Keeping It Cool - Installing a Transmission Oil Cooler Fan Pt 2

Finally, a weekend with no rain forecast. Not that it wasn't the case last week, but these "meteorologists" seem to make guesses rather than actual predictions based on fact. Maybe I'm just bitter since it put a stop to my relaxation activities. Mainly, working on my RV!

So now that I can comfortably(?) lay under the RV and not get soaked, lets finish up the transmission oil cooler supplemental fan install. You know, that's an awful lot of words to just say "fan." We left off with all the parts assembled and ready to install.

My Transmission Oil Cooler in The Front Engine Bay

First I attached the fan itself to the back of the transmission oil cooler. I thought about making it a "pusher" fan rather than a "puller fan" by mounting it on the front, but I believe I will get better airflow by sucking air up from below the front of the engine compartment rather than air from behind the engine and transmission. Once everything is in place, I'll put a temperature probe in there and see what's what.

Opposite side from the Fan With Sticky Pad and Lock in Place

Hold Downs

The fan get's mounted using long plastic hold downs with a circular stopper on one side and a spring and cap on the other. It is inserted through the tabs on the fan and through the cooler itself.

Almost Finished Install - Viewed From Front

You then slide on the supplied padded squares, with the sticky side toward the radiator, over the rod. These stick to the radiator and offer some padding and vibration resistance. Once done, make sure the fan turns freely and doesn't hit the cooler. If it does use a spacer or washer to add some gap. Too much gap is no good, as air will escape around the fan instead of cooling your transmission oil. Then comes the circular lock. BE CAREFUL! This will only go on once. It cannot be removed without destroying the rod or the plastic lock, so make sure everything is where you want it before you push them on. Once tight, snip the extra rod leaving a bit protruding.(1/4-1/2"-ish)

Tight Install Behind Transmission Cooler

I had very little clearance behind the transmission oil cooler, and the top of the fan hits the surround of the engine radiator's supplemental fan, but just a very little bit. It also hangs down a smidgen since the fan is actually 10" across even though the specs show it to be 9" wide. If I were to do this again (NOT!) I would buy an 8" fan so the total size would likely be 9". Ah well, at least when you buy a fan you'll get the right one!

Accessory Switch is Second From Right, Bottom Row

Next was the electrical hookup. This was, by far, one of the easiest I've ever done. The negative lead (BLACK) runs over to the Negative terminal of the battery or, even easier, to a convenient screw already in the chassis. (The Chassis/Frame IS a ground.) The other (POSITIVE) wire will go to one side of a switch near your driving position. Sometimes this is REALLY simple, but often can be tough since the wire MUST go through from the outside to the inside. Then the wire gets hooked up to a fused power source. This should be from your Engine's wiring, NOT the House system. There is usually someplace you can tap into within the existing fuse block. I used the ACCESSORY switch that was already in the dash, fused and unused. You can easily add a switch to your dash (or other convenient location.) If you cannot find power inside, you could run another wire back out, and down to the battery's positive terminal making sure you have a correctly sized fuse installed on the wire. If you go this route save time by running two wires at the beginning!

Supplied Electrical Install Kit

This is the time to decide if you'd like to install a thermostatic switch. It will turn the fan on at a predetermined temperature and back off when it is reached again. I have one, but didn't install it. I want to do some testing before I let the system work on it's own.

Once it's all hooked up, make sure that the fan turns the right way! If it's behind the cooler it should draw air THROUGH it from front to back. If it's in front it should push air through the cooler. If it's wrong, you likely have the wires reversed. On many fans this is the way to reverse the direction anyway so it's not too big a deal if you get it wrong. Just switch the wires at the fan and you're good to go.

WARNING! Some fan manufacturers want you to actually remove the fan blades and turn them over to switch the direction of the airflow. Switching the wires MAY damage this type of fan!

