hello everyone, I have a technical question about my salmson s461 boite cotal.
when moving backwards, something broke and I no longer have a single gear not forward not back


rear differential and clutch look good

I suspect the gearbox, does anyone know what could have broken inside


thank you,Edvard

Hello ,

Before incriminating the Cotal gearbox, see key at the end of the transmission shaft driving the rear axle input pinion.
A classic and well-known S4-61 failure.

Hello,
I think that it is the transmission shaft that is broken .For the rear gear , use the fourth gear
yours sincerely
R Lambert

Thank you all for your reply. After this ‘crack sound’, the car was continuing to work normaly, there were no any ‘strange noises’, I just couldn’t move front or reverse, there were no any gear. When i put gearbox on the table, all looks good, I tried to turn shaft with my hand and it turned normaly on other side, I shifted in reverse, front and neutral and all looks good It crossed my mind that maybe gearbox lost electricity and maybe that’s the reason for not having any gear.
My knowlede about this kind of transmission is limited so don’t judge me if my questions don’t have much sense.

I still think it's the drive gear input cotter pins.
I repeat: classic and well-known failure on the S4-61. There is no noise after this failure.
Box on the table, you must check the 4 electric windings and simulate the 4 possible speeds by supplying 2 to 2 the windings corresponding to the 4 speeds. In front and rear .
Turning the box is useless without electrical 12V source ( battery ) .

I disassembled all possible bolts on gearbox but I can’t separate it/ open it, it opened only for few millimeters. I don’t know how to open it completly. Have any sugestion what I missed?
Thank you in advance

You did not remove the terminal before the electrical current arrived.
You will encounter enormous problems when reassembling if you continue to disassemble without knowing: in fact, your box will be unusable.

jjb écrivait:
-------------------------------------------------------
> I still think it's the drive gear input cotter
> pins.
> I repeat: classic and well-known failure on the
> S4-61. There is no noise after this failure.
> Box on the table, you must check the 4 electric
> windings and simulate the 4 possible speeds by
> supplying 2 to 2 the windings corresponding to the
> 4 speeds. In front and rear .
> Turning the box is useless without electrical
> 12V source ( battery ) .

It was my first trouble with an S4-61. To be sure that you lived the same surprising minutes you must have seen the speedometer moving right because the clutch and the gearbox are working.
Patrice ROUSSEL

if you mean this axle it looks good

You show a picture of the cotal gearbox input shaft.
We are talking about rear axle input sprocket cotter pins .

Bonjour à tous,
J'ai du mal à expliquer étant en vacances donc sans documentation, la faiblesse de l'assemblage du pignon d'attaque sur l'arbre de transmission. Le seul catalogue de pièces détachées disponible sur le site ne fournit pas d'image sur ce qui m'intéresse. Par contre j'ai dans mon ordinateur une photo de la mécanique du pont arrière d'un VAL 3 qui permet de voir les perçages de la queue du pignon qui reçoivent les goupilles. Ainsi Edvard pourra mieux se repérer.
Patrice ROUSSEL

merci, maintenant je comprends le problème