New LS1 Owners - Newbie Tech - Rear Differential Fluid Change Interval

I checked my owner's manual to see how often the rear differential fluid should be changed but I only found change intervals for the transmission fluid when we have an automatic transmission. Now I have two questions! How often should we change the rear differential fluid? How often should we change the transmission fluid when we have a manual transmission?

If you have the Auburn unit it is 6000-7500 miles. I couldn't find the schedule either but I did my first change at 5000 miles (stock rear axle) and will repeat it every 10K.

Manual tranny: if it were mine I would change it every 10K as well, depending on how you drive it.

Brad

I usually change it once after break in and then wait a while.

I usually change it once after break in and then wait a while.


that a good way to do it.if the car is frequently raced it should be sooner.once a year for guys like us is highly recommened though. :nod: then pray it holds up. :bomb:

How hard is it to perform that? Does anyone know of an online "how to" or can you just explain it if you don't mind please? I drive mine pretty hard so I would like to do it.

How hard is it to perform that? Does anyone know of an online "how to" or can you just explain it if you don't mind please? I drive mine pretty hard so I would like to do it.
Good question... I didn't realize it had to be changed that often... :confused:

Good question... I didn't realize it had to be changed that often... :confused:


It doesn't "have to" be changed that much. From memory, F-body owners manuals used to say change it once after a break-in of 7500 miles (from memory, could be off a bit) and then just leave it.

However, that is for "normal" people. To GM, "normal" people aren't adding power mods or going to the track.

I change the diff fluid in my "track cars" once a year.

For the new guys like me wanting to know how to change the rear diff fluid, here is a link I found in the pinned "how to" thread on this board. This board is such a great resource.

http://www.bfranker.badz28.com/fbody/lubeoil.htm

All Data claims 15k for the rear diff change.

The manual states 7500 mile intervals with standard oil. After the first 7500 miles I started putting full synthetic in, so I will change every 10k now. Like everyone says, its how you drive it......................

For the differential, you can buy a cover ($30) with a drain plug to make the oil change task trivial.

For the differential, you can buy a cover ($30) with a drain plug to make the oil change task trivial.
But will it hold up with some power adders??

The reason there isn't a drain plug in the rear,is it don't have to be changed.I have been driving for 53 years and have never changed rear end fluid. I have never had a problem either. The same goes for the stick trans.

The reason there isn't a drain plug in the rear,is it don't have to be changed.I have been driving for 53 years and have never changed rear end fluid. I have never had a problem either. The same goes for the stick trans.

You must not drive your car very hard. :confused:

The manual states 7500 mile intervals with standard oil. After the first 7500 miles I started putting full synthetic in, so I will change every 10k now. Like everyone says, its how you drive it......................

Thats strange - No where in my 02 Helms manual or the manual that came with my T/A does it say anything about ever changing the differential fluid, tho I did change it about 7500.

Thats strange - No where in my 02 Helms manual or the manual that came with my T/A does it say anything about ever changing the differential fluid, tho I did change it about 7500.

Read the owners manual. I believe the interval is in there.

Thanks for all of the good replies so far. All of them have been valuable.


For the new guys like me wanting to know how to change the rear diff fluid, here is a link I found in the pinned "how to" thread on this board. This board is such a great resource.

http://www.bfranker.badz28.com/fbody/lubeoil.htmI read the information at that web page. It looks good. If/when I change it I'll have a print out of that web page with me in the garage. I also found good information at Install University (http://www.installuniversity.com/). The direct hyperlink to their "how to" instructions for changing the transmission fluid or rear differential fluid is TA Performance Rear Differential Cover/Fluid Install (http://www.installuniversity.com/install_university/installu_pages/freshman_year/ta_cover_fluid_install.htm). I'll print this too!


For the differential, you can buy a cover ($30) with a drain plug to make the oil change task trivial.Yes, I saw that at SLP (http://www.slpeng.com/) and it is part number 65003 (http://www.slponline.com/view_product.asp?PARTNUMBER=65003&SHOWIMAGE=On&SHOWEMAIL=Off). If we should be changing our rear differential fluid regularly then this should be a great thing to have. I was going to ask about this in another thread. I'm curious if draining and refilling is good enough - or is it really better to take the cover off, drain, wipe everything up really good, and put the cover back on with a new gasket and some RTV. After all when we change the motor oil we simply do a drain and refill - we don't drop the oil pan, wipe everything up really good, and put the cover back on with a new gasket and some RTV. So I'd guess that draining is good enough and this cover with the drain bolt is good enough.


