How-To: Manual Transmission Oil Cooler Install on 2nd gen Tacoma

I put an oil cooler in my 2009 6 speed manual transmission Tacoma. Yep, you read that right.

A big thanks to @gearcruncher for the information in his thread that lead me to this install:

https://www.tacomaworld.com/threads...l-toyotas-write-up-with-many-pictures.526283/

This really isn't all that different than it is for an auto aside from the fluid passing through the system. It can be done without any drilling which was the most appealing thing for me, although in hindsight I would have drilled for my thermostat and temp sensors which you can read on about.

The pump, filter, cooler, and basic fittings are available in a kit from Drift Motion. You'll need to buy fittings for the hoses and make or buy custom hoses, but I went with simple push-lock stuff. You'll need to figure out how you want to mount and wire yours up, and hopefully take some lessons learned from me.

The only thing you really need to do to make sure this will work for your manual transmission truck is confirm the thread size and pitch on the fill and drain plugs of your trans, and order the correct adapters if they are different. They are both 18mm x 1.5mm on the RA60F trans, which was the default option for me on drop down on their site.

Drift Motion has a great write-up of the product on their website. If you call up Drift Motion, you'll want to speak with either Odom or Aaron. I worked with Odom and he was extremely knowledgeable when I called up. He gave me some thoughtful tips on install and had answers to all my questions

Cost: I want to say it was around $700 all-in the way I did it, but I spent $269 on a cooler when the $69 option would have done the job.

Background:

Original clutch and trans with 120k miles on it. I have been running redline MT 90 and also tried some of the GL5 rated 75w90 they offer for awhile.

A few months ago I started monitoring my crawlbox and manual transmission temps via drain plug sensors I installed. Read more here: installing my temp gauges on my manual transmission

Honestly, I never cared about or had a concern that my trans was getting hot until after my crawlbox install in 2019, when I first started paying attention to how hot my sticks were getting. On a long trip, I noticed the trans shifter was especially hot and decided I should monitor temps.

After observing temps in excess of 240 degrees on multiple occasions I started researching this mod and found little to no information. Most folks seem to be of the opinion it's completely unnecessary for a manual transmission, and you must be experiencing some other significant failure in the transmission to create that kind of heat. I am at over 120k miles on the original bitsand I have beaten on them hard, but I dont think that's the case for me. I think I am just heavier than most and driving in the mountains I am pushing longer and harder with more weight than that trans was designed to handle.

I dont believe there are many people out there that will need this mod. My rig is over 6k on a typical weekend trip. Basically, I'm always towing a trailer. The high temps I observed where on long trips between Denver and Moab through the mountains over multiple passes without stopping, and on a trip to the sand dunes where I was ripping it in hi doing donuts. On that occasions I think there may have been some sand kicked up around the trans inhibiting the natural cooling that time. Under normal highway driving conditions, I have not observed temperatures that would warrant this mod for most folks, even if you're as heavy as I am. A cheaper option would be to pull over for 15 minutes and let the trans cool.

Takeaways:

BUY EASIER TO READ GAUGES: I am not overly impressed with my VDO gauges and sensors. They had the sizes I needed in terms of fittings for the trans and crawlbox, but overall I just have a hard time reading their gauges because they are non-linear and I have no clue what some of the indicators actually mean. I contacted VDO support with no response, so I'm sort of guessing on some of the temps I report in this thread.

DON'T BE AFRAID DRILL HOLES!!!!: I didn't want to have to drill holes in my transmission for this mod, and therefore located my thermostat and temp sensor for the gauge outside the transmission as opposed to getting the reading off the drain plug like I was before the cooler install. At speed, there's enough air cooling around the fitting/thermostat/gauge sensor to cause more than a 60 degree difference between the reading on my gauge and the actual trans temp, so I have bypassed the thermostat and manually flip on the cooler when I am climbing hills to get an accurate reading of the trans oil passing across the sensor.

I would prefer it kick on automatically at 180 degrees and off when it drops below, but with the lack of accurate reading coming off the fittings, I am looking at some sort of timer for now.

