10R80 Owners - ULTIMATE M6G 10R80 Facts + Resolutions to harsh or no shift conditions

[Dave2017GT]

My 2019 GT 10R80 is a hot mess lol. I dont bang away on this thing at all but holy crap is it clunky. I have to reset the KAM every oil change at least because of harsh shifts. If i put it in sport mode and drive it normal it will give you whiplash shifting into 3rd and 5th. I kinda think its all funny at this point becuase i has 17 GT that i traded in becuase that thing was ahot mess too with a slew of different issues including the driver and passenger side doors popping open when going over speed bumps or a harsh pothole. Im not even joking. I certainly wont own this car past the warranty and likely will not buy a Ford ever again. Dont get me wrong, I love my Mustang. I wash and vacuum it every weekend. My neighbor jokes that im gonna wash the paint right off of it and it is the most beautiful car ive ever owned. These issues are a really hard pill to swallow considering the price of it and how awesome it looks.

Im pretty sure that this thread is responsible for at least a 5k loss on resale value lol.

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[speedup]

This is a great thread, so much information. Thank you @Cobra Jet

I have experienced most of the "common" behaviors with the 10R80 as described here, but mine is doing something I really haven't read about.

My house is on an alley, and my driveway has an incline, not severe, I am guesstimating 12-15 degrees. So, when I pull into my driveway (left side pull in) the trans like slips, and I feel the car stop going forward, the engine RPMs go up for a second, then it catches and jerks a little. My trans has a lot of gear whine normally (as described by TSBs and others) but when I get into the garage after this slipping, I hear a grinding/hissing type sound coming from the trans for a few seconds..

Its very odd, and none of my cars I've owned since living in the house have done this, and it seems to only do it in my driveway (slow moving/turning/incline situation) - I don't recall it doing it on flat road conditions (yet)..

anyone else experience this?

 

[speedup]

Not sure if this matters, but the car came with the 3.55 gears option from factory

 

[Triton54]

I have NOT heard of the things your car does ^ how many miles on yours? I can confidently say that, after the dealer worked on mine last week it is much better!! although it takes just a bit more time to get into gear, from park, forward or reverse, just a few tenths of a second, no biggie though cause I am very happy with the way it shifts now! btw, I really like your Avatar! ps, mine has 3:55s also.

 

[speedup]

I bought it used 2 months ago, and it had 2700 miles on it. It has about 4200 miles on it now and has done it since the first time I drove it home.

The weird thing is, it doesn't do it when going straight on inclines, and it doesn't do it when just turning left/right. But when you put the left turn and incline together .. it slips, surges, gets jerky..

 

[gmupatriot]

I bought it used 2 months ago, and it had 2700 miles on it. It has about 4200 miles on it now and has done it since the first time I drove it home.

The weird thing is, it doesn't do it when going straight on inclines, and it doesn't do it when just turning left/right. But when you put the left turn and incline together .. it slips, surges, gets jerky..

I experienced this twice (3.55 gears here as well) when pulling into my brother in laws house. Same thing, angle, a small incline and its like the trans was not engaging. I had to go into, P, then back into D a couple of times for the car to start moving. No idea why! It is very much possible it could be due to low fluid in the transmission. I have the harsh 2-3 and 4-5 upshift and 5-3 or 4-3 harsh downshift as well.

 

[speedup]

I have been wondering about the trans fluid level - I will have to check that. My 2019 build date is 07/19

 

[Triton54]

FWIW, I failed to mention that I asked them to check my fluid level before they do anything, ( I know, I know) they should do this first thing, but i wanted us ALL on the same page on the tranny in this car. They reported mine was good from Flat Rock.

 

[leonrudi]

This is a great thread, so much information. Thank you @Cobra Jet

I have experienced most of the "common" behaviors with the 10R80 as described here, but mine is doing something I really haven't read about.

My house is on an alley, and my driveway has an incline, not severe, I am guesstimating 12-15 degrees. So, when I pull into my driveway (left side pull in) the trans like slips, and I feel the car stop going forward, the engine RPMs go up for a second, then it catches and jerks a little. My trans has a lot of gear whine normally (as described by TSBs and others) but when I get into the garage after this slipping, I hear a grinding/hissing type sound coming from the trans for a few seconds..

Its very odd, and none of my cars I've owned since living in the house have done this, and it seems to only do it in my driveway (slow moving/turning/incline situation) - I don't recall it doing it on flat road conditions (yet)..

anyone else experience this?

Hi there,
i am over here in Germany.
I have sometimes the same behaviour. Especially when the car wasnt used for two or three days. Feels like a lot of slip in the tranny. The engine revs about 2000 RPM, but the car feels like an escargot. Then five seconds or so later it engages properly and everything looks normal. I have to check the fluid level of the tranny the next day.
Any thoughts of that??
P.S. sorry for the poor English.....School is long ago
Cheers
Thomas

 

[Cobra Jet]

I have been wondering about the trans fluid level - I will have to check that. My 2019 build date is 07/19

FWIW, I failed to mention that I asked them to check my fluid level before they do anything, ( I know, I know) they should do this first thing, but i wanted us ALL on the same page on the tranny in this car. They reported mine was good from Flat Rock.

