Very odd starter flywheel problem - help pls

[crawlink5]

I have a 78 Blazer with the factory 400 sb. It had a th350 trans Kcase from the factory and I put a 700r4 in it but didn't touch the flywheel. It looked new.

When I bought it a year ago it started ok but the starter made a noise like it needed shimming (was loud) - I ignored it until the bendix went out with age.

I replaced the bendix and stuck it back on. The gear and the flywheel does not mesh close enough to turn the motor over. Went and bought a new starter. Still same problem. Screems like a banshee but doesn't mesh - the gears just touch at the end of the teeth.

Could that be a wrong flywheel? The flywheel on it looks new enough that it could have been changed out. The motor is balanced correctly as it doesn't noticably vibrate that I can tell. did the 400 have a little bigger flywheel like an extra 1/4 on the diameter? I do believe their was balancing issues like internal and external.(?).

I looked at the threaded mounting holes in the block and didn't see anything out of the ordinary.

Any ideas?

Thanks,
Doug

 

[dave_90_blazer]

there are 2 different sized flywheels for small blocks(153T and 168T), sounds like you have the smaller one, to be sure, count the teeth, mark one, then count while turning the motor by hand, I bet you have a 153T one in there

count and post back

 

[sweetk30]

also the 400 is external and i dont think thay make a 153 for a 400. unless someone has balenced the smaller flywheel or the crank internaly.

 

[R72K5]

you will have to go with whatever diameter flywheel you have

if small then go with straight across inline bolt nose starter

if large flywheel then go with staggered

im sure this is whats going on is you have wrong wheel and starter nose cone issue

 

[dave_90_blazer]

also the 400 is external and i dont think thay make a 153 for a 400. unless someone has balenced the smaller flywheel or the crank internaly.

one thing about this , is , there is a wieght plate you can bolt dowm along with the flywheel to add the neccessary counterwieght, allowing any SBC flywheel to be used

 

[skink4president]

I have a very similar problem on my '73. Check the teeth on your flywheel again to see if they're tapered. If so, you may need to replace the flywheel.

 

[crawlink5]

Teeth are like new. I guess Ill have to count. What should I ask (year, make, model) for on the other nose cone? I now have staggered.