Yet another PTU thread...some history

Discussion in 'Generation 4 - General Discusson' started by Ecoboost_xsport, May 1, 2021.

  1. Ecoboost_xsport

    Ecoboost_xsport SHO Member

    Joined:
    Mar 21, 2020
    Messages:
    1,668
    Likes Received:
    3,161
    Gender:
    Male
    Occupation:
    Mad Scientist
    Location:
    Sacramento, CA
    Home Page:
    Lot's of talk recently about the PTU.

    It is definitely a frequently referenced component and has been known to be the cause of many failures. Wanted to provide some insight to the history of the PTU and some info on the various iterations of the years.

    Essentially, there are really only 2 PTUs we should be talking about when when referring to the 2010-2019 model years.

    - The one with the cooler (found on towing package Explorers, Performance Pack SHO, Explorer Sports, PIU/PIS, etc). The latest Ford PN is DG1Z-7251-F.
    - The one without the cooler (found on all others not mentioned above). The latest Ford PN is DT4Z-7251-G.

    The latest iteration of the PTU (whether you have the cooler or not) IS backwards compatible if you have an older model vehicle. (i.e., you have a 2013 PP SHO, a PTU from a 2019 PP SHO will fit).

    NOTE: There is a 3rd PN (AT4Z-7251-G) listed for the older models (pre-2013). It is a non-cooler PTU. However, when cross referencing fitment between all the models this PN fits, you will find that the newer non-cooler PTU fits many of the same years. From the research I've done and seen on this older model PN, it simply has a slightly different designed case with some raised heat sink fins, but bolt up locations are identical to newer ones. My intuition says the newer one will fit as well, but always make this decision on your own, as there may be something I haven't foreseen. Take this theory with a grain of salt.

    If you are feeling very adventurous, it IS possible to convert to a PTU with a cooler, if you're vehicle does not have it from the factory. It will simply need some additional coolant lines that "T" into the existing coolant system. Maybe someone can provide Ford PNs needed for this if they've done it.

    As for the history of the iterations, the latest version was introduced in late-2016. Below is the evolution of the PTU during recent years:

    - January 2014, a Full Face Thrust Washer, FFTW, was introduced. This new washer was designed to prevent the idler bearing from walking into the aluminum case.
    - October 2015, a second change was made, in this case a loose-fit idler bearing. In dyno tests, this bearing design change showed a twice life improvement over the FFTW design.
    - June 2016, a third change was made. In this case, a new bearing design, one without drawn cups, was installed. This eliminated the walk mode of damage. Dyno testing shows a three to four times improvement over the FFTW design.

    Basing/modeling any design of aftermarket PTU components should really be done using the latest iteration as a start point.

    This information was gathered from:
    https://www.qgdigitalpublishing.com/publication/?i=634589&ver=html5&p=36
     
    Last edited: May 1, 2021
  2. Michigan-SHO

    Michigan-SHO SHO Member

    Joined:
    Mar 15, 2020
    Messages:
    646
    Likes Received:
    788
    Gender:
    Male
    Occupation:
    Cutting Tool Grinder/ Machinist
    Location:
    Michigan
    Maybe we can make this a sticky thread!!!! So it doesn’t get lost in the forum like all the other PTU knowledge. Especially since “PTU” is too short of a word to be searched for.
     
    Ecoboost_xsport likes this.
  3. rubydist

    rubydist SHO Master Staff Member Super Moderators

    Joined:
    Jun 25, 2007
    Messages:
    7,171
    Likes Received:
    3,068
    Location:
    Denver
  4. Jordan_R

    Jordan_R Stock Block Ready To Knock...er..Rock

    Joined:
    Sep 20, 2017
    Messages:
    1,385
    Likes Received:
    3,033
    Location:
    Missouri
    Marvelous find of information!
     
