mountain passes off-road transmission cooler retaining stock cooler

[trinydex]

I installed the mountain passes off-road transmission cooler and retained the stock cooler, sandwiched in the stock location. this will help me use the factory transmission cooler as a power steering cooler. the GX uses ATF as the hydraulic fluid, which is convenient.

as can be seen the first order of business is relocating the horns. I decided to relocate the two horns into one bolt location and point them in the same direction. I didn't want to splice the harness twice. the mounting holes in the passenger side of the radiator support are further apart or just not oriented well. because the holes are further apart, I would have had to extend the harness between horns and also extend the harness from the driver side to the passenger side of the radiator support. I also didn't want to use a different bolt for the horns, this one seemed like the best overall location for horn sound and wore routing efficiency.

I spliced in one green copper wire of thicker gauge in order to extend the harness from the driver side to the passenger side.

I unwrapped the electrical tape in order to expose the wire more fully.

after wire extension a wire loom was used to cover the wire and electrical tape was reapplied to keep the loop and factory insulation tubes from migrating around.

 

[trinydex]

this is the bolt that I decided to use for grounding / mounting. this is the passenger side-most radiator fan isolator bolt. and grounding this set up ended up being an ordeal.

I used a split loom and wrapped up the wire and tucked it under the radiator support, zip tying the loom via these holes in the support.

this was roughly the final orientation. in order to achieve the clearance to get around the fan shroud, I had to remove the horn shrouds and use the mounting hole for the horn shrouds (slightly bored out) to mount the horn. I had to bend the bracket into a z shape in order to offset it enough to clear the plastic cowl piece that covers the grill area.

there was some problems with the voltage drop in the new locations of everything. one of the horns got fried and the horn fuse blew, so I had to troubleshoot the horn circuit.

there's only one wire going into each horn which suggests that the grounding is all going through the housing, the mounting screw and nut and the mounting bracket.

the indexing peg on the horn's metal housing was causing some offset with the bracket (and hence less overall contact between housing and bracket) because I was no longer using the factory clocking on the bracket. I sanded that off and sanded off the insulation / grime build up on the metallic housing of the horn. I added some antiseize, hoping the aluminum content would promote conductivity. I sanded down the paint on the bracket where it touched the frame.

finally, I added a new ground line, following the wire bundle under the radiator support to the ground bolt (10mm) near the power steering reservoir on the passenger side of the engine bay.


I'm unsure which parts of the circuit contributed to how much percentage of voltage drop, but after remedying each of these areas, the horn worked.

 

[trinydex]

the next step was the preparation of the transmission cooler bracket. I had purchased 3 extra rubber isolators (90099-32130) and 3 extra isolator bolt inserts (88467-14070). the inserts of the bushings are important to allow torque spec on the bolts so the bolts won't be loose and loosened on washboards and other road conditions.

first step was to open up the 6 o clock mounting "hole" on the mountain passes bracket. if I could do it over again I would make the u deeper, I made the u as wide as the others, but making it deeper will help with final install.

I got:

1x 1.5" M6x1.0 bolt
1x 2" m6x1.0 bolt
1x 2" M8x1.5 bolt

I also used corresponding sized washers for each of these bolts. the washers need to have the same outer diameter as the rubber isolators (.75").

the 2" M6 bolt goes in the 6 o clock mounting point.

the 1.5" M6 bolt goes in the 9 o clock mounting point.

the 2" M8 bolt goes in the 12 o clock mounting point.

 

[trinydex]

as can be seen in the previous post, I am sandwiching the factory isolator, fully installed in the factory transmission cooler and stacking an isolator installed in the mountain passes off-road transmission cooler bracket. the factory cooler has captured nuts backing each of its 3 mounting points. only 2 of these points crossover with the mountain passes off-road transmission cooler bracket. the third stock point will be installed via one of the factory 1.25" M6 bolts.

the 12 o clock mounting position requires an isolator to be stacked where the horn used to be mounted. with these all in place, the mountain passes off-road transmission cooler bracket is "flush" against the stock cooler and the radiator support.

the 3 o clock mounting point for the factory cooler can be seen here, reinstalled with an isolator and a stock bolt.

full width isolator under isolator installed in 12 o clock mounting position on mountain passes off-road transmission cooler bracket.

top view of stacked isolators.

9 o clock mounting point. one isolator in stock cooler stacked on one isolator in mountain passes off-road transmission cooler bracket.

