Transmission Cooler

[DZZippy]

Does anyone preventatively replace their transmission coolers? Does anyone have a good lead on where to get them?

 

I used to work as a technician on heavy emergency vehicles such as fire engines, ladder trucks, and some airport crash trucks. However, I was not a diesel tech or transmission tech by nature. When I got out of that industry (early 2000s) it was highly recommended to replace the transmission cooler every 7 years. The drivetrain matchup in several of those vehicles is similar to our Monaco’s. The manufacturer recommended replacement of the transmission cooler due to high heat transfer and the fact that the cooler will, regardless, eventually fail. In the past I have spoke with a couple Allison experts in my area that were adamant that the slightest coolant breach into a trans, will no matter eventually destroy a trans. As little as a couple tablespoons can mess with clutch material and it doesn’t matter how much flushing takes place. Essentially once coolant has made entry…looking at massive issues.

I can say that while I was in that industry I have seen some major transmission issues in emergency vehicles, mostly from using the wrong filters, so I will stay with genuine Allison filters and Transynd. I have seen only a total of 4 heavy duty trans coolers fail causing costly trans repairs. Just curious of the opinions out there and what people have done, come across, or experienced. Also, recommendations on sourcing one would be greatly appreciated in the conversation as well.

Thanks to all for any knowledge.

[Adam_C]

I got mine from CG&J Radiators. When I brought it in for a radiator leak they pressure tested the transmission cooler and it failed. Hadn't had any issues before that. 

[DZZippy]

1 minute ago, Adam_C said:

I got mine from CG&J Radiators. When I brought it in for a radiator leak they pressure tested the transmission cooler and it failed. Hadn't had any issues before that. 

I will check them out. Thanks for the info

[Dr4Film]

Check with Jim J, a member here who had installed a separate transmission cooler on his 02 Windsor.

[DZZippy]

Will do. Just for clarification to all, I have and am referring to a separate transmission cooler external of the radiator.

[jacwjames]

I had replaced my radiator in 2015 with a CG&J unit.  Had several issues with the unit.  It developed seep that I cured with Irontite.  But I noticed that I was running higher transmission temps.  I contacted CG&J and they could not tell me how they size the transmission cooler, they offered to sell me a passive cooler (no fan) but I decided to go a different route.

I installed one of these Derale 15876 Hyper-Cool Extreme Remote Fluid Cooler with Fan

I mounted this at the rear of the coach and plumbed it in series with the radiator cooler.  The system made a big difference.  I have to back in to my  garage up a slight grade.  Prior to install I would see temps as high as 230F, now with the cooler installed it won't go above 180F.  While driving I usually am below 170, only going higher if I pull a hard grade but still stays ~180F.  I have installed a snap disc type temp controller on it so the fan does not run continuous, I believe it is ~150F

 

[DZZippy]

23 minutes ago, jacwjames said:

I had replaced my radiator in 2015 with a CG&J unit.  Had several issues with the unit.  It developed seep that I cured with Irontite.  But I noticed that I was running higher transmission temps.  I contacted CG&J and they could not tell me how they size the transmission cooler, they offered to sell me a passive cooler (no fan) but I decided to go a different route.

I installed one of these https://www.amazon.com/gp/product/B008VQGVSU/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

I mounted this at the rear of the coach and plumbed it in series with the radiator cooler.  The system made a big difference.  I have to back in to my  garage up a slight grade.  Prior to install I would see temps as high as 230F, now with the cooler installed it won't go above 180F.  While driving I usually am below 170, only going higher if I pull a hard grade but still stays ~180F.  I have installed a snap disc type temp controller on it so the fan does not run continuous, I believe it is ~150F

 

Wow, nice work. That may be an avenue for me. Thank you.

[jacwjames]

Several people have mounted a different transmission cooler.  VanWill, who owns an older Dynasty completely bypassed the radiator cooler and mounted a cooler with a fan.  Mybe he'll chime in on his install.  He provided me the info and I mounted mine in the same place. 

I thought about buying a cooler like this https://rvchassisparts.visonerv.com/cgi-bin/md/M120007/s1.pl?  which is similar to what Van used but I bought the one I posted a link to instead.  I believe this was originally supplied by Radiator Supply House https://radiatorsupplyhouse.com/pages/search-results-page?q=RS 4821

Not 100% sure but my "gut" tells me I could probably bypass the transmission cooler in the radiator and just use the stand alone. 

My plan on my next trip is to use my Silverleaf and datalog the inputs for transmission temp, boost, engine temp, and voltage to see how often the fan on the cooler actually runs.  I mounted a snap disc like this https://www.ebay.com/itm/313350654626

I mounted this at the oil inlet to the cooler.  BUT I've never seen the fan run using it, hoping if I use the data logging I might be able to tell.  Next step would be to run some sort of indicator light

 

 

[Ivylog]

When you have unlimited money, replace every 7 years. In the real world, if it’s not broke, leave it alone.

[jacwjames]

23 minutes ago, Ivylog said:

When you have unlimited money, replace every 7 years. In the real world, if it’s not broke, leave it alone.

I tend to agree with this other then I saw +230F transmission temps with the CG&J radiator/cooler.  I needed to do something so adding an auxiliary cooler seemed to make sense. 

I had an email exchange with the salesman that I dealt with when I bought the radiator in 2015.  I questioned how they sized the transmission cooler and he couldn't give me an answer and offered no help on my problem.  He did offer to sell me an auxiliary cooler for ~$750.  I am not a fan of CG&J at this point.  In the past I did recommend them but not any more.

[Bill R]

19 hours ago, DZZippy said:

Allison experts in my area that were adamant that the slightest coolant breach into a trans, will no matter eventually destroy a trans.

So the obvious take away for me is to not worry about PM'ing a tranny cooler that is air cooled.  Fortunately I have an air cooled transmission cooler that is cooled by the discharge air of the hydraulic cooling stack fan.  Typically my trans temp will track the coolant temp about 10F below in most cases and tops out at 190F.  

[Dr4Film]

20 hours ago, jacwjames said:

I tend to agree with this other then I saw +230F transmission temps with the CG&J radiator/cooler.  I needed to do something so adding an auxiliary cooler seemed to make sense. 

I had an email exchange with the salesman that I dealt with when I bought the radiator in 2015.  I questioned how they sized the transmission cooler and he couldn't give me an answer and offered no help on my problem.  He did offer to sell me an auxiliary cooler for ~$750.  I am not a fan of CG&J at this point.  In the past I did recommend them but not anymore.

I agree with Jim. I had a new radiator made and installed at CG&J in Gadsden AL for my Windsor back in 2015. The very first thing I noticed was my transmission temps were 10F higher than with the old radiator. Plus, the new radiator started to "seep" at the top about 3 years later. One bottle of Irontite solved that issue.

I, also, no longer recommend CG&J for any radiator work.

[DZZippy]

22 hours ago, Ivylog said:

When you have unlimited money, replace every 7 years. In the real world, if it’s not broke, leave it alone.

Very true. 

44 minutes ago, Dr4Film said:

I agree with Jim. I had a new radiator made and installed at CG&J in Gadsden AL for my Windsor back in 2015. The very first thing I noticed was my transmission temps were 10F higher than with the old radiator. Plus, the new radiator started to "seep" at the top about 3 years later. One bottle of Irontite solved that issue.

I, also, no longer recommend CG&J for any radiator work.

Well I guess I will stray from CG&J then.