Pulling the alternator on 8V92

[Jon Wehrenberg]

"With some effort" is an understatement.

There is no problem getting the fasteners loose or disconnecting the wiring or the oil lines, but then the mechanic is faced with 105 pounds (or maybe more) that he just cannot get in a good position to handle. I do know from my experience with one failing immediately after replacement, when the second alternator was removed and replaced the grunting and groaning that took place the first time was almost non-existant the second time. The key is for the mechanics to know exactly how to handle that dead weight.

The weight is not the sole problem. That alternator is full of oil and if it is mishandled the mechanics get an oil bath, and the oil is black and ugly, the main reason you never let them get at it from the top.

[phorner]

Mike,

Wish I had known you were in Ft. Pierce, as we're only 10 minutes away!

If you need anything, or if I can help in any way, give me a shout.

[mike kerley]

Thanks Paul, Were just setting and waiting. Monday should tell the tale.

Then, we get a good look at the engine seal in that area that's also leaking. I'm told its minor. If so, we'll live with it.

FYI, the mechanic had to pull the exhaust from the generator in order to get the alternator down around the transmission. It was a tight squeeze with a large, heavy and oily monster. Zack (the mechanic) will not be happy if this cookie fails....Nor will I!

[mike kerley]

Yet another update on the alternator replacement> Pardon the long winded post.

Picked the coach up at Fla. Detroit Tuesday afternoon late. It had been road tested and the bill was waiting. Technician had left for the day.

I fired it up and found a good charge on 24Volt meter but only 12+ a little on the 12 volt side. Coach batteries were almost dead at 10.0 volts. I had turned off the inverters, but domestic power was turned on for the test run during the previous week and not turned off. Numerous lights and "devices" were turned on which drained the house batteries.

I aggreed to take the unit home and plug in to get the batteries up. Ran the generator going home and plugged in immediatly. Saw no charge on the 12V side while driving home.

By 11PM, we had the inverters charging and the house batteries were back at 13 volts. Continues to charge all batteries overnight hoping both alternators (the old and the new) would work in the AM with good battery voltage.

No joy on the 12 volt side at 7 AM with the engine running, so back to Fla Detroit. I had already checked every breaker and fuse imaginable, so explained the issue and suggest they check to make sure the new alternator was the correct one. They assured me it was and the 24 Volt charged proved it was working OK. I questioned that what they were seeing was from the small, belt driven alternator, but they insisted I was wrong.

At 10 AM, Troy, from Liberty (who they do much work for) explained to them the two alternator configuration and assured them that what they had changed was the 12 Volt alternator, not the 24 volt and it seems they had installed a 24 in its place. SO, we are back to searching for a correct unit to start the process again. Should go much quicker the second time around and they have accepted the blame for the mistake.

Jon, the firm you recommended has told Fla Detroit they will only rebuild my old unit, no new stock or rebuilt in stock. The old housing had been "patched" by the previous owner with JB Weld or something similar where the case was cracked. No rebuild of that case. Fla Detroit wanted to take the guts out of my old unit and put them into the new case, which I objected to because I do not wish to pay $1600 + many hour labor for an old alternator with a new case. They also mentioned converting the 24V unit to 12 V which I know is not a simple task with wire size and number of windings being a big issue.

The good news is, no oil leaking after changing the alternator case and having the front seal replaced (it was leaking worse than I originally though). Almost like having a Series 60.

Film at 11.

[Jon Wehrenberg]

Apparently the 8V92 alternator configuration is no longer being produced so based on what you have found, Mike anyone with an 8V92 and the big alternator that has alternator problems will end up with their unit rebuilt, or and exchange for a rebuilt one.

If it is any consolation we have been seeing this occur with parts for planes. And as the replacements get more scarce the prices go out of sight. If the market wasn't so small someone would have a business opportunity if they came up with a belt driven alternator driven off the fan drive or the bus pulleys, and a plate to cover where the big alternator now sits.

[Jon Wehrenberg]

Also....forgot to mention and this may prove important. Some coaches use two alternators and while they are both working it is important for the owner to figure out which one is supplying power to the house and which to the chassis. You may think it is obvious but it is not necessarily so.

If and when an alternator pukes a technician not familiar with bus conversions may make an assumption about which alternator has failed or the voltage of the failed alternator and what has just happened with Mike could happen to you.

