"All that is beside the fact that they do fail, and very prematurely."
Have you conducted a professional investigation on any of the failed components so as to determine the true cause of failure? If not, then nothing of any benefit can be taken from your statements as they are not based on...
I don't get your implied meaning with the quotations. I've always understood that torsion on a shaft can cause it to shear, or in this case forces applied to the spline faces.
I find it hard to believe that they would have under-engineered the part using a soft metal and removed ID splines if...
I'm not sure how valid it is to say the coupler is meant to provide play or that it should be replaced. Many instances of this transmission show the coupler is on quite snugly, while in others it is looser and can be removed by hand. As for replacing it, I know of no renault recommendation to...
At this point based on the info here and discussions I've had IRL, I'll probably stick with the heat-treated 4130 and do a cryo treatment thereafter. It remains to be seen if I'll need to heat treat before or after the broaching.
Thanks for the feedback everyone, but please chime in if you...
Why do you recommend 4140?
One limitation I'm not sure how to get around is that the broaching said they can't cut splines in anything higher than Rc32-34. Broaching before hand would potentially make the spline fit too tight, but I don't know if it would be negligible.
The shop was going to...
I'm looking into getting the stock coupler tested to get more info on what it is made of. I do know there was a qualitative difference before and after people installed this upgraded coupler.
The theory Renault had was that the coupler would fail before the rest of the transmission...
I'm looking for some feedback on a project I'm working on to replace a weak input shaft coupler in a Renault 369 transmission. Rather than make the input shaft one piece, Renault used a relatively weak metal for the coupler and only partially splined its ID.
Someone had them remade in heat...
