Yes, it would fit. There is only one drive gear (Thats the one in the trans) all of the different driven gears are designed to fit the same gear.
Different rear end ratios and different tire sizes use different gears to make the speedometer read correctly.
Sounds like maybe someone has changed the rear end in the past to a different ratio.

 

Thanks Mike,
And by the way, The smart *** comments bring me down to earth haha.

I had planned on working on the entire brake system, When I bought the truck there wasn't a whole lot of pressure on the pedal so I knew there was something that needed to be done. I was hoping it would last a bit longer but hey 30 years is a good run.

Are there any tell tale signs of specific failure?or is it one of those things where I'll see it once I pull the wheel off?

The light did come on as a matter of fact the other day. But recently turned itself off when I was working on the Speedo. Possibly broke the light bulb. I'll check that as well.

 

The transmission was rebuilt recently. Could this have affected it? Since you said there is only 1 drive gear (in the trans) That one is standard So I Wouldnt imagine that being the issue.So I need to match that gearing based on the Ratio on the rear end. and possibly the tire size...

 

With disc brakes pretty much everything is out in the open. You should be able to tell what it is once the wheel is off.
From the description I would guess pad failure. There are two types of brake pads/shoes, bonded and riveted. On bonded the friction material is glued to the pad/shoe, with riveted its riveted (obviously).
I've seen the bonded pads fail where the friction material breaks loose from the pad with a clunk then you get metal to metal contact.
This is a possibility, but the true cause should be pretty obvious once you take the wheel off.
Also, if the calipers need rebuilding (good possibility), rebuilts are so cheap trying to rebuild the caliper yourself really isn't worthwhile.

 

Correct, rear ratio and tire size determine the correct driven gear.
With the speedometer reading a lot higher speed than you are actually going it sounds like someone may have changed to a lower (higher numerically) rear end.
If your truck still has the warranty plate on the drivers door (and its the original door for that truck), thats the metal tag mounted on the rear edge of the drivers door, just below the latch. It will have an axle code on it. If you post the code I can tell you what rear ratio your truck originally came with. (My guess is the axle code is going to be 02J)

 

Its actually 17J, How would I tell if that matches whats actually on the rear end? Is that code stamped on the axle by chance?

 

17J= (17) Ford 9" non-locking 3.25 ratio 3300 lb capacity (J) w/ power steering
If you're lucky there will be a metal tag on one of the studs that holds the center section to the axle housing. If its there it will have 3.25 stamped on along with the axle ID (something like WDM-BA).

 

So, My bearings are shot on the front left side. Figure i'll go ahead and replace both sides so that I know that won't be an issue. Doin that this weekend. I'll keep you guys posted with questions i'm sure.


Mike,
Knowing the gear ratio in the back. How do I determine how many teeth i need on the gear end that goes to the transmission? there are numerous different ones for that model truck with different teeth, Which ones line up for a 3.25:1?

 

I'll check in the parts catalog and see how they are listed, if there is some kind of chart. I'll let you know.

 

According to the Ford Parts Catalog the gear you should have is C7VP-17271-A. This is a type 2 (there are about a dozen or so different styles of driven gears) with 19 teeth.
This is for a truck with C4/C6 trans. G,H,or L 78x15 tires and a 3.25 rear.

 

Okay, So I pulled the wheel off. The pads are on fine, the caliper looks good and the disc seems in pretty good shape. But when I grab the whole assembly, I can actually move it around like its not solid on the axle as it should be. A buddy of mine explained the purpose of the bearings and what they do. He also said that if they had come apart or broke that it would cause the whole assembly to be loose like it was. That sound reasonable to you guys? or am I being misguided.

 

That's correct. If the bearings are that far gone on the one side you'll need to replace them and the grease seal. You also need to at least clean and repack the bearings on the other side or preferably, replace those with new ones also.

 

Okay, So i'm having a problem getting the races out of the housing. Everywhere i've read says they should just tap out from the other side. I can't re-use them cause the other bearings tore them up on the way out.

I'll post some pictures of the messed up bearings later. Completely destroyed rolling around in there. I'd imagine that to be my issue.

When the bearings broke down, The inner piece of the inner bearing decided to stay on the spindle. Is there a simple way to get this off? or is it trial and error with a hammer and a screwdriver. I'd imagine I can pull the shield off and it may be a little easier.

Also, What is the area in the middle for? is that just a spacer for the size of the discs, It just seems odd to me that entire center would just be filled with grease.

 

The center really isn't filled with anything, its just vacant space. And to get the races out of the rotor will require more than a "tap". Get a fairly long flat nosed punch, set the nose on the edge of the race from the opposite side of the rotor, give it a couple of good wacks with a big hammer (the bigger, the better...to a point, I wouldn't go past a 4lb sledge), then go 180 degrees and do the same thing. Keep doing this untill you "walk" the bearing race out.
When you install the new races do the same thing, alternate side to side to evenly drive the new race in all the way to the shoulder. Its easy to tell when you gone far enough, the sound will change to a real solid sound.
As for removing the old race, if you have a gear puller that would reach you can try that. Or you can do like you suggested if you can get to the backside, drive it off with a punch and hammer.
Another way is to take a chisel and try to fracture the race along its length to split it.
If you have access to a hand grinder you can grind the race almost all the way through then take a chisel and fracture whats left. You could also do this 180 degrees apart to make it easier.

Don't try to use a screwdriver to do this, it wont work. You need to use a good heavy punch about 8"-12" long and at least 5/16" tip.

 

So I finally have my wiring diagrams posted up and ready to go. You can find them here:

1978 F-Series Wiring Diagram & Gauge Cluster Diagram - Ford Truck Enthusiasts Forums

It shows the split two-picture diagram of the wiring, and the gauge cluster.

It should be able to help you out somewhat, even though it was meant for a 1978.

At the least, it will help you sort out what's going wrong with your wiring and what should be going where.

Good luck figuring out the wiring.