gear shaft hard chrome repair

Onder

Onder

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Have a non-Norton gear shaft that has suffered some slight damage to the bearing surfaces on each end.
Both ends ride in needle bearings. Replacing the shaft is not possible. Is hard chroming and regrinding
the way to go v. building up the shaft by welding and then regrinding?

HARD CHROME PLATING | Hard Chrome Plating & Grinding

Situated in North Nottinghamshire, HCP is a specialist Hard Chrome Plating and Grinding Company. Established in 1986, HCP has a strong client base, with customers in such trading areas as the gas, electric and brewing industries, automotive & cycle production, industrial & manufacturing industries.
www.hardchromeplating.co.uk www.hardchromeplating.co.uk
This is just an example someone suggested.
 
I've had Norton crankshafts repaired by hard chrome plating and regrind on the output shaft with good results, and I have successfully run Commando rocker arms with a needle roller conversion with the shaft hard chrome plated, but with only a very thin plating thickness and no need to grind. That at least shows that the hard chrome was compatible with the needle rollers.

Ken
 
The amount of make up thickness is not a lot. A few of the rollers dug in on the shaft and left a barely visible trench but enough that it will only get worse if I just put in new bearings. So there is hope :) Thanks for the report.
 
Onder said:
Have a non-Norton gear shaft that has suffered some slight damage to the bearing surfaces on each end.
Both ends ride in needle bearings. Replacing the shaft is not possible. Is hard chroming and regrinding
the way to go v. building up the shaft by welding and then regrinding?

HARD CHROME PLATING | Hard Chrome Plating & Grinding

Situated in North Nottinghamshire, HCP is a specialist Hard Chrome Plating and Grinding Company. Established in 1986, HCP has a strong client base, with customers in such trading areas as the gas, electric and brewing industries, automotive & cycle production, industrial & manufacturing industries.
www.hardchromeplating.co.uk www.hardchromeplating.co.uk
This is just an example someone suggested.
Click to expand...
Philpots (of the pitted fork repair business) also offer this service.

www.pittedforks.co.uk

Pitted Forks - Motorcycle Fork Refurbishment - Motorbike Fork Rechroming - Bike Fork Repairs - Eire and UK

For over 65 years, Philpots, based in Luton Bedfordshire, have provided hard chrome plating services to industry, as well as associated services such as hard anodising, metal spraying, grinding and machining.
www.pittedforks.co.uk www.pittedforks.co.uk
 
The trunnions on gas turbine engine blades are routinely repaired by this method..... hard chrome build up, then grind to spec.

This would be the method of my choice.

Slick
 
You might do better to look for needle roller bearings with a smaller ID and grind the shaft to fit. Alternatively, grind the shaft and fit bronze bushes. Chome is good where there is no impact. Also, if the shaft material contains nickel, it might not plate properly.
 
All this grinding and re-fitting, how can it be less expensive than simply buying new OEM parts?
 
Update:
Philpot told me that rechrome will not work with a shaft that runs directly on needles. So now the plan is to grind down the nose of the shaft slightly, sizing for a different bearing. The outer race was not part of the bearing. So now it needs to be bored out to accept a larger OD bearing. The new bearing is a Torrington so the the needles will no longer run directly on this surface.
UK tool room that will do the work needed.
Any help on this now?
 
Grinding down for a smaller bearing might bring out softer material in the bearing contact surface and cause failure. The fact that the needles have "dug in" already points to an issue in that area. In the automotive industry they repair worn out seal surfaces with hard sleeves, I never thought of this before, but do you think that a hard sleeve might be possible?
 
Onder said:
Update:
Philpot told me that rechrome will not work with a shaft that runs directly on needles. So now the plan is to grind down the nose of the shaft slightly, sizing for a different bearing. The outer race was not part of the bearing. So now it needs to be bored out to accept a larger OD bearing. The new bearing is a Torrington so the the needles will no longer run directly on this surface.
UK tool room that will do the work needed.
Any help on this now?
Click to expand...
www.seager-engineering.com

Seager Engineering

www.seager-engineering.com
 
A process called "Spray welding" would be my only type of repair for roller bearing. Plain bearings(crankshaft) spread the load differently then roller. The plus to spray welding and grinding to size, you will gain a surface harder the original. Just my two cents.
 
I did think of spray welding but WHO will take on the task? Patrick is busier than a one armed paper hanger with the crabs which does factor in.
 
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