GO WITH A SMALLER COOLER: I went with a bigger, more expensive cooler because I thought it would actually be easier to mount. It cools pretty quick for my application and I doubt that anyone else out there needs more cooling than me, so ultimately I think the cheaper $69 option would have been more than sufficient to combat my trans temps, it just would have been a different mount to figure out.

For some more details on the history of why I did this mod, see my build thread:

1) https://www.tacomaworld.com/threads...l-and-b-s-thread.356319/page-29#post-25962217



Parts List:

1) Drift Motion Manual Transmission Oil Cooler Kit
https://www.driftmotion.com/Driftmotion-Manual-Transmission-Oil-Cooler-Kit-p/dm3561.htm
Options:

• Filter:INCLUDE 240 Micron AN-6 Oil Filter

• Oil Pump:INCLUDE Mocal 17-311 Metal Gear Pump

• Thermostat Switch:INCLUDE Setrab 180 Deg. 10A Thermostat Switch

• Transmission Cooler:INCLUDE Setrab FP119M22i Cooler With Fan

• Transmission Fittings:ADD (2) 18mm to AN-6 Fittings With (2) Crush Washers

2) 1 x AN-6 female to male 90 degree for transmission drain plug
https://www.driftmotion.com/90-Degree-AN-Male-to-Female-Adapter-Plated-Steel-p/dm3478.htm

3) 5 x AN-6 Push Lock 90 Degree Fittings for trans fill plug, filter output, pump input, cooler input, and cooler output
https://www.driftmotion.com/ProductDetails.asp?ProductCode=DM2378

4) 3 x AN-6 Push Lock straight Fittings filter input, pump output, transmission drain (attached to the dual inline fitting, after the sensors. See #7)
https://www.driftmotion.com/ProductDetails.asp?ProductCode=DM2378

5) 17ft x 3/8" push lock hose
https://www.driftmotion.com/ProductDetails.asp?ProductCode=DM31
-75" from trans to filter mounted vertical near with input near bottom of radiator mount driver side
-12" from top of filter to oil cooler near center of radiator
-24" from oil cooler output near top of radiator on passenger side to oil filter on driver side of radiator next to filter
-75" from pump to trans fill plug
Total 186" or 15.5 ft of hose + 1.5 ft of extra = 17ft

6) VDO 0-300 degree temperature sender 1/8 npt
https://www.vdo-gauges.com/300-f-150-c-1-8-27nptf-801-9-1.html

7) AN-6 inline fitting with dual 1/8" NPT port for both the thermostat (included in drift motion kit) and temp sensor (see above):
https://www.anhosefittings.com/an-male-flare-to-an-female-dual-1-8-npt-female-sensor-ports.html

8) 10ft plastic conduit

9) 1 x set of battery tie downs from AdvanceAuto (for cooler mount)

10) 6 x 10.5" 18 gauge sheet steel (for pump and filter mount)

11) 16" of 1 3/8" pre-drilled flat steel (for the pump and filter mount)

12) 4 x M5-.80x30mm bolts or whatever you have laying around that fits (for securing pump to mounting plate)

13) 4x M8x1in bolts or whatever you have laying around (for securing the mount plate to the truck)

14) quick fist or a round clamp to hold the filter to the mounting plate.

The install:





Cooler Mounting:
I went super simple here. I bought a matching set of battery tie downs from AdvanceAuto and hooked right onto the bottom of the lower core support. I do have some concern that they could cause the core support to crack sooner. I will keep an eye on it. The instructions also say you should try to minimize vibration, so a small strip of foam might not be a bad idea between the core support and the bottom of the of the cooler.




Pump and filter mounting:



I used a piece of 16 gauge steel from Lowes that I cut down to approx 6 x 10.25" and for the vertical support a piece of 1 3/8" drilled flat steel cut to approx 15.5" which I heated with torch and bent the bottom 90 degrees after fitting up the top to an existing bolt hole where my horns were.



I marked my drill holes for the pump and attached with four M5-.80x40mm screws. I'd recommend x25mm or x30mm length as mine are excessively long. I also wound up drilling holes large enough to bring the pump wires through to the back plate with a spade connector on the end so that I can remove the pump later without cutting wires.

For the filter mount, I had a rubber QuickFist laying around that used to hold my shovel on the truck. Works well enough for now.





