B&M Transmission SuperCooler

Alright so I purchased the B&M Transmission SuperCooler and it arrived today, won't install it untill friday / saturday. The reason I bought it was, well lets just say I'm hard on transmissions, and every vehicle I've owned has had a new tranny while I've had it. (Although the previous cars were high milage / known for it...)

So skip ahead to my question, I have a 1994 Cherokee Country Edition, 4x4, 4.0l, yada yada. So I have the 'radiator' transmission cooler, and also the smaller 'stock' transmission cooler. I figure the smaller stock one is pretty much useless and doesn't do that great of a job, so I purchased this B&M one.

So my question is, should I remove the stock transmission cooler, or leave it in place? Since i have the B&M i'm not sure if the stock pump has enough power to pump it through all three, or is two about the most it can do?

Thanks,
Drew

BTW: I've found many threads on the stock cooler / b&m one, but none about 'both' of them. Went 7 pages deep in the search...

If you keep going through auto trannys, why not get a manual? They typically will out last the motor.

If I still had an auto tranny, I would remove the lines going into the radiator and direct them into the B&M cooler. That way the tranny fluid isnt heating up the engine coolent, and adding stress on the engine cooling circut. I dont know about the other cooler, mine didnt come with the extra cooler when I had the auto just the one in the radiator end tank.

AARON

I don't see a problem - I've run external coolers without the internal cooler before.

The argument usually goes that the internal cooler helps the fluid reach operating temperature (~190*) quicker, but I never saw a need for keeping the thermal load on the system. Besides, B&M (used to, anyhow, I haven't checked recently) makes a valve that functions as a thermal by-pass - it bypasses the cooler up to 190* or so to allow the fluid to reach operating temperature before the cooler kicks in. Did you get the kit with that?

Elsewise, there's no harm done in eliminating the internal cooler entirely in favour of the external.

5-90

With my long sagga of tranny problems I ended up using the the same cooler you are using alone, I bypassed the heat exchanger and did not have a aux cooler. I have a temp guage and on the hiway it runs nice and cool, about 150* passes everything. Trail about the same BUT rally racing fire roads and occasionally climbing a hill at slow speeds (40mph apx) with the torque converter unlocked and it shifting into and out of 4th it gets up to 210-250* Im not sure if running the stock heat exchanger would help or not, but for the most part it keeps cool. I kinda like the tranny temp not dirrectly effecting the engine coolant temp.

MrShoeBoy said:

If you keep going through auto trannys, why not get a manual? They typically will out last the motor.

If I still had an auto tranny, I would remove the lines going into the radiator and direct them into the B&M cooler. That way the tranny fluid isnt heating up the engine coolent, and adding stress on the engine cooling circut. I dont know about the other cooler, mine didnt come with the extra cooler when I had the auto just the one in the radiator end tank.

AARON

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Actully I've gone through more manual's than auto's... I broke a race-spec tranny in less than 2 months.


So you guys are suggesting I completely by-pass the radiator tranny cooler, and work either with the external one & b&m one, or with just the B&M alone.

Really, it's up to you. I don't think anyone can make a convincing case for doing it either way. The only advantage of running it through the radiator is to bring the trans fluid up to operating temperature quicker......not really to cool it off. On mine, I bypassed the radiator trans cooler and only used the big cooler. I used a small stock cooler as a power steering cooler, which made a big difference in the steering on the trail. It's pretty easy to run the power steering return line through the small trans cooler.

Just intrested to know which size B&M one you purchased ?

Also if it was me i would leave the radiator one connected and connect your newer B&M one in place of the stock secondary one you have.

Pete

Here is what I did with my Hayden cooler...

Removed the lines from the radiator.

Coolant goes into OEM auxiliary cooler (this is for the HD cooling option / towing package, not all AW4 equipped XJ's have these) then through the Hayden. I had to rearrange the coolers a bit to do this. The OEM aux. cooler is set dead center low from the factory, I moved it over about 6 - 8 inches to the drivers side to facilitate my Hayden 403 cooler.

I also picked up a Hayden 1009 power steering cooler and plumed that in as I had to flush my fluid anyway.

Sequoia

Tenny said:

Actully I've gone through more manual's than auto's... I broke a race-spec tranny in less than 2 months.

So you guys are suggesting I completely by-pass the radiator tranny cooler, and work either with the external one & b&m one, or with just the B&M alone.

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Well I guess if you go through manuals that quick, an auto might be the better option

AARON

I'd preffer to still have it plumb'd into the radiator... The heating of the fluid helps, and in short distance driving it's needed. If you look into the characteristics of ATF I think you'll retain the stock 'cooler' that's located in the radiator, and then plumb in the aux... Just my $.03 though...

Will.

which size GVW B&M do most of you run ? I heard only the .75 thickness ones will fit ?

