Help! Rear Diff. fill plug won't budge [Archive] - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

: Help! Rear Diff. fill plug won't budge


Grizzledbiker
04-25-2010, 08:30 AM
:cool:It appears to be a case of a steel plug installed in an aluminum case. Don't know if they used antiseize or not. 140k miles. Bought it used a couple of years ago. Decided I'd better change rear diff fluid. But, I can't get the dang thing to budge. It's not reverse threads is it? As it is I broke a 3/8 adapter I used on my long 1/2" breaker bar trying to get it to break loose. Thinking of running over to Harbor Freight and grabbng one of those air impact wrenches like I use at work. Anyone experienced with this problem? Chime in please! (I was smart enough not to drain the oil first, still in there. So I'm not entirely stuck in the garage, yet.)

JBMallory
04-25-2010, 09:20 AM
well, your differential isn't aluminum, it's steel, unless the plug is in the cover, and that's aluminum...

DO NOT use an impact to pull that plug unless you know what you're doing, which I'm going to guess you don't, since you used an adapter instead of a square plug socket, which are two VERY different tools...

start with a quality 1/2" ratchet or breaker bar, with the correct size, quality pipe plug socket, and you won't have any problem...

Trailblaze_2002
04-25-2010, 09:35 AM
IT will come out i just did this about 2 weeks ago and it was in there but it did come out. If it helps mine has 194,000 miles on it. So i'm sure yours will come out. Good luck with it. I wouldn't try an impact just yet for the sake of not messing up the plug. You can just use a 1/2 to 3/8 adapter and it should come out that way.

davelowe
04-25-2010, 10:23 AM
:iagree: stay away from impacts on the diff

drolds72
04-25-2010, 10:29 AM
make sure the recess of the plug is good and clean, so no matter what you put in there, it will seat to the bottom, and not strip the plug. I had to use an impact with a 3/8" extension the first time to remove mine. You can also try heating the case around the plug, and letting it cool a few times, then attempt to remove when case is hot.

drolds72
04-25-2010, 10:34 AM
:iagree: stay away from impacts on the diff

Exactly, why?

I have damaged/stripped/broken more bolt heads with constant steady force, than I ever have with an impact. If the plug recess is clean, and the socket/extension seats to the bottom, that plug will zip right out. Heat and shock are particularly effective in overcoming corroded parts, especially when patient enough to let a penetrating oil such as PB Blaster do its thing.

the roadie
04-25-2010, 10:43 AM
...an adapter instead of a square plug socket, which are two VERY different tools....What JB says is very true, and ignored by most home mechanics. I used an Craftsman adapter my first time, and broke it right away. Got it replaced for free, but learned the lesson and researched the problem. The right tool is a lot beefier, radiused, and doesn't have any of the weakening that's needed to install a spring ball as most adapters.

Grizzledbiker
04-25-2010, 11:17 AM
:cool:So where exactly do I procure said pipe plug removal tool adapter? Menard's? Lowes? Not available at my local autozone. They do have impact grade 1/2-3/8 adapter. Harbor Freight is also nearby. I'm tempted to grab an air impact wrench simply because I work with them all the time. And have a compressor more than capable right here in the garage. I do work in a pump factory. http://www.blackmer.com/ We do use plugs very similar to these all the time every day. Not sure what the assembly guys use to install them though. Sure ain't no hand tool.

Trailblaze_2002
04-25-2010, 11:26 AM
:cool:So where exactly do I procure said pipe plug removal tool adapter? Menard's? Lowes? Not available at my local autozone. They do have impact grade 1/2-3/8 adapter. Harbor Freight is also nearby. I'm tempted to grab an air impact wrench simply because I work with them all the time. And have a compressor more than capable right here in the garage. I do work in a pump factory. http://www.blackmer.com/ We do use plugs very similar to these all the time every day. Not sure what the assembly guys use to install them though. Sure ain't no hand tool.

You can get it at most any parts store :confused: I got mine at advanced auto. Lowes or Mernard's should also have them.

