[Jim/Chris]

I have used both from them with great success….I have used several of their oil filled with no issue

[Kurt]

I have used Elreg’s shaft seal to repair a leaking seal and theirs is easy to install and works well.

[DON]

Our recent newly nstalled DN 50 is leaking around case seals-every seal. Marathon is covering local shipping and install costs

[Archived]

I have bought both and used the air cooled one with great success no troubles , some will say that they had trouble with the support brackets breaking I have not had that ever as a problem , I would replace it with air cooled!!!!!

[Archived]

I am approaching 400,000 miles of Prevost driving and so far I had one oil cooled 50DN fail. I am sure the air cooled units have been tested and work well, but based solely on ,my past experience I will probably remain with the oil cooled unit if it should fail.

How has the air cooled unit been shown to be better? I know it is an alternative to the original but I haven’t seen anything to indicate it offers more reliable performance.

[Larry & Diane]

After 125,000 on the original 50DN, I went through a new one which failed quickly and a reman which failed quickly. Went to the air cooled penn-tex…70,000 later still OK and I run mine in very high ambient temps. I did have a problem with my bolts holding the alternator bracket to the block and beefed them up from 7/16? to 1/2″.

In addition to the leaking issue, which almost cost me an engine due to oil loss when the bolts holding the two alternator halves together backed out and 2 sheared off, I don’t find the prospect of an internally failing alternator dumping crap in my engine oil all that appealing.

[Larry & Diane]

The air-cooled Penntex 833 offers 330amps @ 28volts. We have had two customers have us do this modification, and both love it. No more oil leak worries, it looks neater in the cradle, and uses the exact same pully and belt as the 50DN. The other option is C.E.Niehoff, but the series we have used requires cabling upgrades in most cases, and offers higher output at 500amps/28volts.

For an easy, plug and play drop-in replacement, my recommendation is the Penntex.

If your coach is a bus-air with Trace inverters, and you are unsatisfied with you power of your current alternator, consider the upgrade to C.E.Niehoff 500amp, but it is going to cost double, and your coach should be evaluated as to cable sizing and the way it is currently wired to see how extensive the upgrade will end up being.

If I can provide any further assistance, please let me know.

[Archived]

Yes, I agree with Ben. Obviously, Jon hasn’t gone for this upgrade, however, because the penn-tex is not available with a chromed case for use on a Liberty.

[Archived]

If the only problem it solves is it eliminates oil leaks, the solution is not to replace the alternator, but to fix the leak.

My actual reason is if an alternator creates enough heat internally to have Delco specify a minimum flow of cooling oil, and for Prevost to have a kit to insure that flow requirement is met, I cannot feel comfortable with air cooling. It would have to be like shoving a tornedo through a keyhole to get sufficient cooling equal to that of oil.

[Dick]

Supporting our local economy, I have a new “Reman” 50 DN for a great price. Even tho I didn’t have a core in exchange since we must send the old one back to Marathon, I couldn’t pass up the price. Install will occur next Wednesday at S and S

[AL]

I intuitively wondered the same point that John is making. Unless the BTUs that the big alternator gives off and must be pulled away is very modest (which I don’t think would be the case if there was an oil cooler version on the same type of chassis), I have difficulty accepting that the same alternator can be air cooled adequately.

Maybe buses running in cold climates can get by with air cooling, but what about the desert Southwest in the summer with the bus idling? What about in hot, steamy Florida in the summer?

Do the air cooled alternators have a huge cooling fins and fans?

This is another large, expensive device which is prone to getting hot (like the transmission, rear end, engine (chassis and generator) oil, etc.) for which there should be a temperature gauge set up to depict acceptable range and with a high temp warning light.

But maybe since we haven’t had a ton of failed DN50s due to excessive heat discussed on the Forum this isn’t that big of a problem and I’m overthinking this.

[Chas]

Choose new Elreg 50DN as replacement for oil leaking from split housing on rebuilt. Jeff recommmended the new Elreg with zero failure rate.

[Ronald]

As I said in my earlier post, I have 70K miles on mine in extreme desert southwest conditions powering OTR A/C; no indication of failure from overheating.

[Richard]

Al, thanks for the pix of your bumper cover. I had earlier ask about “fixes” to help the cover lay flat. Did you install the screws ?

[Larry]

The bumper is a nightmare and the screws are trying to keep the top level. Screws did help some but I’am not satisfied. Work in progress.

Bottom is cracked at screw hole locations which don’t offer much support. When I checked on the cost of a new bumper I was shocked that they could charge that much for another piece of the same problem. $2200

That bumper is in the same parts book with Crapo mirrors