Couple Pics of Front & Rear Diff Fluid Change

[Freyguy]

I have a 2002 2500HD Silverado CC 4x4 6.0L with about 61,000 miles on it, so I figured it was about time to change the fluids in it. After searching and reading all the posts I could find, I went ahead and got the stuff to do it. I thought I'd take some pics so the guys that haven't done this yet had an idea of what was going on. I decided on using a synthetic gear oil for both front and back, and decided against the expensive grape juice for the rear. I went with Mobil 1 since I had a store credit at Pep-Boys, otherwise I would have used Amsoil. In this pic you can see the 6 quarts I bought (2 front, 4 back), the new front diff cover that is compatible with synthetic, and the tube I picked up to help me fill the diffs.

 

 

Here's a quick pic of the rear draining out. You can see the fill hole on the left and the drain on the bottom. Both removed with a 3/8" ratchet.

 

 

I was rushing a bit and didn't take too many pics, but here's one of the drain plug from the front diff. You can see the massive amount of metal shavings and the "baby poo" color of the oil. Sorry for the poor focus, I haven't figured out close-ups yet.

 

 

Here's a pic of the plug cleaned off just so you can see how small that magnet is under all that junk.

 

 

Here's a side by side of the new white front diff cover next to the old black diff cover. Not much different here. The parts guy at the dealer told me that I was nuts when I asked for a white one, and even had a tech come out. The tech said he never seen a white one and I just told him to look up the part and bring it to the counter. Sure enough, it was white. This was the majority of the work removing the old and installing the new one. It has a nut on it, so it looks simple, but it's far from it. The nut is a 24mm, but the nipple for the breather tube is so long, a regular socket won't fit on it with a wrench. You need a deep 24mm, but who the heck has one of those handy? A combination of a monkey wrench, pliers, channel locks, and needle noses were used to remove and install this piece. Did I mention it was a pain?

 

 

Here's a pic of the back of the covers just so you can tell the difference if your color blind or something.

 

 

Overall not a bad do it yourself project at all. The back oil wasn't in too bad of a condition and still smelled a little "grapey". I don't tow heavy loads too frequently, so I didn't imagine it was bad. The front on the other hand was terrible. I wish I did it much sooner since I use four wheel drive quite frequently. Next I'm gonna switch out the transfer case to synthetic, the tranny to synthetic, and then the engine oil next time I need a change. I think I'm past the trade in point on this truck, so I wanna make it last a long time. I hope these pics helped someone and if you have any questions, fire away.

[bigdogs]

Interesting color on that "white" one. The one on my 03 2500HD is actually white (well was not sure how dirty it is now). I had my front diff fluid swapped at the dealer per the TSB for cold climate areas, so it has the grape juice. The rear I did myself at 5K miles and put in Amsoil Series 2K.

[MR.GOODWRENCH]

HEY

were did you get that niffty hose and how well did it work? I am always trying to find a way to get fluid into diffs without spilling half of the s**t on the floor.

[bigdogs]

Me too, the pump I got did not fit the Amsoil bottles (I understand now they have one for their bottles). Those suction guns don't work well for me either as they usually leak. That hose thing might be the best solution yet..

[Metz Motorsports]

Ok explain the front diff cover thingy. Is this a part that needs replaced when the fluid is changed? I guess I assumed when it came time for that service it might be as simple as the back, or use the evacuation pump at my buddies shop if it didnt have a drain. Thanks for the help...

[bigdogs]

Actually it is not a cover but a vent. The white one is synthetic oil "compatible". The suction gun I was talking about looks like a big syringe for filling the diff case. In my experiece they always leak around the plunger rod. The hose that Freyguy had looked like a good idea and easier than even the little pumps.

[Metz Motorsports]

So that part doesnt need changed unless synthetic is used?

[Mighty HD]

I have ran mobil 1 and havent changed it yet on my HD......hmm...should i?

[Black02Silverado]

Awesome post and pics

 

Thanks, that will help out those that just joined the forum. I put the AMSOIL Series 2k in both of mine at 8k miles. I currently have 56k. I have the black vent and so far so good. No leaks noted. I think there are several others on here that have switched over to synthetic in the front diff and didn't change out the vent with no problems either.

[tmf6902]

I'm a little confused...can someone explain the "Synthetic" plug thingy....I'm nearing 50K and I figure I am gonna be doing this service to my truck in the spring.

[Shooter_va]

What is the part number for the new (white) vent plug?

[MS3DALE]

What is the part number for the new (white) vent plug?

 

Part number is 12479390 with a list of $21.98

[Freyguy]

Thanks guys!

 

The hose was right next to the gear oils at Pep-Boys. They had a couple variations of it, but that was the nicest one. It was only $3.99 so I couldn't go wrong. It worked out great due to the lenghth of it, and the on/off switch. I had plenty of room in the front and back to keep it up high. The plug on it is dang near perfect size too, so I had very little leaking. The only hard part was that it was hard to get air up it so the oil kept flowing, so every once in a while i had to bring the bottle down to get some more air in so I could keep squeezing. Looking back I coulda just poked a hole in the bottle since I knew I was gonna use all/most of it.

 

The white vent (the dealer called it a cover) is reccomended for synthetic oil. Something about the seal in the old black one made them say that it wasn't compatable, and I think some may have said it leaked. You can also see that the old one used a plastic piece for the inside of the vent and the new one uses a metal one. 2002 was the last year they used the black vent, and all 2003 and up have the new white one. I just figured everybody was changing it, so I went ahead and did it. Now I kinda wish I read more because I could have saved some serious time not having to figure out that dang thing!

[Chevyfreek]

Good post, I did all of this to my 01' as well around the 60,000 miles mark. Changed out the vent cap and put in Amsoil synthetic 75w-90 in the rear and 80W-90 in the front. Also put Amsoil synthetic in the transfercase and transmission. I just did the filter change and added about 5 quarts to the trans not a full flush. Can't go wrong with the synthetics...

[blue2kzr2]

It might not be a bad idea to pull the cover off the rear, despite there being a drain plug. My brother is having his axle re-built in a new housing due to one bad bearing. He had his first fluid change done at Jiffy Lube, this one went to the dealer. Jiffy Lube didn't pull the cover, dealer did and found problems. He's VERY happy it's under warranty still, the housing wouldn't be cheap...