IronMan0002005

So I have an 03 v6 manual transmission, and when it's in low gear (1st and 2nd mostly) it has seems to "grab" when you let off the gas. And it does it consistently, and because of my driving habits that's mostly in parking lots or my neighborhood. It feels like there is a lot of friction rubbing something in the drive train and there is a very distinct winding noise when you let off the gas and it starts to "coast" to slow down. Now stepping on the clutch does get rid of the friction and the noise. Because of this I initially thought it was the clutch, but I recently changed that and that didn't fix my problem. I had the transmission looked at while it was off for the clutch change and the Ford Transmission mechanic who looked at it said that there was nothing wrong that it could see. There is plenty of oil in the engine and it does seem to be circulating properly, so I wouldn't THINK that it would be a problem in the engine, but at this point I'm not sure. The fact that stepping on the clutch and "disengaging" the engine from the rest of the drive train stops the noise makes me think that it's something in the engine though, because if it's something further down the drive train, the friction and noise would remain even once the engine was disengaged.

Anyone have any thoughts or experience with this?

NewEdgeSC

Did u replace the throwout bearing and pilot bearing? Sounds like the problem to me, classic signs.

BabyGT

Gonna second that one.

IronMan0002005

Mhm, I changed everything while I was under there. Throw out bearing, pilot bearing, rear main seal, re-sealed and lubricated the sleeve over the input shaft into the transmission, and had the transmission looked at by a ford transmission specialist. Brand new flywheel, brand new clutch assembly with the pressure plate and everything. Everything inside the bell housing is brand new.

NewEdgeSC

I'm sorry to tell you this but if stepping on the clutch stops the friction and noise then your transmission specialist probably isn't a specialist. Something is wrong in the tranny or clutch, period!

OK wait! Are you saying that a whining noise comes from the rear-end when you let of the gas? I would have the rear axle checked for that whining noise because that is what they do when they start to fail. That noise is caused by a damaged ring gear driving a misaligned or worn pinion shaft and it usually only occurs during deceleration. The "grab" that you feel could be a chipped or broken tooth off of the ring gear. How the "specialist" didn't know this is beyond me.

IronMan0002005

Well he only looked at the gear box on the transmission. The differential and rear axle were still on my car, I had to take the transmission to the shop when I went to pick up a last minute part. So you think it's something in the differential?

IronMan0002005

I didn't tell him about THIS problem because prior to my clutch change, I thought the clutch was the source of this problem. But after changing the clutch my problem remains so I continue to search for a solution.

BabyGT

After considering what you describe and the mention of the differential I'd suspect that as well. That's not to hard to inspect for chipped teeth, just remove the rear cover and take a look at it. Make sure you have a pan to catch the fluid though. Credit to NewEdge on that brainstorm.

IronMan0002005

So the thought is chipped teeth on the differential? I hope that puts back together more easily than my transmission lol.

IronMan0002005

I have a question about this theory. The scenario is that I am driving at a slow speed (10-25mph) in first or second gear, when I let off the gas to stop my acceleration. The car seems to catch hard and it makes a winding/whiney noise as it makes this very rough decerlation. If I press the clutch and/or put the car in neutral (so the effect is that the engine is no longer attached to the rest of the drivetrain), the noise and the catching go away. If this problem were the differential, wouldn't the noise continue because the differential would still be accelerating or decelerating all the same, whether the engine is "attached" or not?

My thought would be that it would be something in the engine because it was the only thing that was "removed" to stop the noise. Unless the torque produced by the engine still turning was somehow affecting the differential, ie: the positive torque from the engine meeting the negative torque from the deceleration of the tires meeting at a weak point in the differential? Any thoughts or further explanation on this?