Finished Install

You should use heat shrink tubing or some other method to waterproof the connections that will be outside and usually underneath the RV. They will be subjected to some nasty elements like road salt, water...etc. It's a good idea to protect them. Yes, I know...put the heat shrink tubing on BEFORE you put all the wires together. See even I can learn after several mistakes!

I believe I will see some significant reduction in temperatures. Stay tuned, after the season I'll tally the results and write it all up.

See Part - 1
http://www.thewanderman.com/2012/06/keeping-it-cool-installing-transmission.html

Be Seeing You...Down The Road,

Rich "The Wanderman"
www.thewanderman.com

Keeping It Cool - Installing a Transmission Oil Cooler Fan - Part 1

Supplemental Transmission Cooler

   At some point in its life, my coach had a supplemental transmission oil cooler installed. This is a good thing. If you "cook" your transmission oil, bad things will happen. The fluid is cheap, your transmission isn't. On a recent trip driving through some mountainous terrain, I noticed my transmission temperatures were higher than I'd liked. I decided that adding a fan and maybe a thermostat to automatically turn it on and off  when needed would be a good idea.

Let's talk a bit about automatic transmission temperatures in general. The harder the transmission is working the hotter the fluid gets. Common Sense, right? Pull a heavily loaded RV up a long hill, sometimes with a trailer or toad behind, and the transmission temperature will climb. In fact, it can climb VERY fast. Especially when it's very hot and humid. Many RVs have some kind of transmission cooler already installed. Sometimes it's as "simple" as a few extra pipes inside the engine coolant radiator and sometimes it's a separate radiator entirely. My Aero Cruiser had the former and a previous owner added the latter. For some reason they decided NOT to add an electric fan on this supplemental cooler. I have NO idea why. Most manufacturers of transmission fluid say, if the fluid gets above 300 degrees Fahrenheit for any length of time permanent damage could be done to the transmission itself. Some manufacturers state you can get 100,000 miles from the fluid IF it remains at 175 degrees or below. This chart shows how the life is shortened with temperature increases:

DEGREES F	MILES	DEGREES F	MILES
175	100,000	295	1,500
195	50,000	315	750
215	25,000	335	325
235	12,500	355	160
255	6,250	375	80
275	3,125	395	40

Wow, 40 Miles! I'd hate to have to change the transmission fluid that often! Personally, I can accept every 25,000 miles. So, shooting for an average temperature of 200 degrees seems reasonable. I have seen 250 degrees on a long hill, mostly due to airflow issues. I am hoping the fan will fix this. I COULD remove the plumbing for the auxiliary cooling loop in the radiator and likely reduce the starting temperature a little since the transmission fluid wouldn't get heated by the engine coolant flow. The down-side is getting the transmission fluid up to operating temperature in colder weather. We'll see what the readings are this season and make changes accordingly.

The Fan.

Thermostat Switch and Relay

After researching online I selected a 9" 12 Volt 80 Watt Fan that would move enough air to make a dent in the temperature. When the fan arrived, it was missing several critical installation pieces. After a quick email to the seller, I received a package that came with all the mounting hardware including springs to absorb vibration caused by the road and the engine. I also ordered a remote thermostat that would be adjusted to turn the fan on at 175 degrees (or so) and off  again. This installs on the radiator itself and has a relay that feeds the power to the fan. The remote switch will allow me to manually turn the fan on if needed.

Looked to be easy to install. Of course the location of the transmission oil cooler and the fact that the 9" fan was actually 10" across (the BLADES are 9") meant I was going to have to either let it hang below the cooler or finagle an angled mounting. When I got to thinking about the angles install I believed the slight angle would actually pull cooler air from under the RV rather than warmer air from the engine compartment. Seems logical, no? This being decided, I gathered all my tools and the bits and pieces of the fan install kit and went down to the RV.




