Car fast, but transmission slow...

[SHO307]

I've been having a minor issue over the last few months. Car has just 96k on it now.

I drive for Uber these days, so "Ragin Bull" is getting a real workout daily.

Transmission is acting slow on upshifts, sometimes to the point where I have to command an upshift with the paddles. Problem is inconsistent; some days it's fine, others not so much. Problem became noticeable after I had to take a fare from Denver airport all the way to Keystone...in the dark...over Loveland Pass...in a driving snowstorm. Average speed over the pass was 20 mph. Seems like the trans in this car REALLY hates long downgrades.

Can anybody venture an idea?

 

[SHOdded]

Driving in the hills you want to stay out of overdrive anyway.

When did you last change the transmission, PTU, and RDU fluids. They are well overdue per owner schedule (not Ford schedule).

 

[SHO307]

At about 68k, plus or minus 500 miles.

 

[SHO307]

Anybody?

 

[Johnbigdog]

When you say slow I assume you mean the r.p.m.s are really high when it shifts? Does the PRNDL illuminate the D or the S? Does the transmission downshift and not upshift, or it just doesn't upshift? Are you on a grade? Or flat road?

Check the transmission oil after a drive make sure it's not low.

Do you notice any driveability faults? Engine performance will affect the transmission.

There are PIDs you can monitor to verify the transmission is shifting as desired, gear-rat and tran-rat.

 

[SHO307]

When you say slow I assume you mean the r.p.m.s are really high when it shifts? Does the PRNDL illuminate the D or the S? Does the transmission downshift and not upshift, or it just doesn't upshift? Are you on a grade? Or flat road?

Check the transmission oil after a drive make sure it's not low.

Do you notice any driveability faults? Engine performance will affect the transmission.

There are PIDs you can monitor to verify the transmission is shifting as desired, gear-rat and tran-rat.

Ty for posting. My particular car is a tech package car as opposed to a PP. So I've got the highway gears ( I think they're 2.87s...?) and the factory tune that governs them. Usually the car upshifts quickly---part of that high-efficiency tune rather than performance like a PP vehicle. So the answer to your first question is that when I say it's slow shifting, what I mean is that the shifts are "hanging" when they would usually go up to the next gear. Worse still, when operating in the mountains, on long downgrades (for example, Hwy 24 coming down from Woodland Park to CO Springs) the trans won't upshift and just hangs in the lower gear...until I hit the upshift paddle.

It's gotta be putting a strain on the trans, and definitely killing my gas mileage.

Usually I just stay in D; Sport mode is reserved for snowy conditions when I really need to have a finer control over what the car's doing. As to the rest of the questions, the issue is inconsistent. Sometimes it'll show up on hills, like I've mentioned, but not all the time. Other times are during acceleration on I-25 on-ramps. Steady state cruising is unaffected; it won't drop back a gear once I'm at speed.

 

[Csbbrah]

Maybe try a pcm reset to see if that will help. Unhook negative battery terminal for 20 mins.

Sent from my LM-Q610(FGN) using Tapatalk

 

[RAYJAY]

68k to 96 k is 28 k you could drop the trans fluid and screen, it does take 2 to 3 changes to refresh all of the fluid, also did you do the ptu oil at all ?

 

[Zpak]

For a quick test I like the idea of “resetting” the PCM with the battery disconnect. I’ve noticed after a few days of mountain driving the car seemed to anticipate driving on grades and would stay in lower gears longer.
Also, being a service duty vehicle it should be treated as such and replace ALL fluids very often. Honestly I’d follow SM105K’s fluid change schedule. I’ll allow him to chime in with the link. Very concise write up.

 

[SM105K]

For a quick test I like the idea of “resetting” the PCM with the battery disconnect. I’ve noticed after a few days of mountain driving the car seemed to anticipate driving on grades and would stay in lower gears longer.
Also, being a service duty vehicle it should be treated as such and replace ALL fluids very often. Honestly I’d follow SM105K’s fluid change schedule. I’ll allow him to chime in with the link. Very concise write up.

Yeah, driving a SHO for ride share is brutal on the car. Start stop all the time, long periods of idling, and more wear and tear. I would say you are entering the realm of extreme duty and I would start follow my regiment to keep your car as happy and it can be.

Post one half way down you will see what I do.

https://shoforum.com/index.php?threads/sm105ks-ownership-performance-maintenance-thread.138235/