Jump to content


  • Content Count

  • Joined

  • Last visited

Profile Information

  • Gender
    Not Telling
  • Location
    NW of Chicago
  • Interests
  • I travel
    With pets

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. I have a buddy who's kid built an RV out of an old school bus (known as skoolies). Unfortunately he broke down within a few a few miles of his inaugural voyage. The shop found both fuel filters clogged but also stated that they found pieces of rubber in fuel tank. I've never heard of that. I know rubber deteriorates and I make it a habit of replacing all rubber lines on old cars that I have restored including an old 76 GMC Eleganza motorhome. Anybody ever hear of that? If true, what else has to be cleaned and flushed to get the fuel system clean and reliable? I don't have the year or make of the bus but I can likely get it if important. Thanks Mark
  2. Don't know. Factory installed on both furnaces. Don't have coach here but guessing there is a bead of silicone between that plate and the coach?
  3. This may be an easy fix for anyone who wants to use their furnace on the road but can't because it keeps blowing out. My horizontally mounted rear furnace intake/exhaust kept doing that while my vertically mounted mid-cabin furnace intake/exhaust worked perfectly. After thinking about it for a while I decided to try introducing something that would divert/obstruct/change the air flow over the rear furnace intake/exhaust. Lo and behold it worked. I tested it at 65 mph multiple times and it hasn't failed yet.The 'device' is just a 2" pvc coupling that I first cut in half lengthwise then cut it in half again widthwise. Painted it silver and attached with clear silicone to the rear side of the intake opening so it could divert/obstruct/change the airflow over the intake/exhaust. I have no idea about the exact dynamics and whether it would have worked just as well mounted on the exhaust but it worked. Now I'm looking forward to a warmer coach on the road. Here are a few pictures. And yes I know even Suburban (spoke with them) recommends not using the furnace while traveling but many of us ignore that advice. Should think of a fancy name for it like the "Dynamic Aero Turbulator" and sell em.😄 Mark
  4. As promised. I finally finished my testing of the slow key cycle method recommended by Allison to avoid randomly losing my full throttle downshift ability. The recommendation was to wait 5 seconds in the on position before engaging the starter. I exercised an abundance of caution and waited 10 seconds. I tested it 10 days in a row with 10 cycles each road test. I would start it up in the storage lot, get out on the road, do a full throttle downshift at shift points that I knew it should respond to a full throttle downshift request, validate it worked, then pull over and do another key cycle for a total of 10 cycles per trip. I have a call into Allison to review my findings and determine their next steps in fixing this bug or design issue. I'm not exactly sure how they are categorizing it. Please pass on this information to anyone you know that might be having some performance issues with their Allison trans. Hopefully Allison will communicate this and other issues out to their field team and repair centers. No one I dealt with, including the most recent team from Allison and Cummins, knew anything about this. It wasn't until I got these two tenacious individuals who chose to own the problem rather than simply say their side looked good, that we discovered it was known by Allison and I wasn't exactly alone in experiencing this. Mark
  5. Day 4 and all remains good. 4 days and 40 key cycles. I'll report back when I finish the 10 days but the slow key cycle work around is looking good.
  6. Day 3 tests all positive. Tomorrow, Day 4, will be statistically significant because it has never stayed in "working" mode 4 days in a row since I have been aware of the problem and starting tracking it. I'll post Day four and then wait to post until I have finished the rest of this week's daily tests until I finish Day 10.
  7. Day two: slow key cycle worked again. 10 cycles of off, on, wait 10 seconds, start, drive, try a couple of full throttle downshifts at known shift points. Repeat.
  8. Hi, This is Mark, the OP. Thought I would give a quick progress update. It may help people with an Allison 2500 who are experiencing no downshifts even at full throttle. I've worked with two different teams of Allison and Cummins techs over the last 6 months. That is in addition to the original time and money spent at Allison and Cummins trying to get this thing diagnosed. The first team worked with me down at Tiffin in Red Bay. That ended up with no fix and Cummins and Allison nicely pointing fingers at the other and Bob Tiffin pointing me to Freightliner. By this point the ECM, TCM and TPS had all been replaced without fixing the problem. The coach still would randomly not downshift at full throttle under conditions I knew it should and could. I had demonstrated that to the techs over several days. I had just about given up when I called Cummins about warranty coverage and got a tech person who was genuinely interested in my problem. That got be kicked up to Level 3 and I got a tech that was EXTREMELY tenacious. He ended up arranging a meeting with me, himself and an Allison tech for two days down at a local Cummins shop. Best two days ever with both guys taking turns plugging in their PCs and discussing possible