Gearbox shaft material

[rlo943]

I am looking at doing a repair on a automotive gearbox output shaft. It is common practice within the sport to shorten the output shafts on this particular gearbox by cutting and welding the output shaft on the gearbox. I have a shaft to repair which has broken at the weld, This weld has been good and used for the last two years without any problems but after an issue further down the drivetrain it snapped. I am looking for any information on what material automotive gearbox shafts are normally made of? And any advice on weld procedures and rod type/material. Hope you can help. Thanks

 

[CoryPad]

Without more details on the application, you will only get general information. Alloys used include: SAE 4140, SAE 1050, SAE 4320, and SAE 8620. Welding is not normal for these parts. I wouldn't weld these. Someone else may give some welding advice.

 

[metengr]

I also would not recommend any partial or full penetration weld repairs for gear shafts, period. The problem is that fusion welding on high performance (alloy steel) shafts generates heat that results in changes to mechanical properties of the shaft material.

Normally, if welds are necessary they are placed in locations along the shaft where bulk fatigue strength of the shaft is not compromised. As Cory mentioned you do not provide any specific information as to the type of weld you are considering.

 

[rlo943]

Thanks for your replies. I have repaired this shaft with a welding process from eutectic 680S rods and so far so good, done around 10 races wth it and so far so good. Thanks again