Rear Differential Fill bolt is stuck/seized

[Inv4drZm]

I rounded the front diff drain bolt (SHCS/ internal hex). Hit the hex key in with a hammer and used a 12" ratchet. Could not get it to budge and eventually rounded it off. Should have tried some heat before I screwed it up but I eventually got it off by welding a nut onto it. Got that joker red hot welding it on there and even tacked the outside of the nut after a few shy failed weld nuts before it. The heat helped a ton as it was easy to wrench off of there after I got over the fear of burning my truck to the ground.

Confession over. Felt good to get that off my chest.

 

[Stuffman]

The trick I use is, to hit it with PB blaster for a couple of day after driving around for a while. What I am betting on is the heat difference between the parts cooling down gets the PB in deeper then I hit it with the breaker bar gently back and forth to break the bolt loose slowly. Sometimes I add an old gas pipe to the end of the breaker bar for leverage.

 

[lbhsbz]

The problem is that we have a relatively large thread size bolt with a head on it that is too short. Most sockets have a chamfer to varying extent on the hex, so it tends to only grab about 1/2 of what's there, which isn't much to begin with. Find a socket with little to no chamfer, or modify one to get as much purchase on the head of the plug as possible. I have a set of HF impact sockets that I machined about 1/4" off of for situations like this...they work much better. Also, use the shortest socket you can...less tendency to twist off of the fastener.

 

[ben550]

I had good luck with one of these socket bolt extractors

http://www.mscdirect.com/product/de...164124448769&gclid=CJHXncylqdECFU6BswodlCAHcg

It mangled the bolt (which I replaced with a new one anyways) but it was the only tool coupled with a 1/2 drive breaker bar that got the stripped/seized/rounded bolt out.

Mine was the transmission fill plug (hard to reach area).

 

[Anteupp]

I rounded the front diff drain bolt (SHCS/ internal hex). Hit the hex key in with a hammer and used a 12" ratchet. Could not get it to budge and eventually rounded it off. Should have tried some heat before I screwed it up but I eventually got it off by welding a nut onto it. Got that joker red hot welding it on there and even tacked the outside of the nut after a few shy failed weld nuts before it. The heat helped a ton as it was easy to wrench off of there after I got over the fear of burning my truck to the ground.

Confession over. Felt good to get that off my chest.

thats what happened to me on my tacoma. welded a Nut to the rear diffs fill/drain plug as well lol

 

[nykhannan]

Use MAP gas for 5 minutes, pb blaster, let it sit for 15 smack the face with a hammer. Repeat another time and it'll pop right off.

 

[TechWrench]

Use MAP gas for 5 minutes, pb blaster, let it sit for 15 smack the face with a hammer. Repeat another time and it'll pop right off.

You guys have to learn to think 'old' school. Since the head of the plug is so thin, I went with a pipe wrench. When the socket and breaker bar didn't get it loose on the first try, I went with a big pipe wrench for the 2nd try. As long as you fit the pipe wrench tightly, and make sure it sits flush, it should work without any problem. Once it broke loose, I made sure the threads on both the plug and the housing were clean, and used never seize on them when I re-installed it. Next time I had to remove it, it came off much easier.:thumb3:

 

[flipflopnfly]

I rounded the front diff drain bolt (SHCS/ internal hex). Hit the hex key in with a hammer and used a 12" ratchet. Could not get it to budge and eventually rounded it off. Should have tried some heat before I screwed it up but I eventually got it off by welding a nut onto it. Got that joker red hot welding it on there and even tacked the outside of the nut after a few shy failed weld nuts before it. The heat helped a ton as it was easy to wrench off of there after I got over the fear of burning my truck to the ground.

Confession over. Felt good to get that off my chest.

The front diff drain plug can stay in place (yeah, the 10mm Allen bolt is crap, amazing Toyota still trots them out after being a known problem for 30 years). You can use a transfer pump to drain the front diff fluid via the fill plug (if you can get that 10mm Allen loose) because unlike the other cases a hose can be fitted into the bottom of the differential. Then fill with the transfer pump via the fill opening.

Also, a 24mm hex plug from the transfer case can be sub'd in for the front diff 10mm Allen fill plug. Probably any 24mm hex from the rear diff, transfer case, or a Tacoma manual transmission can be sub'd in, magnetic plugs also, I didn't try any of them because the transfer case 24mm worked fine.

The front diff drain plug is the oddball out of the group, it's the only one with a larger bore. Toyota hasn't changed that design since 1968 I bet and they've sucked on every Toyota 4WD I've owned since 1990.

The torque specs are crazy also for the front diff drain plug, it's the only drain that uses a copper washer in the drivetrain, antique design that sucks. Alright, rant over.

As said above, use a 6-point socket removing the 24mm plugs, do not use a 12-point, use a 3/4 inch breaker bar with an impact socket, a 1" socket works fine also.

 

[flipflopnfly]

You guys have to learn to think 'old' school. Since the head of the plug is so thin, I went with a pipe wrench. When the socket and breaker bar didn't get it loose on the first try, I went with a big pipe wrench for the 2nd try. As long as you fit the pipe wrench tightly, and make sure it sits flush, it should work without any problem. Once it broke loose, I made sure the threads on both the plug and the housing were clean, and used never seize on them when I re-installed it. Next time I had to remove it, it came off much easier.:thumb3:

Yeah, antisieze is a very good thing on any install.

 

[whyowyo]

Wanted to add two more tips for posterity...

Heat the area around the bolt, not the bolt itself. Heat will cause the bolt to expand and make the metal slightly softer. I've had luck heating around stuck bolts, then icing the bolt while hitting it with PB Blaster and repeating a few times.

An air chisel thoughtfully applied to the edge of the front fill plug while applying torque with a pounded in hex has worked for me.

Learned to grind 6 point sockets flat working on moto and mountain bike forks, it works. I all ready had a flat 6-point 24mm on hand when I changed the diff fluid on my rig the first time.