Thats strange - No where in my 02 Helms manual or the manual that came with my T/A does it say anything about ever changing the differential fluid, tho I did change it about 7500.I could not find it in my 2002 owner's manual either. Maybe it is in the owner's manual from other years or from the Camaro? I don't have the FSMs yet. The Pontiac Owner Center (https://www.mygmlink.com/main/US/en/pontiac/home) only has the following information regarding this area and they say to do it monthly:

Check the transaxle fluid level; add if needed.

One of my other cars is a 1996 Impala SS with the 4L60E automatic transmission and a rear differential. From memory I think the owner's manual told me to change the rear differential fluid at 1 year or 7,500 miles, whichever came first, and then not to do it again. This weekend I'll check that car's manual and see what it says...

Read the owners manual. I believe the interval is in there.

Like I said before, nowhere in my manuals (including the $120 Helms Manual) does it say anything about ever changing the differential fluid.

My question is how much oil does the rear diff and manual gearbox hold in an 02? I'm planning on replacing both at my next oil change as the car has 22k and I have no idea if it was ever changed before I purchased it.
-Mike-

you've never smelt a skunky rear end ?

i would feel more comfortable having the cover pulled and my parts examined for wear.


this isnt the first ive heard that theres no recommended change interval for these cars though its obviously adviseable.

I asked a Chevrolet dealership mechanic that I know, he has been with GM for 18 years. He said he has never seen a rear differential go bad because the fluid had not been changed. He said the only reason they go is if they leak and get low on the fluid, or the F body is modded to the point it overpowers the rear diff, and then the owner should upgrade anyways. But he said he has never seen a case where "old fluid" caused any type of failure or even wear on the parts inside the differential.

Now he did say if he had a lot of money invested in a car and was racing it all the time, he would be like you guys and change it every 10k or so, just so that he could look for wear on the parts inside than for the sake of changing the fluid.

He did say make absolutely sure you use the GM additive, if you don't the rear diff will fail.

My question is how much oil does the rear diff and manual gearbox hold in an 02? I'm planning on replacing both at my next oil change as the car has 22k and I have no idea if it was ever changed before I purchased it.
-Mike-
The rear diff if it is the posi unit will take1.75qts plus the 4oz of additive from a GM dealer- the t56 tran takes 4 qts of dexron-III auto trans fliud! I forgot to add that rear fluid is SAE 75W-90 synthetic. The non posi unit uses 1.75 qts of same fluid minus the additive- This is all from the Helms manual :chug:

My question is how much oil does the rear diff and manual gearbox hold in an 02? I'm planning on replacing both at my next oil change as the car has 22k and I have no idea if it was ever changed before I purchased it.
-Mike-

It holds about 1.75 to 2 quarts. It depends on how level the car is. I am installing a AAM cover this weekend. I am painting it RED right now.

Bill
:drive:

I changed my rear end fluid about 2 weeks ago. It was the 1st time i've done that since i've owned the car. I bought the car with 21000 on it and changed it just before 30000.

im curious why the factory cover has a magnet and aftermarket girdles dont.at least my mac doesnt.

im curious why the factory cover has a magnet and aftermarket girdles dont.at least my mac doesnt.

My SLP (AAM) has a magnet but SLP wants you to grind on the rearend to help oil cooling. You have to take half the rear end off before doing the grinding.

Bill
:bang:

my babys get new trans and diff fluid every 15000 miles why take chances? (especialy with a $2500 moser 9") ;)

The reason there isn't a drain plug in the rear,is it don't have to be changed.I have been driving for 53 years and have never changed rear end fluid. I have never had a problem either. The same goes for the stick trans.

a manual is a closed transmission, so they don't need to have fluid changed. and if your gears are not wining, a rear diff fluid change is pretty pointless as well.

car-modders are a different story. you are probably more likely to hear noise in either the trans or the rear diff much more often than a near-stock car.

once again, another nice thing about keeping your car mostly stock ;)