What is this clank?

[Miker]

My 2005 Roush stage 1 has 153,000 on the clock. The engine (full long block) was replaced at around 115,000. The clutch was replaced at the same time. I have completely rebuilt the suspension front and rear. Also installed a Ford performance 1 piece aluminum drive line. The suspension and drive line now has about 1000 miles on them.
So the only thing on the car with 153,000 miles on it is the rear end and the transmission. The rear end was dealer serviced at 118,000 due to a leaking pinion seal. And when I checked the trans fluid it was bright red and did not smell burnt.
The noise it is making is mostly in first and second. It sounds like it is coming from the front of the trans and does not sound like it is dampened by fluid. Once the car is warmed up it seems to happen less but it will definitely still do it. It does it more if you shift slowly. If you shift it fast it seems to not do it. The trans does shift very smoothly beside the noise with no grinding or pop outs. If I get on and off the gas quickly in first or second it will make the loud metallic clank! Please help!

 

[Miker]

It seems like it is probably gear lash as I believe that there is more lash built in to the lower gears and the clank is amplified through the aluminum drive line. But it seems there is no way it should be making that noise if everything is right. I know that people say the TR3650 trans is noisy but I am wondering if a rebuild is in order.

 

[Dino Dino Bambino]

I know that people say the TR3650 trans is noisy but I am wondering if a rebuild is in order.

The TR3650 does normally whine a little in 1st & 2nd but it's only audible because the aluminium casing transmits more noise than cast iron. A little grinding when changing from 1st to 2nd while the transmission fluid is cold is also normal.
Clanking definitely isn't normal but in your case I wonder if the source could be the flywheel or the clutch assembly (loose bolts perhaps?).

 

[pass1over]

A little grinding when changing from 1st to 2nd while the transmission fluid is cold is also normal.

I like to call that nibbling, lol

 

[Miker]

The TR3650 does normally whine a little in 1st & 2nd but it's only audible because the aluminium casing transmits more noise than cast iron. A little grinding when changing from 1st to 2nd while the transmission fluid is cold is also normal.
Clanking definitely isn't normal but in your case I wonder if the source could be the flywheel or the clutch assembly (loose bolts perhaps?).

It seems if it was something in the clutch or flywheel it would be noticeable in all gears.

 

[Samos3]

Sounds can bounce around. I could see a little gear lash (in the trans or rear) making the noise and the aluminum drive shaft amplifying it with a distinct higher pitch of an aluminum tube.

 

[MasterofDisaster]

I have to be really patient shifting 1st - 2d when it's cold. Tapping the throttle helps.

 

[moooosestang]

i'll get a clunch if i granny shift in 1st/2nd, but not every time. usually happens when my wife is in the car and i'm trying to prevent it. I contribute it to the tranny being looser over time. I don't get any grinding at all unless i try to quickly put it in 1st before coming to a complete stop. I've learned to press the clutch in and wait a minute before trying to down shift into first.

 

[Miker]

This is not a gear engagement noise. The trans shifts great albeit a little stiff when cold. I am sure this is either wear in the rear end or too much clearance in the lower gears of the transmission. I noticed when I had the original drive shaft removed that I could rotate the output shaft of the trans quite a bit back and forth when it was in 1st gear. Probably an 1/8 of a turn. I wish I would have tried it in all the gears to see the difference.

 

[moooosestang]

I think 1/8 of slop is normal and probably where the clunking comes from. There's a lot of slop in the drive line by design i think.