| Author | Message | ||
| Brian Brown (Blue_velvet)
Rating: N/A |
Hey Folks: Driving our new Buff on it's first outing went smooth as silk, but during last few hours on the way home (about 2,000 miles into the trip) the trans. temp starting running too high (over 230 deg. F). I checked the fluid thereafter and it was fine, midway up the hot zone. The time it took to pull over and check the temp. cooled the tranny down considerably. From other posts, I understand that this tranny can get hot running locked-up for long highway stretches (not enough air flow, road heat, etc.). My particular installation (V730 was not stock on my bus) DOES NOT have the giant engine coolant/ tranny oil cooler that my Fishbowl had. I wondering if this is a gross oversight and I should track one down and plumb it in. My bus DOES have an air cooler for the tranny oil, but it's stuck up behind the engine bulkhead in that empty space between the bulkhead and the rear axle (old washroom tank, maybe). No free air can seem to get to it. I also suspect that the temp-controlled fan on the cooler might not be working. But I'm planning a trip to SF and through the Sierras in two weeks and would like to make cooling adjustments NOW, rather than on-the-road. You can see a photo and some notes here: http://www.brownland.org/bus/4108/v730.htm I'm open to moving the air cooler, adding an engine coolant cooler, cutting a cooling hole in the tranny door... whatever. Thanks! Brian Brown Longmont, CO PD4106-1175 P8M-4108A-216 | ||
| Jack Conrad (Jackconrad)
Rating: N/A |
Brian, I can only relate what we did on our MC-8. Our bus came with the transmission cooler mounted on the side of the engine. This cooler dissipated the transmission heat into the bus cooling system. We added a heavy duty Hayden cooler that pretty well filled the side door on the passenger side on the engine compartment. We installed an electric fan on this cooler. We ran the cooler hose from the transmission to the top of this cooler, from the bottom of this cooler to the OEM cooler, and then back to the transmission. Since the installation, we have noticed that all temps (water, engine oil, and transmission fluid) run about 10-15 degrees cooler. Hope this helps, Jack | ||
| Tony & Kim Rian (Rianrts)
Rating: N/A |
Jack so your system still uses the stock cooler you just added the hayden cooler to the door with a fan? Where did you get the cooler and how much? | ||
| Tim Strommen (Tim_strommen)
Rating: N/A |
Hello Brian, I'm running an Allison HT-740 and from what I've seen it needs a constant flow of air over the heat exchanger (like a mini radiator - conveniently attached to the outside surface of the engine's radiator on my rig). About the fan, I'd take a look at the control for it and see if: 1) it's getting power 2) the thermostat works 3) the fan works Depending on the type of fan you have and how the fan controls work, you may be able to bypass some functions to test others (like hooking the fan motor directly up to power to see if it even spins under its own power. If the thermostat is separate from the housing of the fan, you may wish to put a light in parallel with the fan motor (but on the dash board) to indicate fan operation or lack of thermostat triggering. Also - if the tranny cooler is in an enclosed space (and that doesn't seem like something a manufacturer would do on purpose so it would probably be a converter's mistake) I'd either relocate it where it can get fresh cool (not road heated) air and lots of it. Cheers! -Tim (Message edited by Tim strommen on April 25, 2006) | ||
| Buswarrior (Buswarrior)
Rating: N/A |
Hello Brian. Yes. Heat kills transmissions like no other. Jack's style of install is hard to beat. From the transmission to a big auxiliary cooler to dump the majority of the heat overboard, then through the stock (engine coolant) cooler and back to the transmission. Most heat is dumped before it goes in the coolant, so the radiator only has to take care of the engine and no chance of overcooling in colder weather. If you ever find yourself climbing hard enough that you can't reach lock-up speed, you'll be glad you did! happy coaching! buswarrior | ||
| Brian Brown (Blue_velvet)
Rating: N/A |
Sooo... if I don't have a heat exchanger (and I sure can't seem to find one), it sounds like I really should have one. The aftermarket cooler was probably used instead of the engine coolant one, and I should probably have both. I realize that the V-drives are a different beast and might not be exactly like some of the T-drives or midship slushbox setups. But they shouldn't be that different. Sounds like I need to get busy! bb | ||
| Jack Conrad (Jackconrad)
Rating: N/A |
