Forum Discussion

Lngbeard's avatar
Lngbeard
Explorer
Dec 11, 2013

Trans cooler installation.

Hi all,
I wanted to be proactive to see if I could keep my automatic tranny alive for the long haul. I have a 27 ft Chateau sport with the 4R100 trans. I am the second owner and decided to bite the bullet and go with synthetic transmission fluid. I also installed a electric fan stacked plate cooler in a non-typical location. Here's how it went, The lay out:

I then used a hole saw for the corners. I anguished long and hard before cutting into my MH.

Finished the hole with a jigsaw where I could. Sealed the edges with Eternabond.

Here's the cooler from the inside. Lots of room. Protected from debris and gets unimpeded airflow.

And a perforated metal screen installed.

Finally a gauge to keep a eye on temps.

Have not exceeded 170 yet so The fan has not kicked on as far as I know.Hope this helps if anyone is looking to add a cooler.
Class C
  • Mich_F's avatar
    Mich_F
    Explorer
    Dec 11, 2013
    I'd hope you won't be running below what the normal operating temperature should be.
  • Lngbeard's avatar
    Lngbeard
    Explorer
    Dec 11, 2013
    path1 wrote:
    How hot was it running before you added fan?


    I think it was usually around 175-185. With a toad on a long pull (Vantage) on a hot day it may have got up around 195.
  • Lngbeard's avatar
    Lngbeard
    Explorer
    Dec 11, 2013
    Mich F wrote:
    I'd hope you won't be running below what the normal operating temperature should be.

    So far it is anywhere between 140-170. I prefer to err on the cool side. Heat is what kills transmissions.
  • Lngbeard's avatar
    Lngbeard
    Explorer
    Dec 11, 2013
    CKNSLS wrote:
    You can OVER COOL a transmission.

    Heat is what kills a tranny. As we usually only use the MH in the summer I believe I am usually in the 140-170 range.
  • sljkansas's avatar
    sljkansas
    Explorer
    Dec 11, 2013
    Nice install. The thing you will need to watch(since it site behind the front wheel)is that the fan and cooler stay clean. your going to throw a lot of dirt and water at it, being where it is mounted.
  • NTORACN's avatar
    NTORACN
    Explorer
    Dec 11, 2013
    A unique location to say the least. I think I would have installed it in front of the radiator if it were me. I had 105,000 miles on my 4R100 tranny when I sold the RV last year. I serviced the tranny at 100,000 miles and there was no debris in the pan, I mean none. Great tranny!! If your tranny never ran over 190-195 degrees, you didn't need to add the cooler.
  • Lngbeard's avatar
    Lngbeard
    Explorer
    Dec 11, 2013
    sljkansas wrote:
    Nice install. The thing you will need to watch(since it site behind the front wheel)is that the fan and cooler stay clean. your going to throw a lot of dirt and water at it, being where it is mounted.

    The running boards and mud flaps do a great job of blocking the road debris. I did find a ding in the screen so something did hit it though.
  • Lngbeard's avatar
    Lngbeard
    Explorer
    Dec 11, 2013
    NTORACN wrote:
    A unique location to say the least. I think I would have installed it in front of the radiator if it were me. I had 105,000 miles on my 4R100 tranny when I sold the RV last year. I serviced the tranny at 100,000 miles and there was no debris in the pan, I mean none. Great tranny!! If your tranny never ran over 190-195 degrees, you didn't need to add the cooler.

    I could not squeeze the cooler in there behind the trans cooler, AC rad,stock tranny cooler and power steering cooler. I also felt airflow was very restricted in the usual place. yeah,,It may be overkill but I do make some steep, long hot climbs with toad in eastern Washington state.

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