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86 Bronco with Freeze plug issues among other things..

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Hey there, I just picked up an '86 Bronco 5.0 late last week... The body was in good shape and was essentially told the battery was bad. When I went to look at it, it started once but not a second time, was running 'OK'. I checked the fluids it was leaking some oil and the radiator looked like it was low and had some rusty water in it -basically telling me this thing has been sitting-. Everything in the right taillight wasn't working, back window wouldnt go down either. I took all of this as an opportunity to make a low ball offer which was accepted. It promptly overheated (twice) on the way home which was an adventure without functional hazards. and was spilling water out of the block where there was no longer a freeze plug. Fixed the taillight (bulbs werent screwed in correctly [LOL]), Cleaned up a lot of smaller issues such as the doors not locking, replaced ignition wires. I popped a new freezeplug in at which point another one popped a leak. So I've basically deduced that all the freeze plugs have some rust on them and once pressurized the next weakest one will blow, so I'm going to replace all of them. In the midst of this I've also found a couple of large exhaust leaks and broken valve cover gaskets on both sides.


So now with that all said, Ive done a fair amount of research on the valve cover gasket replacement, and feel like I have a pretty good handle on how to go about that. I'm mostly looking at it as an opportunity to dissemble a lot of the motor and clean things up with some tlc as theres an alarming amount of random missing nuts and bolts. I figure once I have most of this dissembled im going to attack my freeze plug and exhaust leak issue as I should have a lot more room to work. So I guess that my real question is: Am I going to need to yank the motor all the way out or can I just move it a few inches up (and maybe out) and access these freezeplug locations? I havent pulled an engine on a 4x4 before (I really only have experience with small block 350 chevys rwd) so I'm not sure exactly what and where to disconnect if necessary. It looks like the tranny is sealed -no slip yoke-  so do I just pop the U joints off to drop the driveshaft? Any help is greatly appreciated, looking forward to being back here a lot since this thing clearly needs a lot of work. Thanks!




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Yo VenetianBronco,

Welcome & Congratulations on saving your 86!


Will address as much as I can now and get back later.  Other members will help you  as well.

Freeze Plug Recommendation & pic in an 86 5.0; Napco 263-564; "...This is an expandable frost plug. I've had one last over 9 years, so yes they will work for the Winter..." 

Source: by Sixlitre (Malcolm H, Eddie Bauer) 

btw, Malcolm lives in Canada,  so when he writes "freezing"....


Freeze Plug & Block Heater Installation 
Source: by Ford 


Installation Tips; "...You may be able to install a new frost plug just by using a hole saw to drill access for a socket extension through one of the plastic inner fenderwells.Use a punch in the top edge of the old frost plug and whack itso the bottom lip comes out far enough for you to clamp a pair of vicegrips on. Once you have it with the vicegrips you'll be able to lever it out no problems. Loctite for the frost plug, ultracopper for the rubber expanding repair plug. 

Source: by Sixlitre (Malcolm H, Eddie Bauer) 



Location pic in a 94 5.8 
Source: by WasACop3436 (Chris) at SuperMotors.net Location pic in a 94 5.8; Starter area 
Source: by WasACop3436 (Chris)  Location pic in a 94 5.8; "...The freeze plugs you can see back there are ON the heads - not below them. The ones on the back of the block are all inside the bellhousing.." 
Source: by CodysBigBlueBronco (how much $???)    Location pics in a 94 5.8 
Source: by WasACop3436 (Chris)  Location pics; "...The freeze plugs you can see back there are ON the heads - not below them. The ones on the back of the block are all inside the bellhousing.." 
Source: by STEERING 

Locations in an 89 5.8; "...Three large per side..Rear of the cam journal .Two small in the front by the cam journal. One medium size in the top back of the lifter valley.One threaded per side. One threaded in the front by the dizzy hole..." 
Source: by Aikidoka (Adam O) 




Replacement in a 94 5.8; "...I recently had to replace one of my freeze plugs, the one behind the power steering pump. Just use the brown gasket maker and a socket that just fits inside and just pound it home.. I doubt the others have any more room to swing a hammer than the one I did. I ended up putting a 3ft long piece of pipe inside the socket and hitting it where I had room, like a big extension..." 
Source: by RobertF  Replacement; "...The one behind the engine mount is gonna be a huge pain to do without pulling or at least lifting the motor. Go in from the bottom, after draining the water in the radiator, drain the block as well, or just pop the plug and be ready to get hosed. A screw driver or punch to knock it sideways so you can grab it with pliers is the picture purfect way to do it, but its between the engine and the mount so I really doubt your gonna be able to do it. Once you do get all of it out install by taking a socket a little smaller then the plug, some RTV around the edge, and tap her home..." 
Source: by 81Bronk36 (1BadBronco, Matt K)  Replacement; there are ~8 freeze plugs (and a few bore plugs that look identical) in a V8 block, plus 1 in each end of each head. Yardape said in same thread; Ive done it that way before, undo the mount on the side you are working, lift the engine a bit. The remove the motor mount from the block and your set. To really make your life easier you can remove the exhaust manifold. crazyhorse85 wrote; Most of the time you won't have to pull the engine....Like yardape was sayin i've changed mine with it still sitting in the truck.....Take the manifold or header loose and loosen the mount jack her up alittle remove the mount and there should be enough room to operate....One suggestion replace with brass freeze plugs they last alot longer and don't corriode as bad or fast as steel.....And don't let autozone try to talk you into the rubber exspandable one they don't work worth a crap.... 
Source: by members at Ford Bronco Zone Forums


Driveshaft; do you have the rear shaft that appears like this?

