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I had some work done on the rear end of my vehicle (so that drive shaft was off recently) and today I got under to check for leaking around the pinion and noticed a sizable leak on my transfer case. I have attached plenty of photos.
Transmission fluid appears normal. Edit: Read follow up post.
I was going to go out soon and purchase 3 quarts Ford XL-12 (I know it takes two, but one just in case) and change out the fluid. I was also going to clean it off with brake cleaner and see where the leak was once the fluid is replaced.
Can anyone tell by looking at it where it's leaking from? or if it's an old leak? Any general input is appreciated. I am fixing this truck up one thing at a time.
Leaks on the transfer case usually happen at the drain plug, because people overtighten them. That doesn't seem to be your issue.
I'd clean it all up, change the fluid and check it a few times and see if anything is leaking at that point.
Are you up to date on the correct fluid? I've seen to avoid Mercon V and use transfer case XL-12, but it was discontinued, so is Mercon LV the correct stuff?
I wasn’t aware to check transmission fluid that the truck had to be running.
I just drove it for 3 miles or so and this is my reading. The manual says to drive it for 20 but i would imagine this is close. It could very well be that it’s leaking into my transfer case. Arghh.
Transmission fluid needs to be checked on a hot, up to temperature engine with the engine running in idle on a flat surface, to give you a correct reading. I'd checkout several times at that point.
(To much variances when not up to temperature. Just look at the transmission dip stick)
Are you having any issues with it slipping or is the engine revving high when it's not supposed to?
What I did - I found XL-12 at a ford dealer this summer, that's what I used. The dealers that didnt have it, tried to tell me to use the LV, but I refused to be safe and found the XL-12 instead.
Last edited by mapleleaf1773; Dec 4, 2019 at 01:31 PM.
Transmission fluid needs to be checked on a hot, up to temperature engine with the engine running in idle on a flat surface, to give you a correct reading. I'd checkout several times at that point.
(To much variances when not up to temperature. Just look at the transmission dip stick)
Are you having any issues with it slipping or is the engine revving high when it's not supposed to?
What I did - I found XL-12 at a ford dealer this summer, that's what I used. The dealers that didnt have it, tried to tell me to use the LV, but I refused to be safe and found the XL-12 instead.
I haven’t had any issues with it slipping at all. In fact, it was just at ford two weeks ago and my buddy who’s a tech said how does your transmission shift so well with 223k
EDIT: The reason your trans still works and shifts so well is that it has been maintained well, I'm sure. Mine was religiously changed by the previous owner, and I've continued to do so. It has almost 250K on it now, and shifts great. I've even found chunks of sprag in the pan, and it still is going, LOL. I do put Mercon V in the trans, but I would not use ANYTHING but the original spec ATF, or XL-12 (The Valvoline in the link above is the exact XL-12 they made for Ford).
Last edited by white89gt; Dec 4, 2019 at 04:09 PM.
EDIT: The reason your trans still works and shifts so well is that it has been maintained well, I'm sure. Mine was religiously changed by the previous owner, and I've continued to do so. It has almost 250K on it now, and shifts great. I've even found chunks of sprag in the pan, and it still is going, LOL. I do put Mercon V in the trans, but I would not use ANYTHING but the original spec ATF, or XL-12 (The Valvoline in the link above is the exact XL-12 they made for Ford).
So no one the Mercon LV? I was confused because on Youtube Ford Tech Makuluko said Ford switched over to Mercon LV. Either way, it would be great if I can buy fluid at O'reily's or Advanced Auto because I was hoping change the transfer case fluid tomorrow to see what is going on.
Yeah, I think you're right because the guy I had bought the truck from at 140k kept service records and every time he went to Ford, he had the trans serviced. I wish I kept better track of the level because I'm not sure if it's dropped or not and that would tell me if fluid is leaking into the transfer case. When I checked the trans fluid earlier after driving 2-3 miles, it was passed the add, passed the cold, and about two notches into the hot but less than halfway full overall and shows no signs of shifting hard or slipping.
Joe8512,
DO NOT use Mercon LV in anything on your truck.
Not in the transmission, not in the transfer case.
Not in the power steering.
It will break things.
There was even a TSB out years ago about this.
Use the Valvoline referenced above only in the transfer case.
Also, if you only drove a few miles then the dipstick may not show low, it will be higher once the trans is up to full operating temp.
Add trans fluid only a little at a time.
Transfer case leak
