Normal or Abnormal shifting behavior?!?

[Gabriel-K]

Newbie here-Recovering Ford owner. Just picked up a 2015 5.7, 8 speed with 135k. Clean, no real service records. First item on the list was oil change(even though the lot i got her from just changed it). Pennzoil High mileage. Mopar filter. Next up, I pulled 2 plugs- pretty worn. Aftermarket plugs. So they've been changed at some point. But I will be swapping those out with some NGK 9245's. Coolant flush after that. Has orange in it. Next I was going to do a Tranny flush and filter. This is where my question comes. Now that y'all have enough back story.

Question I have is:
When I'm on the throttle heavy it shifts pretty smooth. However, if I'm easing into it, it shifts a bit jerky. Almost like it's going back a forth between gears. Is this an adaptive throttle deal or an issue I should looking into? Would a flush help or potentially make it worse? Assuming there is a problem at all.

Ang Go...

 

[89grand]

That doesn't sound normal to me. I have a 2019 Gen 4, and mine shifts the smoothest at lower speeds, even though it's always smooth. Every once in a while, it'll seem to shift more than once, but it's subtle, and not what I'd call jerky at all.

 

[Gabriel-K]

That's kinda what I was thinking too.

I should mention that it does have a Flow Master muffler in it. Would having less exhaust pressure cause this?

 

[Atcer2018]

For comparison, I have a 2018 CC LongHorn with the 8 speed. Back story on mine is, certified preowned purchased at 14k two years ago. Since I’ve had it the slow easy shifts are more noticeable than the heavy throttle shifts. At 20k I changed the pan/filter and fluid. Totally unnecessary but I too am a bit OCD when it comes to fluids. No change in shift smoothness after fluid change. At 40k I changed over to a PPE aluminum extra capacity pan and once again changed the fluid even though it cost a small fortune. Still no change in light throttle **** smoothness. I have AlfaOBD and I reset the adaptive memory which seemed to smooth out the light throttle shifts for a short time but now at 42k it’s back to the way it was before reset. By no means would I consider the shifts as abrupt or harsh, it is just a bit smoother at heavier throttle than light throttle.

 

[co-pilot]

hey Gabriel...... not to sound a little dumb .....but are you feeling the mds kicking in and out?....

 

[CalDad14]

I own a 2017 Ram 1500 SLT, 5.7Hemi, CC, short bed, 6-speed, 4x4, 392gears. <27,000kms.

One thing I've experienced, when accelerating from a dead stop. Specifically up shifting from 1st to 2nd and 2nd to 3rd. I have to keep the RPM's at a constant pace. So holding the RPM's at say 1200-1300, or 1700-1800 until the shift is completed. If I get out of the throttle too soon, I find that causes a bit of a "rough" shift. Again, I've only ever experienced this up shifting 1st to 2nd, or 2nd to 3rd. Transmission fluid is good and at proper level. Re-flash of transmission had no impact. My operation of the vehicle is the difference.

If I recall correctly, you said you were coming from Ford? IMO, you have to Drive it! No radio on, no passengers. Listen. Get a good feel for her. I have the A6, and I have a ton of confidence in it. I once had a rental, Ram 1500 that had the 8-speed but didn't drive it enough to get a good feel for her. It was smooth and got through the gears a lot quicker than my 6-speed. That I do remember!

Hope you get it figured out. Good luck.

 

[Gabriel-K]

Not dumb Co-Pilot, I'm learning here. My 1st experience with the MDS. I watched a you tube on how to turn it off. I'll try that and see it that changes the shift behavior. I'll report back later today.

 

[Jeepwalker]

FYI, most guys are recommending the Penzoil Platinum Ultra Synthetic as the go-to lube. That's slightly different than what you listed, but I don't know what the difference is. Maybe not much. Just throwing that out there. Usually ya can find a great deal on Amazon for about $20/5qt jug, if ya keep checking. Reason is b/c of the lifter/cam issues, which it sounds like you are aware of..

I didn't see that you had changed your truck's tranny fluid. I used the dealer mopar product on mine. If you need to, I've recommended on here before calling a couple small town mopar dealers (parts dept), they may take it out of their barrel for you (bring some clean/dry milk containers). It's significantly cheaper that way and you know you're getting the 'right' product. That's if you haven't changed it already.

Hard to say on the tranny shifting. Most everything's electronically controlled. My jeep tranny was shifting awful. Turns out it needed a new solenoid. My scanner wasn't picking it up, but the dealer's did. I normally do all my own work (even tranny work), but that one I farmed out to the dealer bc I had a busy work schedule at the time. They nailed the problem the first time. $325 well spent in my case.

It could also be a little transmission 'shudder'. Caused by friction inconsistancy issues between the plates during shifting. A lot of people panic when they feel shudder and a tranny shop soaks them for a rebuild. But it can also be caused by broken down fluid, or the incorrect fluid (different additive pkg) and the friction coeficient is slightly different, or didn't mix well with what fluid they 'didn't get out'. The guy before you might have had some lube shop on the S side of town change the trans fluid with who knows what brand??. Then 200 miles later the tranny starts jerking. Owner thinks it's going to die (not linking the fluid change with the tranny behavior) and trades off the truck before it does. Soooo....If someone changed the fluid with a different brand, or didn't use the right Mopar stuff, that could cause shudder. You could take it back to the dealer and see if they'll exchange the fluid with the Mopar product.

