Starter Issues/Flexplate destroyed.

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kiko619

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Houston, Tx
My Car
1972 Mach 1
1972 Grande Coupe
Hi family!

I have a question and requesting guidance from the experienced family to see if this happened to anyone else here. Got a mini Hi-Torque starter from Jegs Prostarter PN#: 555-10005 for the 351C. Well I'm having the following issues and I went down a series of process of elimination. Swapped the dead starter I thought it was PnP at least what some people who've used with part. apparently those same peeps didn't run into the same issues as me.

Cranked the first 2-3 times like a beast. 4-6times later sounded like glass breaking followed by have a high pitch winding noise. Removed the inspection plate no visible issues on the flexplate. Removed the starter to check for wear on the Bendix gear none. Removed the valve cover: bent a dang push rod... replaced them all with Melling rods and yield bolts. Did the whole nine yards: rod measuring, shimming, spec torq... etc. put it all back together. for those that are wondering.

Tried to fire it up again and the battery drained from 12V to 9V. started to check every where for a bad/loose ground wire. (wire from solenoid to jumper on starter is HOT to touch) starting with the obvious block to firewall and the wire running from the solenoid. charged the battery up and when I went to crank the battery died again... it gets worse. I left the battery jumper connected to deliver full 12V min. and now the loud winding, glass breaking came back. I dont have a picture right now, but at least 15-20 teeth were completely shaved off from the cranking. Bendix gear is solid with zero nicks and chipping. The flexplate is dead. Planning to replace with the following from Summit PN# SUM-G111SFI.

Can someone please tell me wth has happened/happening with battery drainage also? really appreciate any input so I dont have to tear it all apart on the driveway again. thank you all
 

boilermaster

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michigan
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71 fastback
Kiko619,
has your engine actually ever started with the new starter ?.

When you replaced all of the pushrods, did you rotate the engine with a breaker bar and did it rotate smoothly ?.
Sounds to me that you either have an engine issue (possible hydraulic lock)
or the starter drive is engaging too far on the flexplate, either of these conditions would cause the starter wire to become hot to the touch.
I suggest you do 2 things while you are waiting for your new flexplate,
bench test your old starter, including measuring the distance the drive moves from its mounting flange from static to fully engaged and compare to your new starter, the throws could be different, requiring a starter spacer for the new starter.
also tell us what transmission you have and verify ring gear tooth count.
Boilermaster
 

kiko619

Well-known member
Joined
Feb 28, 2014
Messages
104
Reaction score
5
Location
Houston, Tx
My Car
1972 Mach 1
1972 Grande Coupe
Kiko619,
has your engine actually ever started with the new starter ?.

When you replaced all of the pushrods, did you rotate the engine with a breaker bar and did it rotate smoothly ?.
Sounds to me that you either have an engine issue (possible hydraulic lock)
or the starter drive is engaging too far on the flexplate, either of these conditions would cause the starter wire to become hot to the touch.
I suggest you do 2 things while you are waiting for your new flexplate,
bench test your old starter, including measuring the distance the drive moves from its mounting flange from static to fully engaged and compare to your new starter, the throws could be different, requiring a starter spacer for the new starter.
also tell us what transmission you have and verify ring gear tooth count.
1. The motor has started before with the new starter without any "initial" problems.
2. Ruling out hydro-lock: turned the engine with a breaker bar, rotates relatively smooth, I say relative because its a big mechanical machine takes a bit of force to rotate. 1/4 turns with/without serpentine belt connected.
3. Tranny: FMX 3spd AUTO. Unfortunately, can't bench the old starter, disposed of long ago. next course would be purchasing an OEM part and compare since last one was original. Next time i go under the car I will verify the gear tooth count.

Pinion depth is different for manual vs. automatic ford starters. see the attached.
This is very helpful for a more in-depth assessment of what may be the culprit an improper combination of parts.

Thank you all for the help when I get a chance I will post an update to what i find. JEGS really needed to
 

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