Thread: starting issue

Hi all, got a question for ya..

Just changed a manual gearbox, mounted to an S13 sr20det
Everything went together as normal, no issues..

But, when I go to start the car the starter motor spins, but doesn't engage the flywheel..

Now step 1).. I pulled the starter motor off, checked that the solenoid is engaging,
Its also working fine, gear pops out, motor spins gear all normal..

Back onto bell housing, wired up, turn key, and motor again spins off it head and what sounds like no connection to flywheel..
(won't turn engine over at all) motor free spins..

Step 2) screw driver on terminals in case solenoid is not engaging due to another issue.. same outcome.. free spinning starter..

Step 3).. push car in 5th to move flywheel in case there is an issue there.. same again, no outcome, motor still free spins..

My possible diagnosis.. 1.. bell housing is somehow different?? (is there multiple sr gearboxes?) so its offset somehow and teeth are not connecting between starter and flywheel??

2.. starter motor has some kind of clutch in it that is slipping even though its connecting with the flywheel??

3, solenoid is not engaging even after I tested it out of the car??


All I changed was the gearbox, nothing else has been modified at all, same starter motor, same flywheel as before, one thing different is the gearbox.


Please let me know if anyone has heard of this before or knows what else it may be..

I even inspected both gearboxes and nothing appears different at all.

Has anyone had any issues like this, or with a starter motor not engaging?
but engaging as per normal on a test bench or whatever?

also are all S13 starter motors, manual gearboxes identical?

or were there other models with different bell housings etc??

was it a manual trans before also?

Yeah both 5 speed manuals.

try a different starter yet?

Trying a new one this afternoon, fingers crossed!

After hours of head scratching and Measuring and so forth...

You can laugh now..

The holes on the bell housing had been bored out by the last user, for fuck knows why.. And the starter motor was infact, hitting the back of the flywheel..
It was blind precision to get the starter gear matched up with the flywheel teeth.

For hours I'd infact believed the starter cog was missing the flywheel all Together, As the noise of the Gear pushing out into the flywheel was masked by the cog spinning itself.

Sorry for the shit talk but with no helpful reply from Anyone i guess this was a once off issue that no one else has experienced, so hope it helps someone else out in future if it ever happens.

My last trick that fixed it all..

Place the bottom bolt into the starter loosely to ensure an earth, removed the positive lead from the motor, so only the solenoid activated, pulled the motor back to see the Gear throw out when the key was turned, then held the key until then gear met the flywheel, released the key, and the motor and flywheel gears had meshed, then tightened bottom bolt, re tested the starter with positive connected. And there it was, the whole time the starter had been hitting the back of the flywheel then just spinning the motor on it!

Most people will never encounter this if the holes are not modded from factory but mine were!

People do a lot of "modifying". Lol. I had a lot of wood screws in different places in my car when I first got it. the front tranny mount was also shimmed with washers on the bolts and the tranny was rocking around all over the place.

Yeah it makes for a nightmare if you are unaware of the prior Mods.