Hi folks,

I have a 2005 Dodge Dakota (4wd, 3.7L, Automatic). I'm getting a very loud clicking/tapping (or almost grinding sound? although it's more continues like a tap) from around the transmission area (?), maybe a little bit lower or around where the exhausts manifolds connect (both sides).

It occurs in these situations:
In reverse (occurs the most hear, is constant and never goes away and speed of sound increases when gas pedal is pushed. Occurs during idle, although the click/tap is very slow in idle and slows to a crawl in idle)
10-25 mph (occurs frequently in this range when gas is applied, does not occur if gas isn't applied)
around 25mph (into second gear?) the sound is very fast/loud until about 25 mph or so, where it goes away entirely and fairly abruptly.
It also occurs sometimes in faster speeds (40+), when applying gas. Less loud, less frequent and much softer.
It does not occur at all when the truck is in park (even with gas applied)

For some context, the sound (in reverse and around 15mph with gas applied) is very loud, and this is something other drivers or anyone around can easily hear (gets some head turns lol). Something is definitely wrong. I had the truck sitting a little bit while I was recovering from a medical issue. Thought maybe at first that something was rattling in the exhaust, as I had the cat and manifolds done shortly before it sat for a little...but now I'm not so sure it is the case as the sound has gotten worse/more frequent. I've only been driving it occasionally since I noticed the sound (take the riding mower couple miles down the road to my moms, etc.).

Think it's the transmission dyin? it shifts into gears entirely fine without any issue, jumps, stutters etc. The only indicator of an issue is the sound. Aside from that, the truck is running well. All fluids (including tranny fluid) are topped off and look fine.

Any thoughts? Thanks in advance. I could get a video/audio of it on my cell phone if that would be helpful.

 

Possible exhaust leak due to broken exhaust manifold bolt/stud(s)...very common problem here with numerous previous threads: When the engine is attempting to push a load (in gear), the torque causes the engine to rock in the opposite direction, which exerts a bending/twisting force upon the exhaust system and opens up a tiny gap between the exhaust manifold(s) and the cylinder head(s) where the broken manifold bolt/stud(s) should have been holding it tight. Hard to replicate in park/neutral, even with gas applied, because the engine is not attempting to exert a load to move the truck (no torque applied) and therefore isn't being rocked and twisting the exhaust system.

 

Thanks for the input dude. It turn out, It doesn't appear the exhaust manifold bolts/studs are the issue. All of that (bolts/studs/manifolds) are brand new and appear fine. I did, however, while checking those out, come to the realization that the sound is coming from the transmission on the passenger side near the manifold. So thanks for getting me in the right direction. And it gets weird from here lol. Here's a diagram of where the sound is coming from:




That might not be the exact right tranny, but essentially, two bolts are missing about where I've noted in the picture. Also noted where the tapping sound is coming from that front part of the tranny. That metal flap seems to be reverberating and causing the metal tapping sound (or something is tapping against that metal cover from the inside of the tranny). It almost feels like something is tapping against the metal from the inside, but it might just be that metal cover rattling..not sure. It's really, really odd. The bolts are a decent size, and I can't imagine they worked themselves out? All of the other similar tranny bolts are so tight it would likely take an impact to get them out. I tried to throw in two smaller bolts (to pass through), a washer and nut to see if getting the metal edge flap (?) tight helped, and it does alittle, but i still hear the tapping sound loudly. I don't know much about transmissions, but is it possible something is wrong with the tranny and somethings hitting against it from the inside? Or is it likely just that metal cover rattling cause two bolts are gone?

I do want to try using the correct bolts though to see if it helps more with the sound. The tranny is actually prethreaded for them. If anyone happens to have an idea what the oem bolts are, I suppose I could try that and see if it's just that metal cover rattling when in gear. I'm up for any suggestions lol. Super weird those bolts are just gone and that metal edge is kind of bent up near the bolt holes ever so slightly. anybody see that crap before? I've owned the truck for 4-5 years now...so no clue why the bolts would be gone, unless they came out themselves (really unlikely I think) or the previous owner had done a repair somewhere around there and forgot to put them back in. Any thoughts welcome!

 

I can't speak for the 3.7l engine or transmission, but on the 4.7 there is a thin metal cover on the bottom of the transmission for access to the torque converter bolts. It's possible that a bolt has come loose or something may be bouncing around inside. It's simple to open up and have a look. The service manual doesn't mention anything about how many bolts or where, but there should be at least two through holes meant for alignment studs that may or may not be there.

 

Cool stuff. It's a little hard for me to get fully under the truck for long periods of time with some medical stuff right now (motorbike accident, had to have hip surgery), but once I'm moving around a bit better I'll definitely check for that access panel. Looking online, it seems it would be the same as the 4.7

Are you saying those two holes could be intentionally empty? They do appear to be through holes, and there are two of them.

I was looking around some forums with folks having what appears to be my issue, and I'm really really starting to think that when I had the headers, cat, y-pipe replaced...I think they accidentally bent the dust cover itself in just enough that the bolts that hold the TC to the flexplate are hittin the dust cover...The sound started within 100 miles after I had those done and the dust cover looks roughed up. I also have come to the realization that the same garage simply cut the downflow o2 sensor cable and put in a used pipe/cat (was told it would be new...but it's clearly not after checking it out...old o2 sensor in it not connected to anything as well). Aside from getting the headers on right, I'm realizing they did a really terrible job, knowing I couldn't even get under there to have a look for at least a couple months. They didn't even reinstall the plastic wheel well covering on the passenger side. I'd be tempted to take this back to them or threaten legal action, but it was done 6+ months ago. I just couldn't drive the truck at the time or check the work then. Sucks.

Think I could bend that cover outward somehow? Or am I looking at trying (or having a friend or another shop) to replace the dust cover? I'm hoping nothing got messed up in the tranny if those bolts are in fact tapping on the cover some.

Again, any input appreciated.