DogDaddy
New member
Rebuilt the transmission with new synchronisers and still jumps out of second gear, is there a way to adjust the linkage? or is it a permanent problem?:bang:
Technical 72-124 Spider Jumps out of Second Gear
- Thread starter DogDaddy
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Technical 72-124 Spider Jumps out of Second Gear
Usual reason for jumping out of gear is worn, broken or missing detent balls and/or springs but I would assume you replaced them whilst rebuilding the transmission. Items 8 and 9 on this page from the Spider manual.
You should be able to get them out with a magnet to check them by removing the retainer plate.
Dave.
You should be able to get them out with a magnet to check them by removing the retainer plate.
Dave.
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hi. just joined tonight. i have a 1982 Spider...it too jumps out of second gear. when accelerating, it stays in gear. when i let up on the accelerator, it jumps out. also does not want to go into second when downshifting...gear grinds. is the detent ball or spring the issue here? is it necessary to pull the whole transmission to fix this?
Hi, Welcome to the FF.
As posted above, jumping out of gear could be caused by worn, broken or missing detent balls and/or springs. However, if it jumps out of 2nd when decelerating, and is difficult to engage, it could also be a worn 1st/2nd selector fork.
Jumping out of 2nd could also be caused by a worn gearbox mounting, allowing the gear stick to knock on the transmission tunnel recess.
The detent balls and springs are held in with 2 bolts (12), retaining plate (10) and gasket (11) in the bottom diagram above, They are on the side of the gearbox, and may be accessible without removing the gearbox.
If the selector is worn, the gearbox will need to be removed and dismantled to replace it.
.
FIAT425
New member
Shift forks warn out people rest thier arm on the shifte. Also don't compression brake it's super hard on transmissions!!!
It's important to check the condition of the small teeth that lock the gear to the synchromesh (outer) sleeve and the corresponding teeth inside the synchromesh sleeve. These teeth are what connect the selected gear to the mainshaft and keep it engaged!
You heard me right! The selector fork simply moves the appropriate synchromesh sleeve in or out of engagement with the required gear. The detent springs and balls simply hold the selector rail in the correct position. Neither the fork, springs or balls will hold a gear engaged if the above mentioned teeth are worn. If the profile of these teeth on a gear is worn, the gear will tend to drop out of engagement.
Incidentally, the sound you hear when you crunch the gears when engaging a forward gear is the above mentioned little teeth being bashed against each other (not the actual gear teeth, as many people believe) when the synchromesh unit isn't working correctly or you're being ham-fisted.. If you hear a crunch when engaging reverse gear, you're bashing the actual teeth on the reverse idler pinion against those of the two reverse gears.
Unfortunately, checking/ rectifying the above requires removal and strip-down of the gearbox.
A worn selector fork can cause a gear to jump out of engagement as it's being engaged because the S. sleeve is not being moved far enough to fully engage the gear. Wear in the remote gear linkage or base/mounting of the gear lever on early 4 speed boxes can cause the same problem. Check that the engine and gearbox rear mountings are good. Check that there's nothing preventing full gearlever movement, e.g. displaced rubber boots, soundproofing/insulation etc.
The reverse detent balls and springs give very little trouble. Only problem I can recall was a couple of cases of balls sticking in their guide sleeves due to water ingress/condensation causing a little corrosion (shouldn't happen because there's a gasket under the cover plate!). Or people getting things wrong when assembling the gearbox....
P.S. I rebuilt these gearboxes while employed as a Mechanic at a Fiat Main Dealership, back in the day..... Never had a problem with any I rebuilt...
Al.
You heard me right! The selector fork simply moves the appropriate synchromesh sleeve in or out of engagement with the required gear. The detent springs and balls simply hold the selector rail in the correct position. Neither the fork, springs or balls will hold a gear engaged if the above mentioned teeth are worn. If the profile of these teeth on a gear is worn, the gear will tend to drop out of engagement.
Incidentally, the sound you hear when you crunch the gears when engaging a forward gear is the above mentioned little teeth being bashed against each other (not the actual gear teeth, as many people believe) when the synchromesh unit isn't working correctly or you're being ham-fisted.. If you hear a crunch when engaging reverse gear, you're bashing the actual teeth on the reverse idler pinion against those of the two reverse gears.
Unfortunately, checking/ rectifying the above requires removal and strip-down of the gearbox.
A worn selector fork can cause a gear to jump out of engagement as it's being engaged because the S. sleeve is not being moved far enough to fully engage the gear. Wear in the remote gear linkage or base/mounting of the gear lever on early 4 speed boxes can cause the same problem. Check that the engine and gearbox rear mountings are good. Check that there's nothing preventing full gearlever movement, e.g. displaced rubber boots, soundproofing/insulation etc.
The reverse detent balls and springs give very little trouble. Only problem I can recall was a couple of cases of balls sticking in their guide sleeves due to water ingress/condensation causing a little corrosion (shouldn't happen because there's a gasket under the cover plate!). Or people getting things wrong when assembling the gearbox....
P.S. I rebuilt these gearboxes while employed as a Mechanic at a Fiat Main Dealership, back in the day..... Never had a problem with any I rebuilt...
Al.
