4fb1 camshaft broken piece ?

The place to discuss problems and routine maintenance questions and tips. This is for topics that are specifically diesel-related.
Regular Member
Posts: 1
Joined: Thu Oct 24, 2019 8:53 pm
Location: NY
Isuzu vehicle(s): 4FB1

4fb1 camshaft broken piece ?

Postby Thinktwicez71 » Fri Oct 25, 2019 9:50 am

I got a multiquip compressor with a isuzu 4FB1 diesel engine in it . It was locked up so I had to tear it down to see what was wrong (oil filled cylinders) . When I was taking the cam out I must of broke off a little chunk of a ring near the cam gear . I'm guessing it holds the cam from moving forward and backwards in the head . My question is can I build up the piece that I broke and have a machine shop put it in a lathe and clean it up . The metal looks kind of porous. The cam needs a cleaning up and polish but everything else on it looked good .

Regular Member
Posts: 204
Joined: Sat Dec 06, 2014 7:30 am
Location: Sunny Tampa Bay Florida

Re: 4fb1 camshaft broken piece ?

Postby FiatSpider2 » Sat Oct 26, 2019 10:49 pm

Yes you can if your a good enough welder however it may be best to let the machine shop do both the welding and machining. I had to followup on a repair when one welder at the factory I maintained decided to weld first and ask questions later which resulted in the machine shop refusing to touch it since he used the wrong welding rod, technique etc and distorted the shaft. No reputable machine shop would touch it and guarantee the work after that save one who charged us to remove what had been done, fill it with the proper type rod, true up the shaft and then machine the broken off section back to spec.

It would have been much less expensive and resulted in far less down time if we had just asked first and let their guys do the entire repair.
FiatSpider2 (4FB1 Isuzu Diesel powered 1978 Fiat Spider)

User avatar
Regular Member
Posts: 371
Joined: Thu Mar 24, 2011 9:28 am
Location: Mansfield, Oh

Re: 4fb1 camshaft broken piece ?

Postby DieselJeep » Sat Nov 09, 2019 8:44 am

New cams are available. One of the few that are for 4fb1's in the USA
Unskilled, uneducated, inexperienced, tools/facilities lacking, and faint of heart, be warned:
All vehicles are hunks of crap. Designed by individuals, the majority of which, have never turned a wrench.
Which one do you want to fall in love with?