Can’t find transmission fluid leak, output shaft?

[JExpedition07]

I keep finding transmission fluid on the driveway and the Y-pipe always has a drip on it.....pan is tight but it just keeps leaking. Happens when parked for an hour plus. It’ll be dry and about 2 hours later if parked and not started there will be a few drops on the ground. You’d think output shaft would only leak when spinning so not sure where to go here. Right now the leak isn’t worth going after and I’ll add fluid, but I can’t for the life of me source where it’s coming from.

 

[07navi]

Those pans have to have a good seal or they will leak. Didn't you remove it a while back? The fluid level is always above the gasket level and the oil is thin so if it finds a way out it will leak. I left one bolt out that I lost and it leaked but on the second round of fluid replacement I sealed it good and no drips showing so far.

 

[JExpedition07]

Yes indeed I had it off in January, it didn’t start leaking until recently however. When I did the Torque Converter I left the pan installed since it had just had a fluid and filter change before that job (I tried solenoids and pump bridge seal first). All bolts are installed and torqued. Perhaps there is a piece of dirt or something in the gasket surface allowing it to weep. Unfortunately I’ll have to dump a lot of good Mercon SP to find out....at $11/ quart.

 

[07navi]

Yes indeed I had it off in January, it didn’t start leaking until recently however. When I did the Torque Converter I left the pan installed since it had just had a fluid and filter change before that job (I tried solenoids first). All bolts are installed and torqued. Perhaps there is a piece of dirt or something in the gasket surface allowing it to weep. Unfortunately I’ll have to dump a lot of Merlin SP to find out....at $11/ quart.

Save that Mercon SP ($8 a quart at O'reillys but they never have any) and put it back in. I used 4 ramps (shown in the lifted Expy thread) to get it level for pan removal and checking the level. I cut an inch off a large plastic storage container with a jig saw to get it under (stock tire size) and catch all the fluid since I don't have a plug. Mine is a ZF6HP26 Torqueshift trans. Put it in 4WD (if you have that) and first gear if you go the ramp route. I used one of those red tubed fluid transfer pumps with the push pump from Amazon that is pretty fast and works well. I put a couple air compressor fittings in the ends for some weight.
Yours is dripping from the same place mine was. Since the bolts were hard to get to in the front and it was the second oil dilution change, I wiped off all the surfaces, got a new bolt that I lost, and coated both sides of the gasket with non hardening RTV gasket maker. It's not leaking so far that I can see.

 

[WEDGE]

Have a real good look at the bulkhead connector at the back of the trans. That's where the bundle of wires goes into a plastic sleeve. They're notorious for leaking on the 6R75/6R80's. I've had mine changed on my 2010, and seen dozens of others getting repaired as well (I work for Ford)

 

[07navi]

It's probably the pan if you removed it but if it's the mechatronic case connector; Drop the pan, pull the white tab in the front corner down, and pry the wire connector out of the case. The O rings can dry up and leak.

 

[JollyRoger]

X2 on the bulkhead connector. My 2010 has dripped in that same spot through 3 or 4 transmission flushes, new gaskets, etc, until I discovered the problem with the bulkhead connector. 2 new O-rings from Ford dealer ($11) and another flush, and it's been dry as a bone for months now. There are YouTube videos on how to do this...super simple.

 

[JExpedition07]

Thanks guys, well I checked and around the bulkhead connector looks dry and no sign of a leak.

 

[07navi]

Mine is dry too but I just looked at the pan funny and it started leaking. Tail housing bushings rarely leak and never when just sitting.

 

[Boostedbus]

If you drop the pan to change it again, make sure it drips dry and you wipe both the pan and the case surfaces with brake clean. One little track of oil that runs across the gasket surfaces before you get the pan back up will always weep across that track. Get it buttoned back up dry and problem should be solved unless the pan has been distorted by over tightening in the past.

 

[JExpedition07]

I finally got a reading and topped off the fluid with some fresh Mercon SP today, added 1/3 quart and it is full. Very slow leak that’s for sure. That’s 1/3 quart over about 3 months since I last added. I took my little 8 mm offset box wrench to check torque and got a wee bit on 3 of the bolts yesterday. No drip on the pipe this morning but pan still looks wet.

 

[Sunflowergirl]

I finally got a reading and topped off the fluid with some fresh Mercon SP today, added 1/3 quart and it is full. Very slow leak that’s for sure. That’s 1/3 quart over about 3 months since I last added. I took my little 8 mm offset box wrench to check torque and got a wee bit on 3 of the bolts yesterday. No drip on the pipe this morning but pan still looks wet.

So on my 2016 I had a leak at the rubber output drive shaft seal that was caused by the driveshaft just over time wearing down the rubber and causing it To stretch a bit. Had a new one installed which was definitely much tighter and they cleaned off the driveshaft pretty well but two years later it’s right back to being stretched again. Normal wear and tear. I however never had a leak like you’ve got. Basically noticed it was loose feeing one day under there and if you pressed on it hard enough a drop would come out.

 

[Tocapet]

Have a real good look at the bulkhead connector at the back of the trans. That's where the bundle of wires goes into a plastic sleeve. They're notorious for leaking on the 6R75/6R80's. I've had mine changed on my 2010, and seen dozens of others getting repaired as well (I work for Ford)

Mine was leaking there. (09 with 6R80). It's easy to replace, but you have to drop the pan in order to release the sleeve from the inside. I did the sleeve replacement about 5 years ago and it has not leaked since. It's kind of a pain to check the fluid level and add fluid. You're working a couple of inches from the hot catalytic converter and it has to be warmed up to check.

 

[07navi]

No need to have special instruments to check the fluid temp, it only has to be about 100+- degrees and warm to the touch (even says on my pan). Maculoco on You tube checks them cold to avoid the heat and adjusts for a rise on the little stick. Mine has a hole on the side (ZF6 trans) and it must be level. Cat tip;.......don't touch it.

 

[Tocapet]

Yes, that's newer information. Back when I did it, everyone was saying "normal operating temperature". Later, someone had figured out that you could measure it cold if you used the bottom edge of the crosshatch pattern on the little dipstick for your measurement.

 

[07navi]

Yes, that's newer information. Back when I did it, everyone was saying "normal operating temperature". Later, someone had figured out that you could measure it cold if you used the bottom edge of the crosshatch pattern on the little dipstick for your measurement.

It's not rocket science, just get it warm to the touch or do it the cold way. Amazon sells one special anti heat glove just for that but that sounds wimpy to me.