1980 F350 4X4 C6 Project

[nic55kel]

Gary, You are right, 3/16" sounds way too much even with a collapsed spring.
With the spring in place there is not supposed to be any slack.

I don't know if you looked at the link I posted or not but apparently the caliper brackets can 'spread'.
Hopefully that hasn't happened but if it has various solutions are mentioned.
Not sure how difficult it is to source a good caliper mounting bracket.
Not sure if the bracket is part of the knuckle or separate.

[Gary Lewis]

Bob - I did read most of the thread in the link.  And agree that with the spring in there shouldn't be much movement.  I suspect that something is badly worn and hope it is the caliper and not the knuckle.

[Atlas75]

Thanks for all the good information.  As it turns out the spring was the issue.  I put everything back together today with a new key and spring and the caliper was snug.  Here is a photo of the two.  The old one is basically flat.

[Gary Lewis]

That will make a huge difference!  Glad it worked out.  So, how are the brakes?

[nic55kel]

Great to hear it was only the spring.

[Atlas75]

Gary Lewis wrote

That will make a huge difference!  Glad it worked out.  So, how are the brakes?

The brakes keep getting better with every little thing I do.  I haven’t rebuilt or replaced the calipers yet.  I’m saving that for when I replace the front brake hoses as those are questionable also.  Seems like calipers and hoses naturally go together.

I’ve got a few other things I really want to do before it gets too cold to work outside.  I need to change the rear differential fluid as some came out when I was working on the rear brakes.  What came out wasn’t pretty so I can only imagine what is remaining.  I also want to replace the aftermarket temp gage as it is not currently working.  I keep looking around for a set of used tires to replace the rock hard bias ply’s.  I truly believe they are the cause of the remaining vibration issues.  So much to do…..so little time!  I think I need to build a second garage so I can work indoors!

[Gary Lewis]

I vote for a shop.  

If the calipers aren't leaking and there's material on the pads you won't gain much braking by rebuilding or replacing them.  (That's assuming that the calipers are able to move easily side to side.)

So I'd move on to the rear axle.

[Atlas75]

First time I have been to a pick-N-pull yard since I was in high school.  I think I did alright.  Oddly enough, I pulled a dash cluster in high school as well so I could add the tach to the cluster in my 84 F150.  I hope to do it again in my current truck.

[Gary Lewis]

Carl - First, I hope your truck has gauges instead of idiot lights for the oil pressure and water temp.  That's because the wire harness for idiot lights has a plug that won't work with your new instrument cluster.

Second, if you passed that test then you may find that some of the warning lights in the "eyebrow" are wrong.  The early 1980 trucks had some of the warning lights in different places than the later trucks.  I don't remember which ones, but I think our member Rogue_Wulff posted about them.  You can fix things by moving the wires in the connector - just release the terminal in the connector and move it to where it should be.

[Atlas75]

I definitely have full gauges and no idiot lights.  As for the tach itself, my plan is to physically remove it from the cluster I bought and install it in place of the tach delete plate in my current truck.  I am 99% sure that’s what I did on my 84 back in high school and it worked.  That said, it has been many years since I was in high school so…we’ll see how good my memory is.

[Gary Lewis]

Well, this will be interesting.  There were three flex circuits for 1980 and three for '81-86, as shown below: idiot lights; gauges w/o tach; gauges with tach.

Shaun/Salans7 and I just had a discussion about this.  He's not seen a vehicle w/o a tach have a flex circuit that supports a tach.  In my case, I've added tachs to several trucks that didn't have them, and the flex circuits supported them.

So it will be interesting to see what you find.  

[Atlas75]

Well, maybe I swapped the tach and the printed circuit on my 84.  Like I said, high school was 31 ish years ago for me.  I’m guessing finding a green printed circuit that supports tach will be somewhere after unicorn on the difficulty list.

[Gary Lewis]

You have the cluster with the circuit that obviously supports the tach.  So use it.  But you will want to read this: HOWTO: 81-86 gauge cluster in 80 model (gauge models ONLY!)

[Gary Lewis]

And, having found that, I added this statement to our page at Documentation/Electrical/Gauges and then the Printed Circuit Pinout tab:

These are the pin-outs for the printed circuit connections to the gauges.  However, this is for 1981 - 86 trucks as pins 17 and 18 are swapped for the 1980 trucks.  In fact, if you want to use a 1981-86 cluster in a 1980 truck you need to read this: HOWTO: 81-86 gauge cluster in 80 model (gauge models ONLY!)

[Atlas75]

As I was reading the article I came across this statement.

You can install a factory tachometer into a cluster that was not designed for one, but that will not be covered here.

Has this been documented anywhere?

[Atlas75]

I also just found this.  Apparently someone is making them new??  Something about them looks off though.  I’ll see if they have a website with more info.

https://www.ebay.com/itm/1980-Ford-Truck-Printed-Circuit-Board-for-Trucks-W-Factory-Gauges-W-Tach-Box-78-/272131444371?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l6249&mkrid=711-127632-2357-0

[Gary Lewis]

Yes, LMC is carrying them.  See this post.

As for installing a factory tach into a cluster not designed for it, the gauge circuit w/o tach doesn't have the circuits for the tach.  But the 4 screw holes are in the plastic of the cluster.  And the connections are on the 4 studs of the tach that hold it in.  So you can use ring-tongue connectors on the end of wires to provide power, circuit ground, ignition input, and a ground tell it that you have an 8 cylinder engine.  

[Atlas75]

Interesting.  I wonder why the EVTM for 1980 only shows 2 wires to the tach?

[Atlas75]

I found a post from 81-F-150-Explorer on www.Ford-trucks.com from 2010 that says this:

B post on tach goes to battery power
I post (or C) goes to the tach test lead of the coil
G is the main ground for the tach (this has to be grounded)
8 is only grounded on V8 engines



I think I can get this wired up with that information.

[Gary Lewis]

That info on the wire connections is correct.

And I don't understand why the '80 EVTM shows only two.  But the '80 EVTM is strange, so just add that as one more item to prove its strangeness.