Discussion in 'Generation 4 - Maintenance & Troubleshooting' started by Shokev, Jul 9, 2019.
I ran into this exact same issue. 2015 SHO PP just hit 30k miles. I was going to start with PTU and move on the to diff, as well as spark plugs and full synthetic, ford guy argued for 10 mins, that all it needed was a synthetic blend oil change. I will be trying a new shop soon, unless someone in the KC area has a spot that does good work on these.
They lied too y'all. An they are scum bags. They know about all the issues with the ptu yet they give you that explanation. I have alrdy had one ptu replaced on my car because of the ptu fluid gummed up from over heat.
This sort of thing, like others said, is a clue to cluelessness. It may be that someone else there is willing to be educated. Maybe he didn't have a line in his estimator for "take off cap, pump out old, pump in new".
But not as bad as when I wanted to get a major service on my Gen II (still under warranty) and the first guy I talked to at a dealership said, "Nah, those are hydraulic lifters, they don't need adjusting." I said thanks, hung up, and called other places looking for actual knowledge.
My local Ford dealer says the 2010 ptu does not have a drain plug so they recommend only doing it if it starts making noise. Otherwise, it's 5.5 hrs labor.
Yea once or starts making noise it's too late.
They're not wrong, but at the same time not 100 corect either. This is from the 2010 W.S.M. and the shedualed maint guide.
What state is Chilliwack?
Well, I can't imagine why Ford engineers would design a critical drivetrain component with no means to perform maintenance on it. There's nothing magical about a PTU, it's just a 4x4 differential with a torque-sensitive clutch (or that might be controlled by the computer).
I've never liked the AWD system in my 2010. It's clunky and you have to be gentle with it. Downshifts followed by acceleration confuses the system, causing inconsistent clunking if you accelerate when it's trying to disengage AWD during slowdown. That's unacceptable and it's a software problem, not a hardware failure.
It seems Ford's engineers weren't talking to each other. On the one hand, they did not intend the SHO's engine to last long enough to need maintenance on the PTU. On the other, someone suggested changing the fluid every 60,000 miles. So, not even a pump port, let alone drain plug? Stupid jackasses.
It just gears that are ALWAYS spinning. There is NO electronics or clutches in it. In theory, fresh lube changes should make it last forever unless it was built wrong.
Very unusual given that dealerships should always be looking for things that they can charge for. My dealer charges $300 for a PTU service. That is good money for them if you do it every 30k miles.
I think you're getting the P.T.U. and the RDU confused. Both units are serviceable. My reply to your comment above with the w.s.m. for your car shows the oil can indeed be serviced. You dont have to remove it, you can pump it out like you describe. Much easier than removing it.
The rear diff oil is the same, pump it out.
The Active Torque Coupeling Clutch is not a serviceable unit in that it has a fluid to change, however in some cars it can be service speratly from the RDU.
Now, if you can feel he 4x4 activating and deactivating, there is something wrong with your car. Since there is no rear axle disconect the system is always ready to go persay. So like a 4x4 truck where a 2 speed transference where 2wd is posible, there is a clutch that is used to spin up the driveshaft, then a locking device (IWE or a hub) locks the front axles to the wheels.
Since our cars essentially have a single speed transfer case with no way to become true 2wd, its seamless in operation. Even with a good system if you jack up this awd platform with the car in neutral and spin both rear wheels, it will rotate the front because there is some drag in that ATC clutch.
Your shifting concerns may just be limitations of the powertrain (engine trans) or the powertrain software.
No, only occasionally, but I can reproduce it. Accelerate hard to activate AWD up to fwy speed, then slow to under 20 mph (as in, coming to a stop light), and before coming to a stop, accelerate again. That transition feels like dumping the clutch with a manual transmission. I assume the AWD is returning to FWD as I slow to the stop light, and it can't transition back to AWD again smoothly. This seems to me to be an AWD tuning problem (my car is stock btw). I don't believe it's hardware after owning this car for 5 years. Maybe this would be corrected with a custom tune.
I thought these cars were FWD + AWD on call when torque is needed? It sounds like you're saying it's RWD with FWD engaged on call?
You are 100% corect that this platform is FWD based. The Active Torque Coupleing (ATC) clutch never truly disconnects the front and rear axles even key off. The clutch has a slight drag to it. Enought to rotate the front drivetrain if spinning the rear wheels or to spin the rear with the front.
This is why in some instances, people experience bucking on full lock turns. The clutch is dragging more than it should be so when the P.C.M. compands say 20% lock up, it's getting 30-40%, because the excessive drag, and causes the buck due to the wind up in the 4x4 system like a truck in 4x4 high.
Disconnecting the clutch conector prevents the clutch from locking resolving the windup which usually points to a faulted clutch. It's easier to disconect the conector that use pid data to deactivate the clutch normally.
My 16 does the same as yours, if I'm braking hot and at 30 MPH, even in sport, and I smash that go pedal, there is a (sometimes scary) delay.
I've contributed this to a few things, but never watched PID data to confirm. There is a very aggressive fuel cutoff deceleration. So if you are braking and the engine is engine braking, there is no exhaust gas to spin the turbos to make boost. It's the expanding exhaust gasses that drive the turbo. Therefore this coudle be turbo lag.
Some of it could also be the transmission shifting from 6th(or what ever gear its in) to 1st (or what ever gear it thinks it needs to be in) and the harshness could be the associated need line pressure to make shure the transmission does not slip when shifting.
I will bet you my car, that your delay is not the time needed for the AWD system to kick in.
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