Crunchy synchros ?

[Terje]

Hi!
I am the proud owner of a 1971 Fulvia 1,3 S Coupe. Now, whenever I shift up to second gear I need to do so at very low revs (about 2500 rpm`s) otherwise the gears will scrape and crunch before engaging. Do any of you have any tips on any gearbox oil that will help this problem or is a overhaul the only solution?

The car has done less than 50k miles and the rest of the gears slot into place perfectly!

Any tips welcome! :D

[omicron]

Does this get better when the gearbox is warm?

Without stripping down the gearbox and swapping synchros from low down with the higher gears, we find that using a different gear oil can help. The oil we normally choose is either Mobil 75SHC gear oil or Castrol TAF-X. Both are more expensive than normal gearbox oil but we have found the improvments in gear change to be worthwhile.

[Terje]

Hi Andrew and thank you for a quick response!

Yes it improves quite a bit after a few miles although still noticeable in the higher rev range especially if the shifts are hurried from 1-2. Downshifting from 3-2 is less of a problem for some reason....

As soon as the winter disapears Ill remove the car from storage and try one of the oils you mentioned!

[Kev]

I think second gear on Fulvias is a general issue until the gear box oil has warmed up a bit.

I find double declutching is effective if you want to try and avoid crunchy synchros for the first few miles.

Renewal of the gear box oil using a type that Andrew mentions will undoubtedly assist. You might also consider an additive (although do your research - PTFE based ones are usually rubbished!).

[Terje]

Top notch guys!
Now I only need to master the art of double declutching...
:)

[Kev]

Hi Terje

You don't necessarily have to master proper double declutching (with throttle blipping). A pattern of:

i) Clutch in
ii) Move into neutral
iii) Clutch out
iv) Clutch in
v) Move into second
vi) Clutch out

will help!

This sounds move complex than it actually is! :oops:
Steps i), ii) and v) and vi) are something you're doing anyway as part of normal driving. Steps iii and iv are the additions! The thing is to let the clutch out and dip it in again whilst in neutral before moving into second. If you try this for the first few miles before the gear box oil has warmed up you'll be in good shape!

Good luck.

[Terje]

Thanks Kev!

Although its a shame to deny the public the sound of a double declutching (with throttle blipping) Fulvia 8) , this seems to be more "doable"! and less stressful for the old brain!

[Terje]

Hi again!

Ive just changed the oil to Castrol Taf-x and added some Gear and diff treatment from Fortè and boy did it make a world of difference!
It may not be Toyota smooth but its not far from it! There is no grinding or crunching noises when selecting second gear at all so I would like to thank you for very helpful advise indeed! :D

[omicron]

Pleased to help.