[mike kerley]

How true, Jon. The small, belt driven alternator was changed to provide power to the chassis system by Country Coach. That's a 24 volt unit. The larger direct drive unit was rewired to feed the house system with 12 volts. We all thought what was being changed was the chassis unit, but it was not. There was a large placard on the back door showing chassis charging system and specified 12 volt with the four chassis batteries outlines. That turned out to be a 24 volt unit, belt driven.

the large alternator is connected to a 12 volt regulator mounted on the rear bulkhead. That's the device that keeps the 12 volts steady for the house systems. Right now it is keeping the 24 volt alternator from toasting everything down stream. I'm not running engine anymore than absolutely necessary to get the unit back to Fla Detroit as I dont want to cook that regulator.

Fla Detroit messed up in not checking part numbers closer. It turns out the Tampa branch had been setting on this alternator for some time and were happy to ship it out. Looks like Ft. Pierce branch will now be the owner.

[Jon Wehrenberg]

Mike,

Disconect the field wire from the regulator and it will turn the alternator off so it cannot damage anything. I am making a huge assumption here that they have the large regulator, which at this point may have been fried. The guts to them are also available from Elreg.

You might check these folks for your alternator and regualtor as well.

http://dixie-electric.com/catalog/9801-50DN-003.pdf

[mike kerley]

Jon, How about I take all of them off? Will that just open it up?

I've located (with out Fla Detroits help) a new case for my alternator at "Bus Service, Inc. in Kansas. For a couple hundred $'s, I will test and move the old parts to a new case and reinstall. Full refund on the wrong unit from Florida Detroit.

These guys in Kansas were great. Rebuilt unit from them was $850 + $500 core charge, but the gentleman on the phone said "why dont you just buy the case, its easy to move the parts over". I've elected to have a rebuilder locally test and move the components, but I'll have my old stuff back with a new case, if all goes according to plan. Worse case senerio, I'll put the old parts in the new case and ship it as a core, and buy the rebuilt, but that is projecting a bit.

The group in California wanted $2,200 for a rebuilt, which they would discount $600.00. shipping according to them was $300.00. The case will be much cheaper to ship and only from Kansas. If this regulator is fried, I'll be asking FLA Detroit to replace it at their expense.

[dreamchasers]

How true, Jon. The small, belt driven alternator was changed to provide power to the chassis system by Country Coach. That's a 24 volt unit. The larger direct drive unit was rewired to feed the house system with 12 volts. We all thought what was being changed was the chassis unit, but it was not. There was a large placard on the back door showing chassis charging system and specified 12 volt with the four chassis batteries outlines. That turned out to be a 24 volt unit, belt driven.

the large alternator is connected to a 12 volt regulator mounted on the rear bulkhead. That's the device that keeps the 12 volts steady for the house systems. Right now it is keeping the 24 volt alternator from toasting everything down stream. I'm not running engine anymore than absolutely necessary to get the unit back to Fla Detroit as I dont want to cook that regulator.

Fla Detroit messed up in not checking part numbers closer. It turns out the Tampa branch had been setting on this alternator for some time and were happy to ship it out. Looks like Ft. Pierce branch will now be the owner.

Mike,

I own a 1995 XLV, Country Coach. After reading of the converter swapping the Prevost alternator functions, I went out and traced the wiring on my unit. Sure enough, the smaller alternator (Delco) mounted in a CC supplied housing (the coach AC in mounted on the same bracket, above) is connected to the engine starter (Series 60). What a surprise!

I recently purchased a new Elreg replacement for what I thought was the original Prevost service (Not installed yet.). Humm.....

My alternator case is leaking oil. I replaced the front seal, but did not resolve all the leaks. Mine appears to be leaking where the o'rings seal the main case. I guess that the rubber o'rings failed over the years.

I would very interested in finding our what is the modification, if any, needed to the Prevost alternator to suit the 12 volt service. I wonder if the installed regulator is designed to reduce the 24 volt output to 12 volt service for recharging the house batteries?

I would be very interested in what you find out.

What a great comment on these Country Coach systems. Another instance where keeping up with the comments on the POG forum has lead to learning more of these complex machines.

Thanks,

Hector