I found the cooler and the fan on Ebay (2 separate items). I think the cooler was around $75-80 and the fan was about $45-50. Make sure the cooler has large tubes that the hoses connect to so you do not restrict the fluid flow through the cooler. Our cooler has 3/4" tubes that the hoses connect to and 1/2" cross tubes. Hope this helps, Jack | ||
| Larry Mackey Rating: N/A |
Hello Brian,One thing to remember is that from what I have read temperature issues seem to vary quite abit between MCIs and GM(V-drive).Jack`s system(a great design)may be total overkill for your problem.I like overkill myself,but it appears that you are up against a hard deadline for your next trip. My 4905 uses a large tube 12x12(maybe a bit larger) tranny cooler located in front of the radiator and works well.I did spilt my desert cooler manifold to spray about 40% on tranny cooler and 60% on radiator for extreme driving conditions and unexpected circumstances. Larry(seemed like a good idea at the time) | ||
| Donn
Rating: N/A |
Brian, The first thing I notice is that your sender is mounted in one of the oil hoses.That will not give you an accuate reading.If it is in an outbound line it will read high,an inbound from the cooler,low.The probe should be in the pan.If you want a heat exchanger for the 730 call Nick at Nimco 800-526-8055.Keep in mind that the heat exchanger may raise the water temp since it uses the engine cooling system to cool the trans fluid. | ||
| Brian Brown (Blue_velvet)
Rating: N/A |
Thanks, guys. Yup, it appears I have two senders on each side of the cooler, but in the hoses, and not in the sump. I can control which sender I'm seeing from the dash (and also the engine oil temp). On the trip when it heated up, there was no discernable diff. between the two temps... telling me the oil cooler is not doing its job. So, for this trip I'll relocate the oil cooler to the tranny door area, verify the fan is working, and maybe have a hole cut in the tranny door (I have a buddy w/ a plasma cutter). If I end up needing the heat exchanger, or more cooling in general, I'll have to decide whether I want the engine cooling system to scavenge that heat OR go with more air-to-oil cooling. Non-stock setups have these issues, I guess. If anybody has a stock GMC V730 install in a late-model 4905 or even a transit, I'd love to see some pics or info on the factory setup. Thanks!! bb | ||
| Frank Allen (Frank66)
Rating: N/A |
Bryan, the haydon transmission cooler is avail at napa, they have two different ones, i cannot recall the number but its 4 digit 12 something, ill try to find it. the heat exchanger should be avil from nimco, these work ok but will make the bus coolant a little hotter. having the haydon is a good idea Frank allen 4106 | ||
| Frank Allen (Frank66)
Rating: N/A |
bryan, here is the info, the haydon trans coller is a 1295, there is also a 2295 which has more colling cap and is slightly bigger, ive been told that allison recomends the bigger one when thats all you have. the heat exchger is used a lot and both gives you that added protection, mine has a heat exchanger only. the bud runs about 5 to 10 deg hotter than it used to before i put in automatic. hope this info is useful Frank allen | ||
| PASO ONE (Paso_1)
Rating: N/A |
Hi Brian The cooler on your old VS2-8 tranny was huge compared to the cooler thats on the stock V730. I'm Planning on using the VS cooler with the V730 and also an air flow set up such as yours. You can't have too much cooling capacity in my mind when it comes to automatics. I would be able to give you one of the coolers down the road but not likly soon enough for your SF trip. As I will also have a VH9 cooler. Paul | ||
| Brian Brown (Blue_velvet)
Rating: N/A |
Thanks, Paul. A very kind offer, my friend. For this trip, I'm going to do my oil cooler relocation and fan check... and then see how it helps my temps. If I can avoid dumping heat into the coolant, it'll probably be a good thing... for nine months out of the year, anyways. I'll keep you posted, and see if I could use your heat exchanger down the road. Cheers, bb | ||
| Sammy (Sammy)
Rating: N/A |
Brian, locate an older RTS transit bus.They had large trans coolers mounted vertically to the engine cradle, outboard side. I can scan pages from my RTS service manual and e-mail them to you if you'd like detailed info and pics. Sammy | ||
| Brian Brown (Blue_velvet)
Rating: N/A |
Thanks, Sammy. The pages would be awesome to have. You can get my email address by clicking on my name. An RTS boneyard/ parts source shouldn't be too much trouble to find. There would be plenty of room on the cradle rail to install one. I could set a valve on the coolant side for the times I don't... probably. In fact, my coolant filter already has valves on it. I wonder if these lines are sufficient.  Thanks! bb | ||
| Sammy (Sammy)
Rating: N/A |
Brian, those lines will be too small. Check your e-mail, sent info for you. Hope it will help you. Sammy |