Series 60 DN50 Alternator

[Trendycat]

I haven't figured out why this happened, but for some reason all of the bolts holding my alternator together vibrated out, causing it to split open and spray oil while driving my coach the other day. :eek:

Although I have a Wanderlodge, many of you with Series 60 Prevost share the same DN50 alternator as mine (whether the 24 volt or 12 volt version). Although I caught the problem early (something less than 60 miles after it happened - since I checked the engine while fueling at a Flying J and then noticed the problem when I pulled over to take some photos about 60 miles later), I still ended up waiting for a tow to Cheyenne Freightliner in Cheyenne, WY since I didn't want to drive the coach back there leaking oil.

I'm awaiting a reman alternator (this is a typical replace, not repair kind of shop) to get back on the road.

The coach was new to me in Nov. 08, so I don't know if there had been some sort of work done to the alternator in the first 98K miles of usage, but I'll be sure to keep an eye on this in the future.

On the positive side of this experience, my CoachNet roadside coverage came in handy as they covered the cost of the tow back to Cheyenne - a process that took almost 4 hours between waiting for the tow truck, prepping for the tow (removing the driveshaft, etc) and then towing at 40mph the 60 miles back there.

The tow company I-80 towing based in Laramie/Cheyenne WY did an excellent job, although the heaviest truck they had was barely able to manage safely dragging our 48K+ weight.

Loose bolts in the oil cooled alternator - one more thing for Jon to add to his maintenance check list. :)

(Having trouble uploading a photo of the alternator due to spotty data service here in Cheyenne - will try to edit later)

[Jerry Winchester]

Bruce,

Thanks for the post. Makes me want to run out to the hanger and see how tight those bolts are. Wonder if that was the original alternator or a reman?

Good luck.

JDUB

[Joe Cannarozzi]

One of the bigger leaks on our 8-V was the alternator and two different spots on it.

The flange bolts attaching it to the gear case were all 1 turn loose or more oil was literally draining out, leak one.

The other leak was the gasket on the back plate and although not as loose as the flange bolts a bad leak there too.

Had I not tightened the flange bolts it would have either fell off or got so loose the gear drive may have been damaged.

[JIM CHALOUPKA]

Bruce, sorry for your incident. Thanks for the heads up on checking the tightness of the bolts.
There might be cause for loctite (brown) or lock wire.

I would be interested in how much oil was still in the engine after 60 mi of a leak of that nature.

I wonder what the oil flow volume to the alternator is, per hour?

JIM

[Joe Cannarozzi]

Jim that would be a good question for Jerrys gurus in OK.

I too am curious how much oil cycles.

On an 8-V it is gear driven so if it came apart it would be a catastrophic failure of the gear drive.

On a 60 series being belt driven it would not cause a gear box failure but worse yet if gone unnoticed eventually all engine oil would be pumped out causing catastrophic failure that way.

Looking and thinking back was there any prior indication of the failure? Leaks, noises, belt wear. That seems like something that one would see comming on, if it is a 60 series?

What is in that 95 Wanderlodge an 8-V or a 60 series?

[Trendycat]

Joe,

My 95 Wanderlodge has a Series 60 engine with the belt driven 300Amp, 12V alternator.

I don't know exactly how much oil was lost when the problem developed. Some sprayed out the back of the coach and after sitting for a couple of hours waiting for a tow, there was a puddle on the ground equivalent to about a pint of oil.

I checked the oil level via the dipstick and could not detect a noticeable difference, so I suspect total loss wasn't more than a couple of quarts before I found the problem.

I didn't notice any issues prior to the failure (leaks, belt wear, etc.), but I had never checked the tightness of the bolts holding the alternator together (or even if they were all there in the first place).

Bruce

[Jon Wehrenberg]

Which bolts came out? Were these the bottom ones? Were these the ones holding the rear plate?

I'm not home so I cannot get my files, but I think Ihad a thread with information on where to get a brand new alternator cheaper than a remanufactured one. The brand new one I thought would be made offshore because of the price and that there was no core requirement, but it is the original Delco parts and castings, made in Canada.

I'm going to check my bolts. They have about 5000 miles on them since replacement.

[Trendycat]

Jon,

The bolts that came out were the ones around the middle section of the alternator (holding the two halves together). The ones in the front (pulley side) and the ones on the back plate still seemed secure.

I ended up with a Detroit Diesel remanufactured alternator at a cost of about $1520 plus shipping and labor for installation. Not a lot of sources/options where I had the problem (Cheyenne, WY)

I'll certainly keep an eye on this in the future in the hope of not incurring a similar problem.

This is a photo of the old alternator showing two spots where the bolts are missing. There are three additional bolts around the center section not visible in the photo that were also missing, leading to the alternator separating and spewing oil. I recovered 3 of the bolts laying on the frame of the bus under the alternator, the other 2 must have dropped out on the road at some point in time.

Bruce

[Jon Wehrenberg]

Those bolts should have never come out. For future reference that price was way out of line. When I get home I will post for all the source for a brand new alternator that is produced of Delco parts for half that amount.

I would suspect you could have one shipped direct to wherever the coach is and receive it just as quick as any other source.