super easy 4.0L transmission cooler upgrade!

[DJJordache]

hey guys I just did this and sooooo far it is running cooler. I am getting ready for the summer heat waves.

This is the B&M 70268 7 1/2 in. x 11 in. x 3/4 in 13000BTU and 19000GVW


here is the stock cooler and how it is positioned on it's mount


heres a pic showing that the input and output ports line up perfectly to the stock cooler


showing the difference in size! the B&M is almost 2x. which one would you rather have cooling that 42re that costs around 2K to rebuild?


here it is installed all I had to do to get it spaced correctly was to drill 2 holes in the B&M mounting plates and flipflop one of the stock cooler holders and use 1/4" bolts to hold it to the clamps


this was probably one of my easiest upgrades and required almost no fabrication to fit=)

I will soon be adding another temperature probe to be able to see the temp of the output of the tranny as well as the input I already have and then just a flick of a switch to pic which sensor I want my Autometer to show.

[StinkoMan20X6_]

That's funny. That's the same cooler I'm using except I attached mine to my A/C condencer and ran it in line with the original cooler. The A/C sucks like always but being sweaty is free, not transmissions.

[OverkillZJ]

It's amazing how much cooler a tranny will run with a better cooler, I'd argue it's one of the reasons my tranny has survived the abuse so far, that and amsoil.

[DJJordache]

It's amazing how much cooler a tranny will run with a better cooler, I'd argue it's one of the reasons my tranny has survived the abuse so far, that and amsoil.

exactly and I also have a extra transmission filter inline on the cooler lines before the coolers to make sure they don't clog up and the fluid is EXTRA clean. It uses a large Wix hydraulic oil filter. We have this setup on EVERY one of my familys vehicles.

for example of how well this filter setup works: have you ever heard of a 85 era Chevy 700r4 going over 80,000 without dying? The one in our old Suburban went 240,000 before it started to noticably slip and we had it rebuilt b/c we didn't want it randomly crapping out on us. When the transmission guy opened it up he could not believe how clean it was! It really was super clean inside and the only reason it was slipping was b/c the friction plates were running out of material after 240K miles

[doyll]

B&M looks almost 3X as much cooling. It has 3X the fins and twice the area. I wonder what the BTU of stock cooler is? Great install! Can you give me a little more info on your filter and temp guage installs?

Thanks Again for great writeups!

[DCHZJ]

Oh great.....I KNOW that has not been done on mine. As i hate to pay for a tranny rebuild....not i have another Mod to do........Damn it!

[DJJordache]

I just ran outside and took some pics with my camera phone my real camera was destroyed long story short with my dads model airplane crap (not the little crappy ones, this one was a 50lbs all aluminum one with a 8foot wingspan) and him running one right into me knocked me on my butt got all cut up and dropped my canon RIGHT ON THE LENS! I was more pissed about the camera than my cuts oozing all over the place.

anyways since a pic is worth a thousand words
I'm going to reroute the hoses but here it is of now:
the filter input side:
you will see that it goes into a tee where the fluid shoots right at the temperature sensor and then into the filter which is a WIX 51551 Hydraulic filter.


here is the filter output side

I'll have to dig around to see if I can find a part number on the filter mount, but it's pretty much a remote oil filter mount. The filter is the same OD as our stock 4.0L ph16 or ph8a(loinger) filters but has a larger center thread hole than our oil filters, so there is no worry about flow restriction with this filter. and the Autometer transmission temp gauge is in the A pillar gauge pod.
I just like to think of it as added insurance on the transmission

edit I got the pics backwards

[Cue-Ball]

I know this is a little old but great write-up Jordan, I will probably be doing this next week.

Dirk

[Matt]

Nice write-up. My lil 42re needs all the lovin it can get.

One more thing added to the endless list.....

[Cue-Ball]

One more thing added to the endless list.....

endless list is for sure.

[ZJ Limited]

Thanks for the really great writeup! I do have a question, when's the best time to it - when replacing the radiator or is anytime a good time?

I ask because my 94 ZJ 4.0 with 192k miles is leaking alittle around the stock tranny cooler and I figure I might as well upgrade to something larger. However, I'm still using the stock radiator which I know I should replace one of these days. If it'll make more sense to replace both at the same time, please let me know!

Thanks.

[Cue-Ball]

Does not really matter, might be a little easier while doing the radiator but really about the same.

[LouisianaZJ]

on a side note, you can use the stock tranny cooler as a nice little power steering cooler. just plumb it into the return line that goes into the bottom of the PS reservoir

[nate]

That's where my B&M is. I never had an additional cooler. I've had mine for 3 or 4 years now. Also have a power steering cooler, which is mounted in the stock "bumper" channel.

[DJJordache]

Also have a power steering cooler, which is mounted in the stock "bumper" channel.

ooooo I like that idea, I'm adding that to my to-do list that is a mile long......

[Cue-Ball]

It is also on my list of things to do, I just need to pick up some mounting brackets.

[ZJ Limited]

Alright, after much procrastination, I've finally going to order the B&M tranny cooler along with a 3-row radiator from Radiator Barn. Should the tranny cooler by-pass the radiator or should I continue to go through the radiatior?

Thanks!

[Cue-Ball]

Don't bypass the radiator continue to run through it and the super cooler.

[Matt]

Just got mine in today! Super easy install and hopefully will save me some $$$ down the road.

[ZJ Limited]

Don't bypass the radiator continue to run through it and the super cooler.

Not to doubt or second guess your advice, but how come? I'm curious to know. Thanks.

[Cue-Ball]

There are a couple of reasons that I can think of off the top of my head.
1. That is the simplest way to make the swap as that is how it is already plumbed.
2. if you bypass the rad. you will decrease the amount of ATF fluid in the system (the more the better).
3. You can NEVER have too much cooling for the trans.

[NCXJ]

just a thought, but the a/c condensor makes a damn good trans cooler as well(just needs to be plumed for the lines), and from the junk yard, they're only around 15-25 dollars, and they can be squeezed infront of or behind the setup your running now.

[ZJ Limited]

Cool, that makes sense!

[Cue-Ball]

Shameless plug

For the best possible cooling be sure to use Amsoil full synthetic ATF!!

/shameless plug

[nate]

Yeah I got a p/s cooler from a Ford or Lincoln car of some sorts. Was brand new, still in the box too. Was helping a guy move and he was going to trash it.

Then I took a hole saw and cut holes in the stock bumper, which happens to be in line with the pass side hole of the ARB bumper. It's not the "best" place for it, but I had it mounted in the front of the radiator before, and all the plumbing for that plus the trans cooler, winch wiring, etc made too much crack packed in one spot.

ooooo I like that idea, I'm adding that to my to-do list that is a mile long......