Crunch changing from 4th to 5th

[Daniel]

Quick question.

Just making a list of jobs which need doing when the engine comes out at the end of summer.

Since I've had the 350, rapid gear changes from 4th to 5th always result in a crunch, if you do it at a normal rate it's fine, but if you go for a quick change.....crunch......

Is this a common issue or am I looking at gearbox work?......if they all do it, fine.....if not, it needs to be perfect so I'll get it sorted.

[Günter]

"quick" ? does it mean on track, right ? If so -No , it doesn't happen on mine. Maybe I'm not fast enough ...

[Daniel]

[quote name='G

[Günter]

wear of synchronizers ... just a thought, but thats more common in downshifting processes...

[Rob]

Can't help as to why.. but mine also did that. I just learned to take it easy on the 4th to 5th changes. I would guess its as a result of previous fast shift where the syncho may have been damaged..? I know of one other 350 that did the same.

First thing to check would be correctly adjusted linkage?

[neal]

My old gearbox used to crunch all the time when changing up to fifth. The syncho was replaced but that didn't help. My new box is better but still grinds when I shift quickly on the track.

What I think is, the 5th gear baulk ring isn't strong enough, particularly on an old box. It wasn't replaced with the syncho on my old box (it wasn't broken) but I presume it had weakened with age.

The result of this is that if you change down from fifth by pulling the gear lever back just enough to let the centering spring bring in back to the 3rd-4th plane, the baulk ring doesn't disengage the syncho from the 5th gear selector ring. Then next time you change up to 5th, the selector ring just crunches as it engages unsynchronised with the 5th syncho hub.

The solution I found is to either shift down from 5th by first pulling back to where 6th gear would be before allowing the lever to spring back to the 3rd-4th plane, or shift up to 5th by first pushing the lever into the middle 5th plane then pull back to where 6th would be, then push forward to 5th. The result of this pulling back to '6th' either on the shift up or down is that it disengages the syncho from the selector ring without relying on the baulk ring.

Worth a try...

[Daniel]

My old gearbox used to crunch all the time when changing up to fifth. The syncho was replaced but that didn't help. My new box is better but still grinds when I shift quickly on the track.

What I think is, the 5th gear baulk ring isn't strong enough, particularly on an old box. It wasn't replaced with the syncho on my old box (it wasn't broken) but I presume it had weakened with age.

The result of this is that if you change down from fifth by pulling the gear lever back just enough to let the centering spring bring in back to the 3rd-4th plane, the baulk ring doesn't disengage the syncho from the 5th gear selector ring. Then next time you change up to 5th, the selector ring just crunches as it engages unsynchronised with the 5th syncho hub.

The solution I found is to either shift down from 5th by first pulling back to where 6th gear would be before allowing the lever to spring back to the 3rd-4th plane, or shift up to 5th by first pushing the lever into the middle 5th plane then pull back to where 6th would be, then push forward to 5th. The result of this pulling back to '6th' either on the shift up or down is that it disengages the syncho from the selector ring without relying on the baulk ring.

Worth a try...

blimey, well worth a try, thanks for that!!

[Fred Basset]

Mine does it sometimes, my old one did not. I've started to be able to "feel" it as I change out of 4th. I'll try Neal's 6th gear trick next time I drive her.

Generally I've slowed down the change but it is hard, I drive the Evo more than the Esprit and that has quite the best gearchange I've ever tried.

Regards

Gay

[2003 V8 TT]

My old gearbox used to crunch all the time when changing up to fifth. The syncho was replaced but that didn't help. My new box is better but still grinds when I shift quickly on the track.

What I think is, the 5th gear baulk ring isn't strong enough, particularly on an old box. It wasn't replaced with the syncho on my old box (it wasn't broken) but I presume it had weakened with age.

The result of this is that if you change down from fifth by pulling the gear lever back just enough to let the centering spring bring in back to the 3rd-4th plane, the baulk ring doesn't disengage the syncho from the 5th gear selector ring. Then next time you change up to 5th, the selector ring just crunches as it engages unsynchronised with the 5th syncho hub.

The solution I found is to either shift down from 5th by first pulling back to where 6th gear would be before allowing the lever to spring back to the 3rd-4th plane, or shift up to 5th by first pushing the lever into the middle 5th plane then pull back to where 6th would be, then push forward to 5th. The result of this pulling back to '6th' either on the shift up or down is that it disengages the syncho from the selector ring without relying on the baulk ring.

Worth a try...

Genius!