So what's up with...

[John316]

BW,

Thanks. First off, our retarder doesn't have a joystick. It is activated (at one setting as far as I know) when the brake pedal is used. When you touch the brake pedal, it first activates the retarder, if on, and then as you push down farther it starts using the brakes. We usually down shift when going down a hill, so we usually aren't in sixth headed down any grade of significance.

I don't think that we have a transmission cooler. I sure could have missed it, but I haven't seen it (I really doubt that I would have missed something like that, but hey, I human. If I do have one, where would it be?) I am not sure what the difference between a four and six position, a little more explanation would be great.

So if I understand correctly, don't worry too much about the RPM's. Just try to keep them pretty reasonable, and the computers won't let it over rev.

What about programming the retarder? I would assume that the shop has to do that. What would we want it set at?

Thanks for the help. I really appreciate it!

God bless,

John

[John316]

I just wondered. Could the tranny cooler be behind the rads? Our radiators are mounted above the engine. My guess would be, if we had a tranny cooler, that it would be up there...

God bless,

John

[buswarrior]

Hello J16.

There will some serious sized hoses connected to the transmission running to the cooler, inch or bigger in size. The cooler is integrated with the engine cooling system. It's too long since I peered under a D model to remember the specifics.

For the retarder control, sounds like you have the "idiot driver" feature, no control left in the driver's hands. It is programmed at some compromise position which lets a fleet budget some increased savings in brake wear and that's it. Does the coach also have the warning light on the nose to warn the supervisor that the driver turned the system off?

You, as a busnut and invested driver, want to extract more potential and greater driving flexibility from the machine.

If it was mine, I'd want to add the multi-position joystick so that you may employ the retarder without touching the brake pedal. The joystick mounts right beside the transmission shift pad. And tell the transmission to mind its own business, I'll downshift when I want, not when the programmer wants, thanks!

Coming off the highway, between retarder and downshift use, you only touch the brake pedal in the last few yards to actually stop the coach.

The trouble with brake pedal activated retarders is that you have to push on the brake pedal to get them to work, which mean you have to get a little air into the brakes, which means the shoes are against the drums, which means heat being generated when the goal is to avoid that.

You also are at the mercy of the programming as to how much retarder comes on at what brake pressures, and what downshift stategy might be programmed, again at whatever compromise the programmer was using. If you program for full retarder, you don't always need that, if you program for light, you don't get enough when you want it. If you program for downshift, sometimes you don't want that.

The joystick lets you dial in the retarder in steps to the degree that you want, without the brakes.  In effect it is like a little brake pedal on its own, you are able to toggle in more or less deceleration. It may also still be left programmed for blended use, so that it retards in increasing degrees under increasing brake pressures. The trick is to get all these variables programmed and installed so that the coach still decelerates in a controlled, rider friendly manner, giving the driver choice as to how to employ the features, keep the brakes cooler than otherwise would be possible, and get longer brake lining life.

Oh, and have some fun "driving" the coach!!!

The complexity of the intertwining of these features and the variability of opinions of both drivers and maintenance personnel will make the "right busnut set-up" a hot topic in the years to come!

happy coaching!
buswarrior

[John316]

BW,

Thanks for all of the info. That makes sense why I haven't seen a transmission cooler. I will look for those lines, and find out where they go.

First off, our tranny gauge goes up to 350 (roughly) degrees. When the retarder is used, the transmission heats up pretty quickly. I wonder if we need to get a gauge that goes all the way up to six hundred (since that is what the TranSynd is rated for). Will the transmission continue to heat up while using the retarder, or will it just heat up to a certain threshold and stay there, kinda like a engine's operating temp. The other thing is, what about the little bit of a delay? Would it be possible to be watching the gauge, and then it to be a couple of seconds "behind" in the "reporting"? Obviously the B500 is very expensive to replace, so I don't want to damage it! I had thought that I had seen that Allison said that using the retarder would damage the tranny over time. Does that make sense?

How would we go about installing a joystick? I would assume that we would take the controls from our transmission computer that is in the second bay. It sounds like, from what you said, that the retarder can be programmed to "retard" more when the pedal is pushed harder. Is that correct? Do you think that we could get the software to program the transmission and not mess anything up (that give me the willies thinking about programming something wrong and toasting that B500 )?

Our  transmission does downshift when we are going up a grade, of course, but it doesn't automatically when we are coming down a hill. We downshift manually when we are coming down a grade.

I agree, we would like more control over the bus, since we aren't the "anybody" hired off the street, driving it (when you do a lot of your own maintenance one is very careful ), and we are careful.

So I guess my biggest concern would be over heating the transmission. How easy is that to do?

I really appreciate all of your help!!!

God bless,

John

[buswarrior]

I'm thinking the first order of business is to find out what's what with the tranny temp. There's a problem there. Was that bus a stick shift in the beginning? If that set-up is not stock, you can't trust that the KNOB who retrofitted it spent all the necessary money, or if the shop screwed him.

You want the skinny as to exactly what you need directly from an Allison rep, not a wrench turner, not a shop owner. The Allison reps are pretty good, internet will put you to the one for your area.

