Gearbox Noise help needed

[Fatboy 18]

Any Ideas?

[dave6666]

When I thought my gearbox was going out it was the pinion bearing disintegrating.

[Fatboy 18]

Cheers Dave, I will look into that. What is so frustrating is that the car has been down all winter and the rear diff has just been completely rebuilt. I had no noise from the gearbox prior to taking the car apart to rebuild the diff, Diff was rebuilt by Hauser Racing who have experience with Viper Diffs in Europe and have rebuilt a few.

If I change down to 4th the noise goes away. I can then change back to 5th and 6th and the noise may not reappear for some time and miles later?

[RyanLS.GEN2]

the poly diff bushings will make any differential noise louder than it would have been with rubber bushings

[Fatboy 18]

the poly diff bushings will make any differential noise louder than it would have been with rubber bushings

Thanks Ryan, Good Point. I have contacted the Company to see what they think?

[Dan Cragin]

Many times differential noise sounds like its coming from the transmission. Being that the rear diff is mounted directly to the frame of the car, any gear noise can be amplified.
Some types of gears are noisier than others, I always use Dana gears. If setup correctly they can be whisper quiet. If not setup right they can whine like my wife when I work late.

Most of the time a noisy gearset wont fail, its just annoying.

[Fatboy 18]

Thanks for the Information Dan, the thing is that noise is intermittent, so if I had a noisy gear set I would be expecting it to do it all the time? Not just for a minute or so then disappear?

[daveg]

Mark, when you get the noise, what happens if you throw the clutch in? Does the noise change / go away?

[dave6666]

What gearbox? i.e. year, age, mods, etc.

What gearbox oil or lubricant?

Drain the gearbox to inspect the lubricant?

What LSD in diff?

What oil or lubricant in the diff?

Drain the diff to inspect the lubricant?

[Fatboy 18]

Mark, when you get the noise, what happens if you throw the clutch in? Does the noise change / go away?

Noise is still there but greatly reduced.
My first thoughts were a dried out Clutch Slave / Thrust bearing, but if I depress the clutch pedal that bearing face would be pushing on the pressure plate so the whining rattle might stop?

[Fatboy 18]

What gearbox? i.e. year, age, mods, etc.
2000 GTS Stock LUK CLUTCH, Factory Gearbox, Hurst Shifter. Woodhouse Transmission mount.

What gearbox oil or lubricant? Amsoil Synthetic Manual Transmission & Transaxle Gear Lube SAE 75W-90 api GL-4

Drain the gearbox to inspect the lubricant?

What LSD in diff? Tuetrack OEM Dayna stock parts 307 gears all original

What oil or lubricant in the diff? Brand New Amsoil, SAE 75W- 140 also added Amsoil Slip Lock that is supposed to eliminate Diff Chatter

Drain the diff to inspect the lubricant?

So we are clear, the gearbox lube shifter and transmission mount were all done some time ago and I have had no issues at all.

Last year I broke 3 halfshafts! and found the Broken clutch pack clip in the rear diff.

Prior to the diff clutch clip breaking I was using Amsoil Severe Gear SAE 75W-140 without Slip Lock. (and had been for over 5 years)

[Sveina]

Are you sure you have the right amount of oil in the gearbox? Does the sound behave differently warm/cold?

[Fatboy 18]

Yes to the first part of your question, no to the second part. the noise is intermittent, but it was there long enough for me to record the noise.

[daveg]

Mark,
if the noise wasn't there before you rebuilt the rear end, are you sure the rear end was setup correctly (IE Ring gear, back lash etc..)? cause in effect? I am assuming the U Joints are fine and the tail shaft bushing is fine for the drive shaft..

[Fatboy 18]

Mark,
if the noise wasn't there before you rebuilt the rear end, are you sure the rear end was setup correctly (IE Ring gear, back lash etc..)? cause in effect? I am assuming the U Joints are fine and the tail shaft bushing is fine for the drive shaft..

I took the diff to Hauser Racing, they striped it down and rebuilt it, they gave me a box of used bits (clutch packs and Bearings that they had changed).
I have contacted the company and am waiting for a reply.
If it turns out to be a problem with the diff I would expect them to make good? But I am realistic that I may have a battle on my hands!

This is the problem when you take parts to 3rd party companies. This is why I mainly do all the work I can on the car by myself, I will follow the manual, perform correct torque settings and I know what I have done. But I do not have the tools to strip down and repair a rear diff!

When you take something to a 3rd party company you have to hope they have done right!
The answer at the moment is this is all just summarizing, I have not had a chance since returning home from Switzerland to get under the car and drain the oils to see if anything reveals itself.

[Fatboy 18]

Did stop t the Historic Reims Grandstands on the way home

[00GTS]

Cool photos!

[Fatboy 18]

UPDATE.... So Drained the Gearbox Oil today, a little dark but Zero metallic particles, lots of it so no shortage of Oil

So I'm still trying to work out what to do?

IMG-20190510-WA0016.jpg

[Fatboy 18]

Changed the oil today. Going to drive car tomorrow and see if noise reappears

[Fatboy 18]

Noise is still there Normally starts when in 6th Gear. Put the car in Neutral (while rolling) Noise stops.

[daveg]

Only happens in 6th?
Sure your tranny is full?
What is it filled with (type of fluid)?
Different between when the car is cold vs hot?
And your saying this was not there before the Diff rebuild?

[Fatboy 18]

Only happens in 6th? That's when Noise seems to appear
Sure your tranny is full? New Oil, YES
What is it filled with (type of fluid)? API GL4 compatible 75w-90w, New oil made no difference
Different between when the car is cold vs hot? Car is normally on a highway when noise starts around 65-70 mph
And your saying this was not there before the Diff rebuild? Correct

Sounds like a bearing noise. Drove car home from a car show yesterday without using 6th gear, (up and down the gearbox for over 30 miles speeds varying from 0 to 60mph) I swear I could hear some light bearing noise now and again but it was nowhere near as loud as when traveling at higher speed

I'm now looking at the possible purchase of Chassis ears to help pinpoint the correct area.

[LifeIsGood]

You don't need 6th gear...done.

[Fatboy 18]

LOL Actually I do! I do have a tendency to reach 3 figures rather regularly