Trans shudder at fixed RPM

[kthaxton]

SiriusXM 350 Red, White and Booze

I demand more from my music.

 

[smittyd174]

Drive it like you stole it the love it.

 

[gtwitch]

I am driving it and I really love the truck, so tomorrow it is going back with me to the dealer. I and the mechanic are driving it and the other truck/s together---ANSWERS will follow!
gtwitch in wyoming

 

[Wiredawg]

After reading this from the OP, my assessment is the truck is shifting close to max tq, and as it shifts the shudder is the tq multiplied in the trans. My 03, 09, and 17 do this. 09 and 17 were/are Aisin.

These trucks make big tq low, and thanks to better trannies, instead of slipping, its grabbing or shuddering. Just my experience with Ram Cummins autos.

Let us know what the dealer says.

Cheers, Ron

 

[gtwitch]

Wiredawg, not anywhere near max torque!!! start off from a stop sign or light very light on the pedal and every shift and rpm goes thru 1200 the shudder will be there and lasts for about 100 rpm and is gone until you go thru 1200 to 1300 rpm again and there is the shudder again, so I think it is the torque converter or the flex plate but I could be wrong. Still did not feel it on the test drives on anything but my truck and I have put a about 200 miles on it and I think it is now a stronger shudder than it was so, It is going back to the dealer soon as he opened a case # on it. I just think this dealer does not want to deal with the issue under warantee. I guess we will see and I think I will become this dealer's nightmare for a while because I don't think I'll just go away!
gtwitch in wyoming

 

[Wiredawg]

My truck hits max tq 750 lbft at 1600 rpm, so yours is in a P/U approx. 800-850 max TQ? Not sure where your tq is @ 1200 to 1300 RPM, but I'm betting is 70 to 90 percent of your Max TQ. I would have to drive mine looking at the shift points to see where it shifts, but I'm confident my shudder is the trans grabbing the tq. My 03 shudder was much more pronounced with bigger jump between gears 450 HP and 900 Lb ft TQ and short bed too.

You know your truck and you may have a problem with your driveline or trans. These things are hard enough to diagnose in person, let alone over the Internet. we ride in each others truck and likely reach a common understanding of yours and mine.

One more thing: 6'.4" or 8' bed? short bed add a little more angle in the rear driveshaft.

Good luck getting it fixed.

Ron

 

[gtwitch]

Ron,
I can get it to shudder in neutral or reverse and it will do it stopped with light brake or just moving away from a dead stop at very light throttle above idle so I think there is very little torque being developed. When you are in 4th at 30 mph at 1200 rpm and the shudder is there , if you go to 1500 rpm and then throttle off, as the truck slows down and RPM gets down to 1300 and then before 1200 the shudder will come at near 1200 and then go away before it coasts on down to 1100 rpm and the same thing happens at 40 mph in 5th gear and 1200 rpm and in 6th again at 1200 rpm and what ever gear you are locked in, the shudder comes and goes at 1200 rpm and goes away as you are going up or down from 1200 rpm with or without a load on the drivetrain. I received my new TDR magazine yesterday and saw that FCA has a new flex plate that has ( I think 10) bolts to the new style torque converter for 18 and 19 trucks, sooo! I wonder here!
gtwitch in wyoming

 

[Wiredawg]

Ron,
I can get it to shudder in neutral or reverse and it will do it stopped with light brake or just moving away from a dead stop at very light throttle above idle so I think there is very little torque being developed. When you are in 4th at 30 mph at 1200 rpm and the shudder is there , if you go to 1500 rpm and then throttle off, as the truck slows down and RPM gets down to 1300 and then before 1200 the shudder will come at near 1200 and then go away before it coasts on down to 1100 rpm and the same thing happens at 40 mph in 5th gear and 1200 rpm and in 6th again at 1200 rpm and what ever gear you are locked in, the shudder comes and goes at 1200 rpm and goes away as you are going up or down from 1200 rpm with or without a load on the drivetrain. I received my new TDR magazine yesterday and saw that FCA has a new flex plate that has ( I think 10) bolts to the new style torque converter for 18 and 19 trucks, sooo! I wonder here!
gtwitch in wyoming

Yes sir.

Please let us know what the fix ends up being.

Cheers, Ron