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Discussion Starter · #1 ·
Hi Everyone,

I have a 2012 Express with the hemi. When I am at a stop or nearly at a stop, with the brake not applied, I feel a slight shudder. It's as if the torque converter is grabbing and letting go at a pretty low frequency. I guess you could describe it as a small surge. I find myself applying the brake when stopped even on slight inclines where I didn't need to do that in my old truck. It's not super annoying but its noticeable and was curious if anyone else has experienced this.

Thanks for your help.
 

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Can't help you out with your question however check out this link. Please keep us updated.... I too also noted the other day that there was a slight humming noise and when I let off the gas it stopped???

http://www.ramforumz.com/showthread.php?t=93998

Ed
 
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Discussion Starter · #4 ·
Thanks Chunkem. Captain, I'm not sure, I will keep my ear open the next few days for noise. Have you just lived with the shudder or had the dealer look at it?
 

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I've just been dealing with it. To be honest, I didn't even think about the torque converter (brilliant analysis by the way) and figured the dealer would just say that the rotors were warped, let us know if you take it to the dealer and what they say. I bet your right on the torque converter.

I was hoping that Chrysler had upped their quality control when purchasing the truck. Oh well hope it goes out within the 5 year 100,000.

Wanted to mention that I bet this and the noise is connected, anyone else have that has one, the other, or both, should chime in.
 

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I believe it's normal to have some fluctutation (pulsation) in the output torque from the converter, when at a dead stop (speed ratio = 0). This is usually most noticeable when on an incline, trying to launch the vehicle.

I don't think there's any way to "fix" it. Apparently all converters have this pulsation to some extent, although some designs are worse than others. Kinda like tire noise I guess. All tires make noise, but in most cases it's so little that you don't notice it. Some tire designs create enough noise that they are noticeable.

We don't usually see this complaint on Ram trucks.
 
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Discussion Starter · #7 ·
Thanks for the responses guys. Captain, I did notice a whine in that range on decel today. TransEngineer, it does do it most noticeably on inclines. I also noticed that the truck will roll backwards on an incline, is the converter not designed to prevent this?
 

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All trucks will roll back on a grade - you just have to use a grade that's steep enough!

In Drive, you should always have positive torque on the driveshaft. The torque at the wheels will be the engine torque (at idle), times the converter stall torque ratio, times the 1st gear ratio, times the rear axle ratio. On minor grades, this torque is often enough to hold the truck against rolling back (or even to creep up the grade). But as the grade gets steeper, you will eventually reach a point where gravity wins and the truck rolls back.

If your current truck behaves differently than an older one, it could be a lower (numerical) axle ratio, or a lower stall torque ratio in the converter, or a different 1st gear ratio, or different engine output at idle (which could be due to a lower idle speed).
 

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Not sure if this is what you're describing, but there's also a thud you'll sometimes get when coming to a stop. This has been attributed by many to fuel slosh, but when I complained about it to my dealer they told me it was a thud from the braking system when you have the hill start feature enabled. I disabled mine and the thud went away under such conditions. I re-enabled it once I knew what was causing it.

Anyway, not sure if that's what you're talking about directly, but thought I'd throw my .02 in to the mix.
 

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Not sure if this is what you're describing, but there's also a thud you'll sometimes get when coming to a stop. This has been attributed by many to fuel slosh, but when I complained about it to my dealer they told me it was a thud from the braking system when you have the hill start feature enabled. I disabled mine and the thud went away under such conditions. I re-enabled it once I knew what was causing it.

Anyway, not sure if that's what you're talking about directly, but thought I'd throw my .02 in to the mix.
Interesting point - not one I've heard before. Did you get the thud only when on an incline, or on level ground as well? Hill Start Assist should only be active if you're on an incline.
 

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I know this thread has been posted for a while but I have to comment. My Ram is doing the same thing. Usually when at a steady 35mph speed with eco active I get the torque converter shrudder. Hate to have the dealer rip it apart. Anybody come to a conclusion with this shrudder issue?
 
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