What's your trick to loosening rear diff fill plug?

[4RunnerFan]

Sad thing is my '08 4Runner only has 27k miles and rear diff gear oil was previously replaced at 14k miles. Now fill plug rusted to case (drain plug looks ok). Have sprayed Power Blaster on it for last 3 days, but no luck so far. Per forum advice, have not removed drain plug until I'm sure fill plug can be removed.

Was inspired by this forum to try changing gear oil myself. Have new fill and drain plugs along with new crush washers. Just need to get that #%* fill plug off!

Oh, and once I replace it with new one, how do I prevent this from happening again?!

 

[Presta24]

You can try Kroil if u can get it local or wait for shipping, I would say heat it up with a torch but I dont know if thats wise on the rear end or not. Got an impact? Maybe u can break it loose with that.

 

[CXS]

Yes, heat it up and use a big breaker bar. I hope that works and you don't have to weld a large nut on like I had to...

 

[snhrph]

Sad thing is my '08 4Runner only has 27k miles and rear diff gear oil was previously replaced at 14k miles. Now fill plug rusted to case (drain plug looks ok). Have sprayed Power Blaster on it for last 3 days, but no luck so far. Per forum advice, have not removed drain plug until I'm sure fill plug can be removed.

Was inspired by this forum to try changing gear oil myself. Have new fill and drain plugs along with new crush washers. Just need to get that #%* fill plug off!

Oh, and once I replace it with new one, how do I prevent this from happening again?!

Your gear oil is only 13K miles old. Why would you want to replace it

And I used a REALLY bid wise-grip to open it...

 

[jow]

I pulled my 07 TR4’s rear-end plug and it looked to delicate for an impact wrench. Since it looked so thin and delicate, I used a 6-point socket with good square firm torque with an 18” break-over bar. With the rust which I d/n have, I would be tempter to tap it light to medium toward the rear-end to help break the rust.

If you trust the listed capacity or what you drain, I guess you could fill it through the vent plug. Last, I drilled and tapped a pipe plug (seals with less torque) in a Volvo’s Engine oil drain plug. I had it out for the process but the torque specs was high on non-pipe thread. Good Luck On Your Challenge! jow

 

[SkylineGTRracer]

I just used a breaker bar. I never heated it up.

 

[Presta24]

if u cant get it out, maybe drill a hole in the plug and use a bolt extractor. that will do it for sure, just get a new plug 1st plus if u use a big enough drill bit it will help release some of the tension on the threads

 

[810moto]

i used my hands and a socket. worked like a champ

 

[LEO98]

My center diff fill plug was overtorqued as well. My 12 point socket was rounding the edges. Bought a 6 point, but the edges were too soft/rounded to get a grip. Ended up using a large vice grip - it worked.

 

[4RunnerFan]

Your gear oil is only 13K miles old. Why would you want to replace it

And I used a REALLY bid wise-grip to open it...

The reason for replacing rear differential gear oil is we tow a 2,800# boat and trailer. Owner's manual says to change rear diff fluid if towing every 15,000 miles. We get the boat out of storage on May 2nd, so thought I'd take care of it now.

Also need to change out the front diff and transfer case per 30k mile maintenance schedule.

I'll order some Kroil per Presta24's idea. Sounds like quite the stuff and something I can use around the house anyway. Might just need it for front diff...

Thanks everyone.

 

[Presta24]

The reason for replacing rear differential gear oil is we tow a 2,800# boat and trailer. Owner's manual says to change rear diff fluid if towing every 15,000 miles. We get the boat out of storage on May 2nd, so thought I'd take care of it now.

Also need to change out the front diff and transfer case per 30k mile maintenance schedule.

I'll order some Kroil per Presta24's idea. Sounds like quite the stuff and something I can use around the house anyway. Might just need it for front diff...

Thanks everyone.

I work on industrial machines, and thats all i will use, except cutting fluid/oil

 

[4RunnerFan]

It's done!

What an ordeal. Per Presta24's suggestion, I bought a small can of Kroil. It arrived in the mail yesterday. I applied it to the fill plug, then waited 30 minutes and tried to turn the plug off. No go. Applied some more, waited some more and tried again. No go. Applied some more and waited overnight. Still no go. Decided I just wasn't getting enough weight on my torque wrench (figured I needed at least 100 lbs of force), so removed spare tire and backed 4Runner up onto ramps for better access. That did the trick! My 15/16" 6-sided socket seemed to fit better than the 24mm. Both were just a skoshy bit loose.

I installed brand new drain and fill plugs with new crush washers. Thinking the place that did the job before torqued the plugs on too tight, I used a micro-torque wrench and set them to specs. That was after applying some anti-seize to the base where the crush washer meets the differential housing. Used three quarts of NAPA's 80W-85W-90 API GL-5 rated gear oil. Considered more expensive synthetic oil, but since I need to change it out every 15k miles, figured I'd just go with the cheaper dyno stuff. NAPA gave me a 7% discount after I showed them my AAA card.

BTW, the place that did the job before charged me $220 to change out the gear oil in both the front and rear differentials. Yeah, I know; paid too much. The great part in doing it yourself is you not only save a ton of $$$, but you get the satisfaction knowing the job was done well by someone who really cares about doing it right.