If you do it yourself, First off ensure the level is correct when warm. If that's good, then, you might consider either changing the fluid (^all^ the fluid, not just what's in the pan), and drive it a bit to see if it works its way out (I've had shudder on a GM tk that appeared after a trans fluid change with Valvoline, and went away after changing again using Penzoil trans fluid that contained an anti-shudder agent). Drive it, say, 200 miles, to see if it works its way out. Or you could try adding anti-shudder now and if it goes away, problem solved. There's probably a Mopar anti-shudder additive I suspect.

Transmission shudder isn't uncommon. Google it. It can occur ...like after a fluid change (with fluid the trans didn't 'like' or didn't mix well with fluid that was left in it).

 

[huntergreen]

If your not getting any codes, it could simply be the trans adapting to your style of driving.

 

[crash68]

Coolant flush after that. Has orange in it.

The coolant may look orange-ish but a 2015 truck uses the purple Mopar OAT coolant. The purple coolant is known for changing color from purple to a orangish-rose color(cold), check the color when the radiator is warm. If there is any doubt make sure you do a complete flush as mixing OAT with a HOAT (orange) coolant will cause system gelling.
With 135K on the transmission you'll want to replace the pan and fill with new fluid (ZF Lifeguard 8 or equivalent).

 

[Treburkulosis]

MDS makes my 6 speed lug. I just did my fluid and went with a mopar filter kit. Summit racing has a repackaged mopar kit that is actually mopar just not stamped on the box. I went with Redline AT-4 and man it made a world of difference. I would also suggest using a baster and sucking all of the power steering fluid out and replacing it. Dont forget about your rear end fluid. I just did plugs NGK, Coolant at 136k, Mopar. Redline AT-4 in the power steering, Summit had power stop rotors and pads for the same price as Napa or Car quest wanted for stock replacement. Rear end fluid I went with Valvoline. Id also run a can of seafoam in the upper intake through the PCV or brake booster, 1/3 of a bottle, and then seafoam in the gas. Clean the throttle body with throttle body cleaner. Just some things to maybe think about.

 

[Gabriel-K]

Great stuff guys. I appreciate all the feedback. This why we are all on here.

To clarify on the oil- I did use the Pennzoil Ultra Synthetic Platinum High mileage. As read on the threads here. BTW

Good call on the coolant color. It did appear to be orange in color, but maybe it was a bit rose colored. I'll double back and make sure before proceeding with a drain and fill.

Looks like the best bet on the shifting concern (if there is one) is to replace the pan/ filter along with dealer approved tranny fluid.

 

[Octane]

I use lubeguard transmission treatment in the 10oz botte It stops my transmission shudder that happens when I'm idling along with my foot off the accelerator in traffic.I change my fluid every 30k and add it.(rfe65) 168k and still going strong.

 

[El_Lobo_Gris1500C]

My 2021 1500 8 speed seems to shift smoother or nicer when under heavier acceleration also, but when under gradual easy acceleration it doesn’t shift rough, just shifts quickly, doesn’t ring out the gears to high revs so it doesn’t feel as ‘smooth’ or natural when compared to the 6 speed I had a year ago. Switch it out of MDS and watch the gears change to see if it’s changing properly in sequence and not going up and down in gears?

 

[Jeepwalker]

There exists another method to get all the fluid out: (Perform at your own risk). Remove the power steering return hose, add some clear hose to a small white bucket (and block off the pump side -- so fluid wouldn't leak out). A white bucket can be helpful to allow the mechanic to more clearly see when the 'new' clear fluid comes through. A helper to start/stop the vehicle may be needed. Pour new fluid into the reservoir as quick as possible. The mechanic doing the work should already have sucked all the old fluid out and filled the reservoir before starting. Generally the tech might have to shut down the vehicle once and refill the reservoir (it empties fairly quick). He shouldn't let it ever run dry or too low!!

A person can essentially follow the same process with the transmission too (on the radiator supply/return lines). Reportedly (not by me) the tech could temporarily overfill the tranny a couple qts after the fluid/filter/pan gasket change, but PRIOR to starting up after the new fluid is installed. The point of this procedure as has been reported would be to get ALL the old fluid out of the torque converter. The mechanic should install a clear hose into a 3 or 4 gal white bucket. Have a helper start vehicle and the mechanic should watch the color of the fluid. Generally the engine will need to be shut down after 3 qts or so, and a couple more qts added and restarted. Re-run engine till the fluid runs clear. It'll pump all the fluid out of the torque converter. It might be estimated to take appx ~16-20 seconds to pump the fluid out of the torque converter and run clear. Obviously the mechanic shouldn't run the tranny too low on fluid. This procedure is for *Experienced* mechanics only! Esp good to remove all fluid after a an individual purchases a vehicle where they don't know what fluid has been used/added.

Problem with a lot of the commercial fluid exchange machines is over time they, or the fittings, can become loaded with crud and debris, and a person can't see what goes right into the tranny. It all depends on the heigyne of the garage and mechanic doing the work.

Perform at your own risk. I take no responsibility

 

[Joseph Godvin]

Transmission oil should be changed, at that mileage you have no idea how the truck has been maintained or if they pulled a trailer, the oil might be OK, but the additives in the oil break down and need to be freshened up.