DIY Trans Cooler for ~$300

It can definitely get pretty cold here, I’m in the midcoast region but single digits do happen. That’s probably what I’ll do is an inline thermostat.

 

@Mdl do you happen to know what size thread was on the transmission?

 

Not offhand. Do you have the elbows? Some have also used AN fittings too.

 

@Jego do you have the transmission elbow fittings? Any chance you can check the thread pitch for him?

 

I still have to fab up a bracket but it's pretty light. I also used a Derale thermostat with a 160 degree pill in it. This is the improved racing one, fsm145.

 

Yes, will do in a few minutes...

 

Metric M14-1.5

 

I thought that. I'm hoping you didn't run to the store just for that. Thanks. Hopefully it helps him out.

 

That’s the plan to use AN lines.

 

Thank you good sir!

 

When I saw your post, was about to leave for dinner. It was just a quick stop at AutoZone on my way. Hope it helps.

 

You saved me from taking it apart! Haha

 

Some folks here and on other posts have asked about using @Jmunk 's transmission bracket on supercharged applications. I spoke with him through PM and decided to go ahead and order his kit to install on my Magnuson 2650 equipped 2021 Tundra. Had to make some minor tweaks, but all is good and it is doable with a couple changes mentioned below...

I ordered:
@Jmunk Bracket Kit with AN Fittings
Hayden 689 Transmission Cooler - Amazon
OEM Toyota Cooler Thermostat/Inlet&Outlet Hoses, and Hard Line kit - eBay
8X OEM Toyota Spring Clamps - Toyota Dealer Online
2X OEM Toyota 12mm Flange Bolts - Toyota Dealer Online
2qts OEM Toyota WS Transmission Fluid - Toyota Dealer Online
7ft of Gates 3/8" Transmission Cooler Hose - Oreilly Auto Parts

All the parts above ran just under $700, which is about 1/2 of the current pricing for the GCS kit currently offered. You could certainly make it all cheaper if you choose to skip the OEM hardlines, or even skip the thermostat and remove heat exchanger which allows 90 degree fitts to be installed straight to the transmission body.


From looking at his for sale post on Tundras.com and his installation PDF, I could see that the upper bracket mount was going to use the same hole as the magnusson intercooler bracket, but would not interfer with intercooler, itself, as it is setback quite a bit. I measured the thickness of the intercooler bracket at .125", so I ground down his spacer by .125" to come up with overall thickness of .25". See picture below of the spacer installed with magnusson bracket and his trans cooler bracket...


The second issue I ran into and did not realize until I removed the grille, was that the one of the lower mounting holes of his bracket was going to use the same oversized hole in the lower radiator suuport as the Magnuson intercooler bracket. I initially tried to just place his bracket on top of the intercooler bracket, but the placement dictated by the Magnusson bolt hole in lower bracket made it so that the other lower mounting bolt on transcooler bracket would not align with the threaded hole in the radiator support. There was not enough allowance in bolt holes to allow this to line up, even if I loosened everything. I noticed that with the lower bolt removed from the Magnusson bracket, it was still completelty rigid and did not flex or move, so I decided to just bend that lower mounting tab of the Magnuson bracket out of the way so I could mount Jmunk's bracket in that space. I might go back later and just cut that tab off, but it is not visible or hurting anything at the moment. Below picture shows the bracket tab bent out of the way ands trans cooler bracket mounted... In the future, I will most likely just cut the bracket off where I placed the solid red line...



The only other change I made from his PDF instructions was to cut the lower hose grommet hole higher on the plastic shroud. The suggested lower hole placement left a lot of strain on the the hose, so I moved it up and got a less strained routing of the 3/8" cooler hose. 2 pictures below show the original suggested hole and new higher hole. I later found out that he had mentioned in the sales post to use the hgiher hole location for optimal routing is using his AN Fittings... This has nothing to do with supercharged application




The only other issue I encountered that has nothing to do his kit or having a supercharger was that the Gates 3/8" transmisson cooler hose ID made it extremely difficult to install the hose on the OEM hardlines I installed. I lubed the nipples and ID of hose with ATF and even with that, I fought like hell to get those hoses on to the hardlines... He mentions somewhere that differnet brands of 3/8" hose will have slightly larger/smaller ID's and maybe it's pertaining to installing the hoses on the hardlines, but he uses Napa brand 3/8" transcooler line. I think even if you plan to run hose all the way back to the thermostat unit, this needs to be considered. I could see that the OEM short connector hoses (probably metric) has a slightly larger ID and they installed quite easily on to the hardlines on the other side, with a little trans fluid swabbed in the hose.

Below picture shows the cooler and bracket + hoses fully installed. Did a 5 hour drive after this installation and no issues...



Any questions, feel free to ask away...

Erik

 

This is exactly what I was looking for. I may just go with the GCS kit since is bolt on, I hope. This is a high risk job and I want to make sure it gets done right so paying the extra $$$ is worth it for me.

 

Just ordered my cooler, hose and the brick.

Need to find out who has the dfx for the bracket.