T56 Rollover Noise Finally Fixed

[k31th]

My point being I'm surprised you got the whole 5L in without it spilling out (even with the car on an angle) as the drain plug on the passenger side is a lot lower on the gearbox than the reverse switch on the drivers side. You must have had the passenger side of the car quite high in comparison to the drivers side for it not to spill out while filling.

[Kosij]

I done same as above and got 5L in also.

Used dex lll a few months ago. Brought the car 8 months ago so service history was unknown..... Let's just say the color of the oil that went in was just as good as the color that came out :/

No improvement in noise! If anyrhing worse lol

[k31th]

Dexron III is unlikely to change anything as the factory oil is Dexron III. You need a different oil if you are to quieten it down (unless the old Dexron III was at a low level and you put more in - that might have a minor effect.)

[gaz097]

Drained my 30k old dex 3 and filled it with some penrite today. Not a huge difference but definitely a step in the right direction. Quieter at idle and better on the shifts

[f-wolf]

It's now one month since I but Penrite 70W-75 in to my gearbox. As I keep detailed records, I can now report that fuel use (Litres per 100km) has not changed / gone up.

No Noise... Nice gear changes !!

Edited 22/11/14 07:07 AM by f-wolf

[I JET]

oh man... my gearbox started making what I hope is just the roll over noise. It sounds horrible. Conditions are the same as everybody describes, but I also get the noise on decel in 1st and 2nd (which leads me to believe maybe it is lunched). Im going to seek some advice from a gear box specialist. I'll see what they say but to start with I was going to dump the oil this saturday and have a good look, if the oil doesn't have anything catastrophic in it I will put some new stuff in and see how it sounds. I'm already running the expensive penrite gear oil. I changed it probably 10 - 15k kms ago before the car was tuned.

this sucks balls

[FPVF6355]

It's been a while  but thought Id update this.

Rollover noise came back and got worse over time.

Did some more searching and found some info on driveline fault diagnosis.

''If you put your foot on the clutch pedal slightly and the rattle noise disappears it is NOT the transmission, it is the clutch''

I Also found separately that concentric slave cylinder bearings always make some light pressure on the clutch fingers.

Anyway If I put slight pressure on the clutch pedal (very light) the thing is dead silent

I looked at the clutch master cylinder and found it has a hole at 90 degrees to the piston like a jacking screw was meant to be there, or at least a provision for one.

I used an M6 x 35 bolt and 2 nuts and adjusted the pedal to just starting to make pressure in the cylinder (only just enough to take up any slack in the CSC) and surprisingly the clutch pedal and brake pedal now line up exactly and the switch attached to the pedal is still within working range and any rollover noise is gone completely, 

I am using a twin plate aftermarket PBR clutch that came with CSC and flywheel, it probably needs a corrective shim to set the CSC tolerance properly, instead of doing what I did. But same result.

 

[MattyP]

Congrats mate

 

Thanks for putting a result up!

[Lithfkn]

On 07/02/2016 at 10:48 AM, FPVF6355 said:

It's been a while  but thought Id update this.

Rollover noise came back and got worse over time.

Did some more searching and found some info on driveline fault diagnosis.

''If you put your foot on the clutch pedal slightly and the rattle noise disappears it is NOT the transmission, it is the clutch''

I Also found separately that concentric slave cylinder bearings always make some light pressure on the clutch fingers.

Anyway If I put slight pressure on the clutch pedal (very light) the thing is dead silent

I looked at the clutch master cylinder and found it has a hole at 90 degrees to the piston like a jacking screw was meant to be there, or at least a provision for one.

I used an M6 x 35 bolt and 2 nuts and adjusted the pedal to just starting to make pressure in the cylinder (only just enough to take up any slack in the CSC) and surprisingly the clutch pedal and brake pedal now line up exactly and the switch attached to the pedal is still within working range and any rollover noise is gone completely, 

I am using a twin plate aftermarket PBR clutch that came with CSC and flywheel, it probably needs a corrective shim to set the CSC tolerance properly, instead of doing what I did. But same result.

Sorry for thread mining but does anyone have any more info on this? My roll over noise disappears too when I slightly push the clutch in to line up with the brake pedal. I can't seem to find where this hole is to put a bolt through on the master cylinder. Has anyone got a pic perhaps?

[jako]

first you need to understand what gear rollover actually is And what causes it..

these new gearboxes have needle roller bearings inside of every gear (older boxes had bushings)

so you will have a certain amount of clearance there.

so when you are in neutral the gears aren’t locked onto the main shaft but they are connected to the engine via the clutch and flywheel and they will rattle............if you’re clutch isn’t tuned for that motor. 
 

(pushing clutch in disconnects the gearbox from engine and noise goes away) 
 

the springs inside the clutch disks  amongst other parts are tuned And insulated to stop this gear roll over noise an LS or Cleveland are going to have different NVH to say a 5.4 or a barra every engine type will vary.

 

some disks have a multi rate spring pack With two different springs some have a single 

 

different firing orders and stroke length’s will have different NVH 

 

a thicker oil can dampen the noise a bit but in summer it usually comes back as the oil thins out in higher temperatures 

 

Iv just been through this I had bad rollover with a 5.4 3v 220kw car 5speed tr3650

 

replaced oil with Penrite pro gear did nothing amongst other oils.

 

built a new box Another NOS TR3650 with upgraded internals etc etc and adapted a mantic 9000 series twin plate clutch from a 5.0 coyote...... rattled its head off was very embarrassing in McDonald’s drive through..

Thought &$@ Iv buggered this box up when I built it so purchased a  TREMEC T56 magnum xl 6 speed.......bugger me still did the same dam thing lol 😂 

 

 

found out 5.4 engines need a multi rate spring pack on the clutch disks due to there NVH the mantic clutch had small springs to suit 5.0 coyote  the ones needed were completely different a big spring with a smaller one inside it tuned to stop that particular NVH.

 

ended up with a mal wood clutch for a 5.4 problem solved.

 

 

reason these new boxes use DEX 111

is the synchros rely on friction to work.

with a triple synchro the thicker oil “can” Get trapped between the multi layers of the triple synchro assembly And can’t push the oil out fast enough and can cause nibbling issues (better for bearings but not synchros)  plus some of these oils are very slippery and stop that friction and some of the friction modifiers in the oil can harm the yellow metals in these Synchro assemblies. 
 

the noise usually get’s  worse with the air con on as it puts more load on the motor. Also changes the RPM a few hundred 

 

if you have added some Performance bolt on parts without a tune this can upset the tune and make rollover worse

Edited 04/09/20 03:28 PM by jako