6 speed auto transmission Allison with 8.3 Cummins

[tazzzytazus]

Hi everybody!!!! New to the forum and new to RV’ing. My wife and I love camping and love to go to different places. Without doing any research we decided to buy a motorhome. Used 1996 Holiday Rambler Imperial. Seemed to be in great shape. Interior is, now just worried about mechanically. We bought this in August 2017 and took a couple small trips without any problems during the summer. Over the Christmas holidays we took it from Indiana to Florida, Alabama and New Orleans before heading back home to Indiana, 2800 miles total trip. We experienced a few problems and I’m hoping for some advice. I’m a Class A truck driver but little mechanical ability, although I am very good at following directions. Coach came with all manuals, but they seem WORTHLESS for my problems. Any constructive coaching or advice will be appreciated.

1) rear brakes didn’t seem right. Got to Florida and took to an International shop in Daytona Beach. They found the “S” cans were binding and Corvus pins on slack adjuster were seize not allowing brakes to fully release. They were able to repair that - $977.14. They seem to be working fine.

2) when we stopped and put in N, the coach would not go into gear. Auto 6 speed with controller on left side of drivers seat. Repair shop stated the throttle return spring was bad and throttle linkage was binding not allowing transmission to return to idle.....lubricated linkage and replaced spring. On auto shift the coach shows a 6 on the left and the current gear on the right. I believe they call it “On Mode” or “Mode On”. The coach downshifts correctly. But when at a complete stop, it SOMETIMES will shift 1,2, then where the 6 is on the left will change to a 2 and the current gear will not go past 2 or it will downshift back to 2. This was not happening prior to the new spring. Any ideas?

3) I’m getting no heat from the dash while engine running and temp at running temperature....

4) my interior power will shut off periodically while engine running. Stays on while hooked to shore power.

5) LP gas cylinder = 100# about 30% full according to sensor. Will power on and heat for only a few minutes then cut off even though did not get to set temp of thermostat. Bad thermostat? I heard cold weather may affect it.

6) last and probably least, but would be nice. My cruise control are on center column of steering wheel. It does not engage, Check for fuses in the 3 compartments that I have found fuses, none labeled as cruise control or cc.

I’m sure there’s more to come but this is what I can think of at this moment.

Any help or advice is appreciated.

[tazzzytazus]

Lwiddis wrote:
You were lucky on that trip. A 22 year old coach needs a complete mechanical and RV component inspection. Then repair or replacement of defective or questionable components. Then you should have a reliable unit.

That was helpful....... Thank You

[Solo]

tazzzytazus wrote:


3) I’m getting no heat from the dash while engine running and temp at running temperature....

Here's a shot in the dark but, have you checked to see if your coach has shut-off valves on the coolant hoses that serve the dash heater core? I believe your Imperial is on a Spartan chassis so I cannot speak to where they may be but, many are located along the block/transmission area and are not difficult to see and open or close as necessary. The temperature differences of the dash AC and dash heat are regulated significantly by the valve positions. On our Freightliner XCL chassis, it is located on the left side, near the engine block. Here's a picture of ours.

[MontyL]

#4 is an odd one, I'd go after the negative on the coach battery and also check the disconnect relay, as both of mine are just forward of the engine.

#5 is safety shutdown, the controller in the furnace isn't sure it lit. Check the flue for nested critters, etc.

Don't give up on it, you're already vested!

[tazzzytazus]

Stim wrote:
On your S Cams and Slack Adjusters it's common for them to get sticky from lack of use and not being lubed properly.
I have had to free up hundreds of them on semi's but the $900. plus figure seems very high to me. ???

It was all labor at that. I kinda figured it was, but hell, I'm from Indiana, was in Florida, when your in need your most vulerable.

[Stim]

On your S Cams and Slack Adjusters it's common for them to get sticky from lack of use and not being lubed properly.
I have had to free up hundreds of them on semi's but the $900. plus figure seems very high to me. ???

[polar76]

On your heating issue, you may have a booster pump that is not functioning.
On my 97 model Country Coach, it is located on the inside of the frame Drivers side, about as far back as the driveshaft location. just a 12V source and ground wire.

[wolfe10]

Mode= Economy Mode merely changes the shift points-- keeping the engine at lower RPM for better MPG.

It will have no affect on your issue.

Sorry, I don't know where the throttle position switch is on your particular chassis. But, if the left window goes to exactly the same gear as when you turn on the exhaust brake, that is a possibility.

One other point-- you mentioned using the exhaust brake in inclement weather. NOT recommended as a 4 wheel "power drift" in an RV is not a pretty sight. Use service brakes to stop in slippery conditions-- that uses all 4 wheels, not just two. Exception may be very long grades, and if used here in slippery conditions, go REALLY slowly.

[tazzzytazus]

Wow, thanks for all the replies!!!! I I got nothing but insults and criticism from another site when I asked for help on other issues. So much so, that I probably will not go there again, at this age I don’t need the bs.

