d-18 leak without running

Hi. 70 cj5 with d-18, in process of body swap so has been sitting in my garage, not running, for several months. Transfer case was low, so before tub goes on I thought I'd top it off. I put in just shy of a quart, until it started coming out. Put the plug in, left town for 3 days, came back, and what looks like the whole quart is on the floor of my garage. Wasn't started or moved at all. Any thoughts on where a leak would be that would just leak, from that last quart of fluid? It was not actively leaking before; no puddle at least in the past couple months....appreciate any help in narrowing down what might be the problem. I have searched, bookmarked a ton of great info on d-18 leaks, and my FSM should be at my doorstep soon so I'm hoping I can learn more about this on my own as well. Thanks.

 

There are some transmissions that share fluid level with the d-18. Was the tranny topped up as well? The pan on the d-18 showing leaks? The output shafts are famous for leaking.

 

I'll double-check but I don't believe they share levels--I have the T-18, which I believe does not share fluid with the transfer; transmission was full when I checked both, so I only put fluid in the transfer case. Just haven't been able to crawl under it but will this weekend. Thanks.

 

The T14 3 speed (the most likely culprit) shares fluid and when sitting still will dump a bunch in my transfer case. I've worked hard to stop it and have attained a tentative standstill. If I can stop the leak at the oil pump I may have an answer (it blows on the back and I honestly can't tell right know). You got to look for the specific leak, front, back outputs, PTO opening, trans/case mating, even front trans seal (no gasket, leak drains right out). Just look, you'll find it.:v6:

 

Yeah, the Borg-Warner 3-speeds all share oil with the D18 or D20. But I don't see how that's relevant.

If the transfer case needed a quart, and then it drained out, you've got to think that the reason it was low was because the transfer case leaks down to that level. Just because it didn't move doesn't mean anything when the leak is below the level of the oil.

I'm not sure why the OP is so surprised that the oil came out. It wouldn't be low if it didn't leak.

 

Leakin' do be the problem.:v6:

 

Marking it's territory testosterone? Running through rough field will solve it's problem. Over used terminology I know but it's a Jeep.

 

i replaced all seals ,gaskets and used permatex THE RIGHT STUFF. on both sides of same and
straightened edges of bottom cover, torqued bolts to spec.
i dont have one drip.

 

Thanks, everyone. Good point...if it WAS leaking to that level, I guess no reason it wouldn't always leak to that level...I just thought it was surprising how quickly it leaked that much, without driving it. I'll just need to go through bit by bit and find it. I appreciate the direction.

 

I'd bet the output seals have dried up some from sitting so long. Check the pan bolts as well as they could be loose or leaking.

 

my d-18 did the same thing on my 68 cj5. It was hard to tell where it was leaking but after replacing the rear output shaft seal I haven't had a leak since.

 

I had the same problem on my late '60s D18. I just replaced the rear output seal last night and am waiting for all of the residual oil to drip off, but I think that this solved the majority of my problem. :v6: atriot:

 

I crawled under to wipe up the quart of oil on the floor, and started cleaning the leak from the bottom up. Pretty clear it's coming from the front output seal. I'm in process right now of trying to find the steps to just replace that...what tools do I need, can I do it without taking case apart, etc. Will check pan bolts as well. Thanks again for all the help.

 

The faster I go, the more mine leaks.....

 

One other place to check that usually leaks on all of them even when everything is replaced is the bottom pan cover. Mine is completely rebuilt and it still leaks there.

The problem is that several of the cover bolt holes are machined right into the resevoir of the case. Even with a new gasket installed, it leaked because it wasn't leaking around the gasket, it was leaking through the bolt holes. The oil was getting around the threads, and eventually dripping out around the lock washers.

I already tried to goop up those bolts once with gasket maker and it still leaks. Someone else told me to use plumber's puddy on the threads. I'll try that next

 

A friend of mine has a Dana 20 and it leaks the same as mine does. If I go over 55 for a while, it shows oil. Anything under that and no problems.