: How To: 2007 Front diff fluid change

11-08-12, 12:16 PM

This is my first post (I believe), but as I couldn't find any info on this after scouring the internet, I took some pictures of my experience. I didn't cover the whole thing in pictures, but I took a few shots along the way.

Hope this is helpful to someone!

18mm socket (shallow 6-point) or wrench
13mm socket or wrench

(2) qts 75w90 gear oil (I used Mobil 1, $10.99 x2 qts at Autozone)
>2ft clear tubing
Drain pan

Hand or electric pump
Wheel ramps

I started by driving the front on wheel ramps. Once you crawl under the car, you will be able to identify the front differential as seen here:


It is important that you remove the fill bolt prior to draining. It may be stuck, leaving you with an empty differential and no way to refill it if you start by draining.

I sprayed some WD-40 on said fill bolt in the absence of PB blaster. If yours is as difficult as mine, and you lack a handy pipe or breaker bar, you may find the following method useful. It has worked for me in countless applications.
As seen above, simply use a large wrench around the end of your ratchet handle. The benefit is twofold; greater leverage and accommodating angle.

Once the fill bolt is removed, position your drain pan appropriately and remove the drain bolt, as identified below:

Your drain bolt may look something like this:

Make it look like this:

Once the diff is finished draining, reinstall the drain bolt and tighten.

To refill, I strongly suggest you acquire a pump of some sort. I punctured my first bottle by trying to simply squeeze directly in to the fill hole. I then ended up taking a small length of plastic hose and running it from the fill hole up to the area between the fender and engine. I simply twisted the hose on to the tip of the gear oil bottle, turned it upside down, punched a hole in the bottom, and let gravity do the rest. This method is PAINFULLY slow, to the tune of well over an hour. GET A PUMP!

At somewhere between 1.5-2 qts, you should be level with the bottom of the fill hole. You can periodically check the level by using your finger as a dip stick.

Once you are satisfied with the level, set your remaining oil aside, reinstall the fill bolt, and tighten.


11-08-12, 12:38 PM
Very nice write up!!

Mods: Sticky please. ;)

11-08-12, 03:25 PM
I second that...

11-08-12, 04:06 PM
Funny, last night I was on YouTube trying to figure out how to do this...thanks for the info!!!

11-09-12, 10:36 AM
Funny, last night I was on YouTube trying to figure out how to do this...thanks for the info!!!
And the night before I was doing the same thing...

Anyway, I'll be moving on to the rear diff next. That will be followed by spark plugs, transfer case, transmission fluid exchange, trying to hunt down an annoying squeak in the rear suspension when it's compressed a certain way, and perhaps a brake flush. Those will be done in no particular order.

Please let me know if any of these are of interest, or better yet if you've done them and can provide insight.

11-09-12, 01:15 PM
I actually just bought fluids a couple days ago for doing the diffs, transfer and tranny. Seeing this will help spur me into doing it.

11-09-12, 08:58 PM
do you have to add any additives to the gear oil? My old 06 I had to add LSD additive to the gear oil

11-09-12, 10:28 PM
after you do the spark plugs let me know how you feel. I am really interested in the rear plug on the passenger side. What a pain in the ass that was!! Aleast for me with no lift!

11-09-12, 10:59 PM
Thank you for this write up. Very informative!! Its been added to the Sticky at the top of the page.

11-10-12, 09:30 AM
after you do the spark plugs let me know how you feel. I am really interested in the rear plug on the passenger side. What a pain in the ass that was!! Aleast for me with no lift!

That plug was no fun. I actually dropped one in the process so I had to get another one. I think I could replace it pretty quickly now but of course it's not needed for at least 50k

11-10-12, 11:15 AM
Thank you! What fluid did you use and at what mileage interval are you using?

11-11-12, 09:49 AM
interested in the tranny and transfer case oil change!!

11-13-12, 01:13 PM
Front diff done today. Extremely easy. If you can change your own oil, you can definitely do this. Removing the fill bolt was the hardest part, had to use a hot wrench for a little bit and it popped loose. Luckily just needed my MAPP torch and not my oxyacetyl. Ended up putting nearly all of the 2qts back in, about an inch of oil left in one bottle. Rear diff next, then transfer and eventually the tranny

01-29-13, 10:53 PM
What is a "hot wrench"?

01-30-13, 06:11 AM
What is a "hot wrench"?

A torch

01-30-13, 07:33 AM
A torch

Always good to have in your arsenal next to your BFH.

01-11-14, 05:36 PM
Bolts are 24ft lbs

01-12-14, 11:03 PM
Great write up. Thanks. Looking forward to the next project.

01-13-14, 10:14 PM
Good write up. The rear diff is a little more of a pain. It's difficult to get your hand and a wrench on the upper bolts if u got bigger hands. I recommend new oem or felpro gasket. Transfer case is a breeze just like the front diff. Dropping the pan on the tranny sucks but I did it. I guess u can reuse the gasket here but I bought a new felpro for $5.

03-22-15, 03:44 PM
Btw, I'd advise you to place a little antiseize compound on the filler bolt threads. Will make for a much easier removal next time.

Nice Ride
03-27-15, 12:46 AM
Did you do the filer when you did the Trans? Did you have to loosen the exhaust to get the pan out?

03-29-15, 11:01 PM
Never had to drop the exhaust.
Pan is a tight fit, but not a real big deal.

10-19-16, 10:29 PM
Do you need limited slip lube in the front diff ? Since my caddy is AWD i know the rear diff you need limited slip lube with the gear oil.

10-20-16, 10:01 AM
I don't believe you need that in either the front or the rear.

Here is a table from the 07 owner's manual.


I know I didn't put any friction modifiers in when I changed my fluids last year.

Good luck.