Pulled CV joint apart - Replacing ATF after removing axle?

[SuperGreg]

Hey everybody, just put new quick struts on the front of my Explorer to fix the clunk from the bad strut mounts, and put new brakes on because whoever did the brake job before I bought the car did a not so great job (rusty rotors, grinding noise, ripped slide pin boot & almost seized pin that wasn't fixed - new pads though!).

Anyway, even though I took care I pulled the inner CV joint apart on the driver's side. I had to take off the boot, clean & repack with grease, and reassemble. When I removed the axle from the diff about 3 1/2 quarts of ATF came out. It seems like a lot, at least more than other cars I've worked on. Normal? I bought some new Mercon LV and poured 3 quarts into the tranny to start with.

After warming up the car and running it through the gears, I was surprised to find the level was off the high side of the dipstick. I wasn't sure if I wasn't reading it correctly, so I spent some time trying to get a good reading but it sure seems way high. I drained about a quart from the pan and it still looks high (right at the top of the "high" section). I'd like to drain some more but just want to make sure I'm reading the dipstick correctly i.e. maybe pulling it out smears the fluid around a bit?

Anyway what gives? I assume I bought the car with the tranny overfilled, but I never checked it before so I'm just assuming. Unless I did something wrong (i.e. a normal day).

 

[Odrapnew]

Did you check the fluid level with engine running and transmission in park (or neutral) and on level ground?

 

[SuperGreg]

That's right, first I followed the service manual procedure after buttoning everything up (run engine for 3 minutes, engage all gears for 10+ seconds each, check level while running). Then I took the car for a drive and checked it again in the garage with the engine running. After draining some fluid I ran the engine and engaged the gears to be sure before checking it again with the engine running.

 

[Odrapnew]

Hmm...

Maybe it was overfilled previously.
Did you confirm you filled approximately the same amount that came out?

Not trying to sound like a jerk with "obvious" questions, but just need to confirm it wasn't something simple.

 

[SuperGreg]

No problem, sometimes it's the simplest answers

I have a graduated container that I transferred the ATF to after draining into the drain pan. There was about 3.25 quarts in there, plus I missed the drain pan and spilled some on the ground originally when I pulled the axle so I estimated about 3.5 quarts total came out. I only put 3 quarts back in, assuming I'd be on the low side and might have to add some more. Of course I was surprised when the level read high.

 

[KayGee]

Just some silly questions.

Is this a recently acquired vehicle?

Was it checked out before purchase?

Did you check/change fluids to establish a baseline (if recently purchased)?

Sounds like previous owner may not have known what they were doing if the brakes were all screwed up and it had excess amounts of trans fluid. How is the oil level?

 

[SuperGreg]

Yes, I purchased it a couple of months ago. I never did check the transmission fluid, as at first glance I didn't see where to check the fluid and I didn't look up the procedure until I had to pull the axle . It's possible it was overfilled before. My big worry, being unfamiliar with this vehicle, was that the fluid I drained was not ATF and I ended up with an empty diff and an overfilled tranny.

The oil level looks normal.

I did get a pre-purchase inspection at an auto shop, however they missed the strut tower problem and the brake grinding noise problem. In fairness to them though, I didn't notice them either until driving the car for a few days.

 

[KayGee]

Wow. In fairness to you, if you paid a 'professional' for the ppi with a cc, I'd dispute the charge. I wonder what else they missed if they didn't check basic stuff like fluid levels, or brake and suspension noises.

Best of luck.

 

[Odrapnew]

Yes, I purchased it a couple of months ago. I never did check the transmission fluid, as at first glance I didn't see where to check the fluid and I didn't look up the procedure until I had to pull the axle . It's possible it was overfilled before. My big worry, being unfamiliar with this vehicle, was that the fluid I drained was not ATF and I ended up with an empty diff and an overfilled tranny.

The oil level looks normal.

I did get a pre-purchase inspection at an auto shop, however they missed the strut tower problem and the brake grinding noise problem. In fairness to them though, I didn't notice them either until driving the car for a few days.

If you drained the diff(technically a PTU for AWD Explorer), you'd only get 1/2 quart or so. Not a typo. PTU fluid capacity is very low.

 

[KayGee]

If you drained the diff(technically a PTU for AWD Explorer), you'd only get 1/2 quart or so. Not a typo. PTU fluid capacity is very low.

Not sure what you are trying to convey, but your comment seems a bit clumsy and inaccurate. There is a diff in the trans. While the ptu is similar to a diff, it is not the same as a differential in a fwd trans. The ptu is a sealed unit separate from the trans.

 

[SuperGreg]

So if I did a drain & fill on the trans, how much should be refilled? I'm thinking of doing that and then just getting the level right.

Also I'd like to change the oil in the PTU but I didn't find a procedure in the shop manual. Maybe I just missed it.

