Crossover cooling Layout for Oil and Trans. - Why?

[viking76]

Greetings and Salutations.

My apologies if this has been answered elsewhere but I could not find it.

TLDR: I really don't want to have those Trans. Cooler hard lines going underneath the truck if I can avoid it. So I ordered some hard lines that go to the radiator only to find I had Oil lines plugged into those ports already on that side. Doh! Guess I should have checked first. Is there a reason for the crossover?


So I noticed that the cooling line layout for the M1008 (1984 in my case) is different from the civi models. Insofar as oil and trans cooling lines both cross over from one side of the vehicle to the other.

What I have found is that the Oil Cooler lines start on the Driver Side, proceed forward, then make a 90 right to the radiator on the Passenger Side.
Meanwhile, my transmission cooler lines start on the Passenger Side, go across and underneath the transmission/engine, and end up in an aux cooler on the Driver Side of the truck.

From what I have seen on the Civilian models, these lines stay on their own side of the truck and go straight to the radiator on their own side.

So auxiliary cooler aside, what was the reason to cross over from one side to the other?

Thanks All!

 

[cucvrus]

All the 6.2 diesels civilian and military did the same thing. If you want to have the lines for the transmission cooler go over the transmission you have 2 options.
1.) bend steel lines that fit where you want them.
2.) Use hydraulic lines and run them over the transmission.
Keep in mind the engine oil cooler lines run across from left to right and are run thru aluminum tubes. the cross over between the fan and the radiator act as a cooling cycle also. Same as running the transmission fluid thru the steel lines. They act as a cooler to some degree. Good Luck with your truck. I found most CUCV's are missing the P clamps from the bottom of the transmission cover to retain the steel cooler lines secure and in place. I also found that they P clips retain mud and road salt and make a point for corrosion and oil leaks if the rub thru. If you don't have them in place put something in place. Use some grease and clean the lines that are going into the P clamp. Have a Great Day.

 

[viking76]

@cucvrus Thank you for the clarification.

Based on that, I am definitely going to keep to the factory Oil Cooling layout but will reroute the Trans Cooling lines.

Thanks again and have a good one!

 

[Rutjes]

On my friends truck we just made hydraulic hoses to replace the transmission lines. They now go up from the transmission and over the passenger side inner fender. I guess you can cut the hard lines and put rubber hose with a hose clamp on, I've seen this done, but don't like it. Flare the hardlines if possible? I suggest these fittings transmission side. Radiator side I wouldn't know as we skipped the radiator and put a oil cooler in front the radiator.

 

[viking76]

@Rutjes Thanks for the info and link!

 

[viking76]

@Rutjes - I ended up replacing the Trans hard lines with PTFE and AN6 Fittings. I routed over the trans and the driver side wheel well. 2nd Video in another thread. -> https://www.steelsoldiers.com/threads/m1008-upper-oil-line-replacement-video-link.203838/