Bill Ball

I've had a whining noise coming from somewhere under the car for 3 years and 40K miles or so. Very little chnage over that time. It's only apparent in Park or Neutral - i.e., the drivetrain is unloaded. So, I haven't paid much attention to it.

Yesterday I was under the car doing a tranny fluid (8+ Qts of M1) and filter change, and I was able to listen more closely to the noise. It's coming from the open diff.

In Neutral or Park, what is turning back there? Nothing, I thought. It sounds like a bearing whine, but what would it be? I guess it could be transmitted down the driveline and the diff case is acting as a resonant chamber, but it's pretty quiet everywhere else.

What do you think are the likely candidates? The pan was clean as a whistle and the old fluid was cherry red.

Steve Cattaneo

Do you hear the whine if you increase the RPMs in N and P. Do you hear the whine in any gear at a stop. Could be a Torque Converter whine, you changed the transmission filter with the fluid. Nothing in the differential is turning at a Stop and in N/P

jetrainor

Bill......i had exactly the same noise by the sound of your description.....on the hoist, idling, there was a disctinct whining noise from the diff area but as soon as it was put in gear, the nloise disappeared....i have since swapped in a LSD and had forgotten about the noise but noticed yesterday that in park, the noise is gone....obviously something has changed......with the swap came all new bearings of course but there was no noticeable bearing wear on the original open diff....anyway, food for thought.

John

Bill Ball

Yes, it does vary wiith RPM. It is quiet near the TC, but I guess that should be the likeliest candidate. I've been waiting for more of a reason to get in there, such as a bad TT too.

IcemanG17

Bill
With the car not moving.....nothing in the diff is turning either....very odd......it has to be a vibration causing a resonance back there for some reason....maybe the TT bearings are transmitting a touch of vibration back the the tranny.......can you reach the TT housing and see if it feels like its not spinning smoothly?? The exhaust probably is in the way of course....

Mrmerlin

Bill, my guess is the front pump, mine made a noise as well and i swapped in a used front pump due to the old pump and TC seizing the bronze bushing , its quiet now, once there is a load on the fluid then it goes away, so with the trans in park or neutral no load on the pump, maybe the gears are just a bit worn and they wine

Bill Ball

I thought if it might be something in the diff, then I'd pull it, but all indications, other than where the sound is heard, are that it is the TC or front pump. So, I'll just put up with it until I have another reason to pull the TT.

Since I have 189K miles on the original TT, it's been living on borrowed time for the last 50-100K miles. It's probably only a matter of another 50-100K miles before it finally gives up! Darn this car!

Mrmerlin

what usually kills the TT bearings is heat, lots of sitting in stop and go traffice lets the cats cook the TT. OTOH lots of fast driving keeps the TT cooler since air is circulating. Your TT bearings must have been built in the middle of the week ......... Keep em flying

Bill Ball

That's good news. No one ever could accuse me of driving too slow.

RngTrtl

bill, I would check the TC carrier bearings. One of these went on my 85 and they were easily and cheaply replaced (must drop the TT though, but left the tranny in place). No matter what it is the TT is gonna have to be split from the tranny and you will be able to see which bearings are the culprits for sure.

Bill Ball

Well, here we are over 6 years later. I'm still running the original TT and TT bearings. Amazing - 25 years and 268K miles. I did change the TC bearings about 70K miles ago. Also, I replaced the primary pump after some inadvertent damage by a local tranny rebuilder doing a "minor" rebuild when the seal to the TC developed a leak.

The bearing whine from somewhere inside the tranny is still there. It hasn't changed one iota. A mild whine in Park and Neutral only, now present for over 9 years and at least 100K miles with no apparent detrimental effects. The tranny still shifts fine.

Keep on truckin'.

dr bob

Bill,

In my limited experience, bearings make noise that gets louder with speed, but pitch is not proportional to RPM's the way you would think. A 'whine' at the TC area is usually a front pump noise, from just behind the TC. My two cents anyway.

Bill Ball

I'm not sure the whine pitch does increase with RPM. I could record it for playback here. Also, the primary pump was replaced with no change. Regardless, I'm just surprised how it has remained essentially the same for so long.