8HP70 Swap

[JayDizzle]

JayDizzle, my brother..... See this post I created recently after recently purchasing a 2021 Ram 1500 Classic.....

2021 Ram 1500 Classic 5.7 / ZF8 — Low-speed moan/resonance around 1,400 RPM after upshifts. Normal?

I have a 2021 Ram 1500 Classic Tradesman 5.7 Hemi with the ZF 8-speed, around 141k miles. The transmission shifts great... no clunks, slipping, harsh shifts, delayed engagement, flare, or shudder. Honestly, it shifts so well that I’d imagine a new ZF8 would feel about the same. The only thing...

www.ramforum.com

Took it to the dealership. I mentioned that it appeared to be some exhaust resonance noise and pointed at a couple things for him to check out while it was on the lift. He drove it around and then when I got there later it was still on the lift.... he took a screwdriver and tapped the exhaust pipe from front to back.... and at some point there's approx. a 3 ft. section of pipe that has some internal baffle that makes a VERY similar noise. Since you've replaced all these things.... if you REALLY want to get rid of the noise.... tap your exhaust pipe and you'll more than likely here the same "note" when you get to a certain part of the pipe that has an internal baffle. I'm about 99% sure that replacing this pipe is going to get rid of our 1.4k RPM "vibration" noise.

I mean it has to be something stupid like that. At this point, I’ve replaced the entire dang driveline & it still does it.

I’ll get under there & poke around at it. Let me know if you do anything & I’ll do the same. I still watch this thread. And thank you, btw!

 

[Sherman Bird]

JayDizzle, my brother..... See this post I created recently after recently purchasing a 2021 Ram 1500 Classic.....

2021 Ram 1500 Classic 5.7 / ZF8 — Low-speed moan/resonance around 1,400 RPM after upshifts. Normal?

I have a 2021 Ram 1500 Classic Tradesman 5.7 Hemi with the ZF 8-speed, around 141k miles. The transmission shifts great... no clunks, slipping, harsh shifts, delayed engagement, flare, or shudder. Honestly, it shifts so well that I’d imagine a new ZF8 would feel about the same. The only thing...

www.ramforum.com

Took it to the dealership. I mentioned that it appeared to be some exhaust resonance noise and pointed at a couple things for him to check out while it was on the lift. He drove it around and then when I got there later it was still on the lift.... he took a screwdriver and tapped the exhaust pipe from front to back.... and at some point there's approx. a 3 ft. section of pipe that has some internal baffle that makes a VERY similar noise. Since you've replaced all these things.... if you REALLY want to get rid of the noise.... tap your exhaust pipe and you'll more than likely here the same "note" when you get to a certain part of the pipe that has an internal baffle. I'm about 99% sure that replacing this pipe is going to get rid of our 1.4k RPM "vibration" noise.

Just like many musical instruments.

 

[BlingRam]

JayDizzle. I can only assume that your exhaust vibration noise is the same as mine. I'm so glad that I actually took it to a shop instead of cutting the pipe and trying to clamp a replacement straight pipe on.... because it STILL would have made that noise. Long story short, it was one of the exhaust hangers not being welded out enough. I don't remember what it looked like before, but I could only imagine that some leather belt / fabric (or other high temp resistant substitute) would slide between the gaps and solve this problem, also, without even needing to weld. But either way, this should fix your problem....

2021 Ram 1500 Classic 5.7 / ZF8 — Low-speed moan/resonance around 1,400 RPM after upshifts. Normal?

I have a 2021 Ram 1500 Classic Tradesman 5.7 Hemi with the ZF 8-speed, around 141k miles. The transmission shifts great... no clunks, slipping, harsh shifts, delayed engagement, flare, or shudder. Honestly, it shifts so well that I’d imagine a new ZF8 would feel about the same. The only thing...

www.ramforum.com

 

[JayDizzle]

One question comes to mind, though.. did your’s only do it while moving? Mine does not vibrate at all in park. I can have my buddy weld that out, though no problem! I know exactly where that hanger is!

 

[BlingRam]

One question comes to mind, though.. did your’s only do it while moving? Mine does not vibrate at all in park. I can have my buddy weld that out, though no problem! I know exactly where that hanger is!

Never while moving. Only when driving around 1400 RPM. Never would have found this thread, except I was looking for all posts talking about the 8HP70 transmission since I had recently done a filter replacement & refill and had TERRIBLE service from the dealership.

I'm really just learning this new to me truck and hadn't really experienced the MDS vibration until AFTER the trans service. Just occurred to me in the past couple days that my transmission is just fine. But the "WOHHHHH" note at 1.4k RPM is most likely this (or one of) the exhaust hangers. Can test for sure by beating on the pipe around the hanger(s), then use some huge channel locks to clamp the hanger down all the way and beat some more. Or like I said, could try sliding some leather or something between any close gaps between the hanger and pipe or the hanger itself (you can see in my pics that they welded the parallel pieces of hanger together also).

I'm pretty sure you're about to get the peace of mind you've been searching for tho. Enjoy!