I fastened the mount plate to the flat strap and flat strap to the truck using some M8 bolts I picked up.




Wiring:

My original plan was to wire this so that it was all automated and kicked on when the thermostat hit 180, but as previously mentioned, I had to bypass the thermostat and manually turn on the cooling pump and fan via an in-cab switch.



The pump, fan, and relay are intended to be easily disconnected with spade connectors. The relay and wiring are on the back of the mounting plate. The clearance between the mounting plate and radiator is tight, but there close to 1/4" of space so I think it will be fine.

From my fuse panel, I ran about 12-14" of 14 gauge wire, which I then split off into a set of 18 gauge pos/neg wires to run down to the trans for the thermostat and sensor, as well as a set of 14 gauge pos/neg wires to run to my relay and power the fan and pump. Everything in plastic conduit.

The red 18 gauge positive runs to the thermostat, which activates the relay once it hits 180 degrees through a white "trigger" wire that I ran from the trans up to the pump/fan assembly. The black 18 gauge negative wire will serve as a ground for the temperature sensor since the fittings will not conduct a ground for the sensor through the trans like my old did.

The SPDT (single pole double throw) relay harness is confgured as follows:
Red: HOT while relay is OFF (Not used)
Yellow: Hot while relay is ON
Blue: 12v positive source
White: relay "trigger"
Black: ground

The YELLOW wire on the relay harness provides power to the pump and fan and is wired with 18 gauge wire and spade connectors so everything can be easily disconnected.

The BLUE 12v positive input on the relay harness connects to the red 14 gauge wire I ran to the battery.

The WHITE wire on the relay harness is connected to the white "trigger" wire that runs to the thermostat that gets installed at the transmission drain. This white wire will carry the positive 12v signal coming from the red 18 gauge positive wire on the other side of the thermostat once the temp reaches 180 degrees.

The BLACK wire on the relay harness gets connected to the 18 gauge wires for the fan and the pump, and the black 14 gauge negative wire that I ran to the battery all with spade connectors.




The final version of this has rubber grommets installed around the pump wires so they don't get cut open against the edge.



Its tight but theres just enough space between the radiator. Wrapper all the wires in plastic conduit before install.



Fittings and Sensors:

The drift motion kit should have everything you need to provide your AN-6 fittings on the filter, pump, and cooler. My kit was originally missing the fittings for the cooler, but a quick call to Drift Motion took care of that easily and shipped free of charge.

You will need to buy and assemble all of your hoses and fittings between the AN-6 connections. I did a cheaper, easier option with basic push-lock hose and fittings all available from Drift Motion.

Pics of the dual port inline 1/8 npt fitting with the 1/8 npt vdo sensor. See #7 in my parts list above. This dual one was able to accommodate the length of the VDO sensor AND the thermostat:



Showing the sensor sticking through the fitting:



This is the completed fitting setup coming off the the trans. From left to right, the black fitting is included with the Drift Motion kit and adapts the trans to AN-6.

The Silver 90 degree fitting is #2 in my parts list from Drift Motion.

The dual inline fitting is part #7.

The VDO sensor is #6 on the part list the brass piece sticking out the bottom and the thermostat included in the kit is sticking out the top of the dual fitting.

The blue fitting is part #4 in my list, one of the straight push-lock fittings. I also added a small washer to help make contact with the ring terminal I added to act as ground for the sensor, since the fittings won't conduct a ground to the sensor unlike the original drain plug sensor.




Plumbing:

Flow is as follows:

From trans drain to filter input

From filter output to cooler

From cooler to pump

From pump to trans fill



From the front I came around the passenger side, over the steering rack and diff to the trans.








Priming the system:

Once all was plumbed, I left all my fittings just a little loose so that they'd slow leak and, filled the cooler and filter till they were overflowing, and then closed off the system and tightened all fittings, the re-filled the trans till overflowing as normal. I drove around the block with the pump running to warm things up and then topped off the trans again.





