I need to get one for my MT-647, I guess. I was looking at a fan cooled 12" by 12" cooler, 1/2" NPT ports, but I really have no idea what I need. I haven't been able to find a spec for either flow or cooling efficiency. I guess I should also put in a thermostat switch to control the fan, but at what temp? Where do people put them in a MC-5, behind the radiator seems a tad inconvenient.
Thanks, Brian
It's 8 gpm flow for the Allson and set the fans to come on at 205* but anything between 200* and 250* will work, the Allison does not like cold operating temperatures fwiw
Brian, I don't have the Allison manual in front of me, but during normal driving, the transmission is at 180*F, just like the engine. My HT740 is cooled by the engine double oil cooler. The temperature sensor is at the top of the converter, near the oil out hose that goes to the cooler. In hot weather and or climbing hills, the temp goes up from there to 200, 210*. So common sense would tell me to have the fan turn on at 180. I recently installed a filter on that line. I think it helps cool, at least marginally. And of course there is a filter on the other side of the transmission, also remote, all 1" lines. If I installed an oil to air cooler, I would put it beside the engine on the driver's side, just outside the cradle rail. I have space there since I replaced the muffler with a resonator.
JC
PS: I see Clifford says 205*. My trans temp doesn't go that high unless pushed.
I got my transmission temps mixed up with engine oil temp the 600 series run between 160* and 220* but I still set the fan on 205*
I wanted to relieve the radiator of some of the heat from the transmission cooler. I added this cooler http://www.transmissioncoolers.us/DB-341DC-12.html (http://www.transmissioncoolers.us/DB-341DC-12.html) . The hot transmission fluid comes out of the transmission, through this cooler then to the normal shell cooler. Then I'm assured of not running the transmission to cool-the radiator water to oil shell cooler will also keep the transmission running warm on a cold day. I have the aux cooler mounted on the right side engine door with the fan pulling air from the engine compartment to outside. You say that's in reverse-well I found that the big engine radiator fan creates so much pressure, the trans cooler could not over come the pressure and work properly. So running the fan (it is easily reverseable) from in to out works-even the hot engine air will be cooler then the transmission fluid. I have it wired through a thermostat on the out side of the cooler, and a 0n-off-on switch to either turn it off or continuous on. Good Luck, TomC
How much cooler area do I need? Is there another way they rate the capacity of oil coolers?
Brian
The area is going to depend on how many passes the cooler has 1,2,3 or 4 passes ,the heat rejection according to my tech manual for the 600 series is 44,500 to 67,500 btu/hr.
I can tell you for sure a 12x12 for primary cooling is not going to work.When Hayden sized mine for a 740 it was 88 square inches double pass and there wasn't enough room.
So I went with double double engine cooler,they make a remote tube type water to oil like the transit buses used with the V730 it's about 22in L x 5in R I have I removed from a GM but the corrosion is so bad it would be a problem for you
I was thinking water to oil but with the 350 hp turbo engine and stock MC-5C radiators I don't have any spare capacity. I will look for a larger cooler, or go with two in series. They just have that 12 by 12 one on sale at Princess Auto (our version of Harbor Freight, but a little more upscale...). :) Thanks for the capacity numbers.
Brian
Here is a link to Hayden. If you scroll down, you will find recommendations for Allison transmissions. There is also heat dissipation data. I did not run our cooling through the radiator, which can be said to be a mistake since the engine heat will not warm the oil in cold weather. Fortunately, we do not go anywhere very cold. Ed H. had the same setup we have; that is one cooler in front of each radiator. The ones I have are about 14 x 11 and have 6 tubes that look to be 1/2 diameter. I think the fittings are 1 inch fpt. They could be smaller depending on how think the pipe wall is since I am just guessing from the outside look. If you are using only one cooler, it will have to be bigger.
On long grades, we have gotten as high as 230, if I remember correctly. By the time it gets up there, I would be turning on the misters for the radiators anyway. One surprise we ran into was that the transmission temp would begin to climb when we were going down very steep grades on mountain roads that required us to stay in 1st or 2nd gear. This, I believe is from the slipping of the torque converter, which does not lock up in those gears for a 647. If your cooling is going through the radiators, then since the engine is generally running cool in those situations, you would probably be okay. For us, we installed a dash controlled torque converter lockup switch. That solved the heat problem plus gave us much more control in mountain descents. Really, if an incline is radical enough to make you want to stay in 1st or 2nd, you want the transmission locked up. It makes a huge difference with the Jakes too. I believe the 740 locks up in 2nd, so those folks have less of an issue.
