To add aux tranny cooler or not!??

[Polaris]

Just wanted to share what I found out about setting my 2010 xc 90 AWD up for towing a 23' Safari this season. First, I brought it to a reputable Transmission place in town and upon first glance he mistakenly thought that it might already have an auxiliary transmission cooler on it. After getting under the vehicle for closer inspection he determined that it didn't, but that the stock transmission cooling system is extremely robust (thick fluid lines). He ultimately advised against adding an additional system as they have thinner diameter cooling lines than comes stock in the xc 90's. By adding another system it will actually restrict the flow of the tranny fluid and possibly overheat the tranny faster than without adding a system. He further explained to me that most modern trucks and SUV's really do not need additional cooling systems due to how efficient the newer engines and transmissions are now at monitoring their temperature. Lastly, I called my local Volvo dealer and their service manager agreed with that opinion and advised me not to add an additional cooling system. I should add that I spoke to Andy from CanAm at the past RV show and he didn't feel the XC's 3.2L 6 cylinder engine needed the extra tranny cooler either. Just thought this should be shared as many assume that all tow vehicles benefit from an additional tranny cooler when in my case 2 sources highly recommended not doing this and that it could cause overheating to happen faster.

[AWCHIEF]

Sounds plausible to me. I would still keep an eye on the temps.

[dznf0g]

Yeah but there are trans coolers made with very large diameter lines. Shop for medium duty truck coolers (usually spec'ed by gvwr) or racing coolers .

[Thiss]

How about a deeper pan with cooling fins? This is a common and painless upgrade which will allow for more fluid and thus cooler temp. Not sure if there is a option for that particular trans.

[AnnArborBob]

It all depends on where/how you plan to tow. if you are going to stay in the mid-west (US & Canada) then you are likely fine with the stock setup. But if you plan to go in some serious mountain territory (i.e., out west or the Appalachians) where your transmission will get a workout, then an auxiliary cooler would make sense. An occasional run up and down the Niagara Escarpment simply does not compare to a 15 mile long 6 to 8% grade as one finds out west.

[Polaris]

Great points! My vehicle really won't get much of a workout this year pulling the trailer around central and northern Ontario. I would like to take it down to Florida next year once I am more comfortable with it and confident that the bugs are all worked out. I've had tranny coolers on past vehicles. I will definitely inquire further before any major road trips but just find it interesting that both the dealer and a Transmission specialist are recommending that I not!

[jcanavera]

Personally I'm a believer in auxiliary transmission coolers. In many cases when you order a vehicle with the factory towing package, you will see and external cooler. My GMC van came with one.

The reasoning that auxiliary coolers may be needed is that many transmission coolers are no more than tanks emerged in the radiator located down low. That means that water is providing the cooling. This means that the fluid temperature can get no lower than the temperature of the radiator water. Water temperatures in some cases may be as high as 240 degrees in some vehicles, dependent upon outdoor temperatures, climbing hills and engine speed. This means that transmission fluid temperatures may be higher that the water temperature as the fluid enters the cooler. The fluids lubricating properties will wear out faster or fail if the temps get too high. The key is buying a good quality transmission cooler. Here is a link to Hayden who makes high quality external transmission fluid coolers. http://www.haydenauto.com/featured%2...s/content.aspx

Typically you connect the output from the vehicle's transmission cooler into the auxiliary cooler. This means that the temperature of the fluid exiting the auxiliary cooler into the transmission typically may be 50 degrees or so cooler that what exits the standard water cooled transmission filter.

Jack

[dznf0g]

Not necessarily. Maxtow 1500 has internal and external trans cooler and an external engine oil cooler from the factory

[AnnArborBob]

Originally Posted by Polaris

Great points! My vehicle really won't get much of a workout this year pulling the trailer around central and northern Ontario. I would like to take it down to Florida next year once I am more comfortable with it and confident that the bugs are all worked out. I've had tranny coolers on past vehicles. I will definitely inquire further before any major road trips but just find it interesting that both the dealer and a Transmission specialist are recommending that I not!

Try it locally "as is" for a season and keep an eye on the tranny temps. If you don't have any problems then you are all set. I've driven from the Detroit area down to Florida several times and there are no substantial grades along the way so if you didn't need the aux cooler for Ontario you will not need it for Florida. But, if you have a hint of issues while towing locally, I would get the aux transmission cooler ASAP.

[Al and Missy]

On my 2006 F-150 with the towing package there was an auxiliary transmission cooler. It was behind the radiator which was behind the air conditioner condenser. My transmission got up to 234 degrees climbing the 6-mile 8% grade up to the Blue Ridge Parkway going west on US 421. I was only making 25 mph in second gear at 2800-3000 rpm. A lot of heat in the transmission and not much air flow over the transmission cooler.

I was considering an "active" cooler, i.e. one with a thermostatically operated fan. I probably would have done it but ended up trading trucks. If you decide to get a cooler, I'd recommend you go for an active one.

Al

[jcanavera]

Unfortunately putting an auxiliary cooler behind a radiator is a lot like having an immersed tank within the radiator since you are getting preheated air over the cooler. Thankfully GMC mounts theirs in front of the radiator giving it full exposure to the coolest air entering the engine compartment.

[HowieE]

If you are going to tow in the hills or any other road that will require the transmission convertor to be unlocked for a period of time you want to consider a cooler. It is the convertor that build the heat while unlocked.

If you mount one have it forward of the radiator and AC condenser so it sees the coolest possible air.

Another thing is to plumb it after the radiator outflow or, in my case I, removed the radiator transmission cooler by bypassing the radiator altogether. This maintained my trans at 165 degrees in summer and 105 in winter.

Some of the newer TV you can lock the convertor manually. A great feature if available. Mine I modified with a BD Torq Lock. That allowed me to lock the convertor in any gear as long as I was above 33 mph.

[Polaris]

So silly question, how do I monitor my tranny fluid temperature to see if it is overheating?

[FCStreamer]

Originally Posted by Polaris

So silly question, how do I monitor my tranny fluid temperature to see if it is overheating?

If your vehicle does not have a gauge already, you will need a on board diagnostics port (OBD) reader, a little doodad that connects to a port under your steering wheel, and depending on the reader either an app or a device that displays the data the reader is seeing.

[HowieE]

Do not rely on an in dashboard OEM gauge. They fall under the category of Lie-o-Meters.

Any auto store will have after market gauges that are accurate.

Yes you can used the OBD2 port but the equipment will be quite expensive.

[dznf0g]

Originally Posted by HowieE

Do not rely on an in dashboard OEM gauge. They fall under the category of Lie-o-Meters.

Any auto store will have after market gauges that are accurate.

Yes you can used the OBD2 port but the equipment will be quite expensive.

Not so much, Scangauge II is about a buck and a half. Also note that many of the newer (post 2000 model year) vehicles have the trans temp readout as a function of a "driver information center". This type of readout is taken directly out of the datastream of the vehicle computer....same as an OBD port plug-in.

Also, be aware that some OBD port plugins can cause "noise" in the dataline and cause driveability, or other performance issues...and set codes. Happens a lot with various devices.