Hey guys, I've got a situation with my stang thats driving me nuts.. Especially while cruising on the highway. I have a 4.0, mated to a rebuilt TR3650 with a GT aluminum driveshaft and 8.8 rear end.. Borla dual exhaust

As the title says, I have a "driveline" noise that pulsates/drones whenever I am on the gas, no matter the gear... Pop the trans in neutral, and the noise vanishes. Its easier to hear the noise at speeds above 30+ mph and around 2k-ish RPM's

I feel like it might be the exhaust, because its super loud under load and much quieter without one (just revving in neutral, even at highway speeds).. TIA!!!

 

I get noises like that even with my automatic, and yep, pop it in neutral and it goes
away. When the A/C is on, idle in gear, the thing growls. When the A/C kicks off, it
stops. If I ease it forward wile it's growling, it pulsates, and I mean, like, EASE
as in granny crawl forward. If I put it in "2" it lowers a little... Never heard a car
do that before, growl like that...

 

Wow man, I'm surprised to hear that. Do you have a GT? I thought with all my "mod's" that for sure I had an issue related to them.. Especially with my car being a standard. The trans and clutch clatter/schuttering is terrible in my car, especially sitting at a red light.. And it sounds more like a tractor with the A/C running. I love this car, but man it is annoying to drive on a long trip.

 

 

No, sorry, I have a V6 Auto, and it makes that growling noise, and it is being generated
by the motor. As I said, when the A/C is on, it's much worse at idle. Also, in fact, it got
worse when I put new plugs in. Performs better, but growls, and only at idle in gear
with the A/C on, since there is a "load" on the motor. When I accelerate, it will hit
around 1100-1200 RPM and growl, then stop once it gets above that, so it's a quick
growl. Only under load, does it do that... My son even told me when he drove it
for the first time he was like "Dad, your car growls.." I said yeah, I know...

I am going to check the motor mounts, and trans mount when I can.

Also, FYI, that manual trans you have is notorious for noise, you can look that up, it's
actually quite common.

It's not the diff, and I changed the oil last month, and what I took out was clean, so I
did not really have to.

 

 

Have u checked the pulleys and tensioner for any bad bearings

 

I hope its not the balance of the driveshaft, I bought it new from AM when I did the TR3650 swap.. The noise feels/sounds like it is coming from behind/underneath me.. I'll double check the fluid level in the diff but I know for sure its not leaking, and I changed it out with Mobil 1 and friction modifier.

The pulleys/A/C definitely arent related to the problem I am having.. I feel like its driveline related or exhaust.. Because its so drony and loud in the back of the car under load.

 

My 4.0 behaves thesame way.. Just turning the steering wheel at a stop causes an engine growl.. A/C makes my clutch chatter like a diesel tractor lol.

I know all about the TR3650 being noisy... I just didnt think it would carry into the driveline while driving it..?