LS WON

Are there two different kinds of rear end diff. fluid for Amsoil? I know one is severe service and I believe on another you don't need to add the friction modifier which is probably already in it.

LS WON

How were you able to get under there without lifting car up? It is possible or very difficult to slide underneath there and start wrenching away and add the fluid? I would have thought getting those drain plugs out might be a problem at that angle.

lander

Nope, wasn't a problem at all really. The biggest hassle for me was the fill plug was on a bit tight, so I had to cut a piece of pipe to go on the wrench. Other than that, no problems really at all access wise. I used one of those plastic coffee cans to catch the fluid...fit under just perfectly.

KarlK

I used the severe gear 75/90 without any slip additives. 2 years and 20k miles, no problems.

JCTPM

I also used the severe gear fluid 75w-90 with the 4 oz bottle of slip lock additive.

As for getting it done without lifting, I have a 06 and my car is not lowered so the plugs are pretty accessible. As for getting the fluid into the diff, I bought the Amsoil pump which made things alot easier.

LS WON

Is yours a factory 2005?
This Amsoil is like Amway you can only get it at the store. Why is this?
You can only get Amsoil from certain people/ private distributors who sell it unlike Redline which is easier to find at a store.

LS WON

From what I have read on the DIY article here the 06 is easy access but the 05 you need some type of L allen wrench cause there is something in the way. Not sure what size that was for drain plugs.

LS WON

As of January 2008, the oil specified for use in the Corvette differential is Dextron LS Gear Oil 75W-90, part #88862624 (#88862625 in Canada). No additive is required or recommended – just add straight Dextron LS 75W-90 only.

So what do you do if you use Amsoil severe duty 75W-90 which has the option of adding friction modifier? Add friction modifier or not?

JCTPM

Taken from Amsoil website regarding their slip lock additive.

"NOTE: AMSOIL Synthetic Gear Lubes do not require the use of this additive. However, not all differentials respond the same and if chatter is noticed, the addition of AMSOIL Slip Lock will eliminate it. For chattering differentials not running AMSOIL Gear Lube, this product is an excellent solution to the problem."

I just added