Next job sometime this month will be front differential and transfer case. Hoping the self-tapping bolts for the skid plate aren't cross threaded as others have experienced.

Many thanks to all who helped. Very much appreciated. This forum is great!

 

[klennop]

I had an issue with my front drain plug, I couldn't get it out for the life of me. PB blaster for days, breaker bar, heat, when I felt the metal/socket giving more than the plug, I gave up. I ended up taking it in to Toyota with my fluid. They charged me $50. It was worth it considering I didn't want to strip the thing before I brought it in to them. I didn't have any issue with the rest of the drain or fill plugs, just that one.

 

[mastee]

front Drain plug stuck

I did the rear diff and the transfer case yesterday, and i Used a 3" wobble extension on the back fill, otherwise the metal wire was in the way of the ratchet. The transfer case was easy too.

This morning I was successful on the front fill with just the 10mm hex key and a 1' breaker bar, but the drain is presently stuck, I tried the 10mm hex with breaker bar 1st, the key was starting to flex but it would not budge, bought a hex socket set and tried with a ratchet+breaker but nope, bad language did not work as well, now it has a very minor strip and I dont want to f**k with it anymore, none of the dealerships/stores have it in stock either, I am just going to just fill it up and take it in next week, the guy at the dealership said $50-75, depending on how bad it is.......

see pics below

The glass has the tranny fluid sample
The metal spoon has the rear diff fluid sample
The rear diff drain plug

My truck has lots n lot of gunk buildup, which I will be taking car of soon, had to clean to get the keys in

 

[jeober]

Decided I just wasn't getting enough weight on my torque wrench (figured I needed at least 100 lbs of force), so removed spare tire and backed 4Runner up onto ramps for better access. That did the trick! My 15/16" 6-sided socket seemed to fit better than the 24mm. Both were just a skoshy bit loose.

I

Yes, the 15/16" socket is about 0.007" smaller than a 24mm. Good call on that one.

Tight fasteners can be a time killer. I assume you used a 1/2" drive, 18"-20" breaker bar for this. It's my favorite tool.

 

[berettashot117]

subscribed! lots of good info.

 

[4RunnerFan]

Yes, the 15/16" socket is about 0.007" smaller than a 24mm. Good call on that one.

Tight fasteners can be a time killer. I assume you used a 1/2" drive, 18"-20" breaker bar for this. It's my favorite tool.

Yes, I used a 1/2" drive with a six-sided 15/16" socket. On a torque wrench.

Re: front diff drain plug, the Craftsman 10mm hex bit I bought has a slight rounded edge at the end. I stopped at local Toyota parts counter and asked it they sold a better tool. "No, but let's see how your Craftsman fits in a new drain plug. Oh, sorry, sold out of those. Hey Mike (technician who just arrived on service side of parts counter), does your 10mm hex bit look like this?" "Nope. I'll be right back." Sure enough, Mike's bit had straight edges at the end. He said he pounds it into the hole before putting a wrench to it.

So I cleaned the skid plate really well and pit it back on the truck. Like Klennop, I'll take it to the dealer and have them do the job before I round off the inside of the fitting. (Reading on torque wrench on latest unsuccessful attempt was 120 lb ft). Will ask them to make sure torque does not exceed spec at 29 lb ft. While there, they may as well grease the 6 zerk fittings on the prop shaft.

 

[sonerick]

Why are you using a torque wrench to try to loosen your drain/fill plugs? Generally using a torque wrench to loosen a fastener is not as effective and will throw off the calibration. You may want to use a dedicated breaker for loosening from now on.

 

[4RunnerFan]

To answer above question, I actually have 3 torque wrenches. A micro-torque and two long ones. One of the long ones is dedicated to measuring torque, the other (from Dad when he was cleaning stuff out of garage before parents moved into a condo) is rusty and comes in handy for its leverage.


FWIW, I ended up taking my truck back to the place that changed out the fluid in Aug/2009. Told them I couldn't get plug out and wondered if they installed it too tight. Got there at 4:00pm; they weren't busy. Showed receipt and the guy said, "No problem. We'll get that loose for you." I had already removed skid plate. Technician put it up on lift and even with his 200 pounds struggled to bust it loose, but it finally popped. I had to insist he take the $5 I slipped him in our handshake when he was done. Nice guy.

So the deed is done. I changed out the fluid after getting home. Torqued both the fill and drain plugs to 29 lb ft after installing new washers. Updated the Service History in Toyota/For Owners website, and took pics pf odometer and of work as it was being done. Pics include front page of today's paper for date reference. Receipts, pics and front page of paper go into 3-ring maintenance binder dedicated to my 4Runner. Time for a beer!

 

[mnormand]

Due to excellent threads like these, I did the two diffs and transfer case last night. No issues. All plugs came out easy. Mobil 75w-90 :bravo:

Next up, maybe the Mass Air Flow cleaning tonight.
Then a Daystar EZ 4corner level kit on the way.
After that, check all four brake calipers for frozen parts.

The hits just keep on comin! :cheers: