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
Quote from: Bob & Tracey on November 26, 2013, 11:00:20 AMRecently 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.
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.
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
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.
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
Quote from: TomC on November 26, 2013, 12:47:09 PM
We have new 160amp 12vdc alternators for $160.00. Good Luck, TomC
What model/brand ?
How are they mounted and wired in?
what color and weight?
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
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/ (http://www.elreg.com/)
I have dealt with this company and have been very pleased. They also do not require a core.
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
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
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
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.
Take a heat gun and check the temp of an air cooled 50dn after running 4 to 6 hours under half load in the engine compartment and compare it to a gear drive oil cooled one. Even little air cooled ones working hard can get very hot. They aren't that leak prone, however the engines blow so much leakage mist from the fan that it looks like everything is leaking.
I have checked the temps between the 2 Chessie big difference with the air cooled on a Eagle with the separate air intake for the 50D than a oil cooled on a GM
I still doubt that operating temp on an oil cooled one is any issue, but you are a little Eagle biased anyway as I am to GMC's so I'll let this one be.
On our 4104, after a great deal of over or under charge issues, even with several adjustments using the factory repair manual over a couple of years with the direct drive generator 180 amp unit, we removed it and installed a 160 amp re manufactured Leece Neville, we purchased from an electrical rebuilder. We made custom brackets, installed a dual pulley drive adapter to the direct drive location on the engine rear housing, and hooked it up. It had a little voltage adjustment screw on it, which we set once the batteries were full, and never touched it again for 150,000 miles; changed belts once. The main mount was on the engine housing where the trans mounts. I think we might still have the cardboard pattern. The mounting was compact, substantial, and professional looking. The gap between drive and driven pulleys was about 4 to 6 inches when properly adjusted. No direct outside air intake. We bolted the two large regulator lug leads together, and only used one or two of the remaining smaller wires. Connected the big main lug from the generator to the new alternator. Btw,the dual pulley drive came out of an old International cabover with a 6-71 DDA engine.
Removing old generator and regulator probably saved 50 lbs and improved fuel mileage by at least 5 or 10 miles to the gallon.......
I do like Eagles but I fell about the 50D like you do about grease vs oil for hubs JMO belt drives and air cooled are just better
Also, converting to a belt drive 50dn on a GMC would be somewhat of a pita.
Our property tested a half dozen Delco 50DN knockoff's last year. These were direct replacements for the Delco, but were a different manufacturer. They were belt driven, like you find on Series 50 & 60 engines. Our results were not good. We experienced very early failures.