Grizzledbiker
04-25-2010, 11:38 AM
Ok, I'll go poking around and see if i can find one. If not I'll wait till tomorrow and borrow something from work. Problem is I live right smack dab in the middle of heavy rust belt where the roads are coated with a heavy layer of salt almost on a daily basis especially in the early mornings so commuting idiots won't get killed drivng 70mph on wintry icy roads. So yeah there is some white stuff along with rust around bolts and fasteners on the underside of my TB. Regardless of weekly under carriage car washes.

Grizzledbiker
04-25-2010, 01:59 PM
:cool:Wild goose chase this rainy Sunday morning looking for Roadies said ball less adapter. Sorry guys but locally Advance doesn't have it, NAPA doesn't have it, Autozone doesn't have it, Harbor Freight doesn't have it and my last vist clear across town to Lowes and they don't have it. Spent some time in each of these stores and they all scratched their chins, heads or other body parts and even looked up in their books. Sorry! was all I heard. So, Mr. Roadie, how about a bonafide part or item # from an online source and I'll mail order the darn thing. Doesn't need to be done right now anyway. In the mean time I'm going to hit it with some PB blast, let it soak an hour and then try to carefully use an impact wrench with a 3/8 socket extension since that's all I have. Maybe I'll get lucky and it'll finally break free and zing right out. No doubt how it was installed on the assembly line in the first place.

later,
Griz

markarock
04-25-2010, 02:37 PM
The secret to any rust penetrating product is TIME, and lots of it.

In my experience neither PB Blaster nor any similar produce will do anything in an hour. The proper time frame for these products is measured in DAYS, and sometimes even WEEKS. In one particularly troublesome situation I soaked the tubing ends/flare nuts/threads every few days for a MONTH--it was helpful that the "shoulder" of the flare nuts acted like a little well and held a drop of fluid right where the tubing was rusted to the flare nut. Even then 2 of the 8 weren't ready to give. I had to get out the oxy-acetylene torch--my "hot wrench". Unfortunately the tubing was just rusted too thin and I ruined the ends of those two tubes.

These products do work, but not in the time frames most people want or need them to work in. They also need to be regularly reapplied over time for best results. They don't work very well (indeed they don't work at all!) once they've dried or evaporated.

Just my experience.

JBMallory
04-25-2010, 03:16 PM
:cool:Wild goose chase this rainy Sunday morning looking for Roadies said ball less adapter. Sorry guys but locally Advance doesn't have it, NAPA doesn't have it, Autozone doesn't have it, Harbor Freight doesn't have it and my last vist clear across town to Lowes and they don't have it. Spent some time in each of these stores and they all scratched their chins, heads or other body parts and even looked up in their books. Sorry! was all I heard. So, Mr. Roadie, how about a bonafide part or item # from an online source and I'll mail order the darn thing. Doesn't need to be done right now anyway. In the mean time I'm going to hit it with some PB blast, let it soak an hour and then try to carefully use an impact wrench with a 3/8 socket extension since that's all I have. Maybe I'll get lucky and it'll finally break free and zing right out. No doubt how it was installed on the assembly line in the first place.

later,
Griz



It's called a pipe plug socket. Ask for it by name, like I mentioned it, and you will be sold what you need. You need a 3/8" male pipe plug socket, and that will do the trick... PB'laster, maybe a little heat, but it will come out with the right tool


snapon.com

ppm412a

that's the ticket

Grizzledbiker
04-25-2010, 03:20 PM
Right! How true. It takes patience. So far I've broken two standard 3/8" extensions along with a 1/2 to 3/8 adapter in the crazy effort to try to remove this thing. Even with an impact wrench. It won't budge. Probably should attack this thing after it's been driven and warm after work tomorrow. A bit cool and rainy today. I see CFC has some sort of "freeze" product that claims to be designed specifically to remove stubborn fasteners.

Grizzledbiker
04-25-2010, 03:31 PM
I did specifically ask for that. no go. Please give me a link to an on-line source.

bartonmd
04-25-2010, 03:31 PM
well, your differential isn't aluminum, it's steel, unless the plug is in the cover, and that's aluminum...



