What temps are you seeing with Allison 3000 trans in a DP?

[Kim (skyking4ar2) Bertram]

I am able to monitor the trans temps in our new coach, a 450hp Cummins, something I did not have in the old one. I was seeing the temps run from 170 to high 190's between Portland and Bend recently pulling what I thought were reasonable but not steep grades. Allison appears to consider 160 to 200 a normal range.

The coolant temps were bouncing just a bit (analog gauges only), but nothing approaching hot and the outside temps were not ferocious either.

Those of you with this particular model trans, what kind of temps do you see? I ask because I do get a smell inside the coach that I cannot locate at the end of an uphill grade and am suspicious of some kind of blowby hitting something hot. I have a first service appointment scheduled at Freightliner in Redding, CA, but I have to get there, too.  8)

 

[Ned]

Our 3060 temps run between 180-200F.  Occasionally over 200F but with Transynd that's not a problem.  I wouldn't worry until temps get to around 220F.

 

[Ken & Sheila]

With digital gauges I normally see 190 to 195 on the trans with the engine at 195 to 200. My side radiator, trans cooler and charge air cooler are "stacked". Since the radiator fan doesn't even come on until 195 my temps run higher. When climbing grades at 6% for miles at 95 to 100 (AZ, I-17) my engine temps will go to 212 and the trans just a few degrees lower.

ken

 

[Gary RV_Wizard]

My engine monitoring system reports tranny temps in the 170-202 range. Once in awhile 210 on a long downhill with engine brake engaged.

Used to be 170-196, so I'm starting to worry!

 

[SargeW]

My temps on this last trip home were much higher than usual both in coolant and trans temps.  I contribute it to the mucked up radiator (Canadian mud) that I incurred on the last trip.  Since the trans cooler was cooled via radiator coolant, when the coolant temps got way hot, so did the trans temps.  However, when the grades evened out and coolant temps came down pretty quickly, the trans temps took noticeably longer to come back down.  I attributed it to the trans fluid was much thicker than the coolant, so the trans fluid held the temps longer. 

I am hoping after a vigorous wash I will see much lower temps on the next outing. 

 

[Kim (skyking4ar2) Bertram]

  I attributed it to the trans fluid was much thicker than the coolant, so the trans fluid held the temps longer. 

That was part of my thinking, but since I did not have digital coolant numbers, it was a little hard to correlate to the dash gauges.  I am used to watching six different digital cylinder head temps in the plane so I miss my instrumentation. Computerized monitoring is on my list. You gotta love technology!

 

[SargeW]

Absolutely Kim.  I am running the VMSpc software and love the real time digital info. Although it can be a bit unnerving at times.......

 

[Jim Godward]

I am used to watching six different digital cylinder head temps in the plane so I miss my instrumentation. Computerized monitoring is on my list. You gotta love technology!

The VMSpc is a cheap way to go and the VMS XXX is the expensive way.  I got my VMS 200 before there was a VMSpc and love it.  ~$400 is the price of the VMSpc vs $1500+ for the others. Of course you could go for the all glass display to replace you existing dash.  Think glass cockpit!!  VBG

Not sure if all the optional sensors will work with the VMSpc as I have not kept up with the changes to either variety.

 

[Robert K]

My engine monitoring system reports tranny temps in the 170-202 range. Once in awhile 210 on a long downhill with engine brake engaged.

Used to be 170-196, so I'm starting to worry!

Gary ,My temps drop quickly on the downhill with my 3060 normally 180  to 200 on grades

 

[Gary RV_Wizard]

Engine braking on long down grades drives my tranny temps up, with the gears spinning madly (2nd gear is targetted) and a lot of braking horsepower being expended. With the Jacobs engine brake on its max setting, I am getting near full engine horsepower applied as a braking force. To the tranny, that is no different than the horses used to  go up the grade, but the cooling system doesn't seem to cool as well as when climbing. Not clear why that is - it's a side radiator so always fan and thermostat controlled anyway.

 

[elkhornsun]

Trans temperature should be 20 degrees below the engine temperature if you want to keep the trans healthy. Higher than that it is time to stop at a rest area and let the trans cool down. Highest temps will be when there is less cool air passing through the trans cooler for any reason (low vehicle speed or high ambient air temperatures). Important to keep the transmission fluid topped up so there is as much as possible inside to absorb the heat.

