Feel a bump or an attempted shift in 7th gear at around 45 MPH

[sandro00]

This is my 3rd Ram with the 5.7 Hemi but my first with the etourque (2024 Limited) (2009 and 2017 were the prior trucks).
Anyone else get a bump feel? I think it's trying to change gears from 7th to 8th (but stays in 7th) or a loose differential feel when cruising at around 45 MPH. It only happens when costing down hill then when the road levels off there's a jolt or bump in the drive shaft. I hope this makes sense. It drives me crazy. Bought new 2 months ago. 2,500 miles on it so far.

 

[joesstripclub]

These trucks do all sorts of things now to try to be more efficient. You could be feeling MDS disengage, it can make a slight jolt that feels like a shift.

 

[sandro00]

I agree, too many factors. I think it's just a rough shift from 7 to 8 then a quick shift back to 7th at that speed with the 3.92 rear end it has.

 

[EdGs]

Sounds like it's at a shift point.

 

[joesstripclub]

I agree, too many factors. I think it's just a rough shift from 7 to 8 then a quick shift back to 7th at that speed with the 3.92 rear end it has.

use the gear select to lock it into 8 and watch what its doing while you drive. You should notice if it goes 7-8-7, if not its something else.

 

[Docwagon1776]

RPM would drop roughly 300 for a 7-8 shift at 45mph. What's the tach show?

 

[sandro00]

I think it's something to do with the etorque. I'm reading on other threads that it may be something to do with the etourque catching while trying to match the RPMs of the engine and the jolt is felt there (my first etorque). I'll look next time I drive and see what RPMs it's happening at. It's always in 7th gear though. Never felt in any other gear and it's only felt on a decline, then the road levels off it's felt there when the gear catches. I appreciate your insights

 

[sandro00]

use the gear select to lock it into 8 and watch what its doing while you drive. You should notice if it goes 7-8-7, if not its something else.

It doesn't do it at all with the gear selector on -8. Wild!

 

[Ramfanski]

Probably just the extra torque from the motor switching from 4-8 cylinders when you touch the gas pedal. Mine does it in lower gears. Stops when I limit it to 8th gear. I think that turns off the cylinder deactivation.

 

[bluecheese]

I'm having a similar issue, but its in lower gears - mainly 3rd gear.

2021 1500 5.7 Hemi with etorque

If I'm driving in light traffic, and I let off the gas and coast for a bit, when I put my foot back on the gas I hear a "donk" like noise and feel a slight jolt.

I don't believe its the MDS as I've turned it off with the gear limiter and still experience the jolt.

Any ideas?

 

[joesstripclub]

I'm having a similar issue, but its in lower gears - mainly 3rd gear.

2021 1500 5.7 Hemi with etorque

If I'm driving in light traffic, and I let off the gas and coast for a bit, when I put my foot back on the gas I hear a "donk" like noise and feel a slight jolt.

I don't believe its the MDS as I've turned it off with the gear limiter and still experience the jolt.

Any ideas?

Might be torque converter locking/unlocking. The 8 speeds are way different form old transmissions in that they can lock the TC in most gears. I'm not familiar with the etorque so it could be something from that system, or a combo of the two.

 

[bluecheese]

I thought maybe it was the U Joints. But I just checked and they look brand new. No play in the joints or drive shaft