    Ecoboost_xsport likes this.
  5. Nova

    Nova SHO Member

    Joined:
    Jul 27, 2018
    Messages:
    480
    Likes Received:
    753
    Location:
    US
    Awesome info! I just saw someone posted on Instagram about a billet PTU cover that is bigger, holds 5 oz more fluid than original and bolts right up to factory PTU.

    Sent from my SM-G986U using Tapatalk
     
  6. Ecoboost_xsport

    Ecoboost_xsport SHO Member

    Joined:
    Mar 21, 2020
    Messages:
    1,668
    Likes Received:
    3,161
    Gender:
    Male
    Occupation:
    Mad Scientist
    Location:
    Sacramento, CA
    Home Page:
    Uh yeah....about that piece...maybe I'll let @Jordan_R or @802SHO handle this topic...I'm too vested to be objective...

    Put it like this...I won't be giving this guy any of my money for any PTU parts he makes, I don't care how bad-ass or functional it is...

    ...if I have any sway here...I'd say, steer clear of this product. But I'd understand if some of you bought into it...
     
    Last edited: May 1, 2021
  7. 802SHO

    802SHO Built not Bought

    Joined:
    Oct 8, 2019
    Messages:
    1,343
    Likes Received:
    2,323
    Gender:
    Male
    Location:
    Essex Junction Vermont
    Bolt up to a factory non pp PTU 10-12 we know for sure. Just need to remove your PTU. Although it is made to use an external cooler and pump not included. Assuming you plug the cooler port if you don’t want to spend more than double the price of replacing it. But then it’s just bracing at that point without a cooler.

    And the folks with a PP PTU with cooler would need to ditch their cooler....yet the PP PTU has additional casting for the cooler which is more bracing in and of itself. The PTU has been through a few iterations beefing it up internally and now everyone buying a new cooler will get that PTU. Interesting is the PP cooler is cheaper than the new non PP PTU.

    And there’s still the old version non pp available for 10-12 that this plate has been designed off of.

    Currently scheming to make a brace for a non Pp....since the Pp already has one with the cooler casting...essentially. E46CCD95-7EEB-4436-9093-AF82D38CDD66.png CA63FBBE-0690-40C9-9461-982564DB7AA7.png 14F41C08-13C4-4707-A8FC-352E56DFB6BA.png
     
  8. Jordan_R

    Jordan_R Stock Block Ready To Knock...er..Rock

    Joined:
    Sep 20, 2017
    Messages:
    1,385
    Likes Received:
    3,033
    Location:
    Missouri
    Same as John here, but I will say honestly I don't think we need it. Just change your fluid often and if you have a nonpp car a PP ptu has way more bracing and reliability than the nonPP in my opinion. Wouldn't touch the cover if the guy gave it to me for free but he also rubbed me very much the wrong way.
     
  9. Sksho17

    Sksho17 Member

    Joined:
    Sep 15, 2020
    Messages:
    19
    Likes Received:
    33
    Gender:
    Male
    Location:
    Canada
    I find it quite interesting that many people have mentioned in the past that the PTU and RDU (Essentially the awd entirely) is the weak point of the SHO, those who have found out the hard way have found its generally the transmission. Regardless it is great that someone is trying to produce some parts for the platform. How all the drama went down on facebook sucked. I wont take sides in the matter, but i do believe the upgraded ptu components, combined with a properly built transmission would greatly benefit the platform, at least giving us the option of having parts that theoretically can handle more power. I don't think this billet cover on its own would make a world of difference, the best thing it would do is allow us to run an external cooler and have a the total amount of fluid in the system be larger than currently, thus the fluid wouldn't break down as quickly.
     
  10. Ecoboost_xsport

    Ecoboost_xsport SHO Member

    Joined:
    Mar 21, 2020
    Messages:
    1,668
    Likes Received:
    3,161
    Gender:
    Male
    Occupation:
    Mad Scientist
    Location:
    Sacramento, CA
    Home Page:
    I don't disagree with you. I just won't give my money to someone who behaves the way he did. That's just me, no judgement on others who feel differently.

