Transmission leak?
- Thread starter RArrigo
- Start date
There are 50 ways for gear oil to leave your transmission and transfer case, so it’s rare to have one that doesn’t leak at least a little.
Many of the bolts go into wet holes, so it’s important to seal the threads when rebuilding. Gaskets can leak. The shims at the rear bearing cap can leak, the yoke splines and seals can leak. Many of these even leak out of unsealed shift rails at the top of the transmission, and/or where shafts penetrate the cases.
One thing you can do to identify a source is wipe it down and then dust it with flour or baby powder. Then watch for the new tracks to form, which can be followed to their source.
If you really want a leak-free transmission and transfer case, they probably need to be removed and rebuilt, but even that is not a guarantee.
Many folks just accept the fact that old Willys mark their territory.
Many of the bolts go into wet holes, so it’s important to seal the threads when rebuilding. Gaskets can leak. The shims at the rear bearing cap can leak, the yoke splines and seals can leak. Many of these even leak out of unsealed shift rails at the top of the transmission, and/or where shafts penetrate the cases.
One thing you can do to identify a source is wipe it down and then dust it with flour or baby powder. Then watch for the new tracks to form, which can be followed to their source.
If you really want a leak-free transmission and transfer case, they probably need to be removed and rebuilt, but even that is not a guarantee.
Many folks just accept the fact that old Willys mark their territory.
- Oct 5, 2020
- 1,337
- First Name
- Fred
- Willys Model
- Wagon
- Pickup
- Jeepster
- CJ
- Willys Year:
- 1946
- 1948
- 1950
- 1955
- 1961
I’m concerned with the pink fluid.
Transmission gear lube I’m familiar with is #90 yellowish/brownish.
If your truck is a new acquisition I suggest you check the contents. The PO may have filled with standard transmission fluid (ATF), very bad!
Step 1 with new acquisition is obtain the service manual.
Step 2 a complete PM overview and a full lube job. Drain and fill all 4 gearboxes with the right stuff.
Transmission gear lube I’m familiar with is #90 yellowish/brownish.
If your truck is a new acquisition I suggest you check the contents. The PO may have filled with standard transmission fluid (ATF), very bad!
Step 1 with new acquisition is obtain the service manual.
Step 2 a complete PM overview and a full lube job. Drain and fill all 4 gearboxes with the right stuff.
Our old ‘48 came with gear oil that was reddish, so it’s not unheard of.
As for ATF, I’m not convinced it would be all that bad. We had an F-150 with a 5-speed manual trans that specified ATF. It’s also specified in the transfer case of our Nissan Frontier (which has a manual transmission).
As for ATF, I’m not convinced it would be all that bad. We had an F-150 with a 5-speed manual trans that specified ATF. It’s also specified in the transfer case of our Nissan Frontier (which has a manual transmission).
Tralehead
Well Oiled
The P.O. of my Wagon used an royal purple gear oil. He got the system well sealed (yep, I have a non leaking Wagon) but there is a slight film. When I went to check and wiped off the film, it looked pink to me.
And don't be tempted to tighten up those transfer case pan bolts, that's made of stamped steel so over torquing can lead to deforming and then it'll REALLY leak!
It IS possible to get a leak free T-90/D-18 set up, but as @Lookout Ranch says above, it requires removing the entire unit. And just because someone has a mechanic shop, don't assume they know how to do it. It requires knowledge and experience with old vehicles, that's why OWF exists! And if you really want to educate yourself, get your hands on the last issue of Dispatcher magazine, it's got an extensive article on how to help seal a Dana 18 T-case.
That fluid does look red to me, so someone might have used ATF. Not the right choice but I would replace it with with a quality 90wt.
And don't be tempted to tighten up those transfer case pan bolts, that's made of stamped steel so over torquing can lead to deforming and then it'll REALLY leak!
It IS possible to get a leak free T-90/D-18 set up, but as @Lookout Ranch says above, it requires removing the entire unit. And just because someone has a mechanic shop, don't assume they know how to do it. It requires knowledge and experience with old vehicles, that's why OWF exists! And if you really want to educate yourself, get your hands on the last issue of Dispatcher magazine, it's got an extensive article on how to help seal a Dana 18 T-case.
cwdtmmrs
Well Oiled
- Jul 19, 2012
- 7,524
- First Name
- Tim
- Willys Model
- Wagon
- Willys Year:
- 1952
My 1982 MBZ 300D with a manual 5 speed used ATF as well.
First, I would look at the speedometer connection
I don't see any fluid above that point
I don't see any fluid above that point
tnestell
Precision Fit
My speedometer cable leaks fluid. I have tried lots of things and it is still leaking there. Four ounces or so a year with aproximently 1500 miles driven. Most is when i drive it a long distance and the fluid expands more than just riding around town.
- Sep 20, 2017
- 9,538
- First Name
- Jeff
- Willys Model
- Wagon
- Pickup
- CJ
- Willys Year:
- 1955
- 1958
- 1962
I have some red 90wt here, so hopefully that's actually gear oil. These are not modern and I doubt that ATF would be good for them, but it sure would clean up any sludge!
That's not the original transfer case, it's a later model 20.
That's not the original transfer case, it's a later model 20.
19Wagon54
Bigger Hammer
Everyone laughed at me when I said I'm building a leak free transfer case. They were right, I still get about a dime size worth a month.
cwdtmmrs
Well Oiled
- Jul 19, 2012
- 7,524
- First Name
- Tim
- Willys Model
- Wagon
- Willys Year:
- 1952
It can be done, but not easy and takes some effort and cash.
It has been my experience the most common leaks are the pan and speedo cable. You can get yolk leaks if they are worn out or the seals are not carefully installed Speed sleeves are a temporary fix IMO. Not putting sealant on the splines can also cause leaks. I also had to extend my breather up into the engine compartment capped with a mini filter because I run may cases pretty full since I have the D18, Warn OD, BWOD, and Ramsey PTO. IIRC there are only 4 oil seals and 5 gaskets counting the Texas gaskets, the the speedo.
The new speedometer cables (from Walck’s) were impossible to keep leak-free, in my experience. After trying several, and having them develop leaks after a few months of heat cycles, I finally went on eBay and found an old US-made NOS one, and when it worked well, I bought a couple more to have on hand.
These weren’t listed as being for Willys, they might have been for a Packard, but most old cars from that era used compatible cables with the same threads at the ends — they just varied the lengths a bit. A lot of the eBay ads listed cable lengths, so it was just a matter of finding ones long enough.
These weren’t listed as being for Willys, they might have been for a Packard, but most old cars from that era used compatible cables with the same threads at the ends — they just varied the lengths a bit. A lot of the eBay ads listed cable lengths, so it was just a matter of finding ones long enough.
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So today the gasket for the transfer case pan showed up. Had to order one as nobody in this town had one. Lately my town has really sucked for parts for anything older than about 1990. Couldn't even find Valvoline 10-40w dino oil today. It's what I've been using in the Willys with zinc additive. Couldn't find any of that either. Anyway the gasket was twice as thick as the one I took off. I used Prematex "The Right Stuff" this time so hopefully it works better than what I used before. I'll keep an eye on it and let you all know if it's any better. Everything looked good in the transfer case and there was no metal or glitter in the oil of it and trans oil. Hopefully this at least slows down the leaky D-18.
