308 Starter problem

When you say would not "disengage" you mean the starter gear stayed meshed into the flywheel teeth? Not sure, could be some clearance problem or electrical in the solenoid. I assume the rebuilder is a reputable one in good standing. Could the parts used to rebuild your starter be of a "lesser" grade...not trying to cut anyone down here...just curious?

 

I don't know if this helps any Jay, but it seems our starter motors are an odd-ball unit (or an unpopular unit that no parts are made for anymore) from Bosch, since when I had mine out during my engine-rebuild, I thought (even though it was and is still working fine) I should install a new solenoid - do it then while I had access.

Turns out, the Bosch number turned up blank on a local-parts supplier's computer. I re-installed the old one and have had no problems with it (knock on wood). But it looks like I'll be f---ed if this thing ever goes South on me...

 

Is that rub n buff on your engine or paint? Sorry to take this off a little but just curious. I tried rub n buff and it works great but even after months of it being on there I can still slide my finger over it and get a silver residue on my finger. Not sure why just thought you might be able to help.

 

I don't know much about Ferrari engines...yet, but could the problem be corrected by shims? It sounds like a clearance problem (as someone else has already mentioned).

 

I just went through the starter-replacement ordeal on my '76. In my case, I had my mechanic replace the starter assembly with the newer, lighter version from the 328. This unit worked fine at first, but eventually became reluctant to engage the ring gear. It would spin up OK, but fail to crank the engine.

The problem turned out to be the use of incorrect mounting bolts. Three mounting bolts are used to attach the 308's starter, and the ones my mechanic used were just barely long enough to engage a couple of threads in the boss. Two of them had worked their way loose, allowing the starter shaft to fall away from the ring gear.

That's where things got strange. I jacked up the car and pulled the wheel and fender housing off to replace the bolts, but I found that I couldn't tell if the bolts on the starter were 8 mm or 5/16". These two sizes are only 25-thousandths of an inch apart, with the 8 mm size being larger. I tried installing longer 5/16" bolts to replace the bolts my mechanic had used, but I found that they stripped the threads in the starter assembly and spun in place upon application of a reasonable amount of torque. Subsequently, 8 mm bolts did exactly the same thing. Finally, a big chunk of one of the thread bosses fractured and broke off while I was turning its bolt, looking like crystallized pot metal.

In the end, I went with 8 mm x 100 mm bolts and installed locknuts with nylon inserts on them. This was not easy without the ability to see what I was doing, but with the sacrifice of sufficient knuckle skin, it can be done.

The key observation I made throughout this process was that all three bolts MUST be tightened FULLY, or the starter will not work reliably. If one of the bolts is even slightly loose, it appears to give the starter enough leeway to miss the ring gear.

I still don't know what size bolts the starter actually wanted. I have a sneaking suspicion that the starter mounting holes were never actually threaded in the first place until I started screwing bolts into them. It's possible that the 328 starter was supposed to be mounted with nuts all along, and my mechanic somehow missed that little fact of life. Regardless, I feel a lot better with the locknuts in place. The starter works great, and it isn't going ANYWHERE now.

Does anyone know how a 328 starter is really supposed to be installed (i.e, what fasteners were used by the factory)?