Gnarly Rear End

[HanksB3B]

Guys...I'm not quite sure what to do about this but since you actually viewed a post with this title please help !

 

A long time ago, someone must have backed my truck into a tree stump or a rock.  Looks like it was welded at some point and covered with black silicone. But as long as I’ve had my 51 B3B, the  differential  has always seeped and  needed filling every few weeks and has probably run without the capacity of oil it was designed to hold. This has always prevented me from filling it with top quality $ynthetic oil. 

 

Yesterday I removed the feeble silicone patch and started to file the bumpy weld  job in order to see just where it was leaking.  

 

This morning here’s what I discovered. The hole was a tiny pin hole.

 

I tapped it lightly with a center punch and oil gushed out.

 

x

The thinned out metal and poor welding makes me think that since the differential was not at full oil capacity, after fixing that one hole I might be faced with patching another hole above the hole that was leaking.

 

Recently I removed my oil pan and successfully fixed the leak where the dipstick escutcheon meets the body of the oil pan with JB Weld. I think I want to stay away from field welding at this point and don’t really want to go through major motions of removing the differential at this time. 

 

The drain plug is pretty much buggered.  It looks like it was supposed to be a 1/4"-5/16" or 3/8" square drive but I'm not sure.

 

 I have some thoughts about how to fix both conditions but would appreciate any suggestions and want to hear what you guys think. 

 

Thanks,

 

Hank 

Edited December 28, 2013 by HanksB3B

[ggdad1951]

Honestly I'd try to find replacements. ...with all the rear end swaps on here you should be able to get parts?

[Young Ed]

Hank I'd take a stab at that drain plug. Make sure all the gunk is out of it so you get a good bite. Use an extension. If its not 3/8 or 1/2 you'd have to find a proper socket or a piece of square stock to fit the hole. Then you can use an adjustable wrench on the stock sticking out. Drain the fluid well and find someone to weld it up. Finding a replacement housing shouldnt be too hard as Mark said but its a lot of work to swap out.

[HanksB3B]

Hank I'd take a stab at that drain plug. Make sure all the gunk is out of it so you get a good bite. Use an extension. If its not 3/8 or 1/2 you'd have to find a proper socket or a piece of square stock to fit the hole. Then you can use an adjustable wrench on the stock sticking out. Drain the fluid well and find someone to weld it up. Finding a replacement housing shouldnt be too hard as Mark said but its a lot of work to swap out.

Thanks to both of you.  In the final analysis (pun not intentional) it's a big decision involving big bucks to either find a 3.73 or 3.54 internals or to do the smart thing that Jeff did and replace it with a Mopar Jeep Cherokee differential with disc brakes ? Either of those could work as a plan A, My ideas for Plan B are more in the realm of Apollo 13 thinking but before I say anything I'd like to wait for more responses.   

 

Thanks for helping,

 

Hank 

 

P.S.  Jeff might I ask, what did you do with your original differential?

Edited December 28, 2013 by HanksB3B

[HanksB3B]

O.K I can't stand the suspense so to keep things moving before I go outside on this sunny mild California day to work on  my copper vacuum line, tell me what you think of these ideas for the drain plug (I'll keep the Appolo 13 "Metallurgic Dish Fail" open for suggestions.

 

Plan B Drain plug three options:

 

B1: Leave the drain plug alone, drill and tap another on the opposite side.

B2: Drill the existing plug out, make a trip to Harbor Freight, buy and learn to use (never have) an extractor.

      (anyone with experience ? Best  Practice tips would help)

B3: Weld a square stud or 3/8” drive Allan wrench and use my Makita impact hammer to twist and shake it loose.

 

Hank   

Edited December 28, 2013 by HanksB3B

[Frank Elder]

B3 but modified......weld square stock to the plug, but try and use a pipe wrench and cheater pipe first....that way you can go slow and not bugger anything up.

[Dennis_MN]

Make sure that the vent on the top left is working, that is open to relieve any pressure build up. That will keep your JB weld in place.

Leave the drain alone. It was leaking, it's got oil.

[MBF]

If It were mine (so you don't cripple it) I'd get the plug out using the methods suggested, and patch the known hole with some type of epoxy and refill it to see if there are any other leaks. If none are found you're good to go until you find the desired replacement.  If you find another leak that needs patching drain it down below that hole and patch it.  I just had my 1 ton on blocks for two weeks waiting to find and purchase new rear shackles on the rear.  I personally don't like stuff inoperable so that I can move stuff around in my shop as needed. Hope you get lucky with the repair.   Mike

Edited December 28, 2013 by MBFowler

[Young Ed]

Hank have you confirmed that the plug isn't full of junk? If I remember correctly it should be at least 1/2 in deep and very hard to strip. To me it looks full of junk and stripped only at the very top.

[4852dodge]

I had a stuck plug on one of mine, I found that a square cold chisel head fits reasonably tight and turned it with a large adjustable wrench.   You may have better luck brazing the damaged rea area instead of welding.  It's a lower temp and won't blow through the thin steel.

[HanksB3B]

Suggestions leading to decisions toward a solution:

 

            Dennis_MN

• Make sure that the vent on the top left is working, that is open to relieve any pressure build up. That will keep your JB weld in place.
• Leave the drain alone. It was leaking, it's got oil.