6 o clock mounting point from underneath the car. it was difficult to get these sandwiched and then bolted together. this is where deepening the u on the 6 o clock mounting point would have helped with clearances.

extra shot under the car to show routing of stock transmission cooler lines to the new cooler.

had to use worm gear clamps as the new cooler and aftermarket bracket created too tight of a fitment to reuse factory hose clamps.

 

[trinydex]

this image shows the routing of the stock transmission cooler line to the new cooler.

also can be seen is the clearancing that had to be done to make room for the transmission cooler line and the cooler to barge into the cowl.

the line to cut the internal tab of the cowl.

this little corner had to be heated and reshaped slightly outboard.

this tab had to be heated and shaped inward slightly to stay out of the bracket's way.


UPDATE: I was able to use the constant tension spring clamps from the power steering lines (which are only single thickness of spring material) to fit into the gap and eliminate the worm gear clamps.

 

[Sky Soldier]

Nice job and write up. May I ask the question.....can you tell or do you have any way of knowing if stacking the stock cooler and the Hayden cooler is effective?

 

[trinydex]

Nice job and write up. May I ask the question.....can you tell or do you have any way of knowing if stacking the stock cooler and the Hayden cooler is effective?

you mean measuring the oil temps?

 

[Sky Soldier]

you mean measuring the oil temps?

Yes...if you have a way to measure or can monitor tranny temps from in the vehicle via warning lights etc?

 

[trinydex]

Yes...if you have a way to measure or can monitor tranny temps from in the vehicle via warning lights etc?

I won't be doing any data logging. other people have done data logging with the mountain passes off-road transmission cooler.

 

[yeos]

Looks good! I didn't think about reusing the factory cooler as a PS cooler. After installing the Hayden 478 the trans fluid runs significantly cooler. Flat stretches on the highway would get me to around 160-180F with the factory cooler. With the Hayden 478 I am now seeing 130-150F on the same areas of the highway.

 

[tlin]

Looks good! I didn't think about reusing the factory cooler as a PS cooler. After installing the Hayden 478 the trans fluid runs significantly cooler. Flat stretches on the highway would get me to around 160-180F with the factory cooler. With the Hayden 478 I am now seeing 130-150F on the same areas of the highway.

How are you recording this?

 

[cheeze]

How are you recording this?

They're probably logging with a cheapo bluetooth OBD2 reader and Torque app. Lots of parameters missing for Toyotas but tranny temp is thankfully one of them.

 

[yeos]

How are you recording this?

Ultragauge MX and verified with tech stream that the temperature readings are correct.

 

[fvedmo]

Any particular reasons for running it TC-PS-Rad instead of PS-TC-Rad? Was it just fewer bracket mods? Or if in the cold a lot the sandwich might prevent overcooling PS? Seems like having the PS in front might require less bend and cut to fit.

 

[trinydex]

It was just easier to leave the stock cooler where it was and stack the aftermarket cooler on top.

the aftermarket cooler has slotted mounting points (one of which I had to cut deeper). and the stock cooler has OEM fitment dimensions.

it's probably possible to reverse it, I just didn't do so. I would have to go back in and examine to maybe remember why did it this way.

 

[rmswins]

Looks good! I didn't think about reusing the factory cooler as a PS cooler. After installing the Hayden 478 the trans fluid runs significantly cooler. Flat stretches on the highway would get me to around 160-180F with the factory cooler. With the Hayden 478 I am now seeing 130-150F on the same areas of the highway.

I am seeing the same temps with this mod as well. I monitor the trans temp full time with a Scangauge II through OBD II port. Also off-road temps with stock cooler would sometimes go past 200 in the desert sand or slow rock crawling when ambient temps were 100. Now it stays around 170 off road.

 

[captainva]

Do you think this would fit with a winch? It looks like especially with a hidden winch this wouldn't work

 

[fourleggedfish]

Does anyone have the email address or other contact info for the maker of the Mountain Passes Off-road TC? The only thing I can find is his Facebook page, which requires you to login to load the page. I ditched FB years ago, so need some help getting in contact.

Also, how much does this mounting kit cost?

 

[VSPro9]

Does anyone have the email address or other contact info for the maker of the Mountain Passes Off-road TC? The only thing I can find is his Facebook page, which requires you to login to load the page. I ditched FB years ago, so need some help getting in contact.

Also, how much does this mounting kit cost?

His phone number is there. Looks to be around 580 from some posts