Starter motor question

General mechanical enquiry - not Patrol specific.
When starting the Nissan ED33 motor in our bus the last few times first turn of the key often results in a graunching sound without the motor turning over. Subsequent attempts start the motor OK. It seems obvious that there will be wear on the starter pinion...... & better to rectify before it strands us somewhere.
But..... I'm unsure if the wear is most likely on the starter motor pinion itself, or the ring gear it engages with. I'm hoping that just replacing the starter motor will fix the issue.
Would welcome your thoughts.

Cuppa

Hi Cuppa - just trying to get a feel for the sound it makes - not a clicking sound like the solenoid?

Jas

No Jas, not clicking, not the solenoid.
It's the sound that worn gears make when they are slipping/failing to mesh.... I think.
Turn the key a second time & most times it engages & starts.


Cuppa

Unfortunately, Cuppa, you wont know until you take the starter motor out and have a look. I would suggest you check all of the electrical connections to the starter, it may not be getting enough power to throw the starter pinion out to mesh intermittently. Or there may be a plate at the bottom of the bell housing, when taken off, you may be able to see the ring gear.

If its a squawk type sound more then likely it will be wear on the ring gear from the startermotor pinion gear. If you can easily view the starter, remove it ( with the battery disconnected) and rotate the motor manually by the crank shaft bolt ( clockwise) and inspect the teeth on the ring gear and starter. 4cyl engines only stop on 2 different sides of the flywheel, 6 cyl 3 and 8 cyl 4 more then likely there will be teeth missing but on the rare occasion the teeth on the starter could only be worn.

Best bet is to remove it and inspect like i said earlier.

might not be throwing the solenoid out far enough, is the battery as good as the one in your ute for example.
only has to be a little under par to play up.

Thanks folks, makes sense, I just wanted it to be easy!
Batteries (24v) are optima yellow tops in excellent condition & maintained on a Ctek charger. When the starter turns over the motor it does so with gusto, almost instant start.
The engine (4 cyl diesel) was replaced with a second hand engine about 10,000kms ago, but the starter motor off the original engine was fitted.

Cuppa

You'll find motor stops in same spot everytime, With a large screw driver or Socket rotate motor
1/4 of a turn and try, ring gear will be new in this area. Might sound dumb but its true, XF falcon
were famous for it

Mums EA was famous for this too. My gq makes this noise occasionally, but the 2nd turn of the key gets it started. If it was missing a tooth you would know about it. Makes a click, click, click noise every rotation the missing tooth makes with the starter.

You may want to wire a relay to the starter. ??