Flexplate blues.....

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Flexplate blues.....

Rustynuts
Hi, greetings to you all. Newbie here so I hope this topic hasn't been extensively covered(I hate starting a new thread on an old topic) but I seriously need some help.
A few months ago I rescued an 80 f100 Ranger from a local salvage yard. 351w with a bad trans(c6), bought a used trans to go along with it. After installing the trans she ran great for about three days. Then the starter and flexplate started grinding. I changed the flexplate and starter and it started fine for about 10 cranks then right back to grinding. I'm at the end of my limited knowledge and would greatly appreciate any help. Thanks.
80 f100 Ranger swb 351w C6
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Re: Flexplate blues.....

Ford F834
Administrator
Welcome to the group! I am not very knowledgeable with the V8’s but I will throw out a couple of things that may be useful clues...

The F100’s did not come with a 5.8/351 engine. It was only available in F150 and higher. Also, in that era you would most likely be looking at a 351M, not a 351W. (V8 guys, help me out here...). So the first step is to positively ID your engine (transplant? 302?) and make sure you got the right parts. The other thing is to check that your starter is for an automatic. At least on my straight six the manual transmission starters have a shorter snout than the automatics which might cause something like you describe.

Again, welcome and good on you for saving the 1980! Love the 80/81’s 🙂
SHORT BED 4-DOOR DIESEL: 1986 F350 4x4 under construction-- 7.3 IDIT ZF5+GVOD

STRAIGHT SIX 4X4: 1981 F150 2wd to 4x4-- 300 I6 close ratio diesel T19, hydroboost brakes, Saginaw steering

BIG F: 1995 F-Superduty under construction— converting to 6.9L IDI diesel ZF5+DNE2
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Re: Flexplate blues.....

Gary Lewis
Administrator
In reply to this post by Rustynuts
First, welcome!  

As for the problems, are you sure you have a 351W?  That engine didn't come in a Bullnose truck until '81 in the California trucks and '82 in the 49-State trucks.  On top of that, it never came in an F100. But you may well be correct as the W got swapped into a lot of trucks, especially where a 302 had been since it is a fairly easy swap.

However, the source of the engine or transmission may well be the issue with the starter.  Looking at the starter listings from Ford's master parts catalog (Engines/Starters), something changed as of 4/80 that required a different starter, and then on 12/83 something changed again.  And, looking at flexplates (Engines/Flywheels), the 1981 351W's used a different flexplate/flywheel.

So I'll guess that you have a mismatch in starter and flywheel.

Oh, and you do know that a manual transmission starter won't work on an automatic, and vice versa.  Right?
Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

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Re: Flexplate blues.....

Pebcak
In reply to this post by Rustynuts
I second and third what was said before.  I had a similar issue when I got my 86.  The flexplate and starter were two different mis-matched pieces.  I ended up having to go through three starters before I changed out my flex plate to the correct one for my 351W.

Since then I've had zero issues.  Probably just jinxed myself but oh well.
1986 F150 XLT Lariat, 4X2, 351W, 1406 Edelbrock Carb - Currently going through an engine rebuild through a "Father/Son Project"