Clutch or Synchro...?

[martym00se72]

Hi,
I got my Uncle, who has been tooling cars for a large portion of his life now to check over my 83 GTV6 - first time he had seen it. I wanted him to give me a no BS assessment of it. I know a bit but no where near as much as he does - got the expected list of spots of rust around windows, front bearings and ball joints etc, etc (its a longish list... ). Listening to the gear change, he was thinking that the crunch I had put down to the usual suspect of worn synchros as the clutch not fully disengaging. When I got the car, fluid in the clutch resorvoir was minimal but I had bled that before my Uncle checked it out. My question is; is there any way to distinguish between clutch noise/crunch vs synchro noise/crunch. Also, is there any adjustment on the clutch that I can try out to see if that will make a difference?
Cheers
Marty

[Craig C]

From what I have researched there is no ongoing adjustment of the clutch, just the ability to set it up when it goes in new.

[stradale]

It's a hydraulic system so no real adjustment, the clutch pedal "feel" on alfettas and gtv's is heavy and the travel is also longer compared to more modern cars
It should feel consistant all the way through its movement.
Is the pedal sitting low ?, if you put your foot under the pedal and pull up there should be very little play
no more than 10-15 mm the pedal should be up level with the brake pedal
also does the car hold position with the car in gear and the clutch pedal in, or does it want to move forward.

you really probably need to bleed the system if the fluid level is low and see if there is any change

[martym00se72]

I own the car so no probs there. Pedals check out wrt feel, height etc. I have bled the system and kept an eye on it - no leaks so my conclusion is synchro.

Is it common for it to sometimes not even crunch a tiny bit and then sometimes sound like the gearbox has been deposited rather ungraciously onto the ground

[Jekyll and Hyde]

One thing you haven't mentioned is whether its all gears, or just 2nd (and probably first)...

[martym00se72]

It is very evident when I pull up to the lights. Go to put it in 1st and and it can make an almighty crunch. Less evident in 2nd and only rare in 3rd/4th, never in 5th. Have changed the gearbox oil - helped a little. I notice it most when cold. If I am pushing hard, never get it on down or up shifts. I am conscious of the synchro issue so have always (well almost - occasionally I get a bit carried away... ) been a bit nicer on the 1st to 2nd change and don't rush it. Haven't mastered the art of double de-clutch yet but am working on it...

[Sheldon McIntosh]

It is very evident when I pull up to the lights. Go to put it in 1st and and it can make an almighty crunch.

Don't put it into first unless you're not moving (or double declutch down, but even then at very, very low speed and only if you have to).  Before putting it into first, shift to neutral and let the clutch pedal out, before depressing and engaging first.

[Jekyll and Hyde]

It is very evident when I pull up to the lights. Go to put it in 1st and and it can make an almighty crunch. Less evident in 2nd and only rare in 3rd/4th, never in 5th. Have changed the gearbox oil - helped a little. I notice it most when cold. If I am pushing hard, never get it on down or up shifts. I am conscious of the synchro issue so have always (well almost - occasionally I get a bit carried away... ) been a bit nicer on the 1st to 2nd change and don't rush it. Haven't mastered the art of double de-clutch yet but am working on it...

In that case, its most likely the synchros in your car have copped a hiding through their life.  Change slower going up, and yes, double de-clutching will help going down.

[Rigi]

i'm trying to figure out what in the clutch mechanism not disengaging could crunch like a syncro, or is he saying that since the clutch isn't fuly disengaged when you try to slot it into gear the clutch is still partially engaged? if so when your stopped and you have the foot on the clutch in gear wouldn't the car start to move??


I echo Sheldon's comment don't put it into first gear until your completely stopped, it just plain doesn't like it. Also try slowly putting it into 2nd then 1st see if that reduces the crunch.

An aside on double clutching. this is most effective in reducing synco wear on down changes and only when you "adjust" the revs so the engine speed matches the "expected" speed in the gear your going into. Double clutching without matching revs is totally useless, IMO anyway.

[martym00se72]

I only ever come to a stop in second, never first. I am also a compulsive rev matcher, as taught by my Dad many years ago (but he didn't teach me to double declutch) and I am teaching myself to double declutch. The initial supicion was from my Uncle that it was clutch not synchro. I believe it to be synchro, for all the reasons listed above... I guess one of the questions that naturally (to me anyway) follow that I have not actually seen asked is; when the synchro crunches, is that causing damage to my gearbox or is it the synchro that is coping a hiding? - I imagine synchros are substantially less costly to replace than actual gearsets...

[alfagtv152]

Hi Marty,
All sounds pretty normal to me,most cars around that era didn't have synchro on 1st so as said earlier you need to be stationary and the gears in the box to be stationary also-if you need to stick it in quick pull second first then push back into first.Unless the synchro's are fairly new all the symptoms you have described are normal,the correct oil is very important and has been covered on another post but you can easily get Castrol Multitrax(Forgot the proper spelling) with one specifically for superior cold shifting.
I believe using the transaxle gearbox requires a specific technique,patient shifting while feeling each gate as you go through ie first-neutral-second or coming back down third-neutral-second.
Once you have Mastered double de clutching synchro's don't count anymore!.
Cheers
Andrew

[aggie57]

As Sportiva says there is a lot of knowledge in the Alfa community on how these transaxles work and how to look after them.  The noises you describe sound like classic worn synchro's which is a fairly straightforward and common repair job on these cars.

What you can find on the clutches though, particularly if you have one of the original twin-plate units, is that they bind up over time and as they needed to be fully disengaged to work even when new many people tend to drag the clutch when they change gear.  That obviously puts pressure in the synchro's and contributes to poor operation and early failure.

The clutch needs to come off to repair the gearbox anyway so it's a no-brainer to service both together and if indeed you do still have a twin-plate you may consider replacing with a later single plate unit.