I Learned Something About Our Transmission Today

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I Learned Something About Our Transmission Today

November 16, 2010, 03:46:36 pm

We have the Allison HD4060R transmission. Prior to today when downshifting to 4th or 3rd gear to climb a hill or mountain, I would walk back up through the gears one by one when back on a level plane.

Today I climbed a hill and at the top of the hill we were back on flat land. So I pushed the D button and the transmission smoothly shifted back into 6th. I did not know I could do this.

Re: I Learned Something About Our Transmission Today

Reply #1 – November 16, 2010, 04:19:31 pm

Hi George, I can assure you, there are more learning curves ahead, it is never a dull day for me, Maybe it is due to my bad memory, but I keep finding new gadgets and gidgets every day I am in the coach snooping around. I feel I have found some things a few times before but can not recall but they seem familiar

You need to try on a Phenix, that will keep you real busy for a long time with the gadgets etc

The old saying about a box of chocolates

Re: I Learned Something About Our Transmission Today

Reply #2 – November 16, 2010, 04:45:00 pm

Yup, the up and down arrows, D and economy/power mode can all be selected as often as desired and at any speed desired. Said another way, pushing the down arrow 5 times at 60 MPH will do no harm. The Allison ECU understands that command to be: "Please downshift one gear at a time as soon as it can be done in each gear without overspeeding the engine."

Brett

Re: I Learned Something About Our Transmission Today

Reply #3 – November 16, 2010, 04:52:48 pm

Quote from: wolfe10 – November 16, 2010, 04:45:00 pm

Yup, the up and down arrows, D and economy/power mode can all be selected as often as desired and at any speed desired. Said another way, pushing the down arrow 5 times at 60 MPH will do no harm. The Allison ECU understands that command to be: "Please downshift one gear at a time as soon as it can be done in each gear without overspeeding the engine."

Brett

I realize this discussion is for a HD4060 transmission. But does this also apply to an Allison MD3060R transmission?

Re: I Learned Something About Our Transmission Today

Reply #4 – November 16, 2010, 05:16:46 pm

Quote from: ncaabbfan – November 16, 2010, 04:52:48 pm

Quote from: wolfe10 – November 16, 2010, 04:45:00 pm
Yup, the up and down arrows, D and economy/power mode can all be selected as often as desired and at any speed desired. Said another way, pushing the down arrow 5 times at 60 MPH will do no harm. The Allison ECU understands that command to be: "Please downshift one gear at a time as soon as it can be done in each gear without overspeeding the engine."

Brett

I realize this discussion is for a HD4060 transmission. But does this also apply to an Allison MD3060R transmission?

YES.

Brett Wolfe

Re: I Learned Something About Our Transmission Today

Reply #5 – November 16, 2010, 07:36:16 pm

Thanks, Brett. That is also good to know.

Re: I Learned Something About Our Transmission Today

Reply #6 – November 16, 2010, 07:43:05 pm

George,

Both 3000 and 4000 series dating from 1993 are basically bomb-proof when it comes to driver input.

They are programmed with maximum permissible engine RPM, etc and will NOT do/allow the driver to do anything harmful to the drivetrain.

And as one learn to use the shift pad, the options are great-- particularly for those of us who want control over what happens (vs just putting it in "D").

Even in rugged mountain driving, I leave it in economy mode and then use the down/up arrows to select the correct gear. YES, a good driver is much superior to the Allison ECU in choosing the correct gear. After all, the Allison is VERY REactive-- because of the momentum of the heavy coach, it really only "sees" what happened 1/4 mile behind you. We, as drivers can be PROactive-- seeing that we are going from a steep downgrade to a short 8% upgrade and gear accordingly.

Brett Wolfe

Re: I Learned Something About Our Transmission Today

Reply #7 – November 16, 2010, 07:49:16 pm

Brett,

More good info. We have been not using Economy when in foot hills. But it sounds like we can eke out a little more economy by leaving it in and just selecting a gear or two lower as appropriate.

Both Sandy and I have learned so much here.

