5spd 2.7L Popping/rattling under hard acceleration

As the title states, been having some issues with my 2009 R155 5spd with 245k miles on the clock. When accelerating with my foot to the floor in 1st gear (and only in first gear), i get a very nasty popping/rattling noise.. This is only present in first, i can floor it in any other gear and it wont make this noise. Also the truck will vibrate/rattle when decelerating in 3rd gear from 2700-2200RPMs. I thought this was the pilot bearing making noise, so i dropped the tranny yesterday and replaced that. Still the same issue continues.. Any thoughts on what this could be?

All these problems started after replacing the clutch in my truck with one from LCE. Is it possible that this is just part of the break in for my clutch? Doesnt sound like any chatter i've ever heard, and it does it not while slipping the clutch, so i'd venture to say no on this one..

Is it possible the Carrier bearing can make these types of noises?

What i've done/replaced:
3 new spicer u-joints
LCE dual comp clutch kit
New pilot bearing
New TOB
Lightweight LCE flywheel

 

@gearcruncher @b_r_o @MrCrowntown

paging our resident experts

 

Seems as if you would hit the rev limiter by flooring it in first gear rather quickly.

 

Quicker than stock with the lightweight flywheel, but shes a heavy ol girl, so still pretty slow to rev up overall lol

 

bad clutch?

 

How does it act when you drive normally? If you want an honest answer I think the problem is the "lightweight" flywheel and or the clutch assembly. The engine was not designed for that.

The symptoms didn't occur until after the clutch / flywheel was replaced correct?

Maybe I'm just an old man, but I have never seemed to have had a need to floor a truck in first gear. It seems counter productive to me.

I would say if you want to keep this setup, don't floor it in first gear.

 

Clutch doesnt seem bad. Grabs and holds good and doesnt chatter excessively, no TOB chirp, etc. Everything went together easily..

It acts normally except when im decelerating in 3rd gear or if im driving in 3rd and i let of the gas at all in the 2200-2700rpm range, i get a bad rattle/vibration

Correct

With a truck on 295s and about 750lbs of added weight, even with 4.88s it is sometimes necessary to floor it to make this ol turtle get out of it's own way.

Any idea what could be causing this? not flooring it in 1st gear is more than likely out of the question. Need all 182 torques this beast is putting out

 

From just the logical reasoning this is what I have:

Did not rattle or vibrate before clutch/flywheel replacement.

Replaced clutch / flywheel assembly

Now it does rattle and vibrate.

Conclusion something isn't right with the clutch / flywheel or associated parts.

 

That's an interesting symptom.

Carrier bearing sounds possible. I have a shimmy since upgrading my clutch, but never a rattling..

Is your driveline aligned properly? Angles are good?

There's also a possibility that because of the rigidity of the springs in the clutch, the harmonics are just gonna be different.. I know thats not what you wanna hear but that's the mod life lol

 

I could have saved you from dropping the transmission and replacing the pilot bearing ,but am having a difficult time trying to diagnose your popping issue .
In most cases , popping is created from extreme thrust such as a transmission being torqued and the alluminum housing rubs up against the undercarriage of the truck .
Perhaps if you could make a video , it may help us pin point the problem or at least narrow it down .
If you floor the truck in reverse , do you get similar noise ?
Keep in mind that when you floor the truck in the opposite direction , torque is also applied in the opposite direction .
With this being said , you may only have issues with popping in first gear under high torque demand .
Sounds like you need to stick your nose back under the truck and make sure everything is tight and assembled properly .
Is the crossmember installed properly ? Is the transmission mount installed properly ? Can you see if the transmission comes into contact with the under body of the truck ?
From your explanation and without a video , these are the first things I would be looking at .
Its a new clutch , and grabs better than the factory clutch . How are your ,motor mounts ?
The guys who posted above me also have excellent tips .

 

Makes sense to me too. Seems like it has to be relating to something i installed or had apart during the install

I dont think its the carrier since it has the right amount of play in it, but i might end up replacing it if i cant track down the noise. Seems like it's something else though.

What kind of shimmy do you have? and when does it happen?

Driveline is aligned properly and angles seem to be okay. I've never had any problems with driveline vibes before besides ones caused from a bad u-joint

If its normal for it to make that noise, im good with it, but it does not sound normal. Sounds like im screwing something up lol

Good tip, ill get back under there and check this out to see if there is anything obvious rubbing

I can make a video and try to post it later today

have not tried flooring it in reverse, but will also give this a shot and see what happens

Crossmember is installed properly. Trans mount is installed properly. Only thing i can think of is that maybe the white bushing/mount that goes in the crossmember on the bottom of it is not installed correctly? any idea if there is a specified adjustment for that piece? it's the round piece that threads into the bottom of the tranny mount

Motor mounts look good, dont have any issues with them AFAIK, and it's an 09 so it should have the upgraded mounts from the factory

 

If you take a prybar, and really get under your trans mount you can see how much it moves. A visual wont tell anything. Also it might be advantageous to get an IEDL center support bearing and use an angle finder to ensure your angles add up to as close to 0 as possible. Eliminate the excess motion that is engineered to create comfort. All those isolated components can add to the vibes when you start removing isolated components, like the clutch and flywheel.

That's where I am at, unless we wanna talk about transmissions internals lol

 

This might sounds silly, but could it be the engine pinging? That sounds like metallic rattling.

 

i thought the same thing. Filled it with premium, same thing continues

 

You sure its the transmission that's making the sound?
Have you considered the exhaust heat shields? Exhaust heat shields are highly suggested given the description of the symptoms -- hard acceleration in 1st gear, off throttle in 3rd. This would be sympathetic vibrations.

While it may seem overly coincidental that an exhaust noise appears at the same time some major change was made, the proximity of the exhaust to the transmission suggests the possibility of having accidentally hit it while doing transmission work.

 

Great suggestions everyone. Going to do some troubleshooting when i get some more free time. I do think it could be related to the cat heat shield. The front one seems to be tight but when i shake the cats a little bit it makes some noise so maybe there are some rocks in there or something. The back cat's heat shield is gone, mustve fallen off

 

Also pay attention to the heat shields that are bolted to the cab above the exhaust. They can also rattle when they get loose.

 

Yes, i did a preliminary shake-down on those too, and they all seemed to be tight. Will definitely give them a second check though

 

Slip joint on the driveshaft? Mine used to make a crunch noise before I packed that with grease. Only in first when I really got on it

 

Prerunner doesnt have a slip joint. The front of the driveshaft slides on to the tranny output shaft and acts "kind of" like a slip joint. Going to grease this up though as it did seem to fight me when i was putting the driveshaft back in

Thank you for the suggestion sir!