rear diff

[Nizar]

hi
am thinking to change my rear diff fluid but am thinking just to remove the plug and then take all the fluid out with a pump is this ok ????

 

[fishguy1123]

If you don't have a drain plug I believe you should pull the rear cover off and do it that way. Sucks, but probly your best bet.

 

[navigator]

Ideally you would remove the cover as mentioned.
I understand the gasket should be re-usable.
I didn't realize it was re-usable and I pumped mine out like you are mentioning.

 

[Nizar]

If you don't have a drain plug I believe you should pull the rear cover off and do it that way. Sucks, but probly your best bet.

am afraid to break any part or bolts or to damge the gasket that why am thinking of using a pump ..i hope i have a drain plug thanks

 

[fishguy1123]

The "newer" ones don't. Not sure what yrs it was. If you have them they are 3/8 square plugs. Like on a 3/8 ratchet. Just changed mine a few weeks ago but mine is an 02. If you have a drain plug make sure you break the fill plug loose first! Then the drain. My drain was a pita... but you should be able to get it done even if you have to pull the cover. Be carefull when removeing the bolts though. They have loctite on them and you may need to work them back and forth to get them out with out breaking them.

 

[jbones]

I have no plug and did mine a few weeks back. Here's my write up with PICS.

http://gmtnation.com/f79/trailblaze...diff-drain-fill-without-drain-plug-pics-1179/

http://gmtnation.com/f79/no-rear-diff-drain-plug-my-08-ls-1069/

If I recall another member has a write with PICS as well.

 

[RayVoy]

Nizar, I only have one caution.................. be sure the fill plug can be removed before you pull the cover and drain out the oil.

An empty diff, that can not be filled, is not a good situation.

 

[Mark20]

And you want to pull the diff's cover so you can check and clean the magnet inside.

 

[gmcman]

Nizar, I only have one caution.................. be sure the fill plug can be removed before you pull the cover and drain out the oil.

An empty diff, that can not be filled, is not a good situation.

+1

The fill plug is a booger to break loose if it has been stationary for a long time. Use a breaker bar if possible to break it loose, or if you are using an extension keep it as short as possible. Extensions will twist up robbing you of the torque needed to snap it loose. Take a pick or small screwdriver to clean out the square of the plug first to ensure full seating depth, tap with hammer if needed.

 

[STLtrailbSS]

Some tips I have remembered lol I have my stuff sitting here just need to find the time.

Use a TFR (Tough F**kin Ratchet lol )because like said above that thing is probably stiff I plan on borrowing some snap on from my dad lol

Feelpro Gaskets are around $7 at Autozone atleast for SS diff so don't freak out about the gasket

Use red RTV gasket maker with your gasket.Extra protection cant beat it

The oil recommends a friction modifier to make life simple just buy Royal Purple its already present not sure if AMS has it pre added we have a vendor that can answer that for you here, You can also go to a ACdelco dealer for the modifier what I have seen is around $16-$20

Again like said earlier best way is to drop the pan to clean off the magnet of any metal shavings

Hope this helps!

http://www.shop.speedunlimited.com/p-7787-gm-performance-88900330-limited-slip-lubricant-additive.aspx
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Max-Gear-75W90-Royal-Purple_7070082-P_N3242_T|GRP2035_____

 

[sevendj]

Easy but messy job.

Just heed the earlier advice and you'll be fine. A hand-pump is a must. As with anything, make sure you can refill the device before draining it of its' contents: remove the fill plug first always.

You might not want to use some clothing that you care about. Not to mention the smell...

Have fun though! Easy project that saves you quite a bit.

 

[davenay67]

Nizar, I only have one caution.................. be sure the fill plug can be removed before you pull the cover and drain out the oil.

An empty diff, that can not be filled, is not a good situation.

Pure words of wisdom for any component that has a fill hole (gearbox, tranny, transfer case, differential, etc, etc)....always remove the fill plug first to make sure that it can be refilled after draining.

 

[HARDTRAILZ]

Nizar, I only have one caution.................. be sure the fill plug can be removed before you pull the cover and drain out the oil.

An empty diff, that can not be filled, is not a good situation.

Yep....You end up refilling it through the vent hose and that was not fun....

Use a TFR (Tough F**kin Ratchet lol )because like said above that thing is probably stiff I plan on borrowing some snap on from my dad lol

The oil recommends a friction modifier to make life simple just buy Royal Purple its already present not sure if AMS has it pre added we have a vendor that can answer that for you here, You can also go to a ACdelco dealer for the modifier what I have seen is around $16-$20

The ratchet did not matter for me...it took a light application from the impact to bust mine loose.

I use Mobile One and it has the additives in it for a decent price.

 

[Nizar]

thank you guys that was helpful

 

[am-radio]

I want to change my oil in my rear diff. I'm probably going to use Amsoil 75W90 (not sure which one, they have 2 kinds). Do I need to add a friction modifier? I am also going to change the front diff, and I'm assuming just change the oil in the front diff, no modifiers?

 

[The_Roadie]

No limited slip additives ever needed in the front. In the rear, GM says they're not needed, but some folks with G80 automatic lockers (check the glove box for the code "G80") have reported that adding LS additive or using Mobil1 *with* the LS additive included has quieted down some noisy clutch plates. In any event, adding LS additive if it's not needed will not harm anything if it's not needed, but it's sort of a waste of a dollar.

 

[am-radio]

Thanks Roadie! Your knowledge and quick answers are always appreciated.