[03oxwhiteGT]

Prelim: 2003 Mustang GT 5 speed/ 55,900 odo.

I would very much like to have a full group sensus on this problem.

My transmission makes a whining/humming sound from 1 mph on up through acceleration (150 mph); more while in gear (while under load) and obviously less out of gear (coasting in neutral), always in motion though. Shifting is relatively smooth. The sound is louder from 1-3 only because I think that environmental sounds (i.e. exhaust, motor, surroundings) drown out the sound. The sound is comparable to a low sounding K.B. Supercharger (but I'd rather have the real thing). If I let off the gas while in gear (to coast in all gears other than 5th), sometimes the car feels like it clunks forward. Ok my medical mustang doctors, whats the RX for ailment. I have read throw bearings, pilot bearings, clutch quadrant, and even possibly a rear dust seal (read that in a forum reply by rj8806) could all be options. What say you folks?

[gilomach]

louder noise in first to third means noise comes from the front side of the tranny,could be the input shaft bearing or the clutch system bearings,pilot and/or trow out.

[TrueBlueNewEdge]

You read the outout shaft seal could cause noise? I recently installed an FRPP aluminum driveshaft on my 02 GT and have had a whinning noise ever since. I put a new seal in while I was under there. Where did you read this? Seems kind of doubtful but you never know. The good news is you can find rebuilt Tremec 5spd's for under $1000 bucks. Woohoo.

[jep23]

That is the EXACT same problem I was having. CHECK YOUR TRANSMISSION FLUID!!! My rear dust seal was leaking fluid out. I had tranny fluid all over the underside of my car. When I replaced the seal (very easy by the way), I drained the old fluid and only about 1 quart came out. So it was obviously very low. Now the problem is fixed.

[rj8806]

If it is only doing it under load can you make it go away by doing anything else? For instance depressing the clutch?

Is it just a noise or is there a vibration there as well?

Assuming you know what a bad bearing sounds like (growling, metal on metal noise), can you rule this out?
Believe it or not, the 3650 (as well as the T45) are a little noisy by nature. It is just the way the gears are cut and the makeup of the syncros and blockers. Have you tried checking the fluid level? In '03, Tremec switched from non-synthetic ATF to a synthetic ATF, like Mobil 1. What fluid are you using? Pull the fill plug out (side of the main case) and see if the fluid level is correct. It should trickle out when the plug is removed. If it does not, stick your little finger in there and see if you can feel the fluid level. If not, add some fluid and see if that helped.

When is the last time you changed the fluid? If you haven't, I would try that first.

The "clunking" you mentioned also has my mind going in another direction all together.... Have you checked your u-joints lately? A bad one will cause the clunk you described, also would cause noise and a vibration if it is bad enough.





Richard
Tech Support
Tremec TKO, T45 & T56 Transmission Systems