Alternator replacement

ACDNate · 05-01-2018, 05:57 PM

On the trip home this past weekend I lost alternator charge. Tested batteries out they are good, just not pushing juice.

I opened up the bedroom access and the alternator is readily accessible. What I'm not seeing is how to access the belts. Seems like i'm missing something.

Anyone here wrench on their coaches that can offer some advice?

Coach is a 2008 Winnebago Journey 39z, Cummins engine on a Freightliner chassis.

Jim_HiTek · 05-01-2018, 06:24 PM

Can you find the idler pulley? If so, put a LONG bar on it with a socket that fits the big nut on the front of the idler and reef on it. It'll pull up enough (or push down enough) that you can get the belt off. You should have a bungee cord looped around the belt somewhere holding it so it'll stay somewhat tight as you remove it from the alternator pulley. Placed in such a manner that it won't damage the belt. Remove the alternator, reverse the process when the new alternator is in place.

ACDNate · 05-03-2018, 08:32 AM

I think I have it figured out.

One question though. Any reason not to use the leveled to back the rear end up a few more inches to make it easier to get to?

Jim_HiTek · 05-03-2018, 10:21 AM

Quote:

Originally Posted by ACDNate

I think I have it figured out.

One question though. Any reason not to use the leveled to back the rear end up a few more inches to make it easier to get to?

Are you talking about using the leveling jacks to lift the rear of the RV? I certainly wouldn't tell you to do that. You takes yer chances. If you do that, make sure the wheels are chocked, don't just depend on the park brake.

If your Cummins is like my Cat, the alternator is near the top of the engine and it's best to get at it from the top. You might have to hire a skinny kid to get to it for you. My bed frame can be easily taken apart to give more room to work in the engine opening. Even then, it's very tight as the opening isn't very big. I have to put a piece of plywood on top the engine to lay on while working on some things in there. In your case, you should be able to open a hatch in the bedroom to access the engine. You might have to remove your radiator for full access but I doubt it. BTW, you might have heard horror stories about shops removing the rad and taking 3 hours to do it. A good shop wouldn't take anywhere near that long.

One thing I found with my Cat was that an internet search turned up a nice picture of the engine on a stand. Showed where things are. You might try to search google using your engine model number.

ACDNate · 05-03-2018, 10:44 AM

Alternator on mine is right on top with the bedroom access panels opened up. The belt tensioner and getting the belt back on will have to happen from the bottom along with some help from the top side. I'm going to go ahead and throw a new serpentine belt on while I'm in there

Jim_HiTek · 05-03-2018, 11:00 AM

Quote:

Originally Posted by ACDNate

Alternator on mine is right on top with the bedroom access panels opened up. The belt tensioner and getting the belt back on will have to happen from the bottom along with some help from the top side. I'm going to go ahead and throw a new serpentine belt on while I'm in there

Only reason to replace the belt is if it was squealing or has cracks in it.

One way to do the job is to use the alternator instead of the idler to loosen the belt. Assuming yours is adjustable, just loosen the bolts, swing it over a bit, remove the belt and tie it up with a bungee cord. Than remove the alternator, take it to a truck parts store and have them remove the pulley and place it on a new or rebuilt 170 amp alternator. No need to get one from Freightliner...theirs are $600 whereas a generic is only going to be in the $200 range. Takes some time searching but many truck part shops will have a universal that will work. Most RV alternators will have the model number tag still on it.

ACDNate · 05-03-2018, 11:18 AM

My alternator isn't mounted like a typical auto version. It's mounted on a saddle of sorts with 3 bolts. No adjuster bolt.

Jim_HiTek · 05-03-2018, 12:21 PM

Quote:

Originally Posted by ACDNate

My alternator isn't mounted like a typical auto version. It's mounted on a saddle of sorts with 3 bolts. No adjuster bolt.

Oh, too bad. My Cat's 170 Amp pivots on one bolt, and the top bolt gets removed so it can swing a bit towards the middle of the engine when the lower bolt is lose so the belt can be removed. My lower idler is also the type you can reef on with a breaker bar and socket to loosen the belt.