    My point of concern (one I brought up to him before all this, he never addressed and is what sparked him to berate me in private chat, block me then post up selected parts of our conversation in public) is about that external cooler he is trying to implement for this side cover. He is selling this as a cover that will work with the OEM case, adding strength and increase capacity, all great things...sure. But when adding an external cooler to the OEM case, there is potential for damage, in my opinion. The PTU is a vented case design, and despite the obvious poor implementation of this component in the AWD system, I have to believe Ford chose a vented case over a sealed case for a reason (sure, cost is one). Now, let's add his side cover to this component and add an external cooler. Once that hot, viscous gear lube makes its path through that external cooler system it will, obviously, cool AND get less viscous, not much but enough of a differential between outgoing and incoming to cause, for lack of a better phrase, a backup. As it backs up, it will look for a path to escape, and the path of least resistance is the vent. I have seen this happen multiple times in poorly design cooler systems. You will, at best, get oil all over your catalyst and make a smoke show or, at worst, dump all the oil out and cause catastrophic PTU damage.

    Now...what's the fix for this? Convert the PTU to a sealed, pressurized case (closed-loop) and fill oil with no air gap. Then this design will work. But that requires a complete case redesign with seals rated for pressure. Which isn't how hes billing it as.. He's said the axle seals will be better on the cover...fine, but if used with an OEM case, there is still the pinion seal as well as the seal on the transmission side. Oil WILL push past those with any sort of pressure buildup in the case. Many of us have seen this happen even without building pressure from a closed-loop system.

    I asked him multiple times (starting out privately, then when he didn't answer...publicly) about this scenario and he never responded with anything other than "I'm aerospace". He finally had a meltdown and the rest is FB history.

    I'm no engineer, but I have seen things. Hell, I may even be wrong, I'm ok with that, but at least explain to me, a non-engineer, how it would be addressed. This isn't as simple as "adding a pump, some lines and a heat exchanger". My question stands as a legitimate one. I was speaking offline with another individual (I will keep their name private out of respect) who posited the same question to him privately to see how he would respond. And according to them, you know his response? "Just plug the vent" and called the scenario the "stupidest thing he's heard". Doesn't sound very scientific or thought-out to me.

    F$%* this guy. Sorry but no thanks. Again...no judgement on anyone else who decides differently.
     
    Last edited: May 2, 2021
    802SHO and Jordan_R like this.
  11. Majestic

    Majestic SHO Member

    Joined:
    Aug 28, 2016
    Messages:
    539
    Likes Received:
    408
    Gender:
    Male
    Link to the FB discussion? I'd be interested in reading it.
     
    Ecoboost_xsport likes this.
  12. Ecoboost_xsport

    Ecoboost_xsport SHO Member

    Joined:
    Mar 21, 2020
    Messages:
    1,668
    Likes Received:
    3,161
    Gender:
    Male
    Occupation:
    Mad Scientist
    Location:
    Sacramento, CA
    Home Page:
    Me, Jordan and Andrew where blocked by him. Which means all our questions and responses were removed from the discussion as well. We can't see it nor can I defend myself accordingly...however, last I heard by folks I know that aren't blocked, he felt it necessary to post up selected portions of our private convo in that post where I'm unable to see or respond to. Pretty mature?

    Not to mention, a lot of this went down in private chats starting on IG between Jordan, Andrew and myself....

    Here's a link to the only post I can see on the discussion since it was not posted by him. However, the point of the post was to disparage me without having full knowledge of the situation. So I responded...

    https://m.facebook.com/groups/412113472965936/permalink/920249875485624/

    I'm John Diaz, so you know who was me...
     
    802SHO and Jordan_R like this.
  13. Majestic

    Majestic SHO Member

    Joined:
    Aug 28, 2016
    Messages:
    539
    Likes Received:
    408
    Gender:
    Male
    I'll check it out if/when I'm accepted in the group.
     
