Ilovemountains

My transfer case cooler is leaking after installing my headers, I think I cracked it. Does the automatic transmission transfer case only build pressure when its in 4WD? Basically is it safe for me to drive it with the leak if I keep it in 2H. I think I'm safe but have no clue how the AT transfer case works. I don't think its pumping and circulating fluid in 2H but like I said, not sure!

91 4Runner

I'm gonna say no... The transfer case uses the same fluid as the Tranny, this would lead me to believe that it builds pressure as long as the torque converter is moving.

Ilovemountains

Its a separate reservoir I believe, it has its own drain and only holds about 1.25 quarts of fluid. I know when I drained it all to relocate the cooler after I put it 4H for the first time it took a few seconds to engage while it was pumping the system full, after that I noticed the fluid leak.. Ill try to tighten the lines on the cooler more this evening but I think it does have a crack in it, it was a PITA to get the lines off of it and I actually bent the cooler itself a little! Im thinking that when you pull it into 4H or 4L it engages the pump for the transfer case but I really dont know, at the bare minimum Ill top it with fluid, I need to haul a load of wood from Home Depot tonight with my trailer, Im finally building an 8x8 deck and stairs off the back of my garage this weekend so I can access the upstairs room without a ladder!

Ilovemountains

Bump for an answer...I tightend the hose that appears to be leaking onto the cooler but the cooler itself looks a litte tweaked, Ive not driven it since nor have I locked the hubs and put it into 4WD but Id like to know if Im steadily leaking AT fluid from my transfer case as Im driving! I got out of work late and did not have a chance to hook up the trailer and run to Home Depot to pick up at least 1000lbs of lumber this evening but will be tomorrow!! Anyone know how our AT Transfer cases work?

Marc

I as well as others were also under the impression that the transfer case was separate from the transmission on the A340H.

Someone, and I can't remember who, proved to us disbelievers that this was not the case.

They share the same fluid even though there are separate fill and drain plugs.

jammer1313

The fluid for the tranny is also for the transfer case, any leak in you tranny cooling system is bad, fix it, or keep an eye on your fluid level until you fix it, it won't hurt to drive it, juat keep the level up.

The A340H is a complete unit, "google" the A340H and it will tell just how your tranny works.