What is the best way to check the rear end fluid, can it be checked without ramps & jacks ect.?

 

I checked mine at a midas muffler place, they put me on a lift and let me check it for $20.

 

Of course it can. The car does not have to be on a lift...
I easily checked mine in my garage by just laying down behind the car.
The fill plug was easy to reach, and I added 18 oz. of fluid.
The good thing about leaving the car on the ground is that you know it is level, which is required to get an accurate fluid reading.

My method of using my air compressor to transfer the fluid into the differential made it much easier than trying to do it with a plunger pump or squeezing the bottle..




Diagram shows drain plug... Fill plug is to the right...

 

You do know that after posting this in this fashion someone is going to remove the drain plug to check the fluid level........

 

I put mine on stands to check it. Then, I cleaned the undercarriage so I wouldn't be going through all that JUST for the 10 seconds it took to confirm the level.

 

LOL...Yep that is going to happen for sure....

 

Try this:

 

Is that correct for the z51? The diagram I saw confused the hell out of me due to the differential radiator which adds another half a quart or so. Thanks for straightening me out too.

 

Way to go and with a sense of humor. Made me smile
Blue Max

 

Nice

 

Good pic! Thanks.

 

Has anyone actually done the research to know how low differential fluid needs to be before there are any adverse affects? In some cases filling a fluid level to the brim is not needed. I wonder if this is one of them.

Also it has been stated that unless you hear loud noises and grinding coming from the differential, there wouldn't be a need to check it anyhow.


Yeah yeah yeah. I know the responses, "better safe than sorry" and so on.

But are the reactions here based on reality, or to make you "feel" better.

Because I highly doubt GM is shipping tens of thousands of cars with a huge problem, that is so easily solved. Could it happen? yeah i suppose. Is it? probably not

 

Low fluid level would compromise cooling and increase gear wear if not caught early. If you waited until a noise started, it would be too late. If one finds their diff needs 18 oz of fluid to bring the level up to the fill hole as mentioned above, that's way too low. It shouldn't be hit or miss with fluid levels, but its not a fluid that's easy to check and part of the normal service schedule. Since there have been so many posts concerning the low levels, I wouldn't feel comfortable without checking it soon after purchase.

 

What's the device you're using to fill up the diff? I've never seen this before.

 

There is another thread going around some of us have been posting in about changing out the diff oil and I had mentioned when I took the magnetic fill plug out to check my fluid at 4k miles (earlier this week) there was a ton of shavings attached to it. So I just drained out the fluid and added Amsoil synthetic to it. Here are pics of the drain plug and the oil I drained out was black. Glad I checked and I will keep an eye on it to see how it looks in a few months.







After I wiped the gunk and shavings off

 

I had one of the plastic pumps and it broke, so I had to come up with an alternate way to refill the differential..

I drilled a hole in the cap for the fill tube, and one for a smaller air line connected to a nozzle control on my air compressor..

Note, the fill tube goes to the bottom of the bottle, and the air tube just through the cap (keep air pressure low so you do not over pressure the bottle)
Use the nozzle to control the air pressure to the bottle. The air pushes the fluid down and out the tube to fill the differential or transmission. Also, much cleaner because if there are any leaks, it only leaks air, not fluid.

 

I'm relatively small (5' 10", 170 lbs.) and can squirm into tight places without too much effort or pain, so earlier in the week I crawled under mine without any jacking to check the gear oil level. This was done in a paranoid mindset after reading about other owners whose differentials were underfilled at the factory. The level was right at the minimum (½" below bottom of fill hole) or a bit lower, so recognizing that the word "minimum" isn't synonymous with virtue I proceeded to rectify the situation. I bought a quart of the overly expensive ($26.06 MSRP) Dexron LS gear oil for $19.55 plus tax from a local dealer after haggling and added 14 oz. to get it close to the full level. I probably didn't need to do it, but I feel better now. Jacking the car would make the job much easier, especially for torquing the plug (20 ft/lbs), which was a chore in tight quarters.

I used a $3.99 device from AutoZone to get the fluid into the differential. I contemplated Texhawk's idea of using compressed air, but decided to try the Hopkins spout since I was passing by an AutoZone earlier in the day and the cost was practically nothing. This device worked, but the standard plastic hose kinked easily and in tight quarters made the job a PITA. With a bit more room--i.e., if the car was jacked up a foot or so--it might've worked without these issues. I would advise that you try Texhawk's procedure, especially if you already have the raw materials to implement it like I did. When I eventually change the fluid I'll go that route instead.

BTW, my drain plug didn't have as much gunk on it as MikeinAZ shows in his photos, but I only have 2k on the clock.

 

Can someone confirm that the z51 is just as easy to drain or fill?

 

I just read my owners manual and it states that the fill level is 13mm below the threads of the fill plug and that no oil needs to be added unless it is below that level. Maybe we create more problems than we actually solve ?

 

I don't think mine was very low, at or slightly below the ½" point, but OCD forces set in and I added a little to make me feel better. My analyst didn't understand but I didn't expect him to.

I suspect that most are probably filled this way at the insistence of the bean counters, as GM can save at least a pint of the expensive fluid by going with the minimum level.