John McDaniel

Bronco Repair

If you have owned a bronco then you then you definitely know ... things break. What I like most about my Bronco is that when the inevitable happens, generally I can fix it. As long as you have a basic set of tools, sockets, wrenches, screwdrivers, pliers, and a Haynes manual , you are pretty much good to go. The fact is, that with only a 7/16" and a 1/2" socket and wrench, you can just about dismantle a Bronco. I know that I used to feel uncomfortable working on my truck, always afraid that I would do more damage than good. Basically, there is very little you can hurt, unless you really just have no clue what you are doing. That is where these next links come in, these are my observations and hind-sights on simple repairs that anyone should be able to do in an afternoon. The trick is to try to do the simple tasks and build up a little confidence to move on to the next level. Soon you will find yourself tearing into just about everything. Best part is, it can really be a money saver. It's really amazing how fast the $$$ can add up at $50 per hour for a good mechanic, heck even a bad mechanic. So get out there and do it yourself, save yourself some money buy yourself a new Bronco toy with the money you saved.

Vacuum & Emission Line Diagram

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This Diagram is from a 1974 302 ( manual transmission ) with a Motorcraft 2150 carburetor. The truck seems to run great with this configuration, but I have never been able to verify it's authenticity in an official Ford Shop manual. I have heard rumors that the distributor Advance line should be tee'd into the EGR line after the thermal switch instead of receiving ported manifold vacuum from the carburetor. Supposedly, this raises the advance slightly when the engine gets above a certain temp to increase RPMs and thus cool the engine. Again, I've never officially been able to verify this so take it as you wish. Hope this helps someone, I would have killed for a diagram like this months ago, which is why I have posted it here. Enjoy!

Rear wheel bearings & seals

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Background information

The rear wheel bearings are what rides between the axle shaft and tube to provide a frictionless base upon which the axle can freely turn. The seal is a small round circle of rubber or leather that goes around the axle shaft to keep the differential fluid where it belongs ... in the differential. The procedure I am describing is for a 1974 Ford 9 inch small-bearing differential, with drum brakes. Other rear-ends such as the Dana 60, or later model Ford differentials with c-clips may require different tools and/or steps, but the general repair concept stays the same.

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Symptoms

The first symptom of a bad wheel bearing will be the sound of a slight rumbling or grinding noise coming from the rear of the truck when it is motion. As the bearing fails, the sound will grow considerably worse. Another symptom of a bad bearing is some side-to-side movement in the tire when it is lifted off the ground. A bad seal is easy to spot, you will have differential fluid leaking around the tires.

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Solution

The idea is to lift the rear-end off the ground, remove the tire and brake drum, unbolt the axle, and pull it out. Then replace the questionable part, and put it back together. Sound simple? Well, in a nutshell, it is.

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Tools & Supplies

• Automotive Jack Stands
• Jack
• Rear Wheel Bearing - Napa Part # 514003PG
• Socket Wrench
• Thread lock adhesive
• Wheel Seal - Napa Part # 49150SF

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Instructions

1. Before you start you may want to loosen the rear lug nuts to make step two easier. Also make sure to block the front wheel to prevent unwanted rolling. Lift the rear of the vehicle and place the jack stands under the axle, such that both wheels are in the air and the side you will be working on is slightly elevated. The jack stands are very important here, do not use jacks or cinder blocks to lift the vehicle. You will be applying a fair amount of force to the rear components and it is quite possible to push the vehicle off plain jacks or have cinder blocks fail. You really don't want a Bronco resting in your lap and removing body parts, remember safety first! Jack stands are cheap insurance, get some.
2. Remove the wheel and brake drum. Make sure that the parking brake is not set because if it is, the drum will never come off. If you have difficulty removing the drum, look at the bottom on the back-side of the drum. There should a small oblong rubber plug, remove it. From this hole you can adjust the brakes, there is a small sprocket that can be turned to adjust the brake pads away from the drum. You may need two small screwdrivers for this step, one to turn the sprocket, and one to hold back a small lever which keeps the sprocket in place. The drum should easily slide off.
3. Turn the axle until the large hole is over a nut. Remove it and repeat the step until all four nuts have been removed. Be careful with the bolts, they hold the backing plate to the axle tube.
4. Pull the axle out. One of two things will happen here, either it will slide out, or it won't. If it doesn't you have several choices, get an slide hammer/axle puller, put the brake drum on backwards with the lugs and use it as a slide hammer , or attach a chain/cable through the hole in the axle and attach a hammer or such to the other end and then try to yank it out. It will come out, it just may take a couple minutes of cursing and yanking.
5. Inspect the axle for wear and tear. Inspect the axle gear teeth to make sure none are broken. Inspect the area where the seal touches the axle shaft. If you have problems with a leaking seal, it may just be that the shaft is too worn in this area and needs to be replaced.
6. Have the old bearing pressed off and a new bearing pressed on. Any machine shop should be able to do this. I took mine to my local Napa store, told them what it came out of and then picked it up later that day. No hassle, no fuss, and I didn't have to worry if I'd bought the correct parts.
7. Remove the old seal in axle tube and install the new one. To remove the seal you can either use a seal puller tool, or the end of the axle or a large shaft to pry the seal out. Be careful not to damage the facing on the inside of the axle tube where the bearing go. Installation should be similar, either use a seal installation tool or a large circular object to set it. I found that a front hub tool works perfect, it is the exact same size as the seal. The important thing here is not to damage the rubber part of the seal or to bend the seal. Some people have suggested that putting anti-seize lubricant on the outside of the seal will make removal easier for the next time.
8. Carefully slide the axle back into the tube. Please be aware that you can damage the seal during this step, so be careful or you could end up with a leak on your hands. You may have to rotate the axle slightly to get the teeth to line up, it goes in very easy.
9. Re-install the retainer nuts, brake drum, and wheel. I used some thread lock solution on the nuts to prevent them from coming off. Better safe than sorry. If you loosened the brake pads through the adjusting hole, be sure to adjust them back by approximately the same amount or less. Lower the truck and you are mobile.

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Time Estimate

This procedure should take less than an hour depending on how things come apart. If this is your first time, plan on about three hours. Note: This time estimate does not include the time for the bearing press work.

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Cost

Total cost on a per axle basis for seal ($5), bearing ($25), and press work ($20) was about $50.

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Difficulty

On a five knuckle scale, I give this repair two bruised knuckles.

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TBD...

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Something useful will go here also!