Front Differential Leaking Where CV Axles Connect

[JusTheUsual]

The drivers side is leaking worse than passenger side. Like a few drops every night and don't want to run out of gear oil in differential. I have no sounds coming from front end so I don't think cv axles need to be replaced unless that is only seal which I doubt. I asked couple people and they don't know if seal the cv axle passes through if I have to just take out cv axle and replace seal or if I have to take front differential apart because they don't know about this model/make. Chevy guys...

My front differential bolt to check fluid I have never been able to get out in the 7years having this truck and it even started stripping... So I haven't messed with it anymore. Otherwise I would just keep putting gear oil in and not mess with all of this other stuff. I thought about the magnetic drill bit and drilling new hole and putting bolt in but I don't trust myself on doing that.

Ideas, thoughts on all of this?

 

[crunchie_frog]

Yes, there are seals and the axles have to be removed. Just did this yesterday on the driver's side, did the passenger side a few years ago. You do not have to take the differential apart. Getting tools on the seals to get them out is kind of a pain because of the stuff around them. When removing the axle, have the jack stand higher on that side so the differential oil does not drain out when you pull the axle. Then do the same when doing the other side.

 

[koda2000]

I did mine a couple of years ago. Not a technically difficult job, but you have to take a lot of stuff loose. I decided to remove my steering knuckles and front shocks to give myself maximum space to work. I was glad I did, as I found those seals were really hard to drive in. Forget about just tapping them in with a hammer, you'll need a seal driver and a BFH.

Removed tires, brake calipers, caliper brackets, rotors, brake splash shields, axle nuts, disconnected outer tie rods ends, disconnected upper/lower ball joints, front shocks and finally removed the axle half shafts. I'm sure I could have removed less stuff and gotten the job done, but doing all this made removing the old seals and driving in the new ones much easier. This is one of those jobs that might be easier paying someone else to do.

BTW, I also learned that AutoZone's parts lookup lists the wrong seal for one side (they're different left & right) and the only auto parts store that had the correct seal in-stock was Car Quest. There's also a dust/water seal between the axle and steering knuckle (at the hub bearing) which can come apart and is hard to source. I repaired mine with RTV.

Have fun.

 

[JusTheUsual]

Thanks for the info and not looking forward to this. I am thinking about trying to find a place to try and take out that stuck/sort of stripped bolt in diff. for checking fluid so I can just keep putting fluid in diff. until I decide to do these seals. I only have advance auto parts and autozone around here and never heard of carquest store for those seals

 

[crunchie_frog]

Rock auto has the axle seals 710428 and 720429.

 

[koda2000]

Thanks for the info and not looking forward to this. I am thinking about trying to find a place to try and take out that stuck/sort of stripped bolt in diff. for checking fluid so I can just keep putting fluid in diff. until I decide to do these seals. I only have advance auto parts and autozone around here and never heard of carquest store for those seals

IDK if AutoZone ever fixed their computerized catalog error. I did tell them about it. CarQuest may be a regional chain, but there was one in CT when I lived in the northeast. Advance and RockAuto would probably show the right seal, but I prefer to buy local for small parts like seals, rather than wait & have to pay for shipping. Besides, I like to hold the part in my hand and compare it before buying. RockAuto might even charge you double shipping because the seals could conceivably ship from different warehouses. That's something I don't like about RA, and it happens often.

If you do take everything apart, it would be a great time to change your ball joints and tie-rod ends as your 3/4's of the way there.

 

[C420sailor]

It's not a bad job. Also, polish the CV axles where they contact the seals. A ridge tends to form over time.

My poor diff is leaking slowly from just about every seal. It runs through only about 7oz of fluid every 15k, so I just top it off now and then. I'll replace the whole diff when the gears/bearings start to eat themselves.

