7.3L starter, 2 bolt vs 3 bolt?

[Matt Saunoras]

I've got an 02 F-550 7.3L with a ZF-6 here. Amongst all the other crap I'm doing to this thing the cust brought me an oem starter in they got from our parts dept.

 

The issue is the starter I removed is a long 3 bolt and the one the veh calls for is a smaller 2 bolt. I'm not sure which one I should be using and what the differences are.

 

The reason they brought me a starter is the low cranking RPM. Like 90-100 rpm max.

 

Anyone know anything? Perhaps the tranny was changed at one point?

[Matt Saunoras]

I guess it doesn't matter, got a new 3 bolt starter, put it in and everything is fine.  I think the main problem is my parts guy is a dick

[Alex Bruene]

The small, 2 bolt starter is a gear reduction starter.  I think they're way better, and faster than the old, 3 bolt style.

[lmorris]

I didn't think you could get the 3 bolt design anymore. We have always replaced them with the new 2 bolt design.

[Matt Saunoras]

We actually stock a 3 bolt starter which is the main reason I installed it, that and not realizing what the differences were.

 

I see now about the gear reduction on the 2 bolt. The 3 bolt gear is driven straight off the starter body, no wonder the 3 bolt starter fails more often, that's a lot of stress put on it.

 

Well whatever, my 7.3L is gone, it's got good cranking rpm now

[mchan68]

I too, have replaced a lot of three bolt starters with the two bolt unit. Just be careful how you install it. Believe it or not, you can install a two bolt starter in two different ways. Installing it incorrectly will result in the starter just spinning the drive gear (because it won't be at the correct distance to mesh with the flywheel ring gear).

[Matt Saunoras]

I noticed that it will go on either way which just added to my confusion. Yesterday wasn't one of those really rare awesome days where everything just clicked.