Sound With Clutch Pedal Released

[blurple124]

When my car is at idle (this is when I hear it, I have no idea if it does so in gear) there is a "rolling" sound. Almost like a dirty bearing, and not quite a roar. Certainly not the screech of a throwout bearing (my research has told me this sound occurs with the pedal depressed).

It is subtle enough that at idle you forget it is there as it blends in with the engine noise, but you can certainly hear a difference when you push the clutch pedal in.

Thoughts?

[djape1977]

if noise dissapears when you press the clutch pedal than it's coming from gearbox.
input shaft bearing most likely.
check if there's oil in gearbox. replace it for starters, if noise persists, you need to take off the whole gearbox to see what's wrong

[blurple124]

if noise dissapears when you press the clutch pedal than it's coming from gearbox.
input shaft bearing most likely.
check if there's oil in gearbox. replace it for starters, if noise persists, you need to take off the whole gearbox to see what's wrong

Even if the car is in neutral when the noise occurs?

[azruss]

the input shaft is driven by the clutch. If the clutch in engaged, then the input shaft is turning at engine rpms.

[majicwrench]

Yup, brg in trans, anytime your foot is off the clutch the input shaft is turning, doesn't matter if in gear or not.
Changing oil isn't going to improve anything.
Keith

[blurple124]

Damn. So that sounds like a drop the tranny type fix. How long can I go before this needs to be addressed? Like I said, the noise is subtle.

Does the motor need to be pulled? Also, I imagine all bearings get replaced together?

[majicwrench]

As you can imagine the longer you wait the more bearings/parts will be involved, little metal flakes in oil right now if indeed brg failing.
If it is full of fluid likely gonna go a looong time before anything drastic happens, just very gradually get noisier. And yes, you would likely want to change all brgs/seals.
Need to pull trans, not engine.

I have a Subaru with noisy transaxle, been driving it that way for a year+.
Keith

[giuliot60]

I have the same condition blurple, but I'm not going to drop it anytime soon. I changed to gear oil, but it didn't change the sound. At least I know it's clean and filled with correct oil. Let us(me) know what you decide to do because I'm going to have to do it eventually. I may just replace with a rebuilt then repair the original and keep it as a spare.

[djape1977]

after fiddling with fiat gearboxes for 15 years, i've seen all kinds of failures and all kinds of stupid things people have done.

gearbox running fine, very slight noise coming from it in 5th gear:

step one - take a look.
incredible ammount of oil and dirt deposits on the gearbox

step two - check the oil
all that came out was about half a quart of greyish sludge

step three - see what happens with the new oil
poured in 1.8 liters of sae 90 and viola! noise dissapeared.

naturally, this gearbox will have to have oil seals and orings replaced at some point


the owners brings in a 124 spider for a clutch change:

step one - a test drive to confirm it's a clutch plate problem
whoaaa!!! that sounds exactly like a helicopter transmission! all sorts of whining noises coming from the gearbox.

me - "excuse me sir, have you noticed noises coming from gearbox?"
customer - " well maybe a bit, but it's an old car, it's normal to hear a bit of gearbox noise"
me - " here you go, take a key and go for a spin in my 1979 lada. come back in an hour, i'll take the gearbox out meanwhile"

3 minutes later, the customer returns, with a look on his face like a 100kilo bird just dumped it's load on him.
customer - " it's.....silent."
me - " and it's an old car with that same type of gearbox, and it has done about 3 times as many miles in it's life compared to your spider"

naturally, after that, i sold him an re-manufactured spider gearbox.

and for those of you that didn't know it, a lada uses the collotti type 4 speed gearbox which was made under licence from fiat. exactly the same as 124 sedan. there's about 80% interchangable parts with 124 spider's 5 speed box. for example, input shaft, all bearings and oil seals are exactly the same.

point of the story? what might sound as normal transmission noise to you, might in fact be a transmission ready to croak at any moment. if you're not experienced with this type of gearbox, go to someone who is.

[76was124]

So there should be no noise coming from the gearbox when you let out the clutch while in neutral?.

I started and ran my 81 today for the first time since I started its restoration 10 years ago and have a whirring noise while in nuetral. This is with the gearbox fully exposed in the cockpit (shifter hole open,trim cover removed)

I had drained the oil and replaced it with GL5 80w-90.

I had some forks and part replaced by a mechanic familiar with Fiats early in the project (8 years ago), because PO told me it wouldn't stay in 2nd gear. I would think if there were bad bearings the mechanic would have caught that too, but you never know I guess.


Is the gear lube I used correct?
Is any type of noise normal after clutch is fully released an in neutral?

I am hoping I am not just in denial, as it was so much fun to finally drive it today!!

[majicwrench]

"Noise" is pretty subjective. In a perfect world there would be no noise when in nuetral. With trim, boot etc off, you are likely gonna get some sort of "noise" even with a good trans, you have things spinning around in there.
Keith

[76was124]

I had drained the oil and replaced it with GL5 80w-90.


Is the gear lube I used correct?

OK I just realized I used the wrong oil..good news its only been sitting in it for two weeks, and only driven 5 miles.

What's the best way to flush the brass syncros eating GL5 (vs. Just draining it) to get it replaced with GL1?

[giuliot60]

Sounds like the same sound I'm getting 76 in my '81. I'm sure you haven't done any damage with the current oil. I would think draining it, putting in GL1 (Napa sells it by the gallon) running it for a while then draining and refilling would probably dilute the older oil. But I always say, I'm not a mechanic so double check.

Another tip is to buy an oil gun from the autoparts store to refill. It was such a pleasure to use. Again, Napa sells one for $15, the best $15 I've spent. The tube fits right in the fill hole, so you don't have any spill. And make sure to use the lower hole, not the upper allen.

[georgeramos]

my car definitely has the tell tale whirring sound of a noisy input shaft bearing too. i thought the popular concensus was that this alone was not worth pulling the gearbox to repair...

id be interested to hear if thats not the right thing.

thanks

George

[djape1977]

sooner you repair it, the less money you're likely to spend.
longer you drive with busted bearings, it's more likely you'll have to replace whole input shaft