I'm having a new shaft and coupler made but the mating surface on my transmission output has some light surface rust on it. I've read that surface rust on a coupling means that it's essentially no good or if worth it, needs to be resurfaced. Should I be concerned? If so, can I use rust remover or acid on it so I don't remove metal unevenly?
Transmission output rust
- Thread starter Project_Mayhem
- Start date
Assuming it is just surface rust, and hasn’t degraded the output flange, I would clean it up and not worry about it. If for some reason you suspect if affects the ability to align the shaft/coupling and output flange, then that would need to be further investigated. But the output flange does not use a press fit to the shaft coupling.
Rust in the shaft coupling would be something to worry about. But even then, I suspect most used shafts/couplings are rusty
Greg
Rust in the shaft coupling would be something to worry about. But even then, I suspect most used shafts/couplings are rusty
Greg
Without any images, it is impossible to determine what type of rust you are observing, and even then, it might not be possible.
That being said, there are generally three types of rust that I know about. Surface rust is generally a reddish brown coating of iron oxide and can be removed via sanding, brushing or other mechanical means. The second type of rust is scale, which is manifested by delamination and the ability to remove pieces of fully compromised material. The third is penetrating which as the name implies, constitutes a concentrated loss of structural integrity. This can manifest itself by a "crater" or drastic change to the original manufacturing dimensions of the structure being observed.
My rule of thumb is that if you can see that the entire component generally meets the original manufacturing dimensions and you can see things like machining marks, casting numbers, stamped ID marks etc., you are dealing with surface rust. Anything beyond that, and I would have to consider remediation or replacement. This is just my humble opinion and you can take it for what it's worth.
That being said, there are generally three types of rust that I know about. Surface rust is generally a reddish brown coating of iron oxide and can be removed via sanding, brushing or other mechanical means. The second type of rust is scale, which is manifested by delamination and the ability to remove pieces of fully compromised material. The third is penetrating which as the name implies, constitutes a concentrated loss of structural integrity. This can manifest itself by a "crater" or drastic change to the original manufacturing dimensions of the structure being observed.
My rule of thumb is that if you can see that the entire component generally meets the original manufacturing dimensions and you can see things like machining marks, casting numbers, stamped ID marks etc., you are dealing with surface rust. Anything beyond that, and I would have to consider remediation or replacement. This is just my humble opinion and you can take it for what it's worth.
Brush it off with a wire brush. If it isn’t pitted, you should be fine. Maybe coat it with some light oil to keep the rust bloom down.
Greg
Spray the coupling with a good anti-corrosion spray, like CRC Heavy Duty Corrosion Inhibitor (Amazon Link).
I added a bit of Lanocote to my shaft end before I put the coupling on. Made removing it a year later to put on the new Volvo dripless very easy.
Greg
I used anti seize but the general consensus is NO. My coupling hasn't come off but I won't do that again next time.
For outboard props and shafts the general consensus is to grease them up. Strange that it's not for inboards. I'll put something on it.
I have a can of this exact stuff thats been sitting on the shelf unused for years. Should it be used on the inside of the coupler too?
I only used it on the outside of the coupler. I think it best to to have direct metal to metal contact on the coupler, shaft, and flange. The corrosion inhibitor is a bit waxy when it dries. Be sure to rotate the shaft to get all sides.