Is it possible to repair a chewed out RB30 crankshaft?
Welcome to the Nissan Patrol forum. To post a question and to see less adds on the forum then you will have to register
first. We are an easy going friendly forum so join in the conversations and feel free to ask any questions.
Become a forum sponsor for only $20 and see no adds with faster page loading times and many extras benefits.
Is it possible to repair a chewed out RB30 crankshaft?
The mechanic that changed out the timing belt, when I first acquired my Patrol, didn't correctly torque up the harmonic balancer bolt. As a result, the belt retaining washer chewed into the shaft.
I had to change out the water pump a few months later, and this is when I discovered the blunder. I was lucky enough to get the washer to sit within a few thousandths of an inch when I torqued up the harmonic balancer bolt and it has run for nearly 80,000 ks.
Changing crystalline structure of the crank would be my concern. Have a look at stellite 6 hardfacing/welding to build up the flat _ check this company out for starters.
Craig, is the damage to the diameter surface or the end of the crank - can't visualise it. We send a lot of components off site at the mine for surface or diameter rebuilding, even gearsets to be re-hobbed. The deposition materials are usually stronger than the base, but as mentioned by Bidja, you will experience granular growth to some degree - whether its a factor in future failure i would doubt it. We have extremely hard conditions up here in the acid plant and the heat affected zone is usually the first to get attacked. You won't have this on a crank. I would make contact with a crankshaft refurb shop and sound them out first as they will be the ones carrying the warranty. Regards the oil pump flat - would think the application of the metal will first require removal o the parent then deposition of the higher grade material - might be ok by the sounds of it.
Yes Phil metal facing / deposition application to gain improved wear characteristics (ie: thermal/mechanical), for new component manufacture, build up of worn and or damaged surfaces and has been an adopted practice for many yrs. SMEs certainly out there..
The metallurgical changes I refereed to was pertinent to the process (non uniform heat application) demonstrated in the video.
Many yrs ago, me as an apprentice F&M in a materials research laboratory, had a job of cylindrical grinding down a stellite welded repair of a cracked carbon steel roller. Some other application: Stellite faced valves and seats, stellite faced hydraulic lifter(for those that had to continually replace OEM lifters in 253cc V8_carried a bent tent peg in tool box to regularly pop em out).
I'll talk to this mob and see what they have to say. https://www.wagma.com.au/engineering...metal-spraying The oil pump and loose balancer are a common problem on the RBs. And the key stripping out of the RD28 is also a problem we get asked about on this forum. So it might give us a solution.
I was wondering if the non-uniform heat might warp a crankshaft.
The damage is to the shaft at the shoulder for the front engine seal. It acts as a clamping surface for the timing belt guide washer and the timing sprocket. The one pictured isn't nearly half as bad as the one in my Patrol.
The other shaft has an angular flat worn into the end of the machined flat on the oil pump drive. It will only get worse as the pump drive hammers on it when the revs change.
Last edited by mudnut; 16th September 2019 at 12:45 AM.
With the damaged shoulder (clamping face), alternative maybe to consider getting shoulder machined(ground) back to clean face and use thicker or shim washer. Maybe the metal spray process is applicable only to circular rotational bodies, eg: journal shoulder. Not sure if applicable for oil pump drive flat build up requirement.
Interesting to hear what Wagma say.
Last edited by Bidja; 16th September 2019 at 10:18 AM.
Wagma prices: Spray welding and machining of the groove: $260.
Welding and machining the oil D drive : $120
Repairing RD28 Keyway : $420 (Approximately)
He said they would take all care but no responsibility for the welding of the oil pump drive and RD28 keyway, regarding warpage of the crank.
The low temperature of the spray weld to repair the groove should be OK.
Last edited by mudnut; 16th September 2019 at 10:59 AM.
Recon get an other opinion to compare. The company that I googled appear to do a range of application methods and varied product range (just a thought).
Reply With Quote
