Have you checked your PTU fluid level/replaced your fluid?

[RhinoQuartz]

I stand corrected, thank you, was not sure all years held same amount. Given that unit has a "vent tube" is it really possible to overfill? I mean all it might do is burp out a little and be a bit of a mess. Thoughts??

Hmm, not sure if vent holes are standard, one would assume so, but that's a dangerous game to play here lol.
From what I've seen on this forum and others, there's only about 8oz from factory and that seems to be standard, which seems like quite the oversight for it to have gone on for close to a decade of production, on top of the fact that they continuously redesigned the PTU throughout the generation. Makes me think they had a good reason to underfill

In any case, filling it up full might be fine, or it might put pressure on the seal to weaken, can't say for certain.

Personally I think a drain and refill every 30k miles with at least 12oz of fluid would easily increase its longevity.

 

[KayGee]

Hmm, not sure if vent holes are standard, one would assume so, but that's a dangerous game to play here lol.
From what I've seen on this forum and others, there's only about 8oz from factory and that seems to be standard, which seems like quite the oversight for it to have gone on for close to a decade of production, on top of the fact that they continuously redesigned the PTU throughout the generation. Makes me think they had a good reason to underfill

In any case, filling it up full might be fine, or it might put pressure on the seal to weaken, can't say for certain.

Personally I think a drain and refill every 30k miles with at least 12oz of fluid would easily increase its longevity.

Not sure what the point of your post is, but there is a clearly defined ptu capacity and there is no reason to stray from that. Underfilling is just as stupid as overfilling... People should just use the proper amount of fluid.

 

[RhinoQuartz]

Not sure what the point of your post is, but there is a clearly defined ptu capacity and there is no reason to stray from that. Underfilling is just as stupid as overfilling... People should just use the proper amount of fluid.

There is a clearly defined capacity, and yet the amount actually in them from factory is significantly lower than that.

What is the proper amount of fluid then?

 

[Eric Z]

Not sure what the point of your post is, but there is a clearly defined ptu capacity and there is no reason to stray from that. Underfilling is just as stupid as overfilling... People should just use the proper amount of fluid.

I think the question was sort of how much to put in AFTER a drain? Do you just put back the amount that came out? Do you assume all fluid drained out and put back listed capacity? Or can you just fill it till it stops going down the vent tube? If vented, hard to see how it could pressurize and damage seals, but... I thought that starting on the 16's Ford added cooling lines to the PTU's and have seen talk of temp sensors and dash warnings. So yes drain/flush and refill makes good sense, especially on older units. Wonder given the 2020 is "rear drive" platform, how is that PTU set up, but sure hoping it is more durable.

 

[RhinoQuartz]

I think the question was sort of how much to put in AFTER a drain? Do you just put back the amount that came out? Do you assume all fluid drained out and put back listed capacity? Or can you just fill it till it stops going down the vent tube? If vented, hard to see how it could pressurize and damage seals, but... I thought that starting on the 16's Ford added cooling lines to the PTU's and have seen talk of temp sensors and dash warnings. So yes drain/flush and refill makes good sense, especially on older units. Wonder given the 2020 is "rear drive" platform, how is that PTU set up, but sure hoping it is more durable.

I have a 17 but apparently no cooling lines, no ductwork, and apparently not even a drain plug, so it's a little confusing to see what's going on.

 

[KayGee]

I think the question was sort of how much to put in AFTER a drain? Do you just put back the amount that came out? Do you assume all fluid drained out and put back listed capacity? Or can you just fill it till it stops going down the vent tube? If vented, hard to see how it could pressurize and damage seals, but... I thought that starting on the 16's Ford added cooling lines to the PTU's and have seen talk of temp sensors and dash warnings. So yes drain/flush and refill makes good sense, especially on older units. Wonder given the 2020 is "rear drive" platform, how is that PTU set up, but sure hoping it is more durable.

When you do a motor oil change, how much oil do you put back in after you drain it? Do you just put back in what came out? Do you put back in stated capacity? Or, do you just fill it to the brim?

 

[KayGee]

I have a 17 but apparently no cooling lines, no ductwork, and apparently not even a drain plug, so it's a little confusing to see what's going on.

If you have no drain plug, you will need to suction the old fluid out and fill using the fill plug (basically refill until fluid starts coming back out fill hole). You may not get all of it out, but I think you can get 80-90% of it.

Alternate method is to drill and tap a drain plug in bottom of case.