Mike

Thanks for the links. The site I’d rather stay away from is the IRV2 site. I will definitely check out the Allison site when I get back in town. Thanks

Jerry & Jeanne

I do have an exhaust brake, but very rarely use it. In the hills and in inclement weather. My problem I’m having is when I come to a complete stop then start over. I do ride in “Mode On” all the time. My Mack has 10 gears no Mode On mode so had no idea what exactly it was , was told I should leave in this position when driving..... maybe that’s the problem. I should have done some research. Again thanks for your input I appreciate your time, thank you!!

Ivylog

On my bus the generator is in the nose. I’m assuming this electric controller will be near the heating unit?

Brett - Wolfe10

I’was thinking when they put the new spring in they may have forgotten to make changes to any type of adjuster to allow for the tension of the new spring, just didnt know what it may be called. Do you think that’s a possibility? And thank you very much for the transmission codes instruction. That’s awesome and will do that this weekend when I get back in town. Thank you again.

[wolfe10]

jplante4 wrote:
Ok, there are a couple of things that can go on with an Allison.

Firstly, the mode on mode usually delays the downshift on hills until about 1500 RPM. It prevents the constant shifting when doing the rolling hills. If you're a driver, you already speed up in anticipation of hills anyway so you probably don't notice this. On my Allison, I go to mode when I get to the big roads.

If you have an exhaust brake (PAC brake etc), the Allison ECM will select either 4th or second gear on the pre-select and will downshift to the pre-selected gear when RPM allow it as soon as you start braking. Once you come off the brake and go back to the accelerator, the Allison will shift to the normal gear for that speed and start upshifting again. Some people drive around with the PAC brake on all the time. I don't like the way it jerks out of the lower gear when you step on the gas, therefore I turn on the PAC brake only when I need to slow down.

My guess is you turned on the PAC brake at some point.

Agree, this is the most likely cause. Turn OFF the exhaust brake to verify. BUT, any throttle should turn off the exhaust brake (and transmission left window should show "6". Could be the throttle position sensor is mis adjusted. You really want to address this, as you MAY also have the exhaust brake active with this happens. That would be very hard on the engine (on throttle AND exhaust brake at the same time).

Wouldn't hurt to check the transmission for diagnostic codes-- easily done from the driver's seat:

Turn on ignition (engine off).
Press the transmission shift pad up and down arrows at the same time. Your coach is right at the break point for adding checking fluid level from the shift pad, so you will see one of the following come up depending on whether you have this feature: OL or d1. If OL, press the up and down arrows again to get to d1. If there is a diagnostic code, it will display as d1, then a two digit code. Record it. If you get a d1 - -, there are no codes. If you do have a d1, press the mode button to go to d2. Continue until you get a d_ - -.

To exit, just turn off the ignition.

Let us know what you find

[Ivylog]

Your mechanical 8.3/Allison is one of the best combos they ever made. Like the above post, turn the exhaust brake off as that is what's probably defaulting the Allison to 2nd. I only turn the "mode" on in rolling hills as the change in shift points help there the most.
Your heat issue is probably the electric controller that controls the water flow. If you have a generator on a slide you can access it there and using a 9V battery see if you can get the motor to operate. The cheapest solution is to replace it with a manually controlled valve that you open in the winter and close in the summer. This will also help your AC in the summer as the electric controller is bad about not shutting all the hot water off.
Do not give up on this rig.

[jplante4]

Ok, there are a couple of things that can go on with an Allison.

Firstly, the mode on mode usually delays the downshift on hills until about 1500 RPM. It prevents the constant shifting when doing the rolling hills. If you're a driver, you already speed up in anticipation of hills anyway so you probably don't notice this. On my Allison, I go to mode when I get to the big roads.

If you have an exhaust brake (PAC brake etc), the Allison ECM will select either 4th or second gear on the pre-select and will downshift to the pre-selected gear when RPM allow it as soon as you start braking. Once you come off the brake and go back to the accelerator, the Allison will shift to the normal gear for that speed and start upshifting again. Some people drive around with the PAC brake on all the time. I don't like the way it jerks out of the lower gear when you step on the gas, therefore I turn on the PAC brake only when I need to slow down.

My guess is you turned on the PAC brake at some point.

[mike_brez]

I think you are far away from needing to get rid of your coach.
I would not take it to a rv repair shop for the trans. I would be looking for a Allison transmission repair facility for the trans. The cc also works in conjunction with the trans so your problems my all be related.
Heat could be as simple as a thermostate or a blend door not opening a vacuum hose

Maybe ask over HERE

ALLISON TRANS

[tazzzytazus]

Thanks Mark. Unless my tranny needs replaced, I don’t believe my issues to be large enough to just pack it in and start over. I must admit though, I have given it some thought. I just hate to give up on anything. My bank account may state otherwise when it’s all said and done.....

Really hoping to get some “fix” answers vs. throwing in the towel.

[MarkTwain]

Not being real mechanically steep myself, I would take the Rig to a "good, reliable RV repair shop with a good reputation for quality work and ask them to check out all the issues you are having and how much it would cost to repair all the problems. Then decide if the financial cost is worth fixing or is it time to sell and buy another RV. If you buy another used RV I would take it to the same repair shop to have it checked out BEFORE you buy it. Just my 2 cents worth.