Community Forums

Just Cruising · 01-07-2010, 10:26 AM

Hi,
We purchased a new 08 in May, 2009 and the forum has helped a lot. I have some futher questions that maybe someone can shed some light on.
A. I have had the AH reworked, insulated etc per the suggestions given here and was not able to get to the heat exchanger located behind the drawers in the kitchen as it is completely boxed in. I was quoted at least 10 hours to remove the counter tops and rework that unit as it puts out almost no warm air into the coach, but the back part of the cabinet areas are very warm. Has anyone done this? How did you get to it?
AA. Also, has anyone been able to locate a source for a 2 1/2" blower fan?? I am thinking of trying to add one to the bath and dash runs where it is hard to get to the source problem.
B. After I got the coach I had to replace all the batteries. I did so using Interstate replacements. I have had to wash out the battery area with soda twice due to overflow and all the paint is now off. I suspect the auto fill is somehow overfilling the batteries even though I just turn it on about once a month for about ten minutes and then shut it off. Has anyone changed to Gell type batteries? I would like to research adding two more coach batteries to make 8 if they will fit as the batteries do not seem to last long if not hooked to shore power or driving. I have checked for a parasite draw and found little. Also, do you have to go to a 200 amp altinator if you do this like the Apex?
C. I have developed a small shutter or vibration when taking off at slow speeds that goes away after about 10 MPH and I have seen posts about u joints going bad. I have about 13,500 miles now and this problem has appeared. I have tried to check the u joints and they seem tight, but I have a mobile service guy coming later today to look at it. Has anyone else had this shutter or vibration when taking off that seems to go away with a little speed?? (perhaps it is just blending with road vibration, but is still present.
Thanks in advance for your thoughts and advise,

Marvin C

EngineerMike · 01-07-2010, 11:01 AM

A. take out the drawers facing the fridge. In mine the exchanger is accessible immediately below the lower drawer, and the hoses were neatly laying on the bottom of the cabinet instead of attached to the exchanger vents. Easy fix, took less than 10 min. One black plastic finger on the drawer slide pushes up, the other down to release the slide, while pulling on the drawer.
AA. google a 120mm or a 92mm "case fan." they are 12V and respond well to variable speed controls that use resistors or rheostats for speed variation. Cheep too.
B. Better to go to AGM than gel. Probably about same cost (high). Once you are recharging 8 batteries, you may find the alternator is overstressed. There is an article on the ACA Tech Library on this w/the Apex (also an 8 battery creature), but you will probably get a year or two more from the OEM alternator. Just want to have the replacement on hand so you know the right one gets installed.
C. On stuff like this where I start falling into wishful thinking, I try to remind myself: "Self, its not nothing." Could be U-joints not properly lubed originally. Could be something else. Doesn't sound critical. Yet.

dgerstel · 01-07-2010, 12:14 PM

Marvin,

I think that your kitchen heat exchanger is installed differently than the ones in the front door coaches. I get this from talking about this problem with other owners of mid-door coaches. If you are going to DRR, look me so that I can look at it.

I have 8 batteries installed and have had no problems with the stock alternator. I do always try to make sure that the batteries are pretty well charged before driving the coach so as not to overload the alternator. I was also told by an Apex owner, not to let the engine idle at low idle when first starting up with low batteries.

Dale777 · 01-07-2010, 02:11 PM

Marvin,

B. Get AGM batteries. I have 8 AGM batteries in my 2006 Alpine Coach Limited 36FDTS. I LOVE them. No watering, outgassing, or corrosion issues, etc. However, with 8 AGM batteries, there is a potential charging issue with the stock 160 Amp alternator, but I work around the problem. See my comments in this link at note #6:
http://www.irv2.com/forums/f104/batt...off-57848.html

C. On this low speed shudder, I strongly suggest that you have a professional check the U-Joints and Ride Height. See these links for U-Joint and Ride Height issues:
http://www.irv2.com/forums/f104/bad-...ngs-14077.html

http://www.irv2.com/forums/f104/u-jo...6-a-22146.html

http://www.irv2.com/forums/f104/vibr...oad-55848.html

http://www.irv2.com/forums/f104/maid...ise-52371.html

Its no fun having a U-Joint go bad when you are traveling. Get it checked out now.

TerryM · 01-07-2010, 07:44 PM

Marvin,

We have an 09, same as your 08. We developed that stutter slowing down to a stop or taking off from a stop. The 10 MPH sounds about like our cutoff point also. Seems like a computer update from Cummins solved that problem. We also had the front u-joint go bad later, at less than 10K, but that vibration was at road speeds while under power, like climbing a hill or passing.

OldForester · 01-07-2010, 08:30 PM

I agree with Dale Dowdy. I have Lifeline AGMs like I believe he does and they work great. I got rid of the wet cells after I got swelling in the batteries because of inconsistent fill, cell to cell. I have not had a problem with the alternator, but I make sure the batteries are reasonably charged, either with shore power or the genset before I drive it after I've drained the batteries.

If you change out the batteries clean the compartment with ammonia and water rather than soda and you won't have a residue remaining afterwards.

J Rod · 01-07-2010, 09:18 PM

Similar issue with our 2000 38 foot. The update was performed by Cummins and also they "clocked" the driveline and "u" joints. Shudder and vibration went away. Think this mean the components were aligned in some fashion. Also understand making sure the valve stems are "Clocked" (180 degrees apart) on the rear wheel. can have an effect on vibration.