Rebuild in an 84 
Source: by justshootme84 (Randy Z, Casual Mudder)  Rest-In-Peace friend


Or this?;



Or this?

Driveshaft Removal, rear in a 90 

Source: by Keith L (TTB Blows, Bling-Bling) at SuperMotors.net


will post now because I may get another error message

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I asked about the driveshaft because some owners have swapped in later year transfer cases.  



1986 Bronco Dealer Brochure by Ford @ 


See these Ford Shop Manual Diagramsby our sponsor @ 


But the Body Manuals & Diagrams timed out.  May be due to my Comcast rip off.


Transfer Cases:


1982-1989 BW1345 31 Spline front input front and rear fixed yokes shift lever is downward parallel to case when in neutral, .875 speedo hole   1980-1986 NP208F 31 Spline front input non-synchronized front & rear fixed yoke


Borg Warner 1345 pics w/ID Location @ http://www.supermotors.net/registry/media/700792



bw1345.jpg  Note that ALL applications use a fixed rear yoke. 


New Process (NP) 208;



208 Overview, Weight, Dimensions, & Image; "...Type: Chain-driven, aluminum; Low-range ratio: 2.61:1 Weight (lb) 79; Lubricant: ATF; Length (in): 8.0 GM); 15.5 (AMC); Width (in.) 20.0; Height (in.) 5.0; Used by: Many full-size vehicles, including Jeep pickups and Wagoneers (which used a left-side front output shaft). A part-time unit that replaced the stronger, heavier NP 203, the NP 208 can't stand up to the horsepower that the NP 205 can, but failure is more often related to low oil level than too much input torque. The 'case utilized left- or right-side front output shafts..." 
Source: by 4wheelingplus.com


1980-1986 Bronco/F Series Specifications by ​​Gary @ http://www.garysgaragemahal.com/specifications.html


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Thank you for all of this info Al, so my driveshaft looks like the one from the "84 rebuild" so if im not mistaken it seems there is a slip yoke under that rubber boot, correct?


Looking at the bigger picture it seems like there is some mixed reviews on the brass vs rubber plugs I'll most likely just do the brass since im based out of southern cal, I'll also go ahead and remove the exhaust manifold since I noticed some loose bolts on that as one of the sources of my exhaust leaks. I understand jacking the engine lets me get the ones under the motor mounts, but I know there's supposed to be at least one plug on the backside of the engine is that going to be accessible without a whole motor pull?

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My tablet can't open pics again, so;

Slip Shaft Location; "...Instead of sliding into the t-case like a car driveshaft would into a trans, a Bronco driveshaft normally is two pieces that slide together. The slipshaft is normally covered by a rubber boot in the middle..." by El Kabong


Driveshaft Slip Spline Lubed by Trucky18

Inspect the driveshaft slip yoke seal for rips, holes or deformation. Replace if necessary.
Using a suitable cleaning fluid, clean all dirt from the driveshaft slip yoke internal splines and the driveshaft slip yoke. Carefully inspect the driveshaft slip yoke splines for wear or evidence of twisting. Check the operation of the driveshaft slip yoke.
Using a brush, coat all surfaces of the coupling shaft front slip yoke splines with Premium Long-Life Grease XG-1-C or -K or equivalent meeting Ford specification.
Using a clean long handle (stencil type) brush apply Premium Long-Life Grease XG-1-C or -K or equivalent meeting Ford specification ESA-M1C75-

by trucky18

I never saw that freeze plug on backside of the engine, but will look for a diagram or pic tomorrow.

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I never saw that freeze plug on backside of the engine


I saw it here (http://www.fullsizebronco.com/forum/21-noobie-bronco-tech-questions-flame-free-zone/41226-freeze-plugs-replacement.html) although im not completely clear about if this guy ever got in or not and replaced them I'm about 75% done on clearing out the *known* stuff to jack the engine and getting everything else out to do the valve cover gaskets

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This site froze up earlier.

I believe you're referring to this pic;


Looks like Steve83 removed bellhousing & flywheel to snap that pic.

Steve is not a member here now, but is in other Ford forums such as;




Register there and PM him, same user name, Steve83

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So... I've gotten most of everything I need off to pull this engine and replace:


-Valve cover gaskets

-few other odds and ends that arent critical but might as well do while I have everything accessible


I only have a few things left and thats to remove the fuel lines, another couple coolant hoses,, drain the oil, and to unbolt the tranny.. I figured these last things wouldnt be a big deal then I started digging into relieving the fuel line pressure and realized most people recommend flipping the pressure release then running the engine for a few seconds  Thats pretty much impossible at this point since my engine is halfway dissembled at the moment: Upper intake off, starter off, distributor off, etc etc... So is there a way to do this manually? I guess I just assumed there would be some pressure relief valve I could unscrew, and Im not seeing any info online...



Edited by VenetianBronco

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Obtain a Fuel Pressure Gauge from local parts store using the loan a tool program.  Have a fire extinguisher on-hand,  No light bulbs dangling, no smoking ( of course).

This is Ford's procedure:

  1. Remove the protective cap from the fuel pressure relief miesk5 note, this is the schader) valve.

  2. what%20is%20this2c.JPG

  1. Connect Fuel Pressure Gauge to the fuel pressure relief valve on the fuel injection supply manifold.

  1. Place end of the adapter hose in a suitable container.

  1. Open the manual valve on the Fuel Pressure Gauge  to relieve fuel system pressure.

  1. Close the manual valve and disconnect the tool from the fuel pressure relief valve. Remove container.

  1. Install the protective cap on the fuel pressure relief valve.

But Ford didn't advise on what to do with the gas in the container. Lol


Some just pile rags around the schrader valve and depress it's pin.   But....


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