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Axle spindle repair

Flail

Cast Iron
Joined
Oct 29, 2013
Location
Bonsall, CA
I have a front strut for a 1972 Porsche 911 where the axle spindle got a bit galled up where the inner bearing rides. Is it ever acceptable to do a weld build up and turn back down to size? If it’s acceptable, what would be the correct filler, weld method and is there any specific heat treat following? If it’s not acceptable, is it due to cracking and sudden failure or some other issue? I’ve done weld build up on electric motor shafts and never had a failure but the side loading on a motor shaft seems quite a bit different than an axle spindle.
 
A quick search on eBay shows those as being between $300-400 to get another. Considering what shop rates are worth these days, the potential damage a broken-off wheel could do to the car and the rising value of air cooled Porsches, why would you even try?
 
I have a front strut for a 1972 Porsche 911 where the axle spindle got a bit galled up where the inner bearing rides. Is it ever acceptable to do a weld build up and turn back down to size? If it’s acceptable, what would be the correct filler, weld method and is there any specific heat treat following? If it’s not acceptable, is it due to cracking and sudden failure or some other issue? I’ve done weld build up on electric motor shafts and never had a failure but the side loading on a motor shaft seems quite a bit different than an axle spindle.
Metal spray would be the correct option not welding.
 
Metal spray would be the correct option not welding.
I went to a metal spray maker's factory in Detroit years ago for a demonstration of their equipment. The shaft that he sprayed got red hot, which would destroy the heat treat (strength) of a heat treated steel part. I do not see how that process would be more safe than welding.

Larry
 
I went to a metal spray maker's factory in Detroit years ago for a demonstration of their equipment. The shaft that he sprayed got red hot, which would destroy the heat treat (strength) of a heat treated steel part. I do not see how that process would be more safe than welding.

Larry
No high temp gradients. Steel only gets stressed by intense gradients. Tig welds warp/crack more than mig, mig more than gas, gas more than brazing. It’s the intensity of heat- not the amount.
 
Welding up the damage surface would be a bad idea. Turning the spindle bearing seat and sleeving would be much better but in any case spinning up one of those struts to machine would take a competent shop. before any repairs are attempted the spindle should be Magafluxed. I was in the German car repair business for 30 years and would not install a repaired strut, nope.
 
Ever seen one of the crappy X1/9 Fiats ?............there was a Fiat X1/9 specialist just around from me .....I must have welded up every part of those cars ,as spares were non existant ...typical Fiat.
 
Incidentally,its illegal here to do any repair to on road car front suspension or steering that needs welding,heat,bending ,straightening ,cutting,modification.............and quite likely your liability cover excludes it too.
 
Thanks for answers and reality checks. I thought about turning down diameter and sleaving but concerned about reducing the diameter and thus strength of said spindle. What do you think of these types of repairs? More or less risky? Seems like a potential liability issue especially with 80,000 pounds at freeway speeds and in the field welds.
 
Nothing wrong with that type of repair. The welding is not pouring heat in and welds are really just pins/keys for bushings and “lock nut” for spindle. Not using weld to hold trailer load.
Now, never trust a f250 driver that brags about 530 am at work. The real work truck is cool.
 
a car is an insurance write off here for any displacement of the front suspension or frame .....it cannot be re registered for road use anywhere in the country.............i suspect this rule was made by the new car sales lobby.
 
Incidentally,its illegal here to do any repair to on road car front suspension or steering that needs welding,heat,bending ,straightening ,cutting,modification.............and quite likely your liability cover excludes it too.
I’ve seen Road Warrior! There were all sorts of sketchy rigs bombing down the hiway!!!

On a more serious note, are there no hotrodders in Australia? Are they only able to put manufacturers factory aftermarket parts on and do nothing of their own mods like shortening springs, wider wheels, lift kits? Jesus, the world is getting more Nancy by the minute!
 
Yes ,there are hotrods here ......but very strictly controlled .........a few years ago ,there were some very iffy people approving modified cars ,but the loophole was closed ,and the inspection licenses of over 1000 shady characters cancelled .........Unfortunately caught up in the bikie wars ,and the cops efforts to crush the outlaw bikers........Unfortunately there is no RICO here ,and the cops cant just arrest the outlaws for being involved in crime.
 
I went to a metal spray maker's factory in Detroit years ago for a demonstration of their equipment. The shaft that he sprayed got red hot, which would destroy the heat treat (strength) of a heat treated steel part. I do not see how that process would be more safe than welding.

Larry
spray (that i use) starts at 125 degree but not over 500. been doing heavy vehicle repairs on spindles for many years with no failures
 
Green locktite. Give it a try.
I’m curious if this is the correct approach as the bearing outer race is pressed into the hub but the inner race is a slip fit on the spindle. Don’t bearings like this wear out faster or overheat if both inner and outer races are fixed in place?
 
spray (that i use) starts at 125 degree but not over 500. been doing heavy vehicle repairs on spindles for many years with no failures
+1 There's a lot of different spray methods, the temp is controllable on the better/newer ones. I have a Metco spray rig for sale if you want to do it yourself.
 
I’m curious if this is the correct approach as the bearing outer race is pressed into the hub but the inner race is a slip fit on the spindle. Don’t bearings like this wear out faster or overheat if both inner and outer races are fixed in place?
Yes, the inner race should be a slip fit.
 








 
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