308 Gearbow whine

If it were me, I would change all of them. If you change only one, the others may not be far behind and you will be doing a DO (Do Over).

 

Any bearing that can be changed when accessing the faulty bearing, should be changed.

 

Hello from Germany,

first question which comes to my mind; which agents have advised to change the bearings ? Sometimes they offer the most expensive solution first.
This issue is really hard to diagnose without experience and having heard the sound. Also; how long do you own the car ? It takes some time to become accustomed with those 'special' sounds. Or can you confirm, that this whining is new on your car ?
How many mls. has your car ? A high pitched whining sound from a transmission can also be caused by backlash between the gear's teeth, which is caused by certain wear, which is normal on high mls. cars.
Also a certain amount of noise from these transmissions is normal and state of the art on these older cars. AND the distance from your ears to the engine / transmission is much less than on other cars what makes any 'special' noises much more noticeable.
In a contemporary test report from Germany's biggest car magazine they mentioned all kind of mechanical noises - also whining - on a test car fresh from the factory.
To make a long story short; my car - 308 GTB - with now 110.000 kms whines too. But the noise didn't change or increase over the years since I bought it with 60.000 kms.
It just don't hear it any more. Except I open my ears for it
Your profile says, you are a musician ? I assume you have a different / better hearing than average.
308 transmissions are generally rock solid. Especially on later FI cars with less torque. I rarely hear of really necessary rebuilds. Most rebuilds are 'while you are in there-jobs'. Say, when the engine came out for other reasons.
There's a tendency to spend a fortune on eliminating noises on these cars.

Best Regards

Martin

 

I have a noise also. Mine sounds like a low pitched rumbling sound that stops when you step on the clutch. Everyone who heard the noise was convinced that is was the throwout bearing. I repaced all bearings in the gearbox and clutch areas but the noise is still there.

 

Play / too much clearance in the clutch lever bushings with vibrations making a rumbling sound ? Mine are squeaking a little, depending on outside humidity. These are the same type of bushings like on the rear uprights or on the steering column, where it exits the cabin. And they show the very same behaviour when they are worn. Too much play, all kinds of noises or sticking.
These friction bearings of the clutch leverage are inside the bellhousing and I assume they can be replaced with some special custom made tools while performing a clutch replacement.

Best Regards from Germany

Martin

 

I don't mean to make light of your noise, I have one, (from the machinery, not my beloved wife), and it is most prominent when the transfer case is low on fluid, then less, (normal???) when the gear oil is brought up to level in the transfer case. I have been through this sequence three times in the last two weeks; ok -noise, refill gear oil through transfer case fill, noise gone, drive it, noise reapears, (while seriously spotting the parking areas), refill oil, ok, drive it 200 miles, noise, refill, no noise.

At the conclusion of this post, i am going to order new o rings and a new transmission input shaft seal.

My suggestion, is to fill through the transfer gear case fill plug, with the rear fluid fill plug off, letting any excess flow over the open hole, plug it, (and the fill hole), then drive it. If the noise is the same, then you have a problem, if it is more than the normal noise. Perhaps, get a professional opiniion, as i did at the Thunderhill track day from "John", the Ferrari of San Francisco tech on hand.

I would try to make sure it is a "problem indicating noise" before dumping a ton of money on an "OK" noise. Second opinions are a good way to make sure you spending your money wisely.

hth,
chris


I know it is unwise to drive a leaker, but i had no down time between the track day and the "picnic day/ be with the wife 200 miles away", so i am now getting to it.

good luck,
chris

 

If it stops when you step on the clutch it ain't the throwout bearing . .. . sounds like the typical whrrrr/growl of the drop gears . .. . monitor the mangetic plugs in the gearbox . . if you're not getting chips don't worry about it IMO.

edit: a biz associate who flies helicopters was explaining to me how they monitor wear on his machines . . . there's a light connected to a magnetic drain plug that turns on when the build up closes the connection . . .when the light comes on they pull the mangetic plugs and they have a chart that they rate the chip size (if any). .. chips are really bad . .. when everything is working okay the build up is just a very fine "sludge" of metal particles . . . if they find a chip they document it and continue to monitor unless they start seeing more or bigger chips . . . I've thought about putting some kind of light system on my 308 for monitoring . . . just sharing how I came to the conclusion above about not worrying if you're not seeing chips.

 

Thanks for the input. The noise in my gearbox only appears when the car is well warmed up to operating temp. At start up there is no noise.

 

for what it's worth ....
i changed to synthetic oil about three years ago ... the first > second gear change was much improved when cold.
.... but the gearbox is much noisier ... so now thinking of reverting back to mineral oil.
cheers, d

 

What type/brand of trans fluid are you using?

 

My noise started after changing the fluid also. I started with Valvoline, then tried another dino oil that I don't remember, and then Redline. The noise never changes no matter what fluid I put in it. The shifting into second was improved with all of the above.

 

Mobil 1 SHC 75W–90

cheers,
david