I've just finished installing a Thermal Dynamics DB-00341DC remote cooler just like Tom C has. Unfortunately Makco's price is a lot higher than some eBay sellers - I paid about $140 more than I could have. It seems fairly decent quality: the cooler itself is made in China, and the fan's made in Mexico. The supplied mounts are rather hoky, but it's easy to make something better. It has 1" FPT fittings, so they connect well to my -16 transmission hoses. I repurposed my old Kysor Alarmstat 195-degree temperature switch to turn on the fan, and I also have a sealed toggle switch to override the temperatures switch. I was slightly surprised when I was testing my new cooling system at how quickly the transmission fluid is heated up by the engine coolant - after only a few minutes of idling, the transmission fluid at the new cooler was getting quite warm. If I can reduce my coolant temps by 5 degrees or more, I'll be happy. At this point I'll try almost anything!
Yes, I know a larger cooler would be better, but I only had space for the one I bought. I mounted it behind the rear wheels (but not in the path of debris thrown up from the tire) so it will get the airflow under the bus as I drive. It's not the ideal location, but it should work pretty well. I also mounted my hydraulic fluid cooler there as well instead of having it in front of the radiator - I don't want anything that can reduce airflow to the radiator or increase its incoming air temperature. As soon as I finish rebuilding my hydraulic pump and take my bus out for its maiden voyage with a completely new cooling system, then I'll know if my obsessing over cooling details has paid off or not.
John
What would you think of something like this: http://www.transmissioncoolers.us/DB-1290.html (http://www.transmissioncoolers.us/DB-1290.html) with dual fans fitted, maybe 10" diameter with 1300 cfm each? That would give me 38,000 to 52,000 btu/hr, and up to 2600 cfm. The dual fans would let me run them from 24 volts in series.
Brian
Brian-that's the same cooler but without the built in fan I quoted.
Brian,just don't undersized you are like Lin your setup is going to be for primary cooling not auxiliary cooling
So it's go big or go home! A friend of mine has one that I thought was too big, so I will take a closer look at it, maybe it will work. Thanks, guys, I think I have a handle on this now. On to the driveshaft... Next question coming soon!
Brian, check and see if the modulator pin is inside you transmission,I may or may not have one for the 600 series I have a sack full of 740 pins
Like Lin said, on my 5A the PO put a cooler to the outside of each radiator ......no fans needed, never ran hot, in fact the temp gauge usually never rose very much. Never saw it get above 160 degrees. Even though Clifford says the Allisons don't like cold temps, mine never gave me a single moment of trouble in the 12 years/90,000 miles that we had it, the PO never had a problem with it during the 127,000 miles that he drove it and the new owner hasn't had any problems with it either in the 15,000 miles he has put on it so far. I did switch over to transynd when i got it. :)
I installed a Hayden 2305 cooler to cool the MT654 I installed in my MCI7 several years ago. Its rated at up to 108,000btu heat rejection.
This link
http://www.haydenauto.com/upload/HaydenAuto/Documents/Cat_Hayden/2007-hayden-trans-oil-coolers.pdf (http://www.haydenauto.com/upload/HaydenAuto/Documents/Cat_Hayden/2007-hayden-trans-oil-coolers.pdf)
shows the various coolers and Allison requirements ( page6 ).
This is the chart I used when I purchased the cooler. I also installed 2 fans on the cooler, but have never needed them.
The cooler is mounted in a single mesh door that replaces the double doors on the rear of the coach.
Quote from: Ed Hackenbruch on October 24, 2016, 08:45:43 AM
Like Lin said, on my 5A the PO put a cooler to the outside of each radiator ......no fans needed, never ran hot, in fact the temp gauge usually never rose very much. Never saw it get above 160 degrees. Even though Clifford says the Allisons don't like cold temps, mine never gave me a single moment of trouble in the 12 years/90,000 miles that we had it, the PO never had a problem with it during the 127,000 miles that he drove it and the new owner hasn't had any problems with it either in the 15,000 miles he has put on it so far. I did switch over to transynd when i got it. :)
If you tore one down that has been run cold you would see why Allison wants the 160* to 220* it shortens the life you go from a 1 mil mile down to 3 to 500,000 which would last the average bus guy all his life.They do just as good on 10/30 or 15/40 engine oil as it does on the Transynd IMO,the more oil you can get into the system the better off you are even with the 7 inch pan the 600 series hold about 1/2 the oil of a 740 with a 5 inch pan
So, not too hot, not too cold, but just right... Great. Now I have to channel Goldilocks... ::) Now I found a cooler that I am afraid is too big... :(
I mentioned I was looking for an oil cooler to my buddy and he said there on one on a John Deere engine in his storage yard that used to cool a compressor that I could have if I thought it would work. I went and got it. It is a double pass, double row cooler with a core of 20" by 24" by 3" There are five tubes per pass, total of 20 tubes, each tube is 3/4" OD, it has fine aluminium fins that look in decent shape. Overall size, what with the header tubes on top and bottom, is 32" by 23". It weighs about 50 lbs empty, and it would probably hold over a gallon. OK, I just worked it out, 1.25 us gallons. Add a quart for a filter, another quart for hose and fittings, almost two gallons of extra fluid.
