New To Me 4.6is

[Mr.Couch]

Originally Posted by Henn28

Fantastic work, love the car.

I totally missed where you put an air cooler in for the transmission. Have you followed the temps while driving, and what t-stat did you use? ZF says the low end of the 5HP24 operating range is 170, so that’s what I’m going to aim for when I do this swap to a CSF universal air cooler. I’m not sure what size to use tho yet as this is new territory for me. My torque converter is undersized for the 4.6, and I know my tranny runs on the hot side of the official ZF range (190) so I want to get the air cooler sized right so I can cool the fluid to 170 reliably.

Can I trouble you for some pics of the install when you have the car in the air next time? Would love to see how you mounted it, fabricated the lines, etc.

You may want to look at the CSF e39 M5 radiator. All aluminum, significantly more cooling capacity and now that you don’t have the water tranny cooler it should be plug and play as far as hoses. Size-wise I’m not so sure, but I bet it’s very close, or can be made to be. https://csfrace.com/csf_products/dir...oling-systems/

Thank you! You didn't miss anything, I'm in the process of planning out the transmission cooler as I'm going to have to do multiple repairs all at once to cut down on time. Here is what I need to attack.

Power Steering
Since I have a slight power steering leak I came up with the idea to upgrade that system a little bit.
I have a turner motorsport baffled power steering resevoir ( https://www.turnermotorsport.com/p-9...traight-mount/ ) which I have all new lines and hoses for. I'm going to remove the factory power steering cooler and add a Mishimoto universal cooler, the same one that I will be using for the transmission cooler. ( https://www.mishimoto.com/mishimoto-...ooler-kit.html )
https://www.realoem.com/bmw/enUS/sho...diagId=32_1347
Using this diagram for reference, #14 is the cooler. I have confirmed that the quick disconnect line for the return on the cooler & return line to the rack are the same quick disconnect that the transmission lines use. I have adapters that connect to the quick disconnects ( https://www.turnermotorsport.com/p-5...ooler-fitting/ )

So here is the plan,
Install new baffled power steering resevoir
--New OEM suction hose from resevoir to pump
--New OEM return hose from resevoir to quick disconnect adapter (-10an) to mishimoto universal p/s cooler tucked in front of the pusher fan in front bumper (Aligned to drivers side)
--From Mishimoto universal p/s cooler (-10an line & quick disconnect adapter) to New OEM return pipe to rack.
--New OEM pressure hose
--Fill & make sure no leaks


The reason I am looping this together with the transmission & cooling system work is because I would like to only take the bumper off once, mount the universal coolers, install the new radiator, etc. One and done

Transmission cooler
I have the notorious 2-1 bump after driving for a bit and the transmission temps (I assume) get to high. I have not yet done a reading on the temps but the previous owner had installed a low temp thermostat & termostatically controlled puller fan which do indeed keep engine temps down. Here is the plan I have for the transmission cooler upgrade.

Install new OEM supply and return lines. Instead of them connecting to the stock BS cooler and then to the radiator I have come up with two ideas.

BMW E39 Radiator & transmission cooler
This is the first idea which would consist of installing an e39 (Up to 09/98) transmission cooler which is an air cooler PN 17221740798. If I used that cooler & the support bracket that holds it to the back of the radiator PN 17111740796 I could essentially just delete the 4.6is transmission cooler & not have to fabricate anything. This would also allow me to use an upgraded CSF e39 radiator (if the same as a 540i m62) or just use the oem radiator PN 17111702969. So for this plan to work...
-Install new 4.6is supply and return transmission lines
--New OEM early e39 transmission cooler lines can be spliced with New OEM 4.6is transmission cooler lines at the soft rubber portion of the line.
--Transmission cooler mounted in support bracket to radiator
--New OEM radiator from early e39 540i (Which is the same manual or auto)
--New CSF upgraded radiator
--Full transmission service and pray it lower temps, doesnt leak, eliminates the bumping downshifting from 2-1 when hot.

Option 2, Install a universal cooler
With this option I'm still installing new OEM supply and return lines for the transmission. I would then use the quick disconnect adapters from above in the power steering section to mate to (-10an) lines to the same mishimoto universal transmission cooler, mounted directly next to the power steering cooler & lines running to the passenger side of the truck. The only issue with this is now I need to figure out a radiator solution so that I can properly delete the BS transmission cooler that comes standard on the 4.6is. It's possible to run the same transmission I listed above but I have not yet confirmed this to work. With this option I have already purchased a thermostat that would work in line so that I can ensure the transmission warms up properly but this also might be overkill considering I wouldn't be running a thermostat for the first option & I can also just take it easy when starting/driving cold.



In conclusion,
I know I didn't answer your question directly but after doing the research I do indeed believe that both transmission cooling options will work, I just don't know which one i'm going to pull the trigger on. I think i'm leaning toward the almost OEM option (1) and see if that OEM cooler does enough to lower the temps. Realistically, anything will be better than what is currently in the truck.