Allis chalmers I600 back hoe starter problems

[I 600 MAN DAN]

Hi everyone, newby here ,I've been a lurker on this sit for a while and have learned a lot from the people here. M y current problem with my 1967 I 600 Allis Chalmers backhoe with a Perkins diesel is the starter. It was turning over weakly I did a load test on the battery and its ok. tried charging it up over night to see if that helped but when I tried starting it the next day it turned over weakly again the there was a bang and nothing.
i pulled the starter out and bench tested it and it seems to work fine. Any ideas what could have broken? i had a look in where the starter engages the fly wheel and the teeth look good so not sure whats going on. any suggestion would be welcome.

Thanks Dan

 

[Steve@Advance]

Did you try turning the engine with a pry bar on the flywheel gear while the starter was off? It
should be reasonably easy to turn without force.

An engine that is difficult to turn can be held back by a hydraulic valve that failed to center, or
a bound up accessory. Be sure to eliminate all external possibilities before concluding the engine
is bound internally.

A starter that bench tests good is not necessarily a good test. It could have mechanical or
electrical problems that let it free spin, but be entirely different under load.

 

[I 600 MAN DAN]

Hi Steve I'll try the prybar tomorrow, we'll see what happens.

Thanks Dan

 

[teddy52food]

With the starter turning, what is the amp draw at what voltage?

 

[I 600 MAN DAN]

Well I tried turning the fly wheel with a pry bar, it turned so I put the starter back in and nothing
. I then decided to pull the injectors to see if it was hydrauliced in the cylinders. Tried it again with the injectors out and it turned over great. Put everything back together and it starts like new now. Not 100% sure what it was but nothing seems broken so I'm pretty happy.
Thanks again for your suggestion Dan

 

[Jim.ME]

(quoted from post at 19:42:57 07/23/21) Well I tried turning the fly wheel with a pry bar, it turned so I put the starter back in and nothing
. I then decided to pull the injectors to see if it was hydrauliced in the cylinders. Tried it again with the injectors out and it turned over great. Put everything back together and it starts like new now. Not 100% sure what it was but nothing seems broken so I'm pretty happy.
Thanks again for your suggestion Dan

I will hazard a guess there was a bad connection or interface between the starter and block you improved when you R&R'd the starter.

 

[SVcummins]

Just because a starter will turn on the bench does not mean
its good