New to 75 ts

[Divano Veloce]

fixed petrol vapor leak... it was the filler pipe split along the seam. Smeared the seam with a soldering iron to seal it up!

I think i know what the source/cause of the vibration is....

very bad alignment of prop shaft at tranny over an extended period has worn the clutch input shaft where it fits into the rear donut. With a new(ish) donut and tranny/propshaft alignment correct the rear donut is not centered on the clutch input shaft.

[Divano Veloce]

In pursuit of prop shaft vibrations i have sofar done the following:

Replaced tailshaft complete with good second hand unit.
replaced all motor and transaxle mounts
Adjusted rear motor mount to achieve 7mm clearance between bellhousing and tailshaft
checked propshaft alignment at clutch by loosening guibo bolts and observing clearance at yoke to guibo, gap was always biggest at the bottom (when shaft is rotated). Added spacers under tranny mounts and achieved good alignment.

After all of this the vibration has been altered and improved but is still there enough to be annoying.... I also noticed that there was a large amount of radial play at the rear guibo with the yoke bolts loose...

So I have finally measured the radial clearance between the clutch input shaft and the spigot in the rear guibo.... its about 0.4mm. So the rear end of the prop shaft could have up to 0.2mm of runout when assembled. Is this a likely cause of vibration?

i measure the clutch shaft where it is centered in the rear guibo to be 18.92mm. It looks a little worn and the chamfer is rounded...

Also the front clutch shaft bearing is stuffed.

My plan is to replace the clutch bearings and either replace or sleeve the clutch shaft. If anyone access to a rear guibo and tranny can they measure their clutch shaft so i can determine if mine is worn undersize?

cheers

[Evan Bottcher]

Can anyone measure their clutch shaft so i can determine if mine is worn undersize?

Snicker. 

[GTVeloce]

Can anyone measure their clutch shaft so i can determine if mine is worn undersize?

Snicker. 

Do you get a noise from that region with the car in neutral, idling and with the foot off the clutch? I used to until I replaced the clutch housing bearings.

[Divano Veloce]

Thanks Evan for your contribution

the small bearing floats axially in the housing so doesn't take any load from clutch disengagement. Its the one that's a bit (quite) loose. Yes Evan, its loose.

[Divano Veloce]

Underwhelmed with the response to my request for assistance (what? no-one has a guibo or transaxle in the shed and a vernier?) I bought another complete 75 with the intention of wrecking it and taking the measurements. Extreme perhaps but i was upset with all of you (except Julian).

Its body is straight but super rough, is every shade of Alfa red and the clear coat is peeling on most panels.
Mechanically it had some issues - leaking water pump, driveline vibration (of course), rear brake discs worn undersize, loose front wheel bearing, no power steering belt or tensioner pulley, gutless below 5000 rpm.
Electrically.... had a wire running from the battery to a switch in the cabin and down to the fuel pumps.... no fuse! Rear windows don't work.

THe good points, LSD and synchros seem great, awesome above 5000rpm, interior is mint, arc seems to behave, brakes are good.

So once home i got out the motronic schematic, multimeter and some alligator leads to do some fault finding of the fuel pump and vvt. For circuit continuity tests i disconnect the ecu from the loom to ensure that i don't fry anything (autoranging DMM)

The fuel pump issue was an easy fix, the wire from the fuel pump relay had become disconnected from the back of the fusebox.

I then earthed one terminal of the vvt solenoid and applied 12v to the other (with the motor running). If the VVT solenoid and variator are working the idle should get really rough or even stall... nothing happened. So i whipped the cam cover off and energised the solenoid and apart from a very quiet click there was nothing, no actuation of the variator. I pulled the solenoid apart to find its cock is worn into more of a choad, and it was installed the wrong way around.

I swapped a vvt solenoid from the champagne car and tested at idle then test drove. This confirmed what i had suspected about my other 2 twin spark cars (one has grunt but no top end the other great top end but nothing down low). This car now has both torque and power and 448000kms on the clock, brilliant! Now i just need to sort out the other two "good" cars!

In the meantime i have decided not to wreck it. It will get club reg when it turns 25 in a couple of weeks. I will spend the absolute minimum to keep it roadworthy and reliable (kind of SBR philosophy). So what i need are the following: second hand 2000 or TS water pump, VVT solenoid (or else i will have a new cock made for it), new rear discs.

If i cant get the Berlina top end power sorted there's no point taking it to Sandown again, or Phillip Island or anywhere else really. So instead I might take this car. Its completely standard so complies with comp regs for standard class. If i remove the air conditioning components and power steering pump would the car still comply? I'd like to install the biggest standard equipment bars available too, I believe they are from a Potenziata? Torsion and sway. This should make for a quick, low cost and fun track/autocross experience!

[GTVeloce]

Exactly which part do you want measured? I have a clutch sitting at home I can measure (although it is old and I don't remember how good it is) but there is a dirty big yoke on the front. Is it the bearing in front (driveshaft) or behind the yoke (clutch)?

Also, you have stolen my idea for a cheap race car! Beef up the suspension if you like but a bigger priority would be decent pads and fluid for the brakes and possibly some ducting onto the front callipers. Allows you to keep going hard all day and not retire early with no brakes...

[Divano Veloce]

I finally got some time to work on cars today.... progress has been glacial.

But the Berlina has only a couple of weeks of permit days left.... So its time to get another car on club plates.

I reinstalled the clutch with new bearings in the champagne car today, got clutch bled and gear linkages working ok. Tomorrow its cam cover and VVT, plug leads and test drive. I am hopeful that the clutch bearings and improved prop shaft alignment will have addressed the vibration.

I begrudgingly purchased a new water pump for the red 75, and a set of spark plug leads. Just need a VVT solenoid and i can have both cars on club reg!

Any TS big cam converters done away with their VVT?? I could put a solenoid to good use.

[Divano Veloce]

Champagne 75 passed RWC and will be on club plates when it turns 25! Some other good news is that the persistent vibration is improved (but still there)...  centering of the rear guibo on the clutch input shaft i think is the key... Motor still seems a bit sluggish down low but sensational above 4500-5000 rpm.

When i get time I'll swap all the nice parts off the Red car onto the champagne car. Then get RWC on red and club plates....

The red car is such a great candidate for a club car... i cant wait to get it on the road!