theories as they were gathering and diagnosing data and findings. The end result is that it looks like it is a software bug on Allison's side. Not confirmed yet but data is pointing that way because they are seeing this problem elsewhere on other vehicles. It is is tied to, and triggered by, cycling the key on and off. The thought is If you cycle the key off and then on too quickly, the software pulls the wrong value for the "road speed limit" parameter and that in turn causes the transmission to not downshift at full throttle. I am just starting to test this theory by cycling the key from off to on and then waiting 10 seconds before starting the vehicle. This slow cycle supposedly allows the data to fully load into the TCM. Quicker cycles cause that load to get interrupted somehow. I should finish my testing this week. Today it worked correctly 10 times in a row but my experience is that those results are not definitive. My data to date says that anytime I leave the RV sitting over night I have about a 50% chance of it being in "working" mode versus "not working" mode" the next day. So until I get a few more days of those data points I won't really be comfortable saying this slow cycle works. Allison says that they are doing the slow cycle on a fleet of garbage trucks and it has worked 100% of the time. Just to refresh what my problem is. I know my trans shift points at full throttle by heart now on flat roads in good conditions. It will downshift at 25, 35, and 45 (other points too but these are the three I use as test points) at full throttle every time when it is in "working" mode. When it flips over to "not working" mode after a key cycle, it will NOT downshift at those same points. It just slowly accelerates. I'll keep everybody posted on the rest of my testing this week. Mark
  9. I purchased the coach 1.5 years ago but never tried driving with the furnace on until this fall. It happens every time from what I can tell. Just went on a short trip today at a max speed of 45 and it was off when I arrived at my location but nowhere near it's setting of 68. I'm assuming it is the outside wind but as I'm sitting here typing I can't say for certain. Could be other reasons for shutting down. When I get to where I'm going I just flip the switch to off and then back on and it starts up immediately.
  10. My rear Suburban furnace blows out when I drive. My mid-cabin furnace works fine when I'm driving. The only difference that I can see is that the mid-cabin intake and exhaust vents are vertical and the rear furnace vents are horizontal. I'm pretty sure on my unit the rear heats the wet bay so I would like it to work. One difference that I just thought of is that the mid-cabin may be a few more BTU. I know that Suburban doesn't recommend this use and I've read that there may some states that don't allow it. I want it to work. Mark (aka Elizabeth, the true forum member)
  11. It was fine but very slow to load up or recalculate. That may be because the memory module was failing and ultimately failed. The screen would blank out and fill with hundreds of little blocks with the words "GIR LOW MEM" in them. You would have to shut it off and then go into settings to select the map which the memory failure would un-select. This worked a few times but the problem quickly got worse and it would fail within five minutes of resetting. Stupid money to get repaired and the part is taking over two months to arrive at the repair facility. I was in a hurry to get it fixed which is why I went with the repair but I would do a lot of research on alternatives before I would go this route again. Mark
  12. I was asking in general. Thanks again to all who responded and Merry Christmas! The bus video more than convinced me there will be no "winging" it.
  13. Ouch!!!! Yeah, don't want to do that. Not even at slow speeds. Mark
  14. Thanks for the replies. Coach is a 2015 Tiffin RED 33aa. 35 feet long, 13 feet high, 31k pounds fully loaded with full fuel, propane, fresh water and toad. Wife is getting the Truckers Atlas. Not sure what else we'll get, have to look up the suggestions posted. Does anybody just wing it? I was just talking to a buddy of mine a few minutes ago who has traveled 150,000 miles in a 34 foot Class A and he says he has never used anything other than paper maps and now Google maps. Just asking, not suggesting it. Wife is a cautious soul so it would never happen anyway. Personally we would like to just use our phones and not screw with the Kenwood. Mostly because it is slow and hard to access for my wife since it is the driver's cockpit and angled towards the driver with no ability to swivel it towards her. To see it, she has to unbelt and kneel in front of the stupid thing. Mark
  15. Our Kenwood is in the shop for the next few months getting repaired. Yep, the next few months waiting for a part. Crazy. The problem is we are leaving for a month long trip from Chicago to Texas and we don't have an alternative for bridge clearance - our main concern. We both have Google Maps on our phones and use that app frequently in concert with the Kenwood. Any apps available to add on to Google Maps? We really don't want to buy a stand alone GPS since our Kenwood is coming back to us some day but I'm not going to cheap out and not buy something only to end up with many thousands and thousands of of dollars in roof repairs as I scrape off the top foot or so of my coach😁 Mark (aka Elizabeth the actual forum member and my wife)
  • Create New...