MBFowler

• Get the plug out using the methods suggested.
• Patch the known hole with some type of epoxy and refill it to see if there are any other leaks. If none are found you're good to go until you find the desired replacement. 
• If you find another leak that needs patching drain it down below that hole and patch it. 
• I personally don't like stuff inoperable (couldn’t agree more)

 

Young Ed

• Hank have you confirmed that the plug isn't full of junk? If I remember correctly it should be at least 1/2 in deep and very hard to strip. To me it looks full of junk and stripped only at the very top.
• I had a stuck plug on one of mine, I found that a square cold chisel head fits reasonably tight and turned it with a large adjustable wrench. (I will try clearing the hole and tailoring a square cold chisel and turning it with either a large wrench or if I can my Makita Impact hammer.  
• You may have better luck brazing the damaged area instead of welding.  It's a lower temp and won't blow through the thin steel. (couldn’t agree more after the fact, but it’s too late now)

 

After the leak is fixed (hopefully not leaks) (and assuring the vent is operable) I could use fiberglass with epoxy resin over the “dome” and then move on to conventional bodywork methods finalizing with black epoxy paint until a suitable alternate i.e. having the original reconditioned with a 3.54 or 3.73 pinion or Jeep Cherokee differential is made to work.

 

The Plan:

• Use the smallest self tapping machine screw,  backed by a small washer, over a small malleable aluminum washer made from a beer can (good excuse to down a Coors Light). Goo it all up with JB Weld and wait for morning. 

 

Thanks for helping your suggestions cleared up some  and really changed my mind on a couple of tasks,

 

Hank   

[B1B Keven]

Hank,

I've got an extra housing if you end up going that way. 

[Jerry Roberts]

Once you get the drain plug out , it is probably pipe thread , available at the hardware store . 

[Dodgeb4ya]

 I'd carefully clean up the quarter inch deep by 5/16" square recess drain plug as much as I could. Maybe use a new narrow chisel and try to sharpen the square recess up and maybe deeper if possible. Then get a piece of high strength 5/16" square stock, dip it in course valve grinding compound and pound it in the plug. Use a square drive socket on the 5/16" stock and while pushing hard on the bit turn it out-hopefully it will bite enough and come out.

JB weld the leak on the housing. Clean it very well first of course.

Bob

[Don Coatney]

Bob;

Is the 5/16" square stock you pictured a lathe cutting tool?

 

[HanksB3B]

Bob;

Is the 5/16" square stock you pictured a lathe cutting tool?

 

 

 

 I do need help sourcing a 5/16" square tool. Where would I get such an animal ?

 

Thanks,

 

Hank   

[Plymouthy Adams]

usually you can find this in the hardware stores..square stock is still popular...as you will need but a small section of the stuff to form a tool..look to the smaller specialty boxes with designated use of key-stock...

 

another possible source is adapting a facet seat removing tool for your purpose..look to the plumbing supply department...however I am not sure the strength of this rather low cost item..

[Dodgeb4ya]

Yep Don. I use lathe bits. Also some number stamps work too. They both are pretty tuff.

[Plymouthy Adams]

good post on the number stamps...I had forgot those readily handy devices...

 

my 700 shadow spark plug tubes required special hex tool for service...just welded a bolt head of appropriate size to a bar.  Instant tool..stay away from the dealership..

Edited December 29, 2013 by Plymouthy Adams

[Jeff Balazs]

hey Hank;

Sorry my old axle was part of an exchange when I got the Cherokee axle.

It was a 4.10.......new one is a 3.55......and I almost wish It was a 3.23. Stock would be way too low for maintaining speeds around here. 1st on my 4 speed never gets used.

Good luck with your repairs.

 

Jeff

[RodFru2u]

Hank, I have an old Multi Square Plug Wrench I picked up at a swap meet years back, I just crawled out from under my '50 B-!-B to check. This is an old "Black Hawk " Tool, the square ends fit the bigger on the transmission drain and the small plug on my rear end, the square plug on the rear end seems to be a 11/16 " Box end works and is a tight fit. If you need it to remove or size it to make a tool just let me know.    Rod

[Don Coatney]

Innovation of tools. This thread got a slight hijacking to my liking.

[48Dodger]

It kinda pains me to think you will be putting so much time into that axle, Hank. You've been talking for a few years about replacing the diff with a taller gear or swaping in an upgrade. The fact is the stock axle is heavy. I don't know exactly how much heavier....but they are, based on my experience of physically moving axles around the place by myself.  

 

Get some blankets.....drive your truck to the Cherokee store (junkyard) and get a "new" axle. Work on that instead of the one you got. I know we live in California....but it is winter....the time when all this kind of stuff gets done in a cold shop. Spring is coming and you have a BBQ to drive to in Clements!

 

48D  

Edited December 29, 2013 by 48dodger

[Jeff Balazs]

Hank;

I am with Tim on this. I don't see how you would ever be able to get any real use of your truck here with the stock gearing. Our driving conditions are about as different from the intended purpose of these trucks as it gets. I had to come to this same realization myself. It was painful but I am glad I made the changes I did.

Jeff

[Plymouthy Adams]

http://www.ebay.com/itm/BGS-Tools-Oil-Pan-Special-Key-8-In-1-1012-/230908045326?pt=UK_Measuring_Tools_Levels&hash=item35c331280e