Information:
RA60F Manual Transmission drain and fill plug thread pitch is 18mm x 1.5mm

Larger cooler Option ($269)
Setrab FP119M22I
http://www.setrabusa.com/products/fanpacks/fp119m22i/index.html

Cooler Dimensions:
Width: 8.27"
Height: 6.1"
Depth: 4.38"

Smaller Cooler Option ($69)
Long Engine/Transmission Oil Cooler- 5.5x11
https://www.driftmotion.com/Long-5-5x11x1-5-p/dm1893.htm
Cooler dimensions
Width: 11"
Height: 5.5"
Depth: 1.5"

Approximate dimensions of space for oil cooler
Left radiator mount to center (width): 10.5"
Core support to top of radiator (height): 13.5"
Front of core support to bumper (depth): 5" with trimming inside of grill surround

 

Temperature observations:

Pre-install I would typically hit 180-200 after 30-45 minutes and would then run at around 220-230 after 60-90 minutes over the passes getting out of the front range. I usually get some downhills and it cools a bit either to 220 or so, but stays above 200 once the trans is warm, even with a short gas stop. I usually seem to hit the 230 plus after that through the next series of hills.

When I am just driving on flat highway, the trans usually stays between 180 and 200 all on its own. I am only seeing the higher temps on long trips through mountains with multiple high elevation passes.



Keep in mind that post install I am only getting a consistent, accurate temp reading off the relocated sensor in the cooling line when the fan and pump are running, so its harder to monitor the temps the way I was before. I have to cycle on the pump for a few mintues to get the reading, so its immediately cooling. While moving, the impact of air cooling the sensors is that it never really seems to register above 120 degrees (and therefore isn't triggering the thermostat) until I manually flip on the cooler. When I flip it on after 20-30 minutes, the gauge immediately rises up above the 180 line and then starts to gradually fall as it cools, as we would expect. On my last trip out to Moab I got the temp over 200 before turning on the cooler as I was getting to the top of Monarch pass, and it was dropping below 180 within a few mintues. I usually shut it off once its below 180 and I am done my climb, and then the gauge will drop back slowly to the 120 range as the oil stops flowing and air cools the lines.

On the trail while I am moving slow, the lack of air cooling on the line seems to allow heat transfer to give an accurate reading. When I have flipped on the cooler on the trail to check the temp, the gauge reads the same at about 120 after running a few mintues.

One last set of temp observations that I think are meaningful are from my trip out to Montrose a few weeks ago when I had significantly lightened my load in preparation to have my rear suspension welded up. I shed at least 800-1000 lbs of weight between my flippac, skids, decked system, tools, and gear. On that trip I turned on the cooler periodically to check the temp and even on my climb over Monarch pass, it never got much over 180 degrees. I think this is important because it tends to support my theory that my excess weight is what's generating the extra heat on the long climbs.

 

Whelp you sir are a first I have seen here on TW. Cooling a manual trans on a tacoma.

 

I'm either a pioneer or idiot.

 

As my great, great grandfather used to say... pioneers take all the arrows.

 

Excellent write up. The takeaways are appreciated.

 

This is awesome !! Looking forward to the temp readings .
Big thanks to Littles for taking the time out to do a write up .

In the past I have used up to 4 of these pumps and 4 coolers on 1 truck .
Transmission
Transfer case
Front diff
Rear diff

 

Was it a baja race vehicle?!?!?

 

I have an automatic. But I'm very impressed with your write up and photos!!!

 

I can honestly say I’ve never heard of cooling MT gear oil , but it sounds like yours was running plenty warm.

 

Thanks for the positive feedback. I had fun doing it and hope it helps anyone who has thought about it.

I threw some of my temp observations into the second post. Not exactly scientifically collected, but I at least tried to acknowledge some of the variables.

 

This is very interesting. What gear oil and weight are you running?

 

That's a good question and I'll add the information to the OP.

Currently running Redline MT90 GL4, which I believe is what I was running when I made my initial pre-cooler observations.

I have also run the redline GL 5 rated 75w90, but I believe that was before the sensors went in so dont have any comparative information on temps with the different oils.

I do realize I probably could have spent a little more time playing with different oils before going this route.

 

Thanks.
I notice in my owners manual that GL-5 oils have been dropped from the approved lubes on the later 6-speeds leaving only GL-4 ones.

 

This is great, thank you for sharing it.