If you can work slow and steady like, usually things in these big beasts reveal themselves to be easier then you think. For instance, there's an air dam above the rad in my rig and no one mentioned how easy it is to just loosen so it lays down, giving much more access to the surge tank (and top of the engine). Making that a 45 minute job to replace, not a 6 hour job like some said on forums.

Well, have fun!

staggerlee · 05-03-2018, 02:39 PM

Quote:

Originally Posted by Jim_HiTek

For instance, there's an air dam above the rad in my rig and no one mentioned how easy it is to just loosen so it lays down, giving much more access to the surge tank (and top of the engine). Making that a 45 minute job to replace, not a 6 hour job like some said on forums.

Well, have fun!

After removing that air dam, are you able to get to that one bolt that you removed from under the bed?
Does that bolt face the same way as the one on the side?
Thanks,
Lee

Jim_HiTek · 05-03-2018, 03:46 PM

Quote:

Originally Posted by staggerlee

After removing that air dam, are you able to get to that one bolt that you removed from under the bed?
Does that bolt face the same way as the one on the side?
Thanks,
Lee

No, removing the air dam doesn't help with the two bolts on the passenger side but you can easily get to the top two bolts on the engine side of the surge tank. The other two, on the passenger side wall bolted to a frame, are still difficult. The one nearest the back of the engine, you just cut the tank bracket off. Very easy. The one further back, that takes some time and skill. Probably why I wasn't able to get it off at all. Even after cutting the tank out, still didn't have the tools or skill to get that bolt out. Used the saw to cut it off, didn't bother to use a new bolt for the tank there because I couldn't get a tool on the bolt head. So the tank has 3 bolts instead of 4, but it's nice and solid.

Removing that air dam (or at least loosening and folding it down), gives more light inside the engine compartment, it's easier to see stuff from that new angle, plus there's lots of stuff you could get to better. That is with help standing behind the RV.

The two bolts on the left side of the surge tank (standing behind the RV) go up and down, the other two on the passenger side and right side of the tank, go left to right.

ACDNate · 05-05-2018, 10:39 AM

Removal was quite the experience.

I spent about an hour getting mattress out, propping bed, pulling access panels and pulling negative on batteries.

I wasn't able to get to the tensioner at all. There's a transmission or engine cross member blocking easy access from the bottom. I will need a 4' or so cheater pipe to move it when i get back to install. Looks like i'll have to go from the top closet access to get to it. Either that or remove a whole lot of stuff to access it. Not going to be easy.

All total about 2 and a half hours to remove. That included 30min of head scratching wondering why the alternator wouldn't drop after pulling the 3 mount bolts. Then i found the 4th bolt

ACDNate · 05-09-2018, 08:30 PM

Got the alternator back in today. Went in much easier than anticipated. When I removed the old alternator I bungee corded the serpentine belt up to keep it position.

I was able to put one of 4 bolts in and rotate it under the belt. Was able to get it in without having to mess with the tensioner.

Jim_HiTek · 05-10-2018, 07:37 AM

Quote:

Originally Posted by ACDNate

Got the alternator back in today. Went in much easier than anticipated. When I removed the old alternator I bungee corded the serpentine belt up to keep it position.

I was able to put one of 4 bolts in and rotate it under the belt. Was able to get it in without having to mess with the tensioner.

Great when it all goes back together without much trouble. Getting these things back together tends to be much easier then pulling them apart.

Journey39n · 05-11-2018, 12:42 AM

Wow, some models seem to present quite a challenge for this replacement. Last year, my alternator went out. Called a mobile RV Tech, he came out to my park, verified the alternator was not putting out enough juice. We lifted up the two access panels on the bedroom floor, he reached over to the alternator, removed the wires, loosened the bolts. Then he went under the engine, and used a bar to hold the belt tensioner over, while I reached in, and moved the belt off the alternator pulley. Then he finished removing the bolts, lifted the alternator off its mount, and up into the bedroom. Inspection, test, and removal took about 30 minutes. He procured a replacement and returned to the park, removed the pulley from the old alternator, and installed on the new one. Then reversed all the steps to install the replacement unit. That took about 20 minutes. All has been working well over the last year. About three months later, I had the old alternator rebuilt, and now carry it around as a spare for myself, or to sell to someone that might need one, if near me in a park.