Hello everyone- New time poster, but long time Bronco lover. I had an opportunity to pick up an 86' Full Size Bronco with the 4.9 and 4sp manual trans. Truck is in good condition, not much rust, and seems to run, drive, and stop as it should. I am an ok wrench (replaced a few clutches, brakes, water pumps and radiators, rebuilt a transmission with the help of really good instruction manual, and some other basic shade tree stuff). My initial inspection revealed a few things that need addressing. For the questions below I am wondering how hard is this to do myself? Alternatively, any ideas on what a shop would charge?

1. The rear main seal almost assuredly needs replaced. Pretty good coating of oil on oil pan and front of trans.
2. The front differential seal where the passenger side axle shaft go into diff seems to be leaking.
3. The rear window seal in tail gate (wiper seal?) is shot. Surprisingly, the rear window does go up and down.
4. Rear pinion seal needs replaced
5. AC stuff is there, but needs to be converted to the modern stuff (whatever that is) and recharged.
6. Big clunk on driver side front end on bumps. Could be ball joint?

There are other little things, but I'm not too worried about those. Mostly just want the truck to hold fluids without turning driveway into an oil slick.

Thanks!

 

address the safety related issues first like the clunk in the front end.

i would recommend washing the motor really good to confirm where the leak is. could be a valve cover leaking.

get a haynes or chiltons manual and get cracking on the other items. the AC stuff will need to be done by a licensed AC shop.

 

Nice find , as Kem stated safety items first, My 85 f150- for years leaked( All seals)- Keep oil level checked regularly ! (I ran it for years -Yes- years before I addressed the leaks)Try and check each axle (dope) too! My truck has the same engine 4.9 and had 500 k before the timing chain sprocket-stripped !Great reliable engine. I struggle with a leak now from the oil pan . Your truck is one I have been searching for Bronco 4.9- 4 speed xmission- carbed . They are hard to find in descent shape After completing my build listed below (signature_), they are easy to work on and fun to drive. Good luck TR

 

Nice find on the Bronco! Big fan of the 300 / 4.9 myself, and have had a couple of them.
What transmission is in there? A granny gear or an overdrive transmission? (Just curious).

On your issues:

Definitely start with the easier gaskets first. The rear main seals on these are usually not an issue, but the valve cover, and particularly the lifter / pushrod covers are (especially on an older engine).
These are easy to replace on a carb'd engine, and cheap. The pushrod cover is along the driver's side of the engine, behind the distributor and fuel pump. When this leaks, it gets oil everywhere.

This can be done at home, but sometimes the procedure can be pretty exacting, with setting pre-load on the bearing for the gears, etc. Get a Chilton's manual and look at the procedure and see if it's something you're comfortable with. Otherwise, I had mine done at a shop, and it's only about an hour's worth of work, and the price of the seal.

These are easy to replace. You just pull up on them and pop the clips out. Put the window all the way down and then start on one of the ends. Pull it up until it pops the clip out and then work down it to the other end of the tailgate. This is the same for both the inner and outer seals. Reverse to install.

Same as the front diff seal.

This is something I'll be doing this summer. For mine, I'm just going to replace everything with new components, and then take it to a shop to have it checked over, and charged up.

Possibly a ball joint, but hard to tell with just *clunk* as the descriptor. It could be anything from a broken shock, or a bad ball joint, to a bad tie rod end.
Jack up the front end until the tire is about an inch or two off the ground. Then, slide a crowbar underneath the tire and lift up on it, and watch all of the suspension components. (Note: this is a LOT easier with a friend). Look for what's loose, and what moves that shouldn't. Replace as necessary. It could even be two to three worn out components.

Good luck and have fun!
And if you have 300 / 4.9 related questions, be sure to check out the dedicated inline 6 forum.

 

I did a full restoration on my 86. and rebuilt all of the front end including the hubs, new u joints seals, etc. I started by watching a YT video or two, I find that much more informative than the usually vague Chiltons or Haynes manuals. the front end was the worst of the drive train overhaul.. it wasn't as much hard as there's just a lot to it so it takes some time and patience... good luck, would love to see a picture of it.

 

Also check the radius arm bushings. My F150 needed some, clunked around. Felt like something was banging around right under the driver's feet.