50DN alternator

[Bob & Tracey]

Recently I saw a suggestion to remove a 50DN alternator and replace it with a belt driven one. Is the 50DN that prone to failure?

Thanks,
Bob

[Oonrahnjay]

Recently I saw a suggestion to remove a 50DN alternator and replace it with a belt driven one. Is the 50DN that prone to failure?
Thanks,
Bob   

     Bob, I don't have one on my engine and I've never had much experience with them, but from what I've read, the total failure (basically taking out the engine) may not be very common but it is such a big amount of damage (work, time and $$$$) that it's a huge problem if it were to happen. 

[chessie4905]

   GMC has used them on thousands of coaches, city and intercity. Yes, they can fail and cause that potential damage, however if installed correctly and in good condition are fine (they DO need to have the mounting ring properly centered prior to mounting, and drive and driven gears to be the correct combination), and good bearings with proper lubrication from oil feed line. The info is in the DDA shop manual. If they were prone to a significant number of failures, they would have been discontinued years ago.

[luvrbus]

Those are supposed to be removed and rebuilt every so often fleet owners would remove one and replace the bearing every 100,000 miles ,GreyHound did I have some old service records from Dallas that shows it and Boomer here that was a part of his PM maintenance for years 

The regular bus guys 99% are not going to service one I can tell you for sure

good luck

 

[Bob & Tracey]

Seeing that I have no history of the alternator on our 8V71 would it be a good idea to change to a belt driven one or have the 50DN serviced? I really have no need for the high output, no large inverter to power.

[TomC]

When I had my gear driven 50DN exchanged for a rebuilt unit, I noticed that the updated alternator has an external oil line from the front to pressure feed the rear bearing. Originally designed, the rear bearing only used splash lub. So check that out to see if your alternator is updated.

We have new 160amp 12vdc alternators for $160.00. That's a whole bunch less then the $1,200 to rebuild the 50DN-$1,500 with new regulator. Good Luck, TomC

[eagle19952]

We have new 160amp 12vdc alternators for $160.00.  Good Luck, TomC

What model/brand ?

[treeplanter]

How are they mounted and wired in?

[John316]

what color and weight?

[TomC]

Delco SI28 I believe. You could buy two and have the same power output for a fraction of the price of the 50DN-and the 100lb weight of the 50DN.  Good Luck, TomC

[Jon]

A brand new 50DN (not a knockoff) can be bought for much less than the prices quoted for rebuilding or replacements here:

http://www.elreg.com/

I have dealt with this company and have been very pleased. They also do not require a core.

[TheHollands!]

I have a 50dn and have an oil leak through the screw holes on the front plate. Is there some kind of seal behind there that I can replace or do I need a rebuild? I looked into getting a rebuild a while back and found that a lot of alternator shops weren't set up for this. Thanks, Craig

[luvrbus]

The 50D gear driven oil cooled alternator never made any sense to me except for space reasons, oil cooled with 200 degree + oil  who are they kidding  I'll take 90+ degree air any day and it doesn't leak the black stuff either

[TomC]

Freightliner makes military trucks. We use a non smog Series 60 (military uses different air then we do) and the trucks run on 24vdc. The alternator is a monster 450amp at 28vdc belt driven with it's own air cleaner which is 12,600watts! Our list price on this alternator is $5,500.00! And the trucks use 4-7" round LED headlights at $375.00 ea.  Nice to know where our tax money is going. Good Luck, TomC

[Lin]

Unless you are running several AC's through an inverter, there is no need for the capacity of a 50DN.  If peace of mind requires that you it out, you might as well install something that is more manageable.