Re: I Learned Something About Our Transmission Today

Reply #8 – November 16, 2010, 08:05:12 pm

George,

If you read your (fill in the blank...) Caterpillar, Cummins etc operators manual (actually all but the DD two stroke engines), the most economic way to climb a grade with a modern turbo after-cooled diesel is at or just above peak torque RPM-- even at high throttle settings. And if you open you window on a grade, you will hear the owner operated 18 wheelers operated just that way. Ya, the 18 wheelers who don't pay their own fuel bill may still have them wound up to the governor-- but as I said, they are likely not buying the diesel.

The Allison economy mode basically means that the Allison engineers read the engine manual and therefore offer you the choice of "most economic" (economy mode) OR "I don't care how much diesel it takes, I don't want to slow down 1 MPH on that hill" (power mode).

No right or wrong answers-- but you do have the choice of what the Allison does.

Brett Wolfe

Re: I Learned Something About Our Transmission Today

Reply #9 – November 16, 2010, 09:23:42 pm

Brett, you excluded the DD 2 strokes, why? Is there something I need to know about getting the best economy out of my DEDC?

Re: I Learned Something About Our Transmission Today

Reply #10 – November 16, 2010, 09:35:23 pm

Kent,

Unlike the modern four stroke turbo diesel, the DD two stroke should NOT be lugged (run at WOT at peak torque RPM).

Your engine likes its RPM's. Totally different technology.

BTW, the most fearsome DD I have ever encountered was on a Mexican built Sultana bus in Mexico in the early 1970's. The largest bus I have ever seen-- tandem FRONT axles as well as drive and tag!

DD 12V71 (yes, that is 12 cylinders) with 10 speed manual transmission.

Cruising speed 145 KPH. That is just shy of 90 MPH! And with the straight pipe exhaust, you KNEW it was coming.

Brett Wolfe

Re: I Learned Something About Our Transmission Today

Reply #11 – November 17, 2010, 09:13:40 am

Is there any way to improve mpg with the DD two stroke? I was pretty well spoiled by the 9 to 10 mpg on my U225.

Re: I Learned Something About Our Transmission Today

Reply #12 – November 17, 2010, 10:14:57 am

Put it in neutral and push it...

Re: I Learned Something About Our Transmission Today

Reply #13 – November 17, 2010, 10:17:57 am

Quote from: wolfe10 – November 16, 2010, 07:43:05 pm

George,

Even in rugged mountain driving, I leave it in economy mode and then use the down/up arrows to select the correct gear. YES, a good driver is much superior to the Allison ECU in choosing the correct gear. After all, the Allison is VERY REactive-- because of the momentum of the heavy coach, it really only "sees" what happened 1/4 mile behind you. We, as drivers can be PROactive-- seeing that we are going from a steep downgrade to a short 8% upgrade and gear accordingly.

Brett Wolfe

I know this is a very dumb question, but how is the economy or power mode selected? I recall the transmission has the D, R and the up and down arrow buttons to select different gears when in drive. But I don't recall seeing power or economy buttons.

I am learning a lot here also. Thank you.

Re: I Learned Something About Our Transmission Today

Reply #14 – November 17, 2010, 10:24:52 am

Dave, George suggested my wife push in a PM he just sent. Neither suggestion is going to happen.

Re: I Learned Something About Our Transmission Today

Reply #15 – November 17, 2010, 10:30:14 am

Quote from: ncaabbfan – November 17, 2010, 10:17:57 am

Quote from: wolfe10 – November 16, 2010, 07:43:05 pm
George,

Even in rugged mountain driving, I leave it in economy mode and then use the down/up arrows to select the correct gear. YES, a good driver is much superior to the Allison ECU in choosing the correct gear. After all, the Allison is VERY REactive-- because of the momentum of the heavy coach, it really only "sees" what happened 1/4 mile behind you. We, as drivers can be PROactive-- seeing that we are going from a steep downgrade to a short 8% upgrade and gear accordingly.

Brett Wolfe

I know this is a very dumb question, but how is the economy or power mode selected? I recall the transmission has the D, R and the up and down arrow buttons to select different gears when in drive. But I don't recall seeing power or economy buttons.

I am learning a lot here also. Thank you.

There is a button on the shift pad that says "mode". The default setting (i.e. every time the ignition is turned on) is POWER mode. Push the button and it goes to ECONOMY mode and the little light comes on. Push it again and you are back to POWER mode.