First order of business, calibration of the temp gauge?  It may show 350, but is it really 350?

What temp does the tranny run going down the road? You want it fairly close to the engine.

What cooler is on it, model/size, what size hoses, filters been done? size of coolant hoses taking the heat away? plumbed where they should have been? Your very expensive transmission may be in peril if there is some BS been done in the install or in the maintenance the previous owner did on the cheap.

The Transynd may withstand 600, but the transmission seals won't.

The Allison material will have all the poop for the driver control.

happy coaching!
buswarrior

[Sammy]

John, if you have an MCI D model the trans cooler should be mounted on streetside of engine cradle, laying down parallel to engine. It's got 2 large trans lines going to it on top - like #16 line and will be plumbed to water pump with short hoses too.If you have the old style cooler it will be black in color and look like a 5" diameter cylinder laying on its side, about2 feet long.It's a sealed unit, can't clean out cooler unless it's cut open and re-welded. New style cooler is aluminum and the ends are removable - 4 bolts on end cover, making it more servicable. It's larger in diameter too.The new style cooler definitely does the job. 

[VanTare]

John, Sammy and B W are the bus guys but ! on my Allisons in the Newell the B500 had a integral cooler mounted to the rear of the transmission with only 2 small coolant hoses ran to it no big oil lines

David

[John316]

Thanks a BUSLOAD for the answers!!! They have helped a lot!!! I will get under tomorrow and look and see what we have. I am surprised that I haven't seen that cooler yet, since I have been under, in, over, above, through, and scraped ( ) in there, and haven't noticed it. I think that I will go under there tomorrow since it will be soooo warm (49) tomorrow (sorry Jack, I couldn't resist, it should get up to 60 here ).

Thanks a lot for the answers. I will report back tomorrow and let you know, and answer the rest of your questions.

God bless,

John

[John316]

Okay here it is. I looked and found the cooler (not sure why I hadn't noticed before, I have seen it a million and one times ). I didn't look real close, but it appeared to be the older style . Sammy you helped me out with describing exactly where it is, and what it looks like. It has two huge (maybe around 1inch) lines going into it. It is mounted to where the coolant will run though the middle of this "can" and then cool the fluid.

Our transmission appears to run just about (maybe a tad hotter) the same temp as our engine. How would I check to make sure that the gauge is accurate?

It looked to me like the cooler was installed properly (which makes sense, our bus used to be a Peter Pan). I would say that the size of the pipe taking the coolant away was probably three inches.

So when we use the retarder should it heat up?

I will contact our Allison rep in our area.

[buswarrior]

You bought the bus direct from Peter Pan?
And originally an auto, not a retrofit from stick shift?

If stock and direct, that's a plus. PP is a good fleet.
Don't trust the brokers.

The temps will be in the ECM, and an infra red temp gun is your best friend.

If you are going to own an electronic bus, owning the full monty electronic reader will pay for itself quickly.

Some big lines, eh?

Yes, there is going to be heat, since all the dragging the brakes used to do, is now "dragging" inside the retarder. Those big lines are intended to dump that heat just as quickly into the engine coolant and into the rad, and away, at a time that the engine isn't dumping heat into the coolant.

You might consider a "Jack Conrad" style auxiliary transmission cooler mounted in a side engine door to dump the heat directly overboard before going through the stock cooler.

If it's a good upgrade for an HT740, it has to be an even better one for a B500R!

happy coaching!
buswarrior

[Sammy]

John, I'll try to get you some info on new style trans oil cooler .
The retarder makes a HUGE amount of heat as it slows the coach.Trans temps to 300 or better in a ridiculously short time as it is slowing down.I used my ProLink to compare trans temp guage reading to actual trans ECU (computer) reading. I use an infrared temp gun too and have the small Raytek temp gun, works fine for me. 

[John316]

Thanks a lot guys, that answers a lot of questions. Sammy I would love to know if we could upgrade to the newer coolers. I like Jack's type cooler, but I will see if I ever do that (time ).

We didn't by the bus directly from PP. We got it through a broker (which I don't trust  ), but I do know for a fact that it was a PP just before we got it. It had been taken out of the PP fleet and sold to the broker, where we bought it shortly after. The automatic transmission is stock, and hasn't been messed with, as far as I can tell.

I have been trying to get the IR gun from HF, but they have been out of stock every time that I have gone, recently. So you think that I should get the ProLink?

I really appreciate the help, BW and Sammy!!!

God bless,

John

[RickB]

Just in case... here's the link to the aux tranny cooler.

Maybe we could do a "group" buy together... Kinda like the Bus Converters Sam's club!

http://www.bulkpart.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=2&Category_Code=Allisoncooler

Rick

[buswarrior]

Scan tool is the first step in diagnosis for anything on an electronic vehicle.

It's all about the electrons now, not wrenching.

You will have little difficulty selling it in the future, since every busnut moving forward into the electronic buses will need one.

Need one, not want one.

happy coaching!
buswarrior

[John316]

Where do I get one?

Thanks,

God bless,

John