OK to bypass transmission cooler inside the radiator?

[BMRisko]

OK, well I am in the process of replacing my transmisison due to water getting in it and totally ruining it. (Long story) I had this transmission rebuilt 35k miles ago and the shop bypassed the tranny cooler in the radiator, made my stock auxillary cooler a power steering cooler and added an aftermarket cooler. I will be keeping the same set-up with my new tranny, but I am swapping out the "aftermarket" cooler for a B&M supercooler (low-pressure drop design). Now to the question, should I really be plumbing the lines to go through the radiator cooler as well or is that not really necessary? I can see living in extreme cold how the radiator cooler would heat up the fluid, but in TN it never really gets super cold. So should I be too worried about bypassing the radiator section of the cooler and just keep the lines routed as the shop had done? Any info is appreciated.

[Robert J. Yates]

I think you'll be fine running what you have and not going back to plumbing it through the radiator. As you say, if it never gets super cold there you should be ok but remember too cold a fluid can be as bad as too hot a fluid where trannys are concerned. If cold weather is a concern, you could go with the B&M fan cooler and wire in a manual switch to actuate the fan for the hot days.

Frankly, I am almost wishing I went your way - I added a stacked plate cooler for my PS in front of my radiator recently and it has apparently affected the airflow through the grill. My rig has always run warm on the freeway (don't know why) so anything I do in the grill has a noticable impact on the temp guage. My tranny cooler is actually a large bore billett style cooler that is tucked underneath as I didn't want to cram to much stuff in teh grill. I'll probably go with a remote oil cooler next as I really do not want to get rid of the PS cooler. Now I just have to find a place to mount it.

[MJR]

The rad cooler help the trans to maintain a even operating temp better and warming the fluid when its cold.