Trans cooler installation.

[Lngbeard]

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.

[Mark_Kovalsky]

wolfe10 wrote:
Mark,

I agree the in-radiator transmission cooler is indeed a cooler, but as part of the radiator, it will be warmer than his separate cooler.

Are you assuming that, or have you actually measured the temperature in the cold side of the radiator in cold weather?

I've measured the temp, and while it is warmer than air temp, it is only by a couple degrees. The radiator is so efficient at cold temps that the coolant in the cold side of the radiator stays near the ambient temperature. It is NOWHERE near engine temperature. So if you route the lines backwards you severely compromise the cooling capacity of the system without improving the cold weather operation. It's a bad trade off.

[j-d]

X2, Jose. We have storage compartments right behind that bulkhead on each side.

[DaHose]

Very nicely done. Mine has a propane tank in that spot, or I would consider doing the same.

Jose

[Lngbeard]

Matt_Colie wrote:
I think that is a spectacular that creative idea. But, I only worked in and around the auto industry for three decades.

Matt

Thanks Matt. I appreciate the kind words.

[Matt_Colie]

I think that is a spectacular that creative idea. But, I only worked in and around the auto industry for three decades.

Matt

[TNRIVERSIDE]

Mark Kovalsky wrote:

TNRIVERSIDE wrote:
If your additional cooler is in series with your factory cooler it should not let the trans run too cool. The factory trans coolers have a thermostat to not allow the fluid to circulate through the cooler until the trans gets to the operating temp. It will then open and close to regulate the trans fluid at the correct temp.

The factory 4R100 DOES NOT have a thermostat! Ford never installed any type of thermostat on the 4R100 transmission. That started with the replacement for the 4R100, the 5R110 TorqShift.

You may be thinking of the pressure bypass on the side of the 4R100. That is designed to open if the cooling circuit is restricted. It won't open due to cold temperatures until way below 0°F. With synthetic ATF it will never open due to cold temperatures.

Mark thanks for the correction. There I go assuming. I know my 09 F150 has a thermostat in the cooler circuit so I ASSUMED all (or most) other Ford units did too. I am always impressed at the amount of knowledge there is here.

[wolfe10]

Mark,

I agree the in-radiator transmission cooler is indeed a cooler, but as part of the radiator, it will be warmer than his separate cooler.

And, as I mentioned, I would fit a cover over the secondary cooler in the winter-- so routing is not as important.

I did basically the same thing with a transmission cooler I installed in the fuel return line on my DP. Covered it in winter, exposed the rest of the year.

[Mark_Kovalsky]

wolfe10 wrote:
I agree on covering the secondary trans cooler in winter.

Also, best routing is from transmission through secondary cooler to factory cooler and back to the transmission. That can keep fluid from being too cold.

As a former Ford transmission cooling engineer, I'll tell you that you have that backwards. The best routing is from the front of the trans to the radiator cooler, then to ONE aux cooler, then back to the rear of the trans. The radiator will NEVER warm the ATF. It is a cooler, not a heater. It is very effective as a cooler, but absolutely useless as a heater.

[Mark_Kovalsky]

TNRIVERSIDE wrote:
If your additional cooler is in series with your factory cooler it should not let the trans run too cool. The factory trans coolers have a thermostat to not allow the fluid to circulate through the cooler until the trans gets to the operating temp. It will then open and close to regulate the trans fluid at the correct temp.

The factory 4R100 DOES NOT have a thermostat! Ford never installed any type of thermostat on the 4R100 transmission. That started with the replacement for the 4R100, the 5R110 TorqShift.

You may be thinking of the pressure bypass on the side of the 4R100. That is designed to open if the cooling circuit is restricted. It won't open due to cold temperatures until way below 0°F. With synthetic ATF it will never open due to cold temperatures.

[carringb]

TNRIVERSIDE wrote:

If your additional cooler is in series with your factory cooler it should not let the trans run too cool. The factory trans coolers have a thermostat to not allow the fluid to circulate through the cooler until the trans gets to the operating temp. It will then open and close to regulate the trans fluid at the correct temp.

The 4R100 does not have a thermostatic bypass (the 5R110 does). It only has a pressure bypass to protect against a plugged cooler. It can bypass in extreme cold from the higher viscosity, but regulating temperature is not its purpose.

[wolfe10]

I agree on covering the secondary trans cooler in winter.

Also, best routing is from transmission through secondary cooler to factory cooler and back to the transmission. That can keep fluid from being too cold.

[TNRIVERSIDE]

carringb wrote:
PS - I'm not trying to imply the added cooler isn't a good idea. It is!

But for winter driving, you may want to cover it if the transmission is not getting up to temp.

If your additional cooler is in series with your factory cooler it should not let the trans run too cool. The factory trans coolers have a thermostat to not allow the fluid to circulate through the cooler until the trans gets to the operating temp. It will then open and close to regulate the trans fluid at the correct temp. The installation look great to me. Nice job.

[carringb]

PS - I'm not trying to imply the added cooler isn't a good idea. It is!

But for winter driving, you may want to cover it if the transmission is not getting up to temp.

[carringb]

The transmission needs to periodically run over 170F to keep moisture down. I've seen more 4R100s fail from never getting up to operating temp, than running too hot. Mine runs around 200F when towing in warm weather, and will exceed 230F on steep climbs when my combined weight is over 20,000 pounds.

I have 366,000 now and the transmission is still in great shape. About 200,000 of those are towing miles. I do a full transmission fluid exchange every 100,000 miles.