CrAnSwIcK

iTrader: (5)

This has been a hot topic here on Evom throughout the years. I'm not going to revive an old thread, cause those just die...It usually goes something like this: "Hey i got this weird sound when i drive" Answer: "maybe it's this, maybe it's that, or the other", OP never heard from again, so the cause of the noise is rarely revealed, and correlated to the symptoms...

Here's my story:

So i've kept pretty quiet about the car, but i was having some drivetrain vibration/noise...I've removed the transmission, and disassembled it, which is ok, cause i was having other issues as well, for those that have driven my car lately, they would have known that my gear shifter does not return to center in neutral, and this could be a cable issue, but in my case, upon removal of the transmission, i discovered that the return spring in the control housing was not operating correctly. this will be rectified during this year's overhaul...also after a very thorough inspection of the transmission internals, i was unable to find any source of vibration, or evidence of wear or damage as a result, leaving me to believe it's either coming from inside the LSD, or from the axles...i did find that the bearings inside the bracket that bolt to the block on the passenger side axle have a substantial amount of play, which is likely the cause, but i wanted to be sure the transmission was serviceable...i will also be replacing the shaft bearings again for good measure.

Symptoms: I did take a video of the noise during driving and with weight off wheels, but for some reason audio recording on my phone was disabled, and by the time i figured it out the transmission was out of the car, lol, sorry guys...

Car in Motion - inaudible at speeds below 20km/h. Happens in all gears, slight vibration/noise. Sort of a howling/buzzing. Dependant on vehicle/wheel speed, not engine RPM. Only occurs under load/acceleration. DOES NOT occur during deceleration (negative acceleration, lol), or with foot off the accelerator. Does not vary while turning. wheel bearing, CV joints, and TOB ruled out.

Car stopped - no noise, again TOB ruled out

Wheels off the ground - all gears, same as car in motion, DOES not occur in neutral with clutch engaged, or with the clutch disengaged...ruled out input shaft (both bearings)

Hypothesis:

LSD internal noise/or improper preload
output shaft bearings/excessive endplay
inner axle shaft bearing housing.

Source of Noise:
TBA

SSP-Ralliart

iTrader: (1)

could still be the CV axles. Only need enough play to cause an imbalance but not make a noise. You could have axial play in the LSD also but i would think it would make noise both under load and decel. while on the ground you can grab the CV axle shafts and see if there is any place which there shouldnt be. Ive replaced quite afew for vibration under load only and they arent affected by RPM and only speed. I would look into that first

SSP-Ralliart

iTrader: (1)

play not place.

Thomar

the suspense is killing me.

CrAnSwIcK

iTrader: (5)

i have the axles out of the car, the CV joints have no play...but like i said the block bracket/inner shaft bearings on the passenger side axle are toast, like, side to side, in and out, and even turning the bracket one revolution by hand makes an audible groan...i noticed when i took it out, but pulled the tranny anyway to make sure...

i did check the axles before i started tearing it all down, but i was checking the CV joints, i overlooked the inner shaft bracket...

SSP-Ralliart

iTrader: (1)

then replace the axle and go from there. If there is a known defective part replace it to eliminate the possibility. There would be an audible noise but i dont know if that could cause a vibration unless under load it compresses the ***** inside the carrier. Replace and get back to us.

CrAnSwIcK

iTrader: (5)

i can only feel the buzz slightly in the shifter, it's not like a violent vibration...

Canada_Comp

iTrader: (1)

This center bracket bearing normally has lots of play. When I blew my engine and had everything out i noticed it was super loose, so i ordered a new bearing kit and put it in. exact same play. I don't recall any groan though.

CrAnSwIcK

iTrader: (5)

so my best bet now is replacing the main bearings, and increasing the preload on the diff by a few thou...

pj//ralli

I have a 05 AT Ralliart I have the same issue, some people have told me that the it had problems with the torque converter, I've been to several mechanics and they told me that it seems that the lock up of the converter is slipping... I really don't know what it is and I have no time right now to deal with it, so let me know whats happening with yours and how you fix it...good luck!!

Canada_Comp

iTrader: (1)

could it be the notorious all of the bearings in your tranny are going? specifically input shaft? because of the helical cut of the gears, there would be a thrust load in certain directions on accel and decel. since you said decel is okay, maybe get new tranny bearings/shims, as well as diff bearings and shims?

last time you tore apart your tranny did you use solder to set the preload on the diff? also, checked the snap-ring clearances on the input and countershaft?

CrAnSwIcK

iTrader: (5)

yes, everything was within tolerance spec..

CrAnSwIcK

iTrader: (5)

little update:

So i had the transmission back together and installed 2 fridays ago, not including today...with the wheels off the ground, it still made the clackety clack rattling noise, but the howling noise under load was gone...

what i replaced was right side axle bearing, and the engine side output shaft bearing, upon destruction of the old OPS bearing i did find that the outer race was all pitted and corroded, and decided that was likely the cause of the groaning noise. i also over-shimmed the diff by .003". not sure if the rattle with the wheels off the ground is just backlash in the diff, but it doesn't make noise while driving, so i'm ok with it....

Canada_Comp

iTrader: (1)

right side axle bearing as in wheel bearing? or that center bearing thing that attaches to the engine to help make the axle shafts equal lenths?

I find that my quaife lsd makes a clackity/ grinding noise when the steering wheel is turned and you step on the gas when it's colder than -5c. kind of sounds like abs but a lot louder, or i guess like sawing something with a coarse tooth saw but louder

CrAnSwIcK

iTrader: (5)

you sure it's the diff?

and yes, i mean the bearing on the axle shaft...