Transmission Question

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blurple124
Posts: 393
Joined: Sun Aug 28, 2011 3:46 pm
Your car is a: 1978 Fiat 124 Spider

Transmission Question

Post by blurple124 »

I wasn't sure which section to put a tranny question in, so I figured this was close.

Here are the symptoms:

1. Bearing noise with trans. in neutral, clutch pedal released, sound goes away with pedal depressed. Can't tell when it is in gear.

2. Driveshaft is spinning with car in neutral, clutch pedal released. Have not checked effect of depressing clutch pedal.


The first sounds like an input bearing, but I could be wrong. I'm a bit confused on the second. It is spinning very slowly, so the car does not lurch as a result (this was observed with the car up on jacks, wheels off, etc.)


What are your thoughts?
Charlie
1978 Fiat 124 Spider 1800 - Antonia
1997 Jeep Wrangler TJ Sport
majicwrench

Re: Transmission Question

Post by majicwrench »

Could certainly be an input bearing.

Driveline turning is just life. Gear oil slinging around. Ignore it.
Keith
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azruss
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Your car is a: 80 Fiat 2000 FI

Re: Transmission Question

Post by azruss »

with the car in neutral and clutch released, the only thing spinning is the input shaft. It has the pilot bearing and the front tranny bearing on that shaft. the pilot bearing is small and will give you a high whine. the front bearing is much larger and would give you a lower, wheel bearing kind of sound.
131
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Your car is a: 1982 131 Superbrava warmed 2.0 litre.
Location: Tasmania, Australia

Re: Transmission Question

Post by 131 »

With the clutch released the input shaft is spinning at the same rate as the crank, the pilot bearing doesn't come into the equation.
Mick.

'82 2litre 131, rally cams, IDFs & headers.
redcars
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Your car is a: 1981 Spider 2000
Location: Collinsville, IL

Re: Transmission Question

Post by redcars »

With the car in neutral and the clutch released the input shaft and the lay shaft with its three bearings are all spinning. As stated above the pilot bearing is not spinning in this mode.
1987 Lotus Super 7 clone
1981 Fiat Spider 2000 AT
1982 Fiat Spider 2000 5sd
1970 Fiat Coupe
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blurple124
Posts: 393
Joined: Sun Aug 28, 2011 3:46 pm
Your car is a: 1978 Fiat 124 Spider

Re: Transmission Question

Post by blurple124 »

Well all of that makes sense, because I hear a wheel bearing noise, and not a wine.

So I think it is safe to assume that the front bearing isn't so healthy. What kind of time frame am I dealing with here?


And how involved is it to replace something like that? I've worked on just about everything but a transmission before...
Charlie
1978 Fiat 124 Spider 1800 - Antonia
1997 Jeep Wrangler TJ Sport
BEEK
Posts: 1833
Joined: Wed Mar 24, 2010 10:45 pm
Your car is a: 1975 Spider
Location: clermont fl

Re: Transmission Question

Post by BEEK »

does the noise go away when you put it into gear, with the car raised?
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
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blurple124
Posts: 393
Joined: Sun Aug 28, 2011 3:46 pm
Your car is a: 1978 Fiat 124 Spider

Re: Transmission Question

Post by blurple124 »

I will check and let you know.

Leave the car on blocks, put it in first, release the clutch, this is what you are looking for?
Charlie
1978 Fiat 124 Spider 1800 - Antonia
1997 Jeep Wrangler TJ Sport
BEEK
Posts: 1833
Joined: Wed Mar 24, 2010 10:45 pm
Your car is a: 1975 Spider
Location: clermont fl

Re: Transmission Question

Post by BEEK »

yes, but use 4th and check, then try 1st
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
djape1977
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Your car is a: 1970 fiat 124bc
Location: Belgrade, Serbia, eastern Europe

Re: Transmission Question

Post by djape1977 »

blurple124 wrote:Well all of that makes sense, because I hear a wheel bearing noise, and not a wine.

So I think it is safe to assume that the front bearing isn't so healthy. What kind of time frame am I dealing with here?


And how involved is it to replace something like that? I've worked on just about everything but a transmission before...
if you have rebuilat an engine than gearbox is not a problem. i asume it's a manual?

sooner you replace it the better. driving with shot bearings results in increasing damage to gears and other stuff inside. prolonged use will in the end render the gearbox unrepairable. depending on ammount of play in input bearing, which is impossible to know without removing the gearbox, you might be fine for next 10k, or it might be just on the brink of catastrophic failure. i've seen stripped teeth from gears more than once, as a result of driving around with bad bearings.
moggyman64

Re: Transmission Question

Post by moggyman64 »

Hi blurple 124

Any further developements on this thread, I have the same problem and am keen to see your outcome.

Regards

keith
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blurple124
Posts: 393
Joined: Sun Aug 28, 2011 3:46 pm
Your car is a: 1978 Fiat 124 Spider

Re: Transmission Question

Post by blurple124 »

Well, today I ran the car up on blocks a requested.

neutral, 1st gear, 4th gear (I assume same for the rest) the noise persists.

The sound only goes away when the clutch pedal is depressed. This also stops the driveshaft from spinning.
Charlie
1978 Fiat 124 Spider 1800 - Antonia
1997 Jeep Wrangler TJ Sport
BEEK
Posts: 1833
Joined: Wed Mar 24, 2010 10:45 pm
Your car is a: 1975 Spider
Location: clermont fl

Re: Transmission Question

Post by BEEK »

unfortunatly it sounds like transmission bearings. not the end of the world though.
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
moggyman64

Re: Transmission Question

Post by moggyman64 »

This is exactly whats happens with my transmission, which bearings need changing and is it a fairly straight forward procedure to remove and replace the bearings, is there any specialist tools required? I have rebuilt engines before but never done any work on transmissions.

Regards

Keith
BEEK
Posts: 1833
Joined: Wed Mar 24, 2010 10:45 pm
Your car is a: 1975 Spider
Location: clermont fl

Re: Transmission Question

Post by BEEK »

the fiat 5 speed is a simple transmission. nothing real special required to overhaul. i just took 200 pictures when i overhauled the last one. i was thinking of putting together a guide. i will be 1 chapter in my book of overhauling a spider :)
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
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