Pete

I stuffed a 30GVW 1.5 inch cooler in the front. Had to disassemble the front clip, but no problem. Do not use the through the radiator/condenser push clips. My thoughts here are vibrations on the trail.
I fab'd up a bracket to hold the cooler, plumbed the lines outside the radiator, installed a filter and temp guage, and I do not sweat the tranny temp anymore. In fact it only rises (110*) on the trail when on the fire roads in 3rd when the clutch will slip. Engine runs a full 10 degrees cooler. I put an aux switch in for the electric fan so I can bring the fan on to help airflow over the trans cooler if needed before the thermal switch for the engine temp turns it on. So far haven't needed it.
Highly recommended to put a aux cooler in, bypass the radiator, include a filter and temp gauge. It's a major piece of mind.

Goatman said:

Really, it's up to you. I don't think anyone can make a convincing case for doing it either way. The only advantage of running it through the radiator is to bring the trans fluid up to operating temperature quicker......not really to cool it off. On mine, I bypassed the radiator trans cooler and only used the big cooler. I used a small stock cooler as a power steering cooler, which made a big difference in the steering on the trail. It's pretty easy to run the power steering return line through the small trans cooler.

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Heat transfer will ALWAYS be greater in a Fluid-Fluid configuration. Fluid-Air exchangers are not as efficent.

That's why the new Supercooler is 1/4 the size of the Rad, and the OEM Internal cooler is only about 4 feet(if even that) of Coiled tube.

I've seen the super cooler stacked plate style on sale at U-Haul. Has anybody tried them?
I once installed a cooler in an older XJ a few years ago by attaching it to the
front of the A/C condenser using plastic ties and rubber pads.
lousy installation, the plastic ties eventually got hard and brittle.
I plan to install one on my current XJ, I'd like to have a more solid installation,
however I am concerned with vibration messing the cooler up.

I wonder how many engine over heating issues are related to a slipping/overheating tranny? If the heat exchanger is exchanging 250* tranny fluid with would like to be 190*(less obviously in the radiator) engine coolant at the end of the radiator/coolant cycle, how much bad is it doing than good? If the heat exchanger is in the lower portion of the radiator as it appears to be its basically preheating the engine coolant right before it goes back into the engine right?

I dont have any engine temp issues but maybe ill try running the heat exchanger again and check for any noticable differances.

I've got a B&M temp gauge and the stock aux tranny cooler right now, but after our trip to Hot Springs this past weekend, I'm going to be swapping out the stock tranny cooler for either a B&M 19k GVW SuperCooler (11'' x 7.5'' x .75'', $46 @ JEG's) or a model by Imperial that's a whopping 12"x11" ($70 @ Advance Auto Parts). Both are the stacked plate design.

With the stock aux cooler, watching the temps the engine is usually running hotter than the tranny is all the time, so I'd say that most of the time the tranny fluid is getting heat from the engine coolant, and not vice versa. There's only been a few times when I've seen my tranny temps exceed my engine temps. My tranny temp gauge is plumbed into the "hot" line out of the tranny.

When I swap in the new cooler, I'll probably cut the soft lines going to the factory aux cooler (since it's got nice quick disconnects to the stock tranny lines), remove it, and plumb the new one in in its place. I think I'll still keep the lines plumbed into the heat exchanger in the radiator though.

My steering is messed up now too though, (very stiff for about 45* each direction from center, and in that range it "sticks" and doesn't self-center now) so it may finally be time for either a Durango steering box or one from PSC. Richard, have you had any issues using the factory aux tranny cooler for your PS cooler? The PS lines are high pressure aren't they? Vs the low-pressure tranny lines.

another quick (and possibly dumb) question, but on the B&M stacked plate coolers, does it make any difference which way the inlet/outlet ports are orientated? ie: out to the side, or to the top or bottom?

The tube/fin design always seem to have the ports to the side, but the mounting flanges and shape of the stacked plate design seem better suited to having the ports going either up or down.

Jeepin Jason said:

The tube/fin design always seem to have the ports to the side, but the mounting flanges and shape of the stacked plate design seem better suited to having the ports going either up or down.

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There is one more difference between the two. The tube/fin design is a single
tube with no connections other than the hose connections.
The stacked plate has a lot of parts that were welded together. I always felt that the tube can take vibration better without developing leaks.
In fact I am thinking about looking for one to install.

Hmm, I hadn't thought of it that way. B&M touts the "ruggedness" of the stacked plate design though, and it's resistance to damage. To me, it does look a bit more "solid" than the tube/fin ones. Plus, with a much greater surface area, I would think that the stacked plate design would also cool better?

Do you know of any stacked plate B&M coolers that have developed leaks?

Jeepin Jason said:

B&M touts the "ruggedness" of the stacked plate design though, and it's resistance to damage.
Do you know of any stacked plate B&M coolers that have developed leaks?

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I used a stacked plate type once. Within 2 years the plastic ties were brittle
and started breaking. (The heat most likely). I could not find those ties and little plastic square washers that hold the cooler on the condenser.
The cooler it self was still ok at this point, the attach hardware were not.
I had to find some large tie wraps and make my own washers.
At the time, I considered mounting the cooler on the chassis but I didn't come up with a way that looked good. I was concerned with vibration. Soon after that I sold the vehicle. No leaks up to that point.
If somebody has a better way to attach one of these without using the factory hardware, I'd consider it.