FWIW, The TB diffferential housing is aluminum... Aluminum hog head, steel cover, steel axle tubes.

Mike

the roadie
04-25-2010, 03:32 PM
I got mine at HF years ago IIRC. Sorry you had to go on a bug hunt. Now I'm worried it's discontinued, since I found a set but it doesn't include our 3/8" size anymore.

Here's the Snapon picture

http://buy1.snapon.com/catalog/OBJECTS/49700/49648.JPG

Northern Tool and Sears list the Sunex SUN2841 kit

http://www.northerntool.com/images/product/images/153962_lg.jpg

SK Tools makes them, individually and in sets. 41242 is the 1/2" drive, 3/8" male size. $7.50 or so. Google for it or find a SK retailer.

Grizzledbiker
04-25-2010, 03:50 PM
thank you

Grizzledbiker
04-25-2010, 05:50 PM
Pep Boys don't have it. Car Quest might but they closed early today. On-line tooltopia wants $6.24 but then they want $9 shipping! I'm thinking of ordering their grey pneumatic 11 pc set. It's $28.46 plus $8 shipping.

drolds72
04-25-2010, 06:10 PM
Salt is what I had to deal with. MN uses a ton of it. I could not get enough of a swing with the breaker bar with the height the jackstands provided. Took me longer to fill the compressor tank than it did to get the plug out. When I replaced it, I used teflon thread sealer- was able to use a 16" 3/8" ratchet every time after that. Like I said before, key is to clean out plug recess with a pick or something and make sure whatever you stick in there seats to the bottom. That special socket with the sharper edges with just strip it faster if its not all the way in.

jacob789456
04-25-2010, 06:15 PM
Ours is so rounded, chipped, stripped, etc... from trying to get the plug out I have given up and am going to have to take it to a shop and have them tap a plug into the rear cover.

Grizzledbiker
04-25-2010, 06:38 PM
Ordered both the 1/2" and the 3/8" drive S-K 3/8 male pipe plug sockets from tooltopia. Shipping was $8 for the both of them. Total delivered price is around $20. I'll go out in the garage now and pick up my toys. Tackle this again after tools arrive. Suckers better not break on me.

JBMallory
04-25-2010, 07:16 PM
FWIW, The TB diffferential housing is aluminum... Aluminum hog head, steel cover, steel axle tubes.

Mike

I had to go check, who's a-hole idea was that?

bartonmd
04-25-2010, 07:23 PM
I had to go check, who's a-hole idea was that?

Yep... I didn't believe Roadie when he first said it, so I went and looked, myself... I had never seen an aluminum center section in a live axle, myself...

Mike

the roadie
04-25-2010, 07:37 PM
AAM - American Axle & Manufacturing. Gifted the world with our insane 7.25" front diff with an aluminum housing as well. Good for grocery getters - more difficult to trust offroad in 4LO.

I hadn't read this press release for a few years, back when I was researching WHO designed the insane ring gear size. Now I see it again, THESE ARE THE GOOFBALLS responsible for the high breakage rate on the splined disconnect as well! Not GM.

"Lifetime lubrication" INDEED. :hissy::no: :weird: :suicide: :bonk:

http://media.aam.com/index.php?s=43&item=535

American Axle & Manufacturing Introduces a New Front Axle Module

PRNewswire
DETROIT

American Axle & Manufacturing Holdings, Inc. (AAM) which is traded as AXL on the NYSE, today introduced the Integrated Oil Pan (IOP) front axle module with electronic disconnect which will be used in the all-new 2002 General Motors mid-sized Trailblazer, Envoy and Bravada sport utility vehicles. The IOP front axle module will be on display at the 2001 SAE World Congress held in Detroit, March 5-8, 2001.

"The selection by General Motors of AAM's IOP front-axle module for its new SUV program demonstrates GM's continued confidence in our people, technology, products, processes, systems, and performance," says AAM President & Chief Operating Officer Joel D. Robinson.

The IOP front axle module was designed and developed by AAM engineers to meet customer needs for improved performance, durability, weight reduction, packaging, operating temperature control, and vehicle system electrical interface compatibility and control.

