Changing differential fluid - A step by step "HOW TO"

well I found a level spot and opened the fill hole...NOTHING came out...so it took almost 4 qts and isnt overfilled...What's wrong ?

shoud I drain it all and start over ??

do I need to be worried ?

 

I fail... I got all the stuff I needed.. get under the truck to loosen the fill bolt.. thing is on harder than (insert joke here..).. Even splayed with some penetrating oil.. no avail..

Ended up starting to round the bolt..

what now?? Get a new bolt from the dealer??

 

Well, that is why I'm conflicted, it held 3 3/4 and didnt come out of the fill hole....I'm trying to detrmine why.....

so should I just dump and start all over ( hate to waste all the Mobil 1 I put in there but I DONT want a differential issue either)

I'm asking the experts.....

 

ok, guess that's the answer....I'll try to do it on level ground this time....

 

don't worry about being on level ground. just put in 3 qts and your additive (if you have the LSD) and you are done.

 

Wow.. Success... Seriously feeling better about getting this done rather than the spark plugs, especially with the trouble the fill plug gave me. Fill plug was stuck, starting to get rounded, and probably had over 100 lbs of torque. The drain had less than the oil drain plug. Bought some pb blaster.. Got a vise-grip as tight as possible, and used a hammer. 10 mins and a couple adjustments later. Loose...

Dealer is out of the fill plugs. Could have ordered, but went with the drain plug instead. Now I have twice the metal shaving-magnet power.lol... May go ahead and order the fill from Toyota and change it out. Bought 2 drain plugs just in case I ended up rounding the drain as well.

My one small additional advice is to find yourself a 24mm 6-sided. Not sure if it would have made a difference, but my set came with a 12-sided. Because there is a fraction of play, started slipping and thus rounding the bolt.

Also if you are doing for the first time, hit it with some penetrating oil just in case. Never hurts. I shot it with wd-40 after it started rounding. Now I got me a can of pb blaster and will hit bolts with that from the start.

Don't know, but truck did just feel smoother after the change.

Btw: Lucas oil with dealer GM additive.

 

Well, I got the old stuff ( overfill) dumped and re filled to 3 qts....so finally done with that stinkin stuff ( at least for a little while)

my truck held 3 3/4 ( used a graduated bucket to verify) and still didnt seep out the fill hole...Just an FYI ( cause I know some people use that as a way to measure what is in there)

Thanks to all who helped...

 

One suggestion would be to check your drum brakes. if you put 4 q and still did not overfill that means oil is going somewhere where it should not go.
There is possibility your seal is leaking and I would check that first.

 

Rule #1 never use 12 sided socket on the fill plug

 

Hmmmmmmm Interesting.....would it be leaking out of the drum brakes ? I'm not sure I could take them apart. ( the rear brakes)...but as I said it's @ 3 qt's now

should I be worried ?

 

only if you see diff oil on the ground. if not, you are good to go. just keep an eye on it. check once a week to see if any rear components are wet with oil

 

Did it overfill from the fill plug? If not you are not at the level required.
Honestly I would put as much of oil as it needs to get to fill plug or until finally leaks out from somewhere.
there are 3 seals that hold oil in. One on the pinion, and two on the axles. Your truck is 06 DC LB which means you should have Limited slip and hence take even less oil. (you need additive with limited slips) So if you put 4qt and still was not leaking there are only few possibilities.
1. Your truck was down the slope at quite extreme angle.
2. You miscalculated/miscounted 4qt
3. One of the seals is leaking and oil is going somewhere else first.

First two you should know

last one may need to be checked.

 

I just wanted to confirm that ONLY the 2005-2008 Sport models will need the LSD additive? I have a 2009 Sport and I believe the LSD uses the brakes? If this is the case, when do you guys think I should change it: 30,000 or 60,000? Should I go with a synthetic (I know that the 2008 Sport models and prior do not respond well to synthetic). Any other pointers?

Thanks

 

How he is going to overfill differential when truck is park level and has fill plug removed? (unless he is using the breather to fill up the diff)
My concern would be that oil must be going somewhere. Its a bucket so if bucket is not filling up my guess would be there is some hole on the bottom of the bucket. If there is a hole then level will go down as soon as he puts the plug back, and if level is low at the R&P, then he is going to smoke that thing up.
If that was my truck I would be very curious where that oil is going, since it is possible that one of his axle seals is not holding up.

 

X2. 12 sided sockets are not for heavy duty work.

 

well, as I wrote I have 3 qts in there now ( used a graduated bucket for accuracy.

It doesnt seem as 'smooth' as it did when driving now and I do have Synthetic in there ( mine doesn't have the LSD sticker) so I presumed it was a open dif ( no button inside the truck either)

Now I'm confused AND worried....this was purchased from a graler 2 weeks ago ( certified)

I drive TOO many miles to have it fall apart already