Question: Allison coolant lines through the radiator or not

[2004LB7]

i have a large transmission cooler that i used to have in my LB7 that i removed and plan on putting in my LMM.

it measures 27" wide by 18" high and about 1.5" thick.

here are some photos of when it was in my LB7.







I really liked the way it ran, the transmission temp gauge hardly ever came off of the bottom of the gauge. even when towing. only time if i would see it move (160ish*) is if i was in some long stop and go traffic in 100* weather. all other times it stayed at the 150* mark.

the engine temps also seemed to stay a little lower too. probably because the radiator is not having to deal with the transmission temps as much.

now, my question is, i am wondering if it is worth it to bypass the engine radiator all together on this installation. or should i route it through like stock routing?

if i bypass it, do you think this cooler will handle all of the heat of the transmission? will it have a hard time warming up in the winter? i live in the sacramento, CA area so my winters are not all that cold.

I was also thinking if i freed up the transmission cooler on the engine radiator, would it make a good remote oil cooler? i am guessing that the connectors may be too small for an oil cooler even if i changed out the threaded connectors on it

so what do you think? route it the same? bypass the water to transmission cooler? will the water to transmission cooler work well as an engine oil cooler?

thanks Jason

[OregonDMAX]

Don't bypass the radiator cooler you won't get temps cool enough.

[Mike L.]

No air coming through the front below 35 MPH so you will over heat it. Leave it in the radiator.

[2004LB7]

Ok, thank you. Ill set it up the same as my LB7. It worked well that way anyways

I take it from some other threads that the stock transmission cooler is a no go for an oil cooler, correct?

[OregonDMAX]

Originally Posted by 2004LB7

Ok, thank you. Ill set it up the same as my LB7. It worked well that way anyways

I take it from some other threads that the stock transmission cooler is a no go for an oil cooler, correct?

The lb7 trans cooler is really a joke, I wouldn't even use an lbz cooler let alone an lb7-lly cooler. If you are going to make an oil cooler buy a good one or you will effectively just be raising your oil capacity with no real additional cooling

[2004LB7]

I was hopping my stock LMM cooler would be good enough

[OregonDMAX]

It's too small imo and the inlet ports are too small, I wouldn't go anything smaller than -12 which is 3/4" on the whole system. The factory cooler isn't even 5/8 iirc I think it's 1/2" but don't quote me on that.

[2004LB7]

No, you are correct. It is 1/2 inch. That is why i was thinking it was not going to work

Thanks everyone. I will try and get some photos of the install and see how the temperatures fair. Ill update when done

[Awenta]

What cooler is that


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[2004LB7]

"Nascar" oil cooler, found on ebay ~$50 several years back

[Chevy1925]

Unless you put the engine oil cooler in front of the cooling stack, make sure it's big enough to put good sized fans on it.

[2004LB7]

Thanks, will do.

I wont be doing tje oil cooler right now as i do t have all of the needed parts. But when i do i will keep that in mind

[malibu795]

I'm running aftermarket -10 tranny lines with OEM stock LMM cooler, I did put heat reflective sheathing on the cooler lines near the exhaust..
I avg 80-90° above ambient temp... Most I've seen is 130° over ambient(, 210-220 total temp mid- upper 80°s that day...)stop n go dragging 28,000lb Trailer

I Have a trans go jr and 280psi main line spring installed as well.. no noticable temp increase after JR kit and main line spring.. over last ~100,000miles

IDK if I'm norm or exception...

[2004LB7]

Got the mock up done. Partially bolted in. Need to measure for coolant lines

[2004LB7]

Got it installed today. Went down to the local hydraulic shop and had them make me up some lines and purchased some fittings. All in for $162 not including the cooler i purchased a few years back for about $50 on ebay

Took it out for a test drive to make sure everything was good, no leaks, etc. It seemed to shift a little better but that could be the placebo effect

Was about 98~100° out during the drive. Mostly all stop and go in town which is where i have seen the highest transmission temps due to the converter not be locked much. Also had the AC running

The highest temp the transmission got was 163 briefly while sitting at a light. Most of the time it stayed at 160° and a few times it went down a few degrees. The engine temp gauge stayed at the 210° mark and the fan/clutch kicked in a few times too.

Here are some photos