Torque from the vehicle driveline system is transmitted to the IOP front axle, halfshafts, and ultimately, the front wheels, when the vehicle is engaged in four wheel drive. When the vehicle is in two wheel drive, the electronic disconnect uncouples the front axle from the driveline system to allow for reduced rolling friction. The IOP uses a precision electrical actuator to engage the shift mechanism and provide feedback to the vehicle's driveline control system -- indicating the vehicle is in four wheel drive.

The IOP provides a central point of engagement that, along with the transfer case disconnect, reduces the number of rotating parts. The electronic actuator provides consistent "on-demand" engagements over the life of the vehicle. Both features reduce vehicle system parasitic losses (inefficiencies) found in traditional four-wheel-drive systems.

"The IOP front axle module includes innovative and evolutionary design improvements over current axle designs which yield significant improvements in vehicle performance, ease of manufacturing, and driveline durability," says Daniel V. Sagady P.E., vice president, Engineering & Product Development.

The IOP front axle assembly features a cast aluminum housing and die-cast aluminum shift fork, lifetime lubrication, enhanced durability seals and 15 new components. It is produced using a state-of-the-art automated manufacturing process at AAM's Detroit Gear & Axle plant in Detroit, Michigan.

AAM is a world leader in the design, validation, manufacture and delivery of driveline systems, chassis systems and forged products for trucks, buses, sport utility vehicles and passenger cars. In addition to its 14 locations in the United States (in Michigan, New York and Ohio), AAM also has offices and facilities in Brazil, England, Germany, Japan, Mexico and Scotland.

Grizzledbiker
04-25-2010, 09:42 PM
yep like I said looks like a steel plug in an aluminum housing. and I doubt they used any antiseize. cause hey, the target customer for these $35k+ SUV's is not going to be changing this oil by themselves in 60K+ miles now are they?

bartonmd
04-25-2010, 10:25 PM
yep like I said looks like a steel plug in an aluminum housing. and I doubt they used any antiseize. cause hey, the target customer for these 35k+ SUV's is not going to be changing this oil by themselves in 60K+ miles now are they?

More than likely, the previous owners took it to an oil change place who checked the diff fluid... More than likely, the diff was hot at this time, so the tech put a hot plug back into a hot aluminum diff, and since Aluminum expands more than steel at a given temperature, the plug got tighter as the diff cooled...

Mike

c good
04-26-2010, 10:28 PM
I took a dental pick to get all the gunge out of the bottom of the plug. Then I ground the radius off the top of a standard adapter. This allowed the thing to go all the way in to the bottom of the plug. Then I put a breaker bar on it. Then used a scissor jack to push the end of the breaker bar up. I let the weight of the car against the lift of the scissor jack to break it loose. You could use any type of jack. Before that, I'd soaked it with PB blaster, tried some heat, an impact wrench, to no avail. The power of the jack seemed to be the key, along with using a good quality adapter that seated all the way into the bottom of the plug. HTH c good

Grizzledbiker
04-26-2010, 11:33 PM
I've got a 1/2-3/8 adapter broken from trying that same technique. Except I did not do the dental pick thing nor did I do any grinding on the adapter.

bartonmd
04-27-2010, 08:10 AM
I've got a 1/2-3/8 adapter broken from trying that same technique. Except I did not do the dental pick thing nor did I do any grinding on the adapter.

If you were able to put that much torque on it with that method, I wouldn't be opposed to using an impact on it... Not something I usually tell other people to do, but I've done it with good results...

On my S-10 Blazer, the plug was so rusted away that an EZ-out didn't even work... Ended up welding a cheap 3" extension into it, and using an impact, and it came right out...

