2 nd gear issues and vibration.

[ScottB]

I have noticed the second gear in my 5 speed manual transmission, 1980 124, is not synchronizing very well anymore. I also am getting a slight vibration on a harder acceleration in first and a bit in sending gear. It is more noticeable when the load is greater like going up a steep hill. It also seams more pronounce when turning left from a stop.

Would the vibration be due to the second gear sync issue, or is this driveline related. It feels like it is coming more from closer to the differential.

Thanks in advance
Scott B

[18Fiatsandcounting]

Hmmm, lots of possible explanations here, and the symptoms may or may not be related. First off, the synchronizers (all gears except reverse) do wear out, and the symptom is usually a slight "crunch" or "grind" when shifting into gear. It progressively gets worse as the synchros get worse. The only real solution is new synchros, although some people have had luck with a different type of transmission oil, or even just a transmission oil change if it's been a while since the last change. I'd start with changing the oil, with the recommended GL-1. Not easy to find in a store, but it is available online. It's a mineral-based oil, and some NAPA auto stores carry an equivalent.

As for the vibration? Usually driveshaft vibrations are more pronounced at higher speeds than you're describing, and for some reason the vibration occurs at around 40 mph and again at 80 mph. And presumably 160 mph, although I doubt you'll experience that...

Vibration can also be a worn rear transmission mount or a worn giubo (rubber donut) or a worn center driveshaft center support or bearing. All are pretty common over time. U-joints also go bad, leading to vibration.

Vibrations when turning are often traced to a bad rear wheel bearing, although it's usually a rumbling sound rather than a vibration. Raise your rear wheels and take the wheels off and see if you can move the rotors side to side or up and down. You may have to remove the brake caliper to do this. Also check the input to the differential (side-to-side movement or the like) as that can wear out as well.

OK, I've given you enough to chew on for now. Bottom Line: Raise the car up (safely) and check for play in the transmission output, giubo, driveshaft mounts, center bearing, u-joints, differential input, and rear axles.

-Bryan

[RRoller123]

If any are near CT, Danny O'Donnell in Vernon, at Fun Imported, will fully rebuild the transmission professionally for a VERY attractive labor rate, plus use authentic parts. For me it was a no brainer, not even remotely worth my time to try and do it myself, to learn it and probably screw something up. Just a thought. Tim Aucella did the same thing, we are both very satisfied with the work. Drop it off or ship on a small wood pallet by truck. We drove over from the Cape and dropped them off, picked them up, saved a bunch of shipping dough, quite significant, for 2 trans, both directions.

[ScottB]

If any are near CT, Danny O'Donnell in Vernon, at Fun Imported, will fully rebuild the transmission professionally for a VERY attractive labor rate, plus use authentic parts. For me it was a no brainer, not even remotely worth my time to try and do it myself, to learn it and probably screw something up. Just a thought. Tim Aucella did the same thing, we are both very satisfied with the work. Drop it off or ship on a small wood pallet by truck. We drove over from the Cape and dropped them off, picked them up, saved a bunch of shipping dough, quite significant, for 2 trans, both directions.

Thanks for the recommendation, and yes i aint taking on a transmission myself. I got my hands full with he dumb end of things.lol.
Thanks again
Scott

[ScottB]

Hmmm, lots of possible explanations here, and the symptoms may or may not be related. First off, the synchronizers (all gears except reverse) do wear out, and the symptom is usually a slight "crunch" or "grind" when shifting into gear. It progressively gets worse as the synchros get worse. The only real solution is new synchros, although some people have had luck with a different type of transmission oil, or even just a transmission oil change if it's been a while since the last change. I'd start with changing the oil, with the recommended GL-1. Not easy to find in a store, but it is available online. It's a mineral-based oil, and some NAPA auto stores carry an equivalent.

As for the vibration? Usually driveshaft vibrations are more pronounced at higher speeds than you're describing, and for some reason the vibration occurs at around 40 mph and again at 80 mph. And presumably 160 mph, although I doubt you'll experience that...

Vibration can also be a worn rear transmission mount or a worn giubo (rubber donut) or a worn center driveshaft center support or bearing. All are pretty common over time. U-joints also go bad, leading to vibration.

Vibrations when turning are often traced to a bad rear wheel bearing, although it's usually a rumbling sound rather than a vibration. Raise your rear wheels and take the wheels off and see if you can move the rotors side to side or up and down. You may have to remove the brake caliper to do this. Also check the input to the differential (side-to-side movement or the like) as that can wear out as well.

OK, I've given you enough to chew on for now. Bottom Line: Raise the car up (safely) and check for play in the transmission output, giubo, driveshaft mounts, center bearing, u-joints, differential input, and rear axles.

-Bryan

Yes the second gear is slight grind on down shift mostly, but through some revs I sync them up and all good. I will check with the garage whom got it all checked out for me on what they used for the oil change. Otherwise drive it more and go from there.

The vibration, maybe a rumble, is more annoying. It seams to be associated with torque and not speed. Most in first gear and hard acceleration. a bit in second and smooths out from there and with speed.

Thanks on the diagnostic checks. I will start going though that once i get the ball joints back in. I am still waiting on the garage to get my spindles back. Today i go about getting the original ball joint out that was installed using large kind of rivets. No nuts and bolts anyways so more angle grinder work. Love it. lol

Thx
Scott

[18Fiatsandcounting]

The vibration, maybe a rumble, is more annoying. It seams to be associated with torque and not speed. Most in first gear and hard acceleration. a bit in second and smooths out from there and with speed.

Based on this, I'd start with the giubo and the center driveshaft bearing and the rubber support that goes around that. U-joints cause more of a click or a clunk sound, and if the noise was coming from the differential or rear axle bearings, it would of course be more towards the rear of the car.

-Bryan

[ScottB]

The vibration, maybe a rumble, is more annoying. It seams to be associated with torque and not speed. Most in first gear and hard acceleration. a bit in second and smooths out from there and with speed.

Based on this, I'd start with the giubo and the center driveshaft bearing and the rubber support that goes around that. U-joints cause more of a click or a clunk sound, and if the noise was coming from the differential or rear axle bearings, it would of course be more towards the rear of the car.

-Bryan

Thanks i better get on this instead of the exhaust first. lol Tomorrow i think i will check some of that out since it is up on jacks already.
Scott

[Veiveismart]

If any are near CT, Danny O'Donnell in Vernon, at Fun Imported

[seawood]

PM sent.

I'll have to do my tranny I suspect before long. 2nd gear is starting to crunch a bit. Full depression of the clutch pedal helps at this time.

If the car has been sitting, consider changing out the clutch cable as well. Bit of a pain attaching to the clutch pedal but if the cable is not sliding nicely in the sheath, the fire wall takes up the movement and eventually cracks and fails. An extra ground strap from engine to body is another nice bit of preventative medicine for the clutch cable.

[seawood]

And another item.... sounds like it has been a while since the car has been used so I'd change the donut as a matter of course and perhaps the steady /intermediate bearing as well. Either is an easy evolution to do.
Change the oil in the differential and run a magnet through the oil. Have a look to see if any crunchies are in there.
I changed out a pinion bearing I think it was without too much fuss once. Mark the retaining nut to the shaft so they go back the same.
I'm coming down in May to help dad with the boat and will be in WV. for a couple of days. PM if you need a hand or parts.