Technical Clutch or Gearbox? Loud rattle while in gear..

[lavallefiat]

Noise doesn't happen when in Neutral or 3rd gear. Would grind when putting into first before this issue occured. 1968 fiat 500 with rebuilt 650cc engine.

Mechanic told me to order parts related to gearbox like a synchro kit, bearings and seals without having seen it.

What do you guys think?

 

[lavallefiat]

Noise doesn't happen when in Neutral or 3rd gear. Would grind when putting into first before this issue occured. 1968 fiat 500 with rebuilt 650cc engine.

Mechanic told me to order parts related to gearbox like a synchro kit, bearings and seals without having seen it.

What do you guys think?

I should mention when clutch is disengaged sound goes away

 

[the hobbler]

I should mention when clutch is disengaged sound goes away

I have been working on 500s for many years (on and off) but I would remove the gearbox and just check things before making such a suggestion! It probably IS in the gearbox, which will have to come out anyway, so why not do some investigation prior to spending your money.

 

[Toshi 975]

Noise doesn't happen when in Neutral or 3rd gear. Would grind when putting into first before this issue occured. 1968 fiat 500 with rebuilt 650cc engine.

Mechanic told me to order parts related to gearbox like a synchro kit, bearings and seals without having seen it.

What do you guys think?

You have not made it clear as to wether you have a 126 syncro gearbox or a 500 gearbox grafted to a 126 engine. Either way it sounds like you are overdue for a gearbox rebuild and I agree with Tom that you need to get something like a Haynes manual, dismantle and inspect the gearbox internals before rushing into a spending spree. It could be something simple like a failed bearing. Having rebuilt quite a few 126 gearboxes I found that 2nd, 3rd and 4th gears were virtually indestructible but a range of other more minor faults caused problems.

 

[Bounding Bambino]

You have not made it clear as to wether you have a 126 syncro gearbox or a 500 gearbox grafted to a 126 engine.

This is important to know before throwing parts at the transmission.

Honestly the trans needs to come out, access cover opened, to see what exactly you have going on. You could have a 500 gearbox with a 126 bellhousing, or a 126 gearbox, with a 126 bell housing. Its always a guess what it could be until you open it up unfortunately.

The gear kits do replace alot of the rotary parts in the trans, but its good to know for sure before ordering parts. It could even be something unrelated such as a worn shift bushing, or misalignment.

If you need a 2nd opionion let me know, i have a few spare trans parts from when i rebuilt mine, (non syncro) some still good some worn. But honestly the cover needs to be opened to see whats going on.

 

[Bleeding Knuckles]

Hi Lavallefiat, I agree with Toshi and hobbler get the gearbox out of the car and check the inside first. What happens in first or reverse gear when accelerating and decelerating (ie on and off of the gas?) do you get any noise? When draining the oil check for debris - bright and shiny pieces or flakes are from gears and bearings, dull alloy colour means the casing is worn somewhere.
Ian.

 

[lavallefiat]

Hi Lavallefiat, I agree with Toshi and hobbler get the gearbox out of the car and check the inside first. What happens in first or reverse gear when accelerating and decelerating (ie on and off of the gas?) do you get any noise? When draining the oil check for debris - bright and shiny pieces or flakes are from gears and bearings, dull alloy colour means the casing is worn somewhere.
Ian.

Thank you all for the replies. Same noise when accelerating in all gears except for 3rd. Started it up again and noise happens in neutral as well. I've attached a video

20230107_155157.mp4

1 file sent via WeTransfer, the simplest way to send your files around the world

we.tl

 

[Bounding Bambino]

That sounds like some bad dry bearings, Are you sure the trans has any oil in it?

 

[Bleeding Knuckles]

Hi lavallefiat, your video sounds awful - don't delay get that gearbox/engine out of the car and check everything from the clutch back!!
Ian.