 

[Eric Z]

I have a 17 but apparently no cooling lines, no ductwork, and apparently not even a drain plug, so it's a little confusing to see what's going on.

Confusing for sure. I had asked my local Ford dealer if they could change my PTU fluid at last oil change? Service Manager said they had "no procedure" for that and I went online and showed him posts on this forum, showing how it could be done and mentioned that the Fleet guys seem to have method and maybe even a "kit". He checked into it and could find no kit. Mind you, I do NOT think this shop sees a lot of PIUs. So this oil change I showed the Service Manager the extended vent tube and told him I had drained and flushed. He said if they had procedure that might save a lot of PTU replacements. Wondering what the failure rate on PTU's is before 100k miles, before 200k? Would not think this would not be effected much by idle hours, like the water pumps, so is it more or less PIU issue due to severe duty?

 

[Eric Z]

When you do a motor oil change, how much oil do you put back in after you drain it? Do you just put back in what came out? Do you put back in stated capacity? Or, do you just fill it to the brim?

Call me old school, I fill to the dipstick fill line, start and idle for a minute, then re-check level now that oil filter is full. And yes that is usually very close to stated capacity, but motor oil is much thinner than gear lube and mostly drains out (except on my old Mustang that has cooling fins, and baffled oil pan).

 

[RhinoQuartz]

If you have no drain plug, you will need to suction the old fluid out and fill using the fill plug (basically refill until fluid starts coming back out fill hole). You may not get all of it out, but I think you can get 80-90% of it.

Alternate method is to drill and tap a drain plug in bottom of case.

I've had a local mechanic do that back in January
and intend on having it serviced by winter this year again and then 25-30k intervals from then on.
When I say confused, I don't mean by the procedure, I've seen it plenty of time on this forum and others, but what specs are meant to be used.

Confusing for sure. I had asked my local Ford dealer if they could change my PTU fluid at last oil change? Service Manager said they had "no procedure" for that and I went online and showed him posts on this forum, showing how it could be done and mentioned that the Fleet guys seem to have method and maybe even a "kit". He checked into it and could find no kit. Mind you, I do NOT think this shop sees a lot of PIUs. So this oil change I showed the Service Manager the extended vent tube and told him I had drained and flushed. He said if they had procedure that might save a lot of PTU replacements. Wondering what the failure rate on PTU's is before 100k miles, before 200k? Would not think this would not be effected much by idle hours, like the water pumps, so is it more or less PIU issue due to severe duty?

I think the PTU is cooled when the vehicle is in motion to allow air to pass by it - in addition to water cooling if that is equipped. Idling would increase temperature since it is always engaged while engine is running but is being cooled less.

 

[KayGee]

Idling would increase temperature since it is always engaged while engine is running but is being cooled less.

I'm not sure what you are trying to convey, but the gears in the ptu only spin if the vehicle is moving. If the vehicle is idling, there will be heat from the engine/trans/exhaust that will radiate to other components, but I highly doubt just idling would cause any significant wear/damage to the ptu. The ptu gets worn/damaged from power transfer through it, which can only happen when the vehicle is in motion.

 

[RhinoQuartz]

I'm not sure what you are trying to convey, but the gears in the ptu only spin if the vehicle is moving. If the vehicle is idling, there will be heat from the engine/trans/exhaust that will radiate to other components, but I highly doubt just idling would cause any significant wear/damage to the ptu. The ptu gets worn/damaged from power transfer through it, which can only happen when the vehicle is in motion.

I was under the impression that because of AWD, the PTU is constantly engaged while the engine is on. Although I see that that doesn't make sense.

 

[rocky123xo]

PIU PTU's are "water-cooled" which should lead to extended life over the stock ones.
That being said, the general recommendation is to change the fluid every 30k miles. I pay $75 a clip, and it far outweighs the cost of replacing it.
The PTU's themselves are robust, but they're sandwiched between the engine, tranny, and a cat. They ROAST the quart of fluid inside.

 

[peterk9]

^^ Welcome to the Forum.

Peter

 

[KayGee]

They ROAST the quart of fluid inside.

It's about a pint or less, not a quart.

 

[16vcabman]

When you do a motor oil change, how much oil do you put back in after you drain it? Do you just put back in what came out? Do you put back in stated capacity? Or, do you just fill it to the brim?

I refill to the capacity stated and then after oil settles, I check the stick and bring to the full mark on the dipstick.