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Clunk When Downshifting to 1st

11K views 17 replies 9 participants last post by  wadenkelli 
#1 ·
Another member recently started a thread where he is experiencing some issues with his trans in 1st gear and it sparked me to start this thread and hopefully get some help. My issue is similar however my clunk/thump is occurring while slowing down to a stop and seemingly when the trans downshifts into 1st around 10-15 mph. It is just a quick clunk and I can feel it in the seat and steering wheel. I am also getting some vibrations in the wheel while slowing down but my brakes checked out fine. I do have 35" open country's MT's. I haven't been able to determine if it is trans related or driveline related. I am running anarchy with trans tuning. I haven't noticed any other issues with shifting. I have found some old threads where similar problems are being had and the possible culprit was u-joints. If anyone could help me out it would be greatly appreciated.
 
#3 ·
Thanks for the reply. I have a hard time believing its normal gear noise since it just started a little while ago. I have tried playing with different scenarios and what not such as hitting the brakes harder, shifting to neutral, using/not using exhaust brake, etc...but can't seem to get consistent results.
 
#4 ·
I had that same slight clunk at about 20 mph almost every time I slowed down that started at about 14,000 miles. I took it into my dealer and explained the problem, they reflashed the transmission and the problem went away. I’ve had about 500 trouble free miles since then.
 
#8 ·
I have a 2013 2500 HD my truck does the exact same thing. I brought it to the dealer and they flashed the transmission it did not fix the problem. it sounds like backlash in the rear end or the transfer case. I’m going to bring it to a different dealer for a recall next week. I’m going to ask them to look at it while it’s in there I’ll let you know if they come up with a fix
 
#17 ·
I have a 2013 2500 HD my truck does the exact same thing. I brought it to the dealer and they flashed the transmission it did not fix the problem. it sounds like backlash in the rear end or the transfer case. I’m going to bring it to a different dealer for a recall next week. I’m going to ask them to look at it while it’s in there I’ll let you know if they come up with a fix
Same here. Dealer said some trucks just “do that” shouldn’t hurt anything. Which is a completely useless answer.


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#9 ·
Mine went in to the dealer today. They called back and said they're ordering a new valve body for the transmission. They said they also re flashed the PCM which seemed to make the problem go away again at least temporally.

I'm going to get my truck back for now until they get the valve body in (3-4 days).
 
#11 ·
Just called the dealership today because they hadn't called to tell me the part was in yet and of course the parts department said it was never ordered... So, they ordered it today and I have my appointment on Tuesday to get it installed. I'll post again once I have a couple days to try it out.
 
#14 ·
Curious as well, 2013 does it off and on
 
#16 ·
I'm experiencing the same. Dodge suggested that they flashed the 68RFE tranny and I had all T fluids changed. at 65000. Expect it should be better now. Also they said rear Transaxle fluid was shot which could account for reduced anti slip function. I'll let you know when I pick it up.
 
#18 ·
Same story with my 2017 2500 Ram 6.7l.
It started at 16,000 miles. Took to the dealer and they flashed the tranny and it went away. It comes back every 2,000 miles. I take it in and they flash it again. I have done it 3 times and it is doing it again. Next time i go to the dealer i will have them look into it deeper.
 
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