8 speed transmission problems, or just how it is?

[David Stewart]

I have a 2020 1500 Big Horn with 8HP75, 4x2, 3.21 Rear Axle Ratio. First thing in the morning, in reverse if feels like I'm driving on a rumble strip, then the transmission is really sluggish. I have the bump when stopping, and seems to be getting worse at almost 5K. I love everything about this truck except this and the MDS.

Is it okay/safe for the engine to run with the MDS off a lot?

 

[cnitty]

I have a 2020 1500 Big Horn with 8HP75, 4x2, 3.21 Rear Axle Ratio. First thing in the morning, in reverse if feels like I'm driving on a rumble strip, then the transmission is really sluggish. I have the bump when stopping, and seems to be getting worse at almost 5K. I love everything about this truck except this and the MDS.

Is it okay/safe for the engine to run with the MDS off a lot?

Perfectly fine to drive without the MDS on.

 

[joels]

Done and the thump is gone.

cnitty, could you outline what you did? Pics would also help. What grease did you use?

 

[Micah12]

I have a 2020 1500 Big Horn with 8HP75, 4x2, 3.21 Rear Axle Ratio. First thing in the morning, in reverse if feels like I'm driving on a rumble strip, then the transmission is really sluggish. I have the bump when stopping, and seems to be getting worse at almost 5K. I love everything about this truck except this and the MDS.

Is it okay/safe for the engine to run with the MDS off a lot?

oh no, the tranny bump stop on the 2020's. I have had my tranny and valve body replaced, still have the issue.

 

[TheEnder]

My Chrysler 300 with the 8HP45 flares horribly on the first shift of the morning, probably jumps up around 700 RPM on the first shift of the day. After that it’s fine.

No bump stop issues, just the occasional shudder when it’s cold.


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[Ridgerunner665]

Mine is slow to shift first thing in the morning... no rev hang or anything... but it hangs on to 1st gear for a while.... nothing drastic, and it will shift if I give it more gas... leaving my house is all downhill for about 1/2 mile.

I'm not really worried about it, but I doubt the neighbors like it, that Carven exhaust is a little loud.

No bump stop in mine....2018 Bighorn 1500.

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[BWL]

My truck has recently started holding gears a lot longer on flat and slight downhill and starting in a higher gear when doing 3 point turns. Not every time, but enough that I'm concerned. Anybody else with similar experience? As far as I can tell it isn't leaking any more and it's been good for a year since the valve body was replaced. Just started doing it in the last week.

 

[cnitty]

cnitty, could you outline what you did? Pics would also help. What grease did you use?

I just removed the drive shaft and lubed the spline of the two piece shaft.
https://www.amazon.com/dp/B00FM9B6PC/ref=cm_sw_r_cp_apa_fabc_znV6Fb71KBY78

 

[Uncle Damo]

had same problem dealer replaced first trans because torque converter vibration at 6,000 km....second trans for 2>1 downshift bump,relearn ,valve body replaced didnt help at14,000 km ......3rd trans all good with 60,000 km on it ....3:21 gears

In your trans replacements, did you ever receive any CEL or stored codes ? I'm going through a similar situation now but the dealer's being less than helpful without any codes stored.