Ecoboost Performance Forum

Ecoboost Performance => Troubleshooting, Maintenance, TSB Articles => Troubleshooting => Topic started by: Gray Brick on November 30, 2015, 12:13:35 PM

Title: Excessive front wheel tire spin when hot
Post by: Gray Brick on November 30, 2015, 12:13:35 PM
I am getting excessive front wheel tire spin after beating up on the Flex a bit.  Part throttle will spin.

After cooling down it goes away.

Is this due to the computer seeing the hot transmission fluid temperature(205-210) and adjusting the power output to the RDU?

Traction control is off. PTU and trans fluid recently changed.
Title: Re: Excessive front wheel tire spin when hot
Post by: AJP turbo on November 30, 2015, 12:32:27 PM
I dont think 210 is anywhere near what the ecu considers to be hot....normal at worst

Id have to look bit i didnt notice any scalars or functions in the tune taking action until transmission temps reach at least 275...they call it TOT...transmission oil temp

Remember the the oild dipsticks and pans for trans that say oil could reach 350...thats why i find it funny when some of u guys are freaking out about 200 degree fluid
Title: Re: Excessive front wheel tire spin when hot
Post by: Gray Brick on November 30, 2015, 03:10:25 PM
Do the clutches in the RDU get overheated?
Title: Re: Excessive front wheel tire spin when hot
Post by: 66 Galaxie on December 01, 2015, 07:20:57 AM
IIRC the clutches will disengage completely when they get too hot.  Clutch engagement will return back to normal once the temps have returned to their normal range.
Title: Re: Excessive front wheel tire spin when hot
Post by: ZSHO on December 01, 2015, 09:14:48 AM
Brick any codes set?? and certainly the (clutches)can over heat,might also need to check the speed sensors for dirt buildup,corrosion.  Z
Title: Re: Excessive front wheel tire spin when hot
Post by: Gray Brick on December 01, 2015, 02:16:36 PM
No codes...

Is there a PID to look a the temps in the clutches?
You are talking about the clutches in the RDU, right?

Title: Re: Excessive front wheel tire spin when hot
Post by: ecoboostsho on December 01, 2015, 03:13:52 PM
No temperature PIDs that I've seen (or even a sensor to measure it I believe) for the RDU but there is a PID that will tell you what % is being commanded to the rear and if the AWD system is engaged or not.  (See the Torque PIDs thread stickied in the datalogging section).  I would at least be interested in seeing if the car is still calling for AWD when it is slipping or if the ECU isn't commanding it because it knows something is overheated...

There aren't any clutches in the PTU - it is always spinning when in gear.
Title: Re: Excessive front wheel tire spin when hot
Post by: FoMoCoSHO on December 01, 2015, 08:10:46 PM
Temperature monitoring is inferred, not sensor.

http://articles.sae.org/11120/ (http://articles.sae.org/11120/)
Title: Re: Excessive front wheel tire spin when hot
Post by: Gray Brick on December 02, 2015, 02:17:11 AM
Great article...

I will see what I get with the AWD PID.



Title: Re: Excessive front wheel tire spin when hot
Post by: Gray Brick on December 02, 2015, 02:17:49 AM
Is the RDU clutch pack rebuild able?
Title: Re: Excessive front wheel tire spin when hot
Post by: ZSHO on December 02, 2015, 05:10:22 AM
Brick did you ever change the RDU Fluid? How many miles?  BTW have you tried a kam reset or removing the ground from the battery for an hour to reset.  Z    https://www.youtube.com/watch?v=hZAsoqmqhdM (https://www.youtube.com/watch?v=hZAsoqmqhdM)      BTW it sounds like the TCC (torque converter clutch)is stuck in the apply position restricting flow when commanded open,which will cause the converter to overheat.  Z
Title: Re: Excessive front wheel tire spin when hot
Post by: SHOdded on December 02, 2015, 06:17:47 AM
Quote from: Gray Brick on December 02, 2015, 02:17:49 AM
Is the RDU clutch pack rebuild able?
I suppose it could be, but I've only ever heard of outright replacement of the entire RDU in these applications.
Title: Re: Excessive front wheel tire spin when hot
Post by: glock-coma on December 02, 2015, 10:54:45 AM

Quote from: SHOdded on December 02, 2015, 06:17:47 AM
Quote from: Gray Brick on December 02, 2015, 02:17:49 AM
Is the RDU clutch pack rebuild able?
I suppose it could be, but I've only ever heard of outright replacement of the entire RDU in these applications.
I was told when my RDU was replaced it is not a serviceable part and must be replaced as a whole unit.  Except for fluid changes.
Title: Re: Excessive front wheel tire spin when hot
Post by: 66 Galaxie on December 02, 2015, 12:23:18 PM
That's what I have heard too. :-(
Title: Re: Excessive front wheel tire spin when hot
Post by: AJP turbo on December 02, 2015, 12:53:20 PM
U can rebuild it ..parts are available...dealerships prefer to change parts...less likely for things to go wrong
Title: Re: Excessive front wheel tire spin when hot
Post by: 66 Galaxie on December 02, 2015, 02:48:02 PM
That's good to know. Any leads on parts sources
Title: Re: Excessive front wheel tire spin when hot
Post by: AJP turbo on December 02, 2015, 03:37:07 PM
Sure but you won't be able to find anyone willing to rebuild it the labor cost would be more than two by the unit out right that's why they do that. Look around I'm sure you can find the parts also
Title: Re: Excessive front wheel tire spin when hot
Post by: ZSHO on December 02, 2015, 05:24:10 PM
I can confirm that the price on the PTU complete unit has dropped fairly considerable compared to a couple years ago,this is what my dealer informed me after having my PTU Flushed,not sure if this is related to the plant in Mexico.  Z
Title: Re: Excessive front wheel tire spin when hot
Post by: Sabtaj1 on December 03, 2015, 04:31:10 AM
Hey Grey....  Sorry, I just read this post.  So, I had this happen to me as well in my flex once.  I was worried.  Was messing around on the street doing multiple boost launches and then suddenly just blowing off the front tires like crazy.  I thought it was a fluke so I was coming out of a turn and got on it and just smoked the front tires at half throttle.  It has only happened the one time.  Haven't had a problem since.  So I would say its most likely a heat issue that stops the rear from engaging.  I don't think this is anything to worry about to be honest.  I was at first but not anymore.
Title: Re: Excessive front wheel tire spin when hot
Post by: Gray Brick on December 03, 2015, 12:21:05 PM
So is it from a hot trans, rdu, etc.?

It has happened to me a few times and after the Flex cools it goes away.

Trans temps are usually around 205 when it happens... coolant is at 180 degrees.
Title: Re: Excessive front wheel tire spin when hot
Post by: Gray Brick on December 03, 2015, 12:23:07 PM
Unfortunately, the PID's for AWD on/off and modulation are not loaded on my computer.
With these I would be able to see if the signal is being sent to the RDU.

I don't wasn't to visit the dealer to add them.. I would have to tear off all the mods. 
EhPortal 1.39.5 © 2025, WebDev