Will the steel synchro for 3-speed break?

[ritmo75ts]

Hello.I'm from Japan.
My clio197 also had a 4th gear synchro failure and I had to disassemble the transmission and try to assemble it using the synchro for 3rd gear for 4th gear as well.
However, the mechanic said I shouldn't do that as the synchro for 3rd gear would also strip the brake and break.
Is that really possible?
Is it better to use brass synchros or synchros for 3rd gear?

 

[RSRowe]

Your gearbox must have been rebuilt previously if it has a mix of brass and steel.

Either synchro will work. Steel synchros will put more wear into the sliding hub engaging teeth, but these can be replaced if required later on in life.

 

[ritmo75ts]

Thank you for answering.
My Clio's gear box is TL4-024, but this time I will replace it with a used TL4-031 with an overhole.
I also had a steel synchronizer, but the mechanic advised me that it would be better to use a brass one because the brake surface might peel off, so I'm not sure which one to use.
Have you ever heard that it can actually peel off?

 

[RSRowe]

I have not heard that.

Perhaps go with the mechanics suggestion? The brass rings will still last a good while of the cars life.

 

[deekay16v]

Thank you for answering.
My Clio's gear box is TL4-024, but this time I will replace it with a used TL4-031 with an overhole.
I also had a steel synchronizer, but the mechanic advised me that it would be better to use a brass one because the brake surface might peel off, so I'm not sure which one to use.
Have you ever heard that it can actually peel off?

Have seen photos of those peeled off/desintegrated, but never seen on in person.

 

[Foxspeed]

some of the synchro hubs have a "carbon like coating" on them

 

[Foxspeed]

 

[Foxspeed]

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[ritmo75ts]

Have seen photos of those peeled off/desintegrated, but never seen on in person.

Thank you. I have never seen the real thing either, but my mechanic has seen it many times.

 

[ritmo75ts]

some of the synchro hubs have a "carbon like coating" on them

The quality is not so good for a carbon-like coating. The latest Toyota GR86 is carbon-synchro, but it is very different from that.

 

[ritmo75ts]

View attachment 155706

I have three of these synchronized rings. Following the mechanic's recommendation, I decided to build them up with brass synchros (8200368022).
I wonder why Renault changed the material of the synchro from brass to iron. Is it to reduce wear on the synchronizer teeth?