How do you deal with all that oil not draining back into the transmission sump and over-filling it? This was mounted vertically with the in and out on the top, so gravity would keep the oil inside the cooler. If I have to mount this laying down flat (the only space I can think of to mount it is lying down flat on the floor of the passenger side of the engine bay, kind of under where the OEM air conditioner compressor frame is) then what keeps the oil inside the cooler?
Brian
Ed, as I once mentioned to you, I think that it is quite possible that your transmission oil temp sensor was mounted in the wrong place. When I first installed mine, it was suggested that I put the sensor in one of the small plugs on the side. When I did that, the gauge barely moved at all. However, I was soon informed by an Allison shop that those were test ports and would not give an accurate reading, so I moved the sensor to be inline in fluid output going to the cooler. Then it began to behave in a way that reasonably corresponded to the actual use conditions.
Not to hot not to cold you can control it, but that is why Allison preferred the water to oil setup, the gauge should be mounted on the torque converter out cicurit or in the sump but the sump installed gauge will read lower because it has gone through the filters and what ever type cooler you have test ports are not to install a gauge in there is no circulation
Brian,
Judging by the tenor of this thread and the one about shift cable, I take it you are putting a 647 in your MC-5? I did that three years ago to my MC-5 and could share lots of experiences with you. PM me and I'll give you my phone number. I haven't been on the board much this summer so I missed out on a lot.
I added an air to oil cooler, installed vertically at an angle right where the OEM AC compressor would have been. Never had any issues with all that extra oil, but I had to have the engine running to get an accurate oil level reading. I installed a 24 volt thermostatically controlled radiator fan and set it to come on at 195 degrees. I also installed a "T" in the supply line for a thermometer but never got around to installing the sensor. I ran 15-40 in it but planned on switching to synthetic after the second oil change but sold the bus before that happened.
Before putting the engine back in I had to make some motor mount shims. About .8" . And when you have the driveshaft built it's going to be a spendy one. Basically close coupled yokes and you'll need to clock it at 45 degrees. Check out the OEM one, it is keyed to slide together only one way. And it's 45 degrees out of phase. And in an MC5A you have to cut a hole in the floor under the bed to fit the engine back in because of the shim. Maybe a 5C is different there. And finally, I decided to weld spacers in above the body stops to make certain the drive shaft didn't hit the axle when the axle travels all the way up. I think the spacers were about 1". When you see how close that axle housing gets to the drive shaft you'll see what I mean.
-Fred
Thanks Fred, I will shoot you a PM on the board here. I have read about your conversion, I have the threads book marked. I have a feeling that the shims are required to allow the driveshaft to clear the axle at full bump, correct? I am working on the driveshaft now, I have found suppliers of sleeve and shaft ends somewhat reasonably priced on line, but I am waiting for a call from the driveshaft shop that has the stock driveshaft to see what they recommend. I have a yoke output on the transmission, so different from your flange output. My driveshaft will be 17" long from center of the trans yoke to the flange on the drop box.
My current question, which I will start a new thread for, is what is the thread on the drain port on the pan? I need to adapt a dipstick to one of the drain ports.
Brian
granted i am a Eagle with a HT740 and 8v71..... i do not have an air to oil cooler. never, have overheated with the coolant to oil cooler, what am i missing here ?
Quote from: eagle19952 on October 25, 2016, 02:21:59 PM
granted i am a Eagle with a HT740 and 8v71..... i do not have an air to oil cooler. never, have overheated with the coolant to oil cooler, what am i missing here ?
The MCI part ;D ;D ;D,I too have always ran a 740 in a Eagle with the water to oil cooler with a 8V92 and never had 1 heat up
Donald, since this is a retro-fit conversion I don't have a water to oil cooler the way an install designed for an automatic would have. I also don't have excess cooling capacity, this being an MCI with a much higher powered engine than stock. So the air-to-oil cooler will be the only cooler that the transmission has.
Brian
Quote from: bevans6 on October 26, 2016, 04:38:57 AM
Donald, since this is a retro-fit conversion I don't have a water to oil cooler the way an install designed for an automatic would have. I also don't have excess cooling capacity, this being an MCI with a much higher powered engine than stock. So the air-to-oil cooler will be the only cooler that the transmission has.
Brian
i guess, then, that i would wish for both :)