Metric and American threads/bolts on 1980F100. Did a google and the answer was:
1980 was a transitional year, truck had both from the factory.
I hope my truck is done transitioning.

 

Get used to it! Our trucks were a mix of SAE and metric from the factory. Seems there was a soft transition from SAE to metric during that period.

No hard and fast rule about what to expect where. In general terms, if something predated the transition, it tended to stay SAE. Think female threads in an engine block, for example.

If a part was introduced during the transition, it typically had metric fasteners. For example, think of a bracket on the engine. If the bracket had any female threads, those were usually metric. But the bolts into the block usually were SAE.

Be aware there are plenty of exceptions to this “rule”. Some components got more metricky (that’s a word) in later years. Say you’re replacing a timing cover. It may have originally had female SAE threads for the water pump bolts. But later years may have gone metric. An aftermarket parts supplier would like to keep inventory simple, so they only offer the full metric version. You could remove SAE bolts, replace the timing cover, and suddenly the original bolts won’t fit. I’ve learned the hard way to test fit those bolts from the comfort of my workbench versus trying to install them one-handed in blind quarters.

 

Oh ya. That got me a lot of times back in the day. Ford started it with the cars back a few more years. Maybe with the birth of the Fox body IIRC?

 

Like was said, don't count on "1980" as being a transitional year. As long as your truck used a 300 six, a 302/351w, a 351m/400, or a 460, it's going to have standard bolts here and there. If your truck still has a 9 inch Ford rearend, standard bolts there. The 8.8 will have metric. All of the old transmissions will be standard. The AOD is a later transmission and will be metric.

 

My 81 F100 300 / NP435 / Ford 9" has a mix of everything.
I have found motor / trans / rear axle were SAE and everything else was metric when rebuilding my truck, cab off frame so just about every bolt was touched.
Just roll the tool box over to the truck when working on it as it will take every wrench & socket of both SAE & Metric
Dave ----

 

 

We cant give away all the secrets ................ all at once
We like to make learning fun
Dave ----

 

Fun he sats, It'll be fun he said. lol
On a more serious note, you mentioned
to someone else a while back to check
the clutch pivots or something? Can you
refresh my memory?

 

Look under the truck near where the tranny meets the engine, under the drivers side there will be a rod that attaches to the bell housing that will have levers connecting the clutch set up. The ends of that rod will have bearings that allow it to pivot.

https://www.google.com/search?sca_es...koIEAIYAiACKAI

 

Kind of sort of
You really need to check the whole clutch linkage system.
Starting at the pedal on the other side you will see the "arm" that bolts to the clutch shaft. You need to check this where the rod connects to it and goes through the floor.
I believe there should be a plastic bushing but if not make sure the rod and hole are not worn.
Bottom center is the part that bolt to the shaft of the clutch pedal. If you look closely the round hole is not round.

This is 1 end of the rod that connects to the "arm" and goes through the floor to the cross shaft. Both trucks the rods looked like this.

Now the rod after it goes through the floor connects to the clutch cross shaft or some call it a Z bar on other models.
This cross shaft where the rod connects and where the fork rod connects make sure the holes and not egg shape.

Now the BIG ISSUE is the pivots for this cross shaft. If you look at the first picture I posted at the top is the motor side pivot, there is one on the frame side also.
That pivot screws into the block and there is a plastic bushing that fits on it and held with a snap ring.
The pivot on the frame side is a bracket type and bolts to the top of the frame rail. There is a bushing on that side also but cant remember if the bushing goes in the shaft or the pivot now?
There are also felt seals to keep dirt out. LMC has a break down of how this all fits together.

If the plastic bushings fail the cross shaft then rides on the metal pivots and they wear down like in the top picture.
Because you CAN NOT GET this pivot I had to fix what I had with what I had.

I welded all the parts and then grind and hand filed them back into shape and they worked ...........
Till they stop pivoting

Fixed with a bolt with the head cut off and welded to the main pivot. Remember you CAN NOT get this part anymore.

Bolt threads welded to the main pivot and it worked .............. till it didnt
The weld did not go deep enough with the welder, 120 MIG w/gas.
So the fix was again head cut off bolt and drill the pivot and threaded part to install a roll pin and do a better job welding if I could.

Be this time I did find a OEM pivot on Ebay and for not a lot of money as a back up.
Well I needed it as this one broke too But I forgot where I put the new pivot so was down for a few weeks pulling the garage apart looking for it.

If you have a good one or 1 you can get measurements from and have a good machine shop they could make one or a few and you could sell the others.
Heck if I had the machines I would give it a try to make one as I dont think it would be all that hard.
IIRC the thread was 9/16 course, yes a strange size but I was able to find bolts at the local hardware store.

So make sure the plastic bushings for the cross shaft, frame to motor, are in place so the shaft does not damage the pivot.
Dave ----

 

Another reason not to believe everything you see on the interwebs. That “transition” took Ford and other domestic manufacturers a while to finish. Vehicles were a mix of metric and SAE into the 90’s.

 

I have had a couple mechanical clutches. You pretty much have to follow every part of the mechanism from pedal to transmission. Every part that moves should be well lubricated. Pivot points can wear. I don't recall any plastic bushings in the vehicles I owned. I think the were all metal. But I'd go through the entire mechanism and grease each moving part. With the engine off depress the pedal and listen to any squeaks and find those squeaks and grease them back to quiet. I would grease them regularly and any time I heard excessive squeaking I'd grab my container of grease and brush on more. When ever you hear the squeaking you are wearing the joints. Thus the old saying the squeaky wheel gets the grease!

 

Might as well take something else apart. lol

 

I think that muffler has lived its projected life span...

 

Funny thing is, the truck was super quiet. Hardly any exhaust coming out of the
muffler, even very little coming out of the holes and cracks. I never figured out where
the exhaust was coming out. Someone mentioned a reversion valve on the exhaust,
but danged if I know where it is. It's all coming off, then I'll know. The catalytic converter
was obviously plugged up as well. I still have not found any platinum. lol