5spd 2.7L Popping/rattling under hard acceleration

Sounds like clutch chatter...I had the same thing when I was running a performance Stage 2 clutch. Rattling sound from the trans when taking off from a stop. Sounded like a rain maker almost. All research I did led me to believe it was just a normal symptom of a performance clutch

 

Oh interesting! Didn’t know that’s how they did that. Yeah hope that helps! It’d be sweet if it were something simple like that. Best of luck

 

Thanks brother, that's what im hoping for as well!

If it's just clutch chatter, then im fine with it, but i am unsure if it's clutch chatter since it never happens when im slipping the clutch. This always occurs when it is fully engaged. Is it still possible to have chatter under these conditions? If the chatter is normal, then i've got some other issue that's causing the vibrations while decerlating

 

In 1st gear WOT, it sounds like a rattling/grinding/popping kinda noise. Really weird, thought it was ujoints at first since i've had similar noises caused by those, but after replacing those, still no dice. I am leaning towards it being driveline related though just based on the symptoms of when it occurs

 

Definately check out the heat shields.. but i have a feeling that you may have to double check your clutch work. Sigh... pull the trans and check the torque of the clutch cover bolts, etc.

I wonder if you got a defective clutch kit and the those damper springs in the disc are screwed up. Does the disc have springs? All the torque of the drivetrain is going to go against them under hard acceleration

 

Shit.. i sure hope not.. Just pulled it for the second time this past weekend. All the flywheel bolts were still torqued down where i left them. Clutch cover bolts also looked good. Replaced them (since i had to take the clutch cover off) this past weekend and torqued them to the factory 14ft/lbs out of the FSM. Other than an alignment issue, i dont see what i could've messed up. I used the alignment tool, so i dont think that's an issue either..

It's possible. The clutch disc does have four springs. Still waiting to hear back from LCE. About to call them back

 

Solved part of the problem this weekend. Installed my LCE headers and after doing that, it no longer pops/grinds in 1st gear WOT. Im guessing the manifold heat shield was what was rattling under hard acceleration. The truck is still vibrating while decelerating from 40-30 mph in gear. Not sure what's causing this, but that is what i am pursuing now

 

Does it shake at a rate of about 4 shakes per wheel revolution (well actually, 4.1 times per revolution)? If so, its your driveshaft.

If it happens at 5.9 times per wheel revolution (and now you're asking me if I'm insane, because you can't tell the difference between 4.1 and 5.9 times per wheel revolution) in 3rd gear, then its the input side of the transmission, i.e. clutch. I find it very unlikely to be gear or torque related if its input side of the transmission.

 

That there is some shweet vibration diagnostics my friend

 

If you are beating sh** out it, why are you worried about a popping noise when you floor it in 1st gear. You will have more problems than that with your habits, just sayin. Dodge 1500 would never make it past 80,000 miles with your driving style. You are very lucky to get 254,000 driving it like a Taliban fighter.

 

Yea take it easy you Taliban fighter

 

Haha the truck needed a beating to get out of it’s own way when this was happening.. its a little better now

 

Okay to revisit this, it ended up being the clutch disc just vibrates and chatters like a mofo, even when in gear. THere are certain rpm ranges while accelerating and decelerating where it acts up and then it smooths out and is good. Its mainly during light acceleration, cruising in any gear other than 5th, and decelerating. In total i ended up dropping the trans 5 times doing something different each time to try to isolate the problem. It ended up being the clutch disc, so i figured maybe i got a dud so i installed a brand new SPEC clutch in an effort to put an end to this long episode of trans in and trans out. Long story short, the new SPEC clutch has similar vibrations as the LCE dual comp clutch that i started out with. So i decided i had enough of the transmission work, so i have been running it hard for the past 25k or so with no issues. Ive gotten it figured out for the most part so i can keep the vibrations/rattling to a minimum, but i dont really have many options as i need a clutch with at least double the stock tq holding capacity

 

I used to floor this stock go cart all the time so I can relate to your story!! Sold it last year though. Most fun manual I ever had.

 

Only mentioning this because you were on the topic of clutches. Not saying it was related to your vibrations.

I have found in the past that the powder-coating around the holes for the dowel pins, needs to be dremeled clean. That otherwise, it can cause a weird binding of the clutch plate, and thus strange operations. From vibes, to engagement/disengagement issues. Now it is just a standard practice for check and ream if necessary.

 

Thanks for the tip! Definitely noting this for the next time i do a clutch

 

SPEC Clutch, Exedy, LCE, Competition Clutch. Seen the same on all of them. From Hyundai Gen Coups, Tacomas, Skylines. Doesn't matter.

 

When you say you've seen the same, you mean the vibrations i've been experiencing? If so man i wish i wouldve known this sooner. Tracking this down was a bear of a job

 

Just seen the same with problems associated with the dowels going through the powder-coated holes. Regardless of the brand. Only had to come across the actual problem I encountered once, to make sure to remember the source if the cause.

 

Did a little research on gear rattle not too long ago and came across these articles that described my clutch issues to a T. Good info for those trying to track down vibes. Mine is 100% clutch related in my 5spd 2.7L. I have had bad vibes on my LCE dual comp clutch and also the SPEC stage 2+ that is in there now. So if anyone is looking to upgrade and doesnt want vibes, i'd highly recommend getting a clutch that is just enough to cover your power needs. I went with one rated for 385ft/lbs and 401ft/lbs and there are definitely some vibrations during certain rev ranges during accel and deceleration. My truck also has a very slight rattle in neutral like described in the ACT article. Barely touch the gas, or flip on the AC and it goes away. Just wanted to get some more info out there for folks considering an aggressive clutch upgrade in their 2TR-FE

https://tremec-blog.com/clutch-vibrations-identify-cause-and-solve/
https://www.advancedclutch.com/articles/act-technical-bulletins/gear-rattle