Transmission care

[Albert Balika]

I park my 2007 Contessa 42 Bayshore C-9 each year for three to four months. It is difficult to move the coach during this period. Should I excersise the transmission from time to time? I was told I could accomplish this by leaving the park brake on, put transmission in drive while engine running and this would do the job. Any opinions regarding this would be appreciated.

[Steve Huber Co-Admin]

Albert,
IMHO if you are not going to bring the engine up to operating temperature, leave it off.
Steve

[Eric Maclean]

Albert
I'm with Steve on this one in that if the engine is not brought to full operating temp your doing more harm than good .

As for placing the transmission in gear against the parking brake it's a bad habit in the business this is known as a torque converter stall test. The problem with loading the torque converter against a stationary vehicle is because there is no movement on the output side of the torque converter the power being delivered into the torque converter is converted directly into heat this is why people do it to warm the engine and transmission faster unfortunately in doing so it concentrates heat in to the torque converter and the transmission input seal shorting the life of both . If for some reason you decide to raise the RPM while doing this the temps go up very quickly causing fluid degadation and seal or torque converter damage.

Hope this helps
Eric

[Albert Balika]

As always, thank you for your response(s). So, if I understand what has been said, there is no problem with just leaving the transmission stagnant for the three to four month period and upon departure, I bring the engine up to operating temperature and drive away slowly allowing the transmission to warm up properly. I do start the engine every two weeks or so and bring the engine temp up to 130 degrees. I do this to circulate the oil, etc. Please advise regarding this procedure. Thank you

[Eric Maclean]

The only reason to warm up a transmission is to help boil off any moisture / condensation that may have accumulated in the fluid this means driving the vehicle long enough to get the transmission up to full operating temperature usually 20 to 30 miles and of course the longer the better to boil out any collected moisture.
Allison warns about the effect of moisture in the fluid on the clutch packs within the transmission and specify a low tolerance for it .
Unfortunately the type of use that most of these coaches get with long periods of storage even though the fluid doesn't get to degrade from use but because of the long storage especially of stored in wet winter conditions where temperatures swing above and below freezing often . These conditions create more condensation and can be considered the same as extreme duty requiring more frequent oil change frequency.

In a perfect world we would park these coaches in a climate controlled environment.but failing that the best practice is to give the coach a good drive to help boil off any moisture in the fluids (transmission,engine hydraulic) after a long period of inactivity in inclement weather.

On the question about warming the engine up if you are going to do that you need to get the engine up to operating temperature before shut down this is the temperature at which the thermostat opens 160 or 180 degrees not getting to full operating temperature defeats the purpose . During this run up after the first ten minutes the engine sould beset on fast idle approx 1000 to 1200 RPM
On the newer engines with exhast after treatment systems it is not advisable to even do a run up as the particulate trap will load up with soot which under normal operation ( is on the hwy) the proper criteria for a regen will be meet and the computer will initiate regen to burn the soot out of the particulate trap it is almost impossible for these criteria to be meet on an engine without load .
The problem arises as the soot builds up to a point where the engines ECM will set codes and initiate a derate condition and eventually shut down the engine in an effort to protect the particulate trap.
Therefore most engine builders warn against long period of idling at any speed.

My advise is if the vehicle is to be stored for a period shorter than 4 months I would leave it doormat for the period and give it a good drive when you get it out of storage.
Probably not the answer you wanted to hear
Eric

[William Jordan]

130°isn’t near high enough temp and as others have said unless you can take it for a 30 mile drive just leave it alone , don’t start it. In fact I wouldn’t even drive it if I could. Put the attention to making sure the battery is kept charged and maintained. Heavy equipment like this sits unused all the time, ask any farmer. 
On the other hand The generator should be exercised, not because of the engine itself , but the generators electrical contacts.

[Eric Maclean]

Albert
The best way to monitor when to change the transmission fluid and engine oils is by having annual oil samples analyzed this does two things .
1) when analyzed the lab can tell you how much life is left in the fluid and when to change the fluid this can save considerable $ in oil costs as compared the schedule for extreme or severe duty use.
2) if there are any problems in the engine or transmission the analysis will uncover them before a failure .
The analysis will give you a report with Percentages of metal moisture coolant etc which will allow you to track any changes .

If for instance a bearing in the air compressor on the engine where to start to go bad the analysis would show higher concentrations of a certain type of metal and give you some idea where to look to correct the problem before a catastrophic failure.
Hope this helps
Eric