    Ecoboost_xsport, 802SHO and Jordan_R like this.
  14. Jordan_R

    Jordan_R Stock Block Ready To Knock...er..Rock

    Joined:
    Sep 20, 2017
    Messages:
    1,385
    Likes Received:
    3,033
    Location:
    Missouri
  15. Majestic

    Majestic SHO Member

    Joined:
    Aug 28, 2016
    Messages:
    539
    Likes Received:
    408
    Gender:
    Male
    Read it. Will be interesting to see how the one he made works. Are you guys working on one with the improvements you suggested to him?
     
    Ecoboost_xsport likes this.
  16. Sksho17

    Sksho17 Member

    Joined:
    Sep 15, 2020
    Messages:
    19
    Likes Received:
    33
    Gender:
    Male
    Location:
    Canada

    I like your thinking on how a cooler would affect the ptu being that it is a vented set-up. In all honesty I have not looked into what aftermarket setups would be suitable to use a feature like that. i would think a tradition cooler meant for a differential would be okay, given that they are mainly a vented case from the start also. Personally I just upgraded from a non-cooled to a cooled new oem ptu. Given that if you do good maintenance they should last qutie some time. Also sorry to hear that you had a bad experience with the guy making that stuff, even if the product is/was top notch if you don't treat potential customers correctly that's is not good for business.

    and sorry i meant to reply to your post further up, not the one i did. whoops haha
     
    Ecoboost_xsport, Jordan_R and 802SHO like this.
  17. DadMobile

    DadMobile Worlds 3rd least slowest Ecoboost SHO

    Joined:
    Nov 4, 2020
    Messages:
    274
    Likes Received:
    522
    Occupation:
    Dad / Family car parts buyer.
    Location:
    Texas
    Facebook is the devil.
     
  18. 802SHO

    802SHO Built not Bought

    Joined:
    Oct 8, 2019
    Messages:
    1,343
    Likes Received:
    2,323
    Gender:
    Male
    Location:
    Essex Junction Vermont
    Yeah it’s unfortunate the way that guy acted. We were all chatting and he brought his PTU design to us to get some feedback. And we were assuming we would get some meaningful and intelligent responses....really looking up to the guy to teach us...instead he got defensive and angry and left the chat group abruptly. We were all like wtf. Then he popped up later on FB asking for opinions.....doing the same thing that got him flexing his aerospace background on us. And the kicker was he listed a fitting John recommended but when he asked us for feedback he was irrationally quick to tell John to make his own design and use whatever fitting he wanted bc he didn’t care.
     
  19. 802SHO

    802SHO Built not Bought

    Joined:
    Oct 8, 2019
    Messages:
    1,343
    Likes Received:
    2,323
    Gender:
    Male
    Location:
    Essex Junction Vermont
    This is what is exactly going on. Another member hired him to make his PTU nearly bulletproof. He starts making it specifically for that one member. Although he has hopes of manufacturing it for other customers and multiple platforms that use the same PTU.....but in this case the PTU he’s got in his hands is the old design off of a 2010 non Pp.

    He wanted to ask John, Jordan and I for feedback about his design and his intentions. This is where we told him about all the different designs and let him know if he made one from the latest iteration it would be backwards compatible. He asked for one to be sent to him....but in the same conversation he was told of Johns concerns and why.

    Depending on what his feedback is.....if it’s positive feedback then all is good....somehow he solved a problem. But if the feedback is concerns and intelligent questions....that go against the currently design....which is constructive feedback that he asked for.....all of a sudden he flips back to it’s for one customer and if you want to make your own go for it.

    First class jerk.
     
  20. Jordan_R

    Jordan_R Stock Block Ready To Knock...er..Rock

    Joined:
    Sep 20, 2017
    Messages:
    1,385
    Likes Received:
    3,033
    Location:
    Missouri
    I think a key thing to mention here is John, Andrew and myself are also customers of this person. He has thousands of our dollars in his pocket and we aren't just a person inquiring.
     

Share This Page

If you wish to help keep SHOforum running, please click the donation button below