezes, and smokes the belt. I always wanted a single wire alternator. now may be a good time. Stan

 

[Janicholson]

I would not replace it until it makes noise. I would replace the (eventually failed) alternator with the OEM, not a one wire. Jim

 

[JMOR]

My JD 401 more than likely has the same alternator bearings since it was new. Going on over 40 years old, I am wondering if I should replace the bearings? My 05 F 150 alternator has the same bearing with over 100 thousand miles, and is still spinning, with many more hours on it than my JD. Any one replace their alternator bearings as a maintenance item, or wait until the bearings freezes, and smokes the belt. I always wanted a single wire alternator. now may be a good time. Stan

No encouragement from me. I'm among this community:

https://imgur.com/gpukQKH

https://imgur.com/S2plXnQ

 

[Rich'sToys]

No encouragement from me. I'm among this community:

https://imgur.com/gpukQKH

https://imgur.com/S2plXnQ

Agreed.

 

[INCase]

alternator bearings aren't a real common issue. especially if it is still original equipment. So i wouldn't monkey with it unless it gives you issues. aftermarket bearings are likely inferior to what you have in the original unit and you could be constantly replacing them after you replace them.

if it is an aftermarket replacement alternator that could be another story as i've not had good luck with aftermarket stuff lasting.

 

[Duner Wi]

If it was mine I would grease them. Sealed bearings usually are not that difficult to grease once you figure one out.

 

[wore out]

My JD 401 more than likely has the same alternator bearings since it was new. Going on over 40 years old, I am wondering if I should replace the bearings? My 05 F 150 alternator has the same bearing with over 100 thousand miles, and is still spinning, with many more hours on it than my JD. Any one replace their alternator bearings as a maintenance item, or wait until the bearings freezes, and smokes the belt. I always wanted a single wire alternator. now may be a good time. Stan

Unless you have small "bearing splitters" and an assortment of "drivers" and are used to working with alternators my vote is to leave it alone. Often, the brushes wear out before the bearings, although I think you have a Motorola alternator in which the brushes can be changed without disassembly. Often by that time the "sliprings" are badly worn and need to be "turned". NOT the case here, but the sliprings on today's alternators have so little metal in them the there's not enough metal to "turn" so they have to be replaced at rebuild time, NOT an easy "field fix".

 

[Geo-TH,In]

Wait for it to stop working and auto zone sells alternator with life time warranty. AZ stands behind the warranty

 

[Fritz Maurer]

One way to help you decide is take the belt off and give it a spin with a piece of baling twine. If it's noisy / rough sounding or can feel play, take it apart. In most cases it's the big bearing behind the pulley and those are easy to change.

 

[TerryfromSWIowa]

Think about how many rpm your tractor spins vs your F150. tractor would be about 1800 to 2100 rpm vs F150 up to 5000 rpm at times.

 

[rustred]

My JD 401 more than likely has the same alternator bearings since it was new. Going on over 40 years old, I am wondering if I should replace the bearings? My 05 F 150 alternator has the same bearing with over 100 thousand miles, and is still spinning, with many more hours on it than my JD. Any one replace their alternator bearings as a maintenance item, or wait until the bearings freezes, and smokes the belt. I always wanted a single wire alternator. now may be a good time. Stan

take the belt off and spin it,... if you can hear the brgs. it time to grease them. ... preventative maintenance. i got 400,000 km out of my duramax alt, when i took it to napa to get a rebuilt one the parts man said if you get 400km out of this one the next one if free. lol. he knew that would never happen.

 

[wore out]

Think about how many rpm your tractor spins vs your F150. tractor would be about 1800 to 2100 rpm vs F150 up to 5000 rpm at times.

Many tractors have a pulley ratio that spins the alternator faster at a given engine RPM vs. a vehicle alternator.

 

[used red MN]

Think about how many rpm your tractor spins vs your F150. tractor would be about 1800 to 2100 rpm vs F150 up to 5000 rpm at times.

I or I doubt anyone would start their truck and run it at the redline all the time. I understand what you are saying the total revolutions made is the bottom line. The size ratio of the crank to alternator pulley also figures into this.

 

[UncleTom]

The amount of revolutions your f150 alternator has in 100,000 miles is way more than the tractors alternator by far. I sure wouldnt think that would be necessary.

 

[jimg.allentown]

Chances are that the brushes will have worn far enough into the slip rings on the stator to cause alternator failure before the bearings give trouble.
To point out the logic of replacing these bearings before they fail, apply the same logic to every other part of the tractor. After all, every other part of the tractor that has not already been replaced is the same age as those bearings. Does that mean that you need to replace every other moving part before it fails?
Some components have a well defined service life and must be replaced periodically. Those components are included in documentation that usually comes with a new vehicle. Everything else is replaced on an "as needed" basis.

In a word, NO. Don't replace the bearings that are working as intended as a maintenance thing. Besides, new ones will come with a proposition 65 warning that they will cause cancer or reproductive harm. The old ones didn't have that problem.

 

[DRussell]

My JD 401 more than likely has the same alternator bearings since it was new. Going on over 40 years old, I am wondering if I should replace the bearings? My 05 F 150 alternator has the same bearing with over 100 thousand miles, and is still spinning, with many more hours on it than my JD. Any one replace their alternator bearings as a maintenance item, or wait until the bearings freezes, and smokes the belt. I always wanted a single wire alternator. now may be a good time. Stan

Does the alternator on your JD work? Does it keep the battery charged?

 

[thelonepatriot]

No encouragement from me. I'm among this community:

https://imgur.com/gpukQKH

https://imgur.com/S2plXnQ

I'll fix it until you're broke.

 

[Russ from MN]

Do you leave it sit out in the rain? I don't know how well the hood protects the engine compartment, but dust and water can shorten the life of a bearing. Fritz's way of testing it sounds like a good one, I had never heard that before. Spinning it without the engine making noise is a good idea. How's your hearing, do you have hearing aids?

 

[TerryfromSWIowa]

I or I doubt anyone would start their truck and run it at the redline all the time. I understand what you are saying the total revolutions made is the bottom line. The size ratio of the crank to alternator pulley also figures into this.

That is why said at times for the F150 I know cruising would normally be around 2000 to 2500.