Mike

Grizzledbiker
04-27-2010, 06:00 PM
Well guys the appropriate 3/8 male pipe plug socket arrived. So of course I immediately had to try it. I let it soak a few days with PB blast and even tried that CRC freeze stuff. Carefully tried a long breaker bar with an extension and it wouldn't budge. Then got out my 425lbs torgue impact wrench at different settings and it wouldn't budge. (it just hammered the heck out of it. but didn't look too bad.) I then tried the aforementioned breaker bar lifted by a jack technique assuming that sooner or later something would break. Nope. Just annihilated the inside of the plug. fubar! :hopeless This S-K tool is much harder than the plug. So, decided to heck with it and if the rear end does start to really make a lot of noise someday it's probably way overdue to trade it in anyway. I'm done with it. At least I got the transfer case and front diff fluids changed.

- it's been fun, Griz

UPDATE: Now I am considering pulling the cover and drilling and tapping a hole for a fill plug there. Should work ok I would think. Once I drain it I'd better have some way to put some juice back in. Other than that, is it possible to fill this thing through the vent??

JBMallory
04-28-2010, 08:38 AM
you can fill through the vent, but you'll be there all day. Take it to a shop and let someone weld a bolt to the old fill plug and back it out, then put a new plug in with some antiseize

bartonmd
04-28-2010, 08:46 AM
What kind of impact do you have? My dad's got a cheapo Campbell Hausfeld impact is good for ~125 ft/lbs... My freshly rebuilt old school MAC impact is good for... uh... more than that... Every once in a while there's a bolt of something that he can't remove, so he calls me to borrow my impact... Usually zips it right off...

Mike

Hal
04-28-2010, 09:24 AM
UPDATE: Now I am considering pulling the cover and drilling and tapping a hole for a fill plug there. Should work ok I would think. Once I drain it I'd better have some way to put some juice back in. Other than that, is it possible to fill this thing through the vent??[/QUOTE]

You could get a new cover and gasket from parts4chevys.com. Cover = $31.09 and Gasket = $15.46. It doesn't list the plug so you would need to verify if the cover comes with the plug.:m2:

bartonmd
04-28-2010, 04:46 PM
UPDATE: Now I am considering pulling the cover and drilling and tapping a hole for a fill plug there. Should work ok I would think. Once I drain it I'd better have some way to put some juice back in. Other than that, is it possible to fill this thing through the vent??

You could get a new cover and gasket from parts4chevys.com. Cover = $31.09 and Gasket = $15.46. It doesn't list the plug so you would need to verify if the cover comes with the plug.:m2:

so uh... I'm going to go out on a limb and guess you go to an oil change place?

The plug is in the main housing, passenger side, either right above or right below the main casting web (I've got one vehicle that's above, and one that's below, and don't remember which one the TB is)...

He was talking about custom modifying the cover to take a plug, where there was no plug, before.

Mike

Hal
04-28-2010, 05:21 PM
so uh... I'm going to go out on a limb and guess you go to an oil change place?

The plug is in the main housing, passenger side, either right above or right below the main casting web (I've got one vehicle that's above, and one that's below, and don't remember which one the TB is)...

He was talking about custom modifying the cover to take a plug, where there was no plug, before.

Mike
My Bad. I spoke without checking:bonk:. Just used to the fill plug being in the cover. No I don't "go to an oil change place". Never have. I haven't even hit 50K on mine yet.

bartonmd
04-28-2010, 05:51 PM
My Bad. I spoke without checking:bonk:. Just used to the fill plug being in the cover. No I don't "go to an oil change place". Never have. I haven't even hit 50K on mine yet.

Used to have a Dodge, with the rubber pop-in fill plug on the cover? (or a Dana with threaded fill plugs in the covers)

It's good to check the fluid level in the front diff, rear diff, and transfer case every oil change... fill plugs on these aren't just for filling... They're also for checking fluid levels...

Mike

nh484000
06-28-2010, 12:20 AM
I just changed my fluid and had a heck of a time getting the fill plug out. My solution, I heated the housing up around the plug with my torch, came right out. Hope this helps someone in the future.

laguardias5
06-30-2010, 02:31 AM
I'm going to tackle this project soon. Ugh!

fatguy350
02-02-2014, 02:24 PM
My fill plug is stuck and now rounded out. Thinking about welding a nut onto the plug to get it out. Any thoughts?