Gearbox Decel noise.

[brisvr4]

So how many of you VR4 guys have it?
I have a weird clangy, grindy kind of noise on Decel and when I just touch the throttle while cruising.
I'd hate to take the old girl on the cruise on Saturday and have another gearbox let go
Anyone wanna come for a drive this week to compare noises??

 

[Jonson]

Yeah I have that. What are your tailshaft centre bearings like? I know mine are shagged, I only get it at a certain RPM range on Decel, so I'm pretty confident that its the tailshaft going out of round. I'm confident to say its not the Gear box as mine feels like it is coming from the tail shaft tunnel right under the gearstick, but definitely from under the car.

 

[brisvr4]

My carrier bearings are pretty much shot!
It goes away if I push the clutch in but I guess that would take the strain off of the carrier bearings anyways.

 

[cblancergsr]

centre bearing for tailshaft should give you vibrations not noises

 

[brisvr4]

BTW I have poly engine and gearbox mounts too.
I am guessing that they would not be helping as they won't absorb any vibrations at all!

 

[cblancergsr]

when you say poly do you mean poly-urethane
if so they wouldnt abrsorb as much vibrations as rubber mounts

but if your centre bearing in your tailshaft it would feel it real bad through the whole car and definetly throught the streering wheel

 

[mattrat]

tim, i had it really bad when i had a locked fwd vr4 gbox in my ggsr..
sounded like the actual teeth of the gears were chattering against each other... i hammered it and nothing got worse or changed sounds..

 

[Jonson]

Vibrations can cause into noises, when the vibration hits something else then that can turn into a noise. Like when the tail shaft goes out of round and then causes it to move off perfect position on the Transfer case spline.

 

[rob323]

About time you suffered the same problem as most of us.
Welcome to sloppy gearbox bearings and aftermarket clutch pressure plates.
Wait til you remove the bottom squab from the back seat, it's 100 times louder then and really scares the shit out of you .

Don't spose you checked how much play was in the input and output shafts on the box before you put it on, compared to your freshly rebuilt (but stuffed) box?

Which transfer case did you use?

There is a simple fix for it and you don't have to get your hands dirty and only takes 2 seconds......TURN THE RADIO UP FULL BORE!

Although it sounds like it, it won't fall apart on you, some of us lived with that noise for years and it doesn't get any worse.

And like you already know, you will NOT feel shot carrier bearings through the steering wheel .

 

[low_rb]

When my jspec was running i had polly engine/gbox mounts and that combined with the clutch in it gave it all sorts of noises on decel. Comeing down from high rpm at times sounded like the exhaust was draging along the ground.

 

[brisvr4]

I just gave her a nice drink of Syntrans and it seems to have helped to quiet the noises down.
Now all I need to do is find where the damn trans oil leak is

 

[mattrat]

is the best gbox oil hey

 

[GVR40]

rob maybe you should bring a spare gearbox on this cruise...

 

[cblancergsr]

where does the oil appear too be leaking from

if anyone rebuilds a gearbox themself the best sealant too use on any of the housings is flange sealant it is top stuff
silicone doesnt last as long

 

[vr4goleta]

mine has had noise on decel in third since iv owned it(kind of a humming noise), and started doing it in fifth since i put a gl5 in (and very quickly changed to syntrans) but mine is in need of rebuild anyway

 

[JAP63]

The noise (if its the same one im thinking of) is the same noise that owners have been trying to trace since jaws was a gold fish.

Mine had it too, like just about every one elses does, ur box wont fall apart b'cos of it.

 

[bazeng]

Guys,

My advice for those noises, play with your tail shaft angles.

There are specific washers/shims you can buy from mitsubishi for it.
I have played with mine and have pretty much eliminated my decel noise.

 

[Jonson]

I still really think it is tail shaft/transfer case related. You guys can chase the noise from the gearbox, but mine is coming from under the gear stick so I'll look for it there.

 

[rob323]

Mine deceleration rattles went away TOTALLY after I fitted a new clutch (fully balanced in conjunction with the new flywheel). But, after about 1000 kms, the deceleration vibration is starting to come back again, this vibration progresses into a rattle as the springs in the pressure plate loosen up.

I tend to agree with Barry about the tail shaft angle bizzo. As the rubber surrounding the centre bearings sag, it changes everything and as it is only during deceleration (when the torsional forces on the tailshaft are reversed cause the engine is braking the car, not accelerating it), it points to the harmonics/ vibration created by the drive shaft as being the true cause of it.

How did you go about aligning your drive shafts Barry?
I wonder if anyone in the states has converted their car to a single piece driveshaft to eliminate the problem all together?

 

[JAP63]

Mine deceleration rattles went away TOTALLY after I fitted a new clutch (fully balanced in conjunction with the new flywheel). But, after about 1000 kms, the deceleration vibration is starting to come back again, this vibration progresses into a rattle as the springs in the pressure plate loosen up.

I tend to agree with Barry about the tail shaft angle bizzo. As the rubber surrounding the centre bearings sag, it changes everything and as it is only during deceleration (when the torsional forces on the tailshaft are reversed cause the engine is braking the car, not accelerating it), it points to the harmonics/ vibration created by the drive shaft as being the true cause of it.

How did you go about aligning your drive shafts Barry?
I wonder if anyone in the states has converted their car to a single piece driveshaft to eliminate the problem all together?

Have you fitted them bearings yet rob (im guessing not)

When you fit them, might be worth doing that.
Youd think that with new bearings itd fit back up where it should.

What if you fitted the tailshaft bearings, without the shaft in place, and ran a stringline from the centre of the xfer output yoke to the centre of the diff yoke? Then shim the bearing mounts to centre the string inside the bearings, Then once you got the shimming correct, fit the bearings to the shaft and put it back in the car using them shim heights.....sounds like alot of rooting around though doesnt it........

Other than that, youd have to make a jig up or something simmilar to do it.