 

because most people are brainlets who fell for Toyotas marketing campaign that they’re “reliable” (they’re not)



RA60F gear MTF capacity is pathetically low on what is a huge transmission.
For something wheeling in 4LO up rocks on a mountain nonstop it should have more.

B5 S4 01E has more oil and a cooler option with pump built into the gearbox. On a car that does none of the above, and is at higher speed than off-roading therefore more airflow to the coolers

same reason companies nowadays (including Toyota) don’t put fluid pressure or temperature gauges in their vehicles. They know brainlets don’t care, and don’t want to show off the temperature overheating/vehicle underperforming

common on any car with a grain of performance (better than a Corolla)

wouldn’t be surprised if trucks made with towing in mind whether automatic or not have it stock

 

Toyota/Aisin produce a handful of manual transmissions that are pressure fed via an internal gear driven pump.... Notably the H15x Land Cruiser trans. Several of those (not the Land Cruiser) have coolers... including the large and in charge Coaster bus M series trans, and the Celica Alltrac/GT4 variants. The lowly old 1st gen RAV4, which shares parts with the Celica, has a cooling tube in place of the cooler.

The RA/RC is a neat design, and has the ability to supply all bearings and syncros with an internal circulating lube circuit, though it doesn't use a pump to accomplish it. Note though, that many models were not internally drilled to supply this lube to the required locations. A good argument could be made that the potential for the RA/RC trans to perform much better and last far longer, is there, but is the cost to do this worth it? Littles has a good start here.

 

I dont think most people should even need to consider it, to be honest. There are few who it may benefit, but cost is definitely a consideration as it was not cheap. There's savings to be had there as I mentioned with the $69 cooler versus $269 cooler I bought.

Now that I have been running this for a few months through winter and into warmer weather I can share some additional observations and revelations.

Based on what I have observed, under normal driving conditions in both suburban traffic and on the highway, with the ambient air temp under 85-90 degrees, my trans generally has been able to maintain temps under 180 most of the time all on its own, occasionally pushing up to 200 if I am climbing some short hills. Those are perfectly comfortable temps for me. On short trips and colder days, the cooler is unnecessary and will overcool trans well under 150 if left on (my thermostat is still bypassed).

I only saw the consistent 220+ and the spike to 240+ temps on those really hot days that are 90+ degrees out and I am carrying weight through the mountains hammering down. I think we also need to acknowledge that after I installed the sensor, I was to some degree, trying to see how hot it would get if I pushed it hard and didnt stop and pull over and let it cool down. We're talking a 6k lbs +/- through the rockies at 65-75mph, sometimes down in third gear. Some of those 200+ temps were also hot days in Moab on the trail.

Post install, on hot days when it is actually "needed" I can leave the cooler on cruising at 65-75 on the highway, and it hangs 150-180. If it drops below I shut it off. I can easily maintain under 200 with the cooler running through the climbs now.

If you're towing a heavy trailer regularly in hot weather or are similarly grossly overweight like I am in these situations, then you may want to consider installing a temp gauge and getting a baseline reading. It would be a little silly to pursue this without obtaining that information for your truck, and your driving style first, in my opinion.

 

You are right, most probably don't need this... but for those that do... Along with the cooling potential, is the ability of a pump to force oil through the lube circuit. This may require opening up the transmission in order to plumb the lines. This circuit is normally fed by oil catch trays which direct the oil into various passages so it can be distributed to the main and counter shaft bearings, and then to the shaft center bores for the loose wheel bearings, synchronizers, etc. (Toyota cheaped out and did not drill some the shaft feed holes, which leads to wear and tear) The oil is thrown from the gears into these trays, physics does the rest.

While the gravity fed system is a nice step above simple splash lube, pumping nice cool oil through the internals with a little more push behind it, could hypothetically, increase the life and really draw the heat out. Even dumping the return oil into these collection trays could improve things.

Anyway, I've been mulling something over for some time now, and this project is great to see!

 

I was gonna say. It looks expensive as fuck. Especially to use nice parts. Thankful for the informative write up regardless.


I imagine higher temps in a manual trans are not so bad. Engines regularly see up to 220 and only have 0w30 or similar, versus 75w90. Or 75w140 like I have in my rear diff