Which pmgr starter?

[Blacktop]

Hi, I'm considering upgrading the stock starter on my F100 straight 6 manual to a pmgr version.
Anyone know which model trucks had a compatible 9 tooth pmgr starter from the factory?
Searching rockauto seems to show the later trucks had the 10 tooth starter. I believe my manual trans 300 i-6 has a 9 tooth starter🤔

Many thanks,
Alan

[Machspeed]

Good question, Alan! We have information on the wiring of this in our documentation > electrical > PMGR starter wiring, but no findings on the gears. I can't remember when Ford started putting PMGR starters in our trucks but assumed first year could be used. Bad to assume! I'm sure Gary will pipe in on this.  

[Gary Lewis]

Gary doesn't know.

But, looking at the MPC I do see that there's a date of 12/83 when things changed.  Prior to that date the 300, 302, 351W engines took one set of starters and after that a different set.  So I'm guessing that is the date when the change in the tooth count happened.

Just called DB Electrical and talked to Nichole.  They don't have a PMGR starter for that application with a 9-toothed gear.  Their 410-14033 is PMGR and fits a 300/302/351W w/a manual transmission, but it has 10 teeth on the gear.

But the MPC says all 300's from 1980 through the end of the catalog, which is 1989, used the same manual transmission flywheel - E0TZ 6375-A.  So, will a 10-toothed starter work?  I don't know. 

[Blacktop]

Thanks for the detective work😁
When I get chance, I'll drop the starter and confirm it is 9 tooth rather than 10.
Just my luck that the tooth count changed. I may be restricted to just replacing with like for like. Although, perhaps I might source one aftermarket but I doubt it.
Cheers,
Alan

[Machspeed]

Is this going on an 8 or 6 cylinder engine? I looked for my 351 equipped truck via RockAuto and see starters with 9 teeth for my truck. First PMGR starter for F150 with 351 appears to be 1992 via RockAuto and it is 10 teeth. Wondering if this is a RockAuto screw up or they indeed did change from 9-10 teeth. I know people have done this mod and I don't recall this particular conversation. So yes, please post your findings.      

[85lebaront2]

I believe my son determined that the 1990 Lincoln Town car 5.0L PMGR starter fits the 300 six and 302/351W V8s with automatic transmissions. He worked for LKQ corp at the time.

[Machspeed]

Bill, RockAuto shows it to be 10 teeth too.  

[Blacktop]

Its a 1980 300 I6 with manual trans so I believe it has the 9 tooth starter.

[Rembrant]

I don't know anything about starter bendix teeth count, but I know the conversation does come up once in a while. If it's any help, I installed a PMGR starter on my 1980 F150 with 300 inline 6, and that PMGR starter came from a 1996 F150 with 300/6. I didn't count the teeth, but I did remove it from that 1996 F150 myself, and installed it on the 1980, and it worked great! So while I can't guarantee the teeth counts, I can guarantee the year differences. The 164 tooth flywheels didn't change. I kinda miss that old '80 sometimes. It was a cool truck...in a "if ya squint, it's mint" kinda way!



PS: If it's any help, I have a new PMGR starter here in my garage, and it has 10 teeth. It's for my 5.0L build, and I believe I ordered it for a 1996 F150 w/5.0L V8.

[Gary Lewis]

I think that's a big help, Cory.  

[Blacktop]

Thanks for the info. I have a 10 tooth pmgr starter as well. Was destined for my F150 351 so might try it in the F100 instead 👍

[ratdude747]

It's also possible that the starter output shaft position was moved... and they went from 9 to 10 teeth to reduce the amount of gear reduction between output shaft and the ring gear. Since the PMGR has an internal gear reduction, they may not have needed as much reduction in the final ratio, and a larger gear will wear slower.

Rockauto research: The Flywheel was used from 1977 all the way through '96 on all manual transmissions. Likewise, I am seeing the some of the M5R2 4.9L versions spec'd from 1988 through '96 (the M5R2 has an integrated bellhousing)... and the same starter was used on all manual transmission models (for the 4.9L) in 1991.

Since the flywheel and the transmission (bellhousing) didn't change from 1991 to 1992, and the starter and flywheel didn't change between 1980 and 1991, thus, it stands to reason that the starters are mechanically interchangeable. For manual applications, that is. (automatics look like something did change... but that's not the application in question).

[Rembrant]

ratdude747 wrote

It's also possible that the starter output shaft position was moved... and they went from 9 to 10 teeth to reduce the amount of gear reduction between output shaft and the ring gear.

I too assumed that was the case, but had no official proof other than installing a 1996 PMGR starter on a 1980 F150. Since the flywheels didn't change, another thing to note is that the starter shield, or engine-trans separator plate also did not change, and was the same for decades, right up until 1996. They changed in appearance...there's all kinds of different ones...in fact I have not seen two alike, but they have all been dimensionally the same, so the starters were always in the same place, and the flywheels were the same...so it stands to reason that the starters are 100% interchangeable.

[85lebaront2]

That is not necessarily the only difference, the depth of the starter pinion into the clutch/converter housing also may vary, it definitely does on the 460s.

[Tarheel Blue]

Honestly can’t remember how many teeth are on mine, but I still have my OEM starter on the shelf and I had written 9T on it when removed back in 2015 so must have been concerned about tooth count at the time.  I replaced it with a DB for a 302/ 351 w/ manual transmission.
Still works perfectly and will replace with exactly the same if this one ever dies.