 

[peterk9]

Your Owner's Manual has a section on Specifications and Capacities. When you drain it I would suspect that you should add the same amount of fluid if it was full to begin with. The Manual also says the PTU fluid is 'lifetime' (yea, right) so you may not find any procedure on it. There are however, several threads on changing the fluid. Here is just one of them I found using the 'Seach' feature. How to: - PTU Oil Change (Tons of Pics) 2016 Explorer Sport

Peter

 

[Odrapnew]

Not sure what you are trying to convey, but your comment seems a bit clumsy and inaccurate. There is a diff in the trans. While the ptu is similar to a diff, it is not the same as a differential in a fwd trans. The ptu is a sealed unit separate from the trans.

He was concerned that he drained the diff and not the transmission. I understand there is a diff internal to the trans and the PTU is external, he couldn't drain the diff separate from the trans. So, the only other thing he could have drained was the PTU. People mistake the PTU for a front diff.

Unfortunately on my phone, I didn't see which trim he has. I see 2013 Limited, but doesn't say if AWD or not. If he has AWD Limited, he wouldn't have a factory drain plug in the PTU, so he cannot mistakenly drain the PTU instead of the trans.

 

[Keith N]

Super Greg
I did a drain and refill of tranny. The dip stick is very hard to read. Try some light sandpaper to shine it up a bit. Take several readings per procedure and call it good. I sucked a little out with 1/4” tubing connected to vacuum or large syringe. Search for ptu on this forum for lots of good tutorials on changing the ptu fluid. Some have a drain plug but most older explorers don’t.

 

[SuperGreg]

Thanks everybody. I only worried because I saw on another forum someone who did the same thing as me and had to pull the axle, and someone else commented that "At least he'd get some fresh gear oil in the diff" and my stomach came out my butthole and I frantically looked through the service manual trying to see if I'd been driving around with an empty diff, but all signs pointed to "no".

I'll check out the PTU oil change links, thanks!

 

[KayGee]

He was concerned that he drained the diff and not the transmission. I understand there is a diff internal to the trans and the PTU is external, he couldn't drain the diff separate from the trans. So, the only other thing he could have drained was the PTU. People mistake the PTU for a front diff.

Unfortunately on my phone, I didn't see which trim he has. I see 2013 Limited, but doesn't say if AWD or not. If he has AWD Limited, he wouldn't have a factory drain plug in the PTU, so he cannot mistakenly drain the PTU instead of the trans.

I didn't see anywhere that the op actually drained anything. The op said he pulled the axle out and 3.5 quarts of fluid came out. Ptu doesn't even hold a quart. The only fluid capacities >3.5 quarts are oil, trans and coolant. The only fluid that would typically leak out of a fwd trans when you pull an axle out is trans fluid. No sense in making things more confusing than they already are around here...

Also, trim details don't really make a difference here. As I said, ptu is sealed and shouldn't leak when an axle is removed, unless it is damaged.

 

[SuperGreg]

The op said he pulled the axle out and 3.5 quarts of fluid came out.

And just to circle back to the original question, if anybody knows how much fluid typically drains out when pulling an axle, that would be nice! If less than 3.5 quarts I can confirm the trans was overfilled to begin with. I was surprised so much came out, I can pull an axle on my Acura TL and nothing comes out.

 

[KayGee]

And just to circle back to the original question, if anybody knows how much fluid typically drains out when pulling an axle, that would be nice! If less than 3.5 quarts I can confirm the trans was overfilled to begin with. I was surprised so much came out, I can pull an axle on my Acura TL and nothing comes out.

The problem with your question is that there are different service procedures when replacing a halfshaft and for the Ford 6Fxx trans, it typically starts with draining the trans first, so the only people that will likely know exactly how much fluid will come out when a halfshaft is yanked from a full 6Fxx trans are those that ended up in the same boat as you, having yanked out an axle from a full trans. I'm still not sure how you pulled a halfshaft apart when replacing a strut, but stuff happens.

Vehicles are different. I believe Honda is one of the few that have some FWD trans where fluid level is checked non running and they may not leak much or any fluid when an axle is removed (anyway, however they are is irrelevant if proper service procedures are followed). Ford 6Fxx trans do not work that way. Fluid levels are checked at temp and engine running using the dipstick or oil leveling hole.

Your only real option now is to either use the appropriate method to refill and check trans fluid level, or drain and refill again (add 4 qts and start checking levels - I believe you will be between 4.5-5.5 qts on a drain and refill depending on which 6Fxx trans and oil cooler you have).

 

[SuperGreg]

Oh I see. I wish the service manual said that. The only thing I see is in the axle removal/installation instructions is a line at the very end that says "Check the transmission fluid level and add clean transmission fluid as necessary". So I had assumed only a small amount would leak out if any.

Thanks again for the info.