 

[Jim Godward]

Kim,

The temps on my Allison usually runs in the 180s with a top of about 200 if the coolant temperature gets there too.  My coolant normally runs about 192 to 194 and will rise to about 197 to 200 on a hot day and a long up hill pull, think the continental divide at Butte, the Siskayous, the Grapvine in CA, etc.

If you are smelling something hot, check the ehaust system for signs of something being burned on to the piping or the escape of gases around the fittings and manifold.  There will be telltale black soot in the latter case or carbonized deposits in the first case.

I hope this helps.

Have a safe trip.

BTW, My son is moving near Lebanon TN.  Rather large place, 68 acres, horse barn and shop.  Think I can fixup a hook up or ??? for me and friends??

 

[Jeff]

Starting with our last Tradewinds with a 330 Cat on a Freightliner chassis our Tranny temps were down inthe low 180s when we bought it used. I learned that the side radiator temp controller had failed and the fan was running all the tie keeping the engine coolant down at the thermostat temp of 182 degrees. The problem with that was that my fuel mileage was 1-1/2 mpg below what it should have been because of the 40 horsepower the fan was constantly pulling off the engine.


After the fan controller was replaced the tranny temps went up to 190-200 for several years. The last year we owned the m/h the transmission temperature went up to 205 degrees. I was concerned enough to call Allson and was told if the temps consistory went over 230 to have it checked out and 250 shouldn't hurt anything with Transyn.


We purchased a 2006 Tradewinds this spring and the temps now run 205-208 with temps as high as 212 on a long downgrade which prompted another call to Allison which was most enlightening. The tech referred to the cooler as a heat transfer box which is designed to keep the temperature UP during cool months to prevent damage to the transmission. When we are running in cool rain or cod temperatures the tinny will cool below the engine coolant but any other time it is the same or higher.As has been mentioned above the tinny takes much longer to cool back down because it does not have a cooler.


I also asked what the nominal design temperature was for a MH3000 and Allison's answer was 205 degrees so I quit worrying about my temps!

 

[bukzin]

The VMSpc is a cheap way to go and the VMS XXX is the expensive way.  I got my VMS 200 before there was a VMSpc and love it.  ~$400 is the price of the VMSpc vs $1500+ for the others. Of course you could go for the all glass display to replace you existing dash.  Think glass cockpit!!  VBG

Not sure if all the optional sensors will work with the VMSpc as I have not kept up with the changes to either variety.

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What is the difference between the VMSpc and the VMS XXX  (what does the XXX stand for?)

If my Monaco has the 9 pin connector is this a simple 'plug and play' set up?  Or do I have to install sensors and run wires?

Thanks!

 

[Jim Godward]

What is the difference between the VMSpc and the VMS XXX  (what does the XXX stand for?)

If my Monaco has the 9 pin connector is this a simple 'plug and play' set up?  Or do I have to install sensors and run wires?

VMS XXX is in place of the number, like my VMS 200.  Mine has been replaced with one with a colored screen, I believe VMS240.  The VMS XXX units are about $1500plus or minus depending on the unit.  There are additional  sensors that can be added for outside temperature, weather information, freezing road alert and a tire pressure monitor.  I am not familiar with them all but go to their website and check them out, http://www.silverleafelectronics.com/

The 9 pin connector is the only thing you need to hook up for it to work but to dim the display you need to hook it up to the dash light circuit.  I seldom if ever drive at night so dimming was not a priority.

The VMS PC is the most versatile in my opinion IF you have a place for the monitor that does not affect your field of view.  You can also have a mapping program on the monitor for added usefulness.

 

[Tom]

VMS123X products are standalone displays with associated electronics and software. VMSpc is merely software for your PC; It requires the purchase of an interface box that connects between the diagnostic connector and your PC, and the associated wiring harness.

 

[SargeW]

Since I run a laptop up at the front for the DW to run Microsoft Streets and Trips, my location to display the VMSpc software was easy.  I mounted a 7" LCD color screen on the dash and paired it with the laptop the DW uses.