Community Forums

Doug.terri5 · 12-04-2020, 07:25 AM

Hi all!

Has anyone who has made this change had any issues with road spray with the 28si being an open concept alternator with internal fans. The Leece Neville is a closed case with an external fan which seems more appropriate for a diesel pusher but the 28si seems to be a worthy replacement.

Any thoughts are appreciated.

Thanks,

Doug

Ivylog · 12-04-2020, 09:05 AM

Often when replacing the alternator on a Monaco, things stop working-no rpms. It’s recommended to have the alternator rebuilt.

Skip426 · 12-04-2020, 09:12 AM

Actually funny that you've posted about the air circulation differences between the two .
I really don't know if my thinking on the LN external fan is correct; but ; my thought is this , the external fan would be more efficient , in a standard engine/ cooling system layout .
Standard , being a truck layout , air through the rad pulled by the fan , blown over the alternator then over the engine and down to the ground.
Diesel pusher air flow , a little dependent on side/rear rad layout but , airflow over the engine ; particularly the exhaust manifold ; into the alternator , then out the rear of the coach.
My belief is that the short lifespan of diesel pusher alternators is due to two factors , the number of batteries being charged ; many times at max alternator output; and HOT air flow from the exhaust manifold onto the back of the alternator vs, radiator temp air flow over/through from the belt side of the alternator.
When I saw the Delco air flow diagram , I thought any extra airflow through the unit has to help.

I don't know if any member has done the swap to give input on the lifespan of the Delco , but I know I'm interested for my coach.

twinboat · 12-04-2020, 09:29 AM

I would check with this place for info.

https://www.qualitypowerauto.com/

Click image for larger version

Name: Capture%2B_2020-12-04-11-28-01.jpeg
Views: 31
Size: 90.2 KB
ID: 310238

CountryB · 12-04-2020, 10:35 AM

Quote:

Originally Posted by Ivylog

Often when replacing the alternator on a Monaco, things stop working-no rpms. It’s recommended to have the alternator rebuilt.

I don't think that is an issue with the newer (2004 up) Coaches, as the newer models are getting Tach info directly from the engine ECM data stream, and they don't use that old technology "diode battery isolator" which needed a sensing terminal on the alternator. The late model Coaches use the BigBoy/BIRD (or similar) to isolate and charge the Chassis and House batteries. AFASIK. And the Delco units are self energizing so no need for a trigger voltage.

Of course, there's always an exception out there.
But having the alternator rebuilt is cheaper in the end - if they do the rebuild right.

shootist · 12-04-2020, 04:14 PM

The 28 is still a brush style alternator. Step up to a 35 or 40 and they are brushless. A truck shop I spoke with said they replace the 28s all the time.

Chargerman · 12-04-2020, 05:03 PM

When I had my Leese Nevill rebuilt a couple years ago the rebuilder told me that he does a lot of them from Pushers. He said the failure rate is many times higher than a front engine setup. He said the reason for it is that it is mounter in reverse and subjected to a lot more dirt and dust due to its rear engine location. He said that the most important thing I could do to extend its life is to blow it out occasionally with compressed air. I do that as part of normal maintenance/ inspect a couple times a year. We'll see how it goes.

153stars · 12-04-2020, 05:12 PM

There is a lot threads,pics and drawings on upgrading properly ,not every delco has right outputs . The one issue is alt. light when running the genny on the road. I think someone had a work around.

Doug.terri5 · 12-04-2020, 05:34 PM

The original Alternator is not rebuildable at an affordable cost. Between the bearings freezing up and the windings dragging it is pretty much a useless core.

Skip 426 and Chargerman, you and I are thinking along the same lines. Sucking up road spray and pulling it into and through or past the alternator was my concern. The setup has to be hard on any alternator and heat certainly would play a part.

Thanks everyone for the thoughts, ideas and links!

I’ll circle back once a decision and repair has been made.

Doug

BobJones · 12-05-2020, 04:03 AM

Quote:

Originally Posted by CountryB

But having the alternator rebuilt is cheaper in the end - if they do the rebuild right.

I did ours back when my Dad had it just as a maintenance item. I put new brushes in it and the regulator or diode trio, can't remember exactly what. It was not hard, but....I got the wrong regulator (non Duvac?) and that created a problem of fast battery drain. Once I got the right one, good to go. So I had to do it twice but believe me, the Leece Neville is nothing to be scared of. Do it yourself for fun and peace of mind. It was cheap, easy and fast - just the way I like 'em

One day I'll look at the starter for the same reasons. It can be really, really cheap to go through these things and make them ready for another 20 years.

veraken · 12-05-2020, 05:31 AM

Replaced my alternator about 3 years ago. I found the best price at Quality Power. I decided to replace my 160 amp Leece Neville with a 200 amp Delco Remy 28SI. The install was fairly simple (I have a side radiator) except on the DR you don't connect the excite wire since it is self exciting. I had my old LN rebuilt and carry it as a spare.

https://www.qualitypowerauto.com/cat...lternators.htm

dca81 · 12-05-2020, 08:31 AM

Replaced my alternator about 3 years ago. I found the best price at Quality Power. I decided to replace my 160 amp Leece Neville with a 200 amp Delco Remy 28SI. The install was fairly simple (I have a side radiator) except on the DR you don't connect the excite wire since it is self exciting. I had my old LN rebuilt and carry it as a spare

X2, except did it a year ago and when shop tested my old LN they said it was fine. So I carry it as a spare. Was very simple exchange once I found out you had to leave the excite wire disconnected on the Delco 28si (hint...if you do the exchange and engine continues to run after you turn it off the excite wire is connected). No problems or excessive grime I can see. Why did I get an alternator light if the LN was good??? Changed to 28si and cleaned all my connections and grounds...no problem since.

shootist · 12-05-2020, 10:37 AM

Quote:

Originally Posted by dca81

Replaced my alternator about 3 years ago. I found the best price at Quality Power. I decided to replace my 160 amp Leece Neville with a 200 amp Delco Remy 28SI. The install was fairly simple (I have a side radiator) except on the DR you don't connect the excite wire since it is self exciting. I had my old LN rebuilt and carry it as a spare

X2, except did it a year ago and when shop tested my old LN they said it was fine. So I carry it as a spare. Was very simple exchange once I found out you had to leave the excite wire disconnected on the Delco 28si (hint...if you do the exchange and engine continues to run after you turn it off the excite wire is connected). No problems or excessive grime I can see. Why did I get an alternator light if the LN was good??? Changed to 28si and cleaned all my connections and grounds...no problem since.

If you run the gen and the inverter puts out a higher charge voltage than the alternator, if the big boy has the banks connected the alternator light sees the current running backwards as a discharge, no alternator output.