Hi there,
i am over here in Germany.
I have sometimes the same behaviour. Especially when the car wasnt used for two or three days. Feels like a lot of slip in the tranny. The engine revs about 2000 RPM, but the car feels like an escargot. Then five seconds or so later it engages properly and everything looks normal. I have to check the fluid level of the tranny the next day.
Any thoughts of that??
P.S. sorry for the poor English.....School is long ago
Cheers
Thomas

Just a friendly FYI when asking Service Centers to check the S550 Mustang 10R80 fluid level:

To test the fluid level in a 10R80, the trans must be up to proper operating temp and fluid level views when hot.

The 10R80 is used in other Ford products and it has a “universal” dipstick that has (2) distinct markings on it. Depending on what vehicle the 10R80 is in, the Tech and any DIYer MUST be 100% certain they are viewing the proper dipstick mark that pertains to the S550 application!

If the fluid is found to be below “A” on the dipstick, the fluid level is LOW for an S550 10R80!

Make sure the Tech is viewing the proper mark IF the car is being serviced at a Ford Dealer. In fact, request that they take a photo of the dipstick to show you at what level the fluid is sitting when they checked it!

Too many Service Centers are referencing the “B” mark on the dipstick reading for a S550 - that is WRONG.

Again, here’s the link (previously posted on page 1 of this thread) that shows dipstick markings and other pertinent info for checking fluid level:
https://www.mustang6g.com/forums/threads/a10-owners-check-your-oil-level.116410/page-2

 

[leonrudi]

Thanx mate,
i ve considered this and i am really looking forward to it.
I let you guys know.
In the mean time i think i am going to floor the pony a bit on the Autobahn

 

[Cobra Jet]

@speedup

Did you ever get your trans issue resolved?

Based on your descriptions, it sounds like the trans may be low on fluid and/or possibly a valve body issue (if the fluid is low, VB cannot function properly and risk of damage to VB may occur).

The car (and trans) should function exactly the same when driving straight or turning left or right. If the trans is acting up when entering/exiting a driveway or easement on an angle or if turning L or R, it sounds like the VB is being starved of fluid as the fluid sloshes to one side or another.

 

[Thegipper]

Hi everyone,

I started another thread and was notified of this one so I’m moving my post here.

So my 2020 GT PP1 is a blast and I really do love it.....except the interior sounds and the quirkiness of the transmission. I wanted to see if anyone else has experienced the following:

1. When slowing down and having the transmission downshift on its own (not via paddles), there are times from 4-2 or 3-1 it will have a “clunk” as if it’s a manual transmission. It’s very disconcerting because it feels like a very lazy shift like the gears are loose.

2. Once again, only sometimes, when slowing down the power delivery will have a 1-2 second hesitation where no amount of depressing the gas pedal will send power to the engine.

I took it once to get it checked out and the dealer just reflashed the software. It didn’t help for long.

Anyone else experience anything strange with the 10R80?

Thanks

 

[DickR]

Hi everyone,

I started another thread and was notified of this one so I’m moving my post here.

So my 2020 GT PP1 is a blast and I really do love it.....except the interior sounds and the quirkiness of the transmission. I wanted to see if anyone else has experienced the following:

1. When slowing down and having the transmission downshift on its own (not via paddles), there are times from 4-2 or 3-1 it will have a “clunk” as if it’s a manual transmission. It’s very disconcerting because it feels like a very lazy shift like the gears are loose.

2. Once again, only sometimes, when slowing down the power delivery will have a 1-2 second hesitation where no amount of depressing the gas pedal will send power to the engine.

I took it once to get it checked out and the dealer just reflashed the software. It didn’t help for long.

Anyone else experience anything strange with the 10R80?

Thanks

What shifter position (D or S) and what drive mode (normal, sport, track)?

My 2018 GT PP has very smooth off throttle automatic downshifts with the shifter in D AND the drive mode in Normal.

With the shifter in D but in sport or track drive mode the lower gears off throttle automatic downshifts are frequently, if not always, very noticeable or even harsh.

With the shifter in S the downshifts are also very noticeable or even harsh in normal, sport, and track drive modes. My car has over 21,000 miles with no issues.

In summary, lower gear off throttle downshifts are typically very noticeable or harsh except in shifter position D and Normal drive mode.

Note: I "assume" wet/snow drive mode also behaves like normal drive mode. Drag mode????

I hope this helps.

 

[speedup]

@speedup

Did you ever get your trans issue resolved?

Based on your descriptions, it sounds like the trans may be low on fluid and/or possibly a valve body issue (if the fluid is low, VB cannot function properly and risk of damage to VB may occur).

The car (and trans) should function exactly the same when driving straight or turning left or right. If the trans is acting up when entering/exiting a driveway or easement on an angle or if turning L or R, it sounds like the VB is being starved of fluid as the fluid sloshes to one side or another.

Thanks for following up. I haven't made an appointment with the service dept to bring the car in yet. With the lockdown my work hours have been crazy, and I haven't been able to take a day off. Hopefully that will start to ease up soon.

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