Trany cooler

[Chaz]

Here is a page of trany coolers. I'm curious if one of these is what I should use or if there is something else thats better/cheaper.

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

Thanx guys,
    Chaz

[makemineatwostroke]

Chaz, size your cooler right the first time this place has a chart for the gpm flow needed for you transmission plus the cooling required 

www.utxchange.com

[tekebird]

Chaz did you determine the cause?

if you bus has not had a tranny cooler for years with no issues, it should not need one now.

[Chaz]

Will do, twostroke.

Teke,
  Nope, haven't figured it out yet, but the guy who has worked on it in the past fro me said he would "try" to check it out before I need to take it to IA. on Aug. 24th. I just have to start "hedging my bet" at this point. And I figure it can't really hurt to help cool it down a bit more since my bus originalll started life as a manual shift. HTH

Thanx,
   Chaz

[TomC]

Chaz- I installed the DB-341DC-12 for Allison transmissions with electric fan on the right side transmission access door with a 180 degree thermostat.  What I did was to keep the original shell cooler, but ran the hose from the hot side of the transmission first through the new auxiliary cooler then to the shell cooler.  The logic behind this is that the new auxiliary cooler will take alot of the initial heat out of the trans fluid before hitting the shell cooler-hence releaving the shell cooler and the engine radiator of excess heat.  The auxiliary trans cooler was supposed to be plumbed with the thermostat in the intake side of the cooler to turn on when the fluid coming out of the transmission got above 180.  But I plumbed it with the thermostat on the exhaust side of the cooler so when the fluid coming out of the aux cooler got above 180 it would turn on.  Many times running on cool days on the flat, it doesn't come on, but on most hot days it will be on.  By the way, the fan is wired to pull the air from the engine compartment and push it out through the cooler to the outside.  This is done because the big radiator fan creates so much pressure inside the engine compartment, the cooler's smaller fan wasn't powerful enough to pull the air into the engine compartmen.  The aux cooler does make a difference.  Good Luck, TomC

[Chaz]

Great!! Thanx Tom!!! Dallas had mentioned something like that, but your explanation helps allot. Especially the air thing.
 
I was thinking about putting it just forward of where you suggested. There is quite a bit of an open area with only the old s**t pipe from the original restroom. I can easily cut that out and nest it in there out of the way. Do you know if it would do adequate cooling there? If so, "push or pull"?

  Thanx again,
     Chaz

[TomC]

I would keep it with push since it seems to move more air (maybe the fan blades are curved that way).  As long as you have air circulation-and going down the road you'll have alot-put it where it fits then just have the hoses made for it with the proper fittings.  Good Luck, TomC

[JackConrad]

Chaz,
    We added an aux. tranny cooler on our MC-8 (which came from the factory with 8V71/Allison 740 and trans cooler on the side of the engine).  We installed it in the side door on the right side of the engine compartment with an electric fan. Initially, we had fan pulling cool air from the outside, but found the air pulled through the radiators into the engine compartment was overpowering the electric fan. We reversed the electric fan to push air out. We did as Tom did and kept the OEM cooler, running the fluid through the aux. cooler then to the OEM before returning to the trans. This should help with initial trans warm up. After installing this system, all temps (water, oil and trans) run about 5-10 degrees cooler.  YMMV  Jack