With everything laid out and ready to install. It began to rain. Again, a lot. Since I was going to have to lie down on the ground under the RV to install this fan, I decided (for once) to postpone the install until next week. We'll cover the actual mounting of the fan using the supplied pieces and wiring all of the electrical to make it all work. I feel bad this couldn't get done this week, as I REALLY want to get on the road...but getting soaked seemed a dismal prospect.

Tune in next week for the final assembly!


See Part 2 - http://www.thewanderman.com/2012/06/keeping-it-cool-installing-transmission_19.html

Be Seeing You, Down The Road,

Rich "The Wanderman"
www.thewanderman.com

Are You Sagging? - Reinforcing Interior Storage Floors

The Closet

Last season I noticed a distinct sagging at the floor of my "wardrobe" closet. In the Aero Cruiser (at least my floorplan) there is essentially only one closet. Since I can fold my own clothes and really don't need too many "James Bond" style tuxedos, I decided to use it as my primary food storage area. I measured the width, depth and height and found some suitable plastic drawers to fill most of the space. With a small amount left over on one side to hang a few clothes....just in case.

After a season with this contraption in place I noticed that the floor was sagging. A Lot. Beneath the closet, behind the floor to ceiling door is a storage drawer. After pulling it out and putting it aside it turns out the floor of the closet was only a thin wood paneling veneer that has a 1/2" frame all around with nothing supporting the middle. I guess the manufacturers though most people would be using this as a hanging-only closet. Since I routinely store a whole trips' worth of food (some of it in cans!) I really needed to reinforce this before it failed completely. Below the drawer is the rear driver side wheel well and a bit of micro-storage that contains the Transfer Switch and some miscellaneous stuff I've managed to shoe-horn in there. This process will work on most any storage space that you can access the underside of.

Passenger Pete And The First Try.

Of course, I could see that this was going to require some finesse as it would be tough, if not impossible, to build a brace and then get it through the existing opening. The drawer opening is MUCH smaller than the closet floor. I had to be able to attache the reinforcing frame to the 1/2" existing frame AND not let it hang into the area the drawer goes. Not much choice here. I measured about 10 times to make sure I had the exact dimensions (you all know what's going to happen later, right?) Then proceeded to build two identical box frames that I would insert into the opening, attach to the existing 1/2" frame then screw or bolt it all together. 

The First Frame..(Notice The Feet!)

Sounds pretty good. I'm pretty decent when it comes to electricity and mechanics....woodworking is really NOT my strongest skill. Forget about cabinetry. I see so many folks redesigning and building cabinets for their RV's that are better than the factory. I have NO idea how they do that so well!

Back to the project at hand. I had drawn the plans, cut the wood on a borrowed table saw. Screwed the box frames together and then put them into the opening. It was when I was test fitting them that I realized two things. One, there was a 1" gap between the frames that I was going to have to figure out how to fill. Two, I had used the slightly longer wood for the middle of the box. This was going to prevent the drawer from going back in. Ever. Back to the saw. I cut a very long and amazingly straight cut down the length of both middle pieces and made a 1" (you know...I don't think anyone makes a 1" thick piece of stock wood!?!) wide piece to span the gap between the boxes. Back into the RV. Test fit. (Drum Roll Please!)

Not That Pretty, But It Works!

Miraculously, it all fits! Drill some new pilot holes for the screws (as usual, in contorted positions) then hold the assembly up, while holding the screw in place, while using a battery powered drill/driver in a confined space to tighten the screws. Easy.....NOT! I won't bore you with the insane amount of finagling it took to get it all tightened and in the correct spot. Ultimately, I had to try and fit the drawer in. It does fit...mostly. It's much harder to pull in and out now...I could likely sand or plane the box frame down where it rubs, but the drawer won't rattle now. Have to decide that one later on. Everything is a trade-off.

All in all, this is an easy fix to do. Since it's invisible when done...it doesn't have to look all that pretty, but will get the job done.

Look Ma, No Sag!

Be Seeing You...Down The Road,

Rich "The Wanderman"

www.thewanderman.com