 

[JusTheUsual]

Whats the gear oil numbers fluid to put in? Thursday I'm going to try heating that check fluid bolt on differential. It isn't aluminum right? So I can heat it up with torch? and also I need to buy a new bolt if I can get that one out if anyone has the numbers for that bolt. Im buying gear oil and the bolt at advance auto parts tomorrow for thursday

 

[koda2000]

No it's a steel plug in the iron housing. I think the front diff just calls for 80W90 gear oil. The rear is full synthetic 75W140 with Ford friction modifier if an LSD. If you can't get the fill plug out, why do you need a new one? Have you tried an impact wrench? Not a great area to use a torch, too much stuff that can catch fire.

 

[JusTheUsual]

Last time about 3 years ago is when I last messed with it. I've tried getting it out since I've had vehicle for about 7years now. Last time I started stripping it with a ratchet which is very hard to do and I was cranking on that ratchet so hard. It's not stripped bad but ratchet would spin out of it so it is partially stripped and hoping torch would heat it up and take it out. Oh I only have a 1/2" craftsman c9 cordless battery operated impact wrench. I love it

 

[lorraine1]

i would take it to a garage and let them weld a socket extension to it .then put in a new oil plug

 

[JusTheUsual]

I went to advance auto parts and they cant even look up on their computers what front differential gear oil is but did show for the back and no bolt listed. Went to autozone they listed front gear oil 80 90 but they dont list bolt either. I need to find that bolt

 

[koda2000]

I went to advance auto parts and they cant even look up on their computers what front differential gear oil is but did show for the back and no bolt listed. Went to autozone they listed front gear oil 80 90 but they dont list bolt either. I need to find that bolt

Assuming the front diff plug is the same size as the rear, I may have one available soon. I have a used rear diff being delivered ETA tomorrow. I shouldn't need any parts off my old diff (including the fill plug). You might even be able to find a suitable plug at a plumbing supply as it's an NPT thread. It's not really something that's unique to automotive application.

 

[JusTheUsual]

Yeah you just made me think maybe a junkyard to get one if im lucky enough to find one and get it out unlike mine. I just wanted it for tomorrow because my bros house is like 20mins away and away far from anything being his house is out in the woods so after I get it out I don't know. I just wanted it before I go there. Maybe even if im lucky enough to get it out I'll just put old one back in for a day so I know it wont be hard to take out like it is now and get another one to put in but I just wanted a new one so no troubles from it

 

[koda2000]

Yeah you just made me think maybe a junkyard to get one if im lucky enough to find one and get it out unlike mine. I just wanted it for tomorrow because my bros house is like 20mins away and away far from anything being his house is out in the woods so after I get it out I don't know. I just wanted it before I go there. Maybe even if im lucky enough to get it out I'll just put old one back in for a day so I know it wont be hard to take out like it is now and get another one to put in but I just wanted a new one so no troubles from it

I suggest you put some anti-seize on the threads of the plug (old or new) to stop it from locking up again. It doesn't need to be super tight, as the threads are tapered and tighten as the plug goes in. Just make it tight enough so it doesn't leak. If you go to a salvage yard, I'm guessing a plug from any mid 90's to mid 00's Ford will be the same size.

 

[rb142]

Pretty sure the front plug was smaller than the rear one. But Jeeps with the Dana 30 in the rear would be another plentiful source of the plugs. As mentioned, you can likely also find one on the plumbing aisle of your local hardware store.

 

[JusTheUsual]

Put a hand torch(propane bottle torch) to it for a few seconds and came right out. So didn't tons of gear oil... I was like how the hell is there that much in there with it leaking. So I was quite surprised about plug coming right out and gear oil leaking out of it from pulling plug. The gear oil was totally grey and some air in it. And here I was worrying there was no gear oil in it from leaking and never able to get plug out to check it. Let what would ever drain out of it and put in new gear oil. My bro said probably some air got in from seals but that gear oil in it had to be changed with it being grey as grey with some air in it. Put anti seaze on plug and put it back in. I didn't end up hardly stripping from what I thought I did before. So i'll just keep a eye on plug and fluid.

Oh with it dripping and fluid all over where the cv axles connects and it all wet around it I think maybe just the viscosity or it being oil it just spreads easily so it looks worse than what it is and that's why there was a lot of gear oil in it still

 

[rb142]

Those plugs often have thread locker on them from the factory. That's why the heat made it come out easily.