Brett Wolfe

Re: I Learned Something About Our Transmission Today

Reply #16 – November 17, 2010, 10:34:16 am

Quote from: wolfe10 – November 17, 2010, 10:30:14 am

There is a button on the shift pad that says "mode". The default setting (i.e. every time the ignition is turned on) is POWER mode. Push the button and it goes to ECONOMY mode and the little light comes on. Push it again and you are back to POWER mode.

Brett Wolfe

Ah...Thank you so very much!! I greatly appreciate this information!!

Re: I Learned Something About Our Transmission Today

Reply #17 – November 17, 2010, 01:41:18 pm

Quote

There is a button on the shift pad that says "mode". The default setting (i.e. every time the ignition is turned on) is POWER mode. Push the button and it goes to ECONOMY mode and the little light comes on. Push it again and you are back to POWER mode.

Brett Wolfe

I thought that was how it should work on our 99 U270, but the light on ours only lights up when it's in power mode and at initial start of engine, it's in Economy mode. Doesn't bother me at all, since I want to be in Econ mode most of the time anyway, but I'm guessing that's an Allison-changeable option in the TCU.

Re: I Learned Something About Our Transmission Today

Reply #18 – November 17, 2010, 02:54:18 pm

Brett, does your transmission on your 93 have modes? A better question is does my U300?

Re: I Learned Something About Our Transmission Today

Reply #19 – November 17, 2010, 03:11:42 pm

Kent,

The mode button applies to all Allison 6 speed electronic transmissions-- 3000 and 4000 series including ours.

I believe the U300 has the old-style hydraulic 4 speed Allison. If so, no, it doesn't apply to you or the U225, neither of which were fit with the electronic transmissions.

Brett Wolfe

Re: I Learned Something About Our Transmission Today

Reply #20 – November 17, 2010, 06:35:22 pm

Wow, we learn something every day. I never knew I had an economy mode either.

George S - I find that shocking that with 450 horses you ever have to shift down. I just got back from a trip to Washington state, through the Montana and Idaho passes on I 90. I was down to 4th gear and 45 mph and all the time I was thinking - if I had 450 horses instead of these measly 300 I wouldn't have to be poking along here!

Re: I Learned Something About Our Transmission Today

Reply #21 – November 17, 2010, 09:29:02 pm

Gayland,

It is not how many horses are in the year stable, it is the gearing on the treadmill that makes all the difference in the world. On one of our early ventures into the mountains of the front range of the Rockies we did not downshift and ended up over heating the engine. Climbing a very long and very steep mountain grade with lots of switchbacks, single lane in one direction we luckily found an area to pull off. We now are very pro-active about downshifting.

George Hatfield sums it up best: use 3rd gear in the 30s and 4th gear in the 40s. To that we add 5th gear in the 50s when going up steep grades if we go that fast.

Re: I Learned Something About Our Transmission Today

Reply #22 – November 18, 2010, 08:25:40 am

George,

While higher RPM IS the short-term solution to rising engine temperature, it may also be an indicator that you need to clean the CAC (Charge Air Cooler) and radiator.

Think of the dirt deposited on the side of your coach when you drive in rain. Now, picture the many thousands of cubic feet of that same dirt and water ladened air that is sucked into your cooling system. When that muddy water hits the hot metal of the CAC and radiator, some of the water evaporates and leaves the dirt deposited. This dirt slowly starts blocking the air passages of your cooling system.

So, anytime your coach is really dirty, it is a good idea to open/access the CAC from the side of the coach (from bedroom on rear radiator configurations) and with a garden hose nozzle systematically clean the fins. If there is any oily deposit, use a little Dawn as well. You will be shocked at what you flush out.

Brett Wolfe

Re: I Learned Something About Our Transmission Today

Reply #23 – November 18, 2010, 12:34:31 pm

Do any of you find much improvement in the milage in Economy mode vs power? When should you and when should you not use the Economy Mode?

Thanks

Mike

Re: I Learned Something About Our Transmission Today

Reply #24 – November 18, 2010, 12:40:29 pm

Quote from: Mike McFall – November 18, 2010, 12:34:31 pm

Do any of you find much improvement in the mileage in Economy mode vs power? When should you and when should you not use the Economy Mode?
Thanks
Mike

Here is a a good write about the Mode Button.
http://beamalarm.com/Documents/allison_mode_button.htm

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