Looking forward gathering lots of information at Desert Rat Rally. Currently at Seven Feathers enroute to Travis AFB, Salton Sea, then DRR.
Rod Sprague

EngineerMike · 01-07-2010, 11:49 PM

The Cummins program issue makes sense on an 08. I recently had the ECM reflashed to version 42 of the software. I was running on v13 IIRC from the factory. Lotta small glitchy problems to resolve when going to the ULSD programming I guess. I didn't have any vibration or other drivability issues, but certainly possible. A quick call to Cummins will tell you if your ECM version is up to date. Also you probably have the air compressor inlet hose campaign if that hasn't been cleared. You'll know when the hose blows by the hissing sound from the engine (unless you get it fixed first).

Just Cruising · 01-09-2010, 12:55 PM

Hi again,

I thought I would update all who sent me advise on my posts. At this point the driveshaft has been removed by my mobile RV mechanic and is in the driveline shop. It appears that both u joints were on their way out and dry. The front one had some needle bearings missing. With your advice given about stretching they are checking for that issue also. I was not sure if this stretching was in the driveshaft or the yoke, but I suspect it was in the driveline.

AGM batteries will be installed as the Interstate ones fail and if they will fit I plan to add two for a total of eight. I will probably purchase a 200 amp (or larger) altinator that will fit and then carry the 160 amp as insurance if they will interchange.

We will not be able to go to DRR due to an upcoming knee replacement for my wife, but we will miss seeing all there as we had planned to attend.

I will get a hold of Cummins and see where we are on the ECM and hose campains are up to date and if not, get them done. I had the oil & lube done there at 10K miles ($495.00 special????) , so I need to talk to them about the u joints being dry anyway. They do not seem to just do the campains etc unless they are forced to do them, but we will talk.

On the kitchen heat exchanger issue, it is indeed different from the front door entry type. It appears the heat exchanger was installed in the cabinet before it was set and the counter top put on. The problem is that our drawers face forward and when I took them all out discovered that there is a four sided box built into the cabint from floor to counter top that is glued and screwed together on all four sides with just a hole for the 2 1/2" duct to come out of. I am asuming the return air must get into this box area somehow from the back side between the kitchen and bath wall. I have not found a suitable place to add a return vent that would accomplish anything. My next step is to see if I can safely cut an acces hole in the cabinet wall behind the trash can area to fix the problem and then overlay that with a removable panel of some sort. Have to work it out as we go. Before I go to far I want to research the case fans suggested and see if adding one into the duct near the exit from the cabinets might pull enough air to get the heat flowing.

I really appreciate the input from all who posted as it helps to hear what others have worked with.

Thanks,
Marvin C

jackrobinryan · 01-09-2010, 02:25 PM

Re: the battery issues, I'd highly recommend searching and reading some of the battery threads and those on converter (charger) problems. My recent issues has started me down that path...Lots of great reading and experience shared there in the RV Systems subsection.

Which batteries are the problem? Chassis or house? What type of converter is installed? (single stage/dumb or multi-stage/intelligent)

Before replacing my batteries for the second time, I am installing a smart multi-stage converter (ripping out the Parallax) and making some space adjustments to move up to group 27 deep cycle house batteries.

I'd learn more about the specific problem before doing a new alternator.

fwiw
jack

takepride · 01-11-2010, 10:48 PM

Marvin:

I have AGMs and love them. Remember to change all your coach batteries at the same time. Also replace all the chassis batteries at the same time. Though coach and chassis battery banks do not need to be changed at the same time. Confused?

The bad batteries will prey on the good batteries. Replace the entire bank simultaneously.

Jim A · 01-13-2010, 03:04 PM

If you go the AGM route, and I did, remember to change the charging rate on whatever charger system you have. The AGM batteries charge at a slightly different rate than wet batteries.

dgerstel · 02-27-2010, 07:33 PM

Marvin,

Since you didn't come to DRR, I did look up a 40 ft mid door to see how WRV did the install on that unit. It is different than mine, but has the same problems. The plenum, the metal box on top of the heat exchanger should be insulated and sealed.

Make sure that both fans run. Try to make the ducts as short as possible, make the bends as smooth and large as possible and remove any ties cutting into the duct tubes.

Your air intake, if like this one, the hole on left, is plenty big. The outlet vent is too small.

I had a vent like yours and replaced it with one, twice as tall, from Lowes. This is a photo of the new vent I installed.

Just Cruising · 02-28-2010, 10:26 AM

Hi Dale, Thanks for thinking of us when at DRR, we were unable to attend as you know. Our coach is built differently from your pictures in that the side of the cabinet on the right is solid and not open between the drawer guides. I plan on trying to get behind that solid section and see if I can cut it out simular to the pictures you sent of a 40' MDTS. I just need to get time to look it over carefully before I try and open it up for access to insulate and make adjustments needed. The other outlets, plenums etc have been corrected as you recommended before and has made a great difference in the amout of heat coming out. The coach heats up slow now, but does heat up with time, thanks to your input. We have been traveling w/o the motor home and are now home and I hope in the next couple of weeks to get back at it. We had planned to come to DRR, but my wife was scheduled for a knee replacement that was postponed indefinately at the last minute by her arthritus Dr who felt she should wait. In any case thanks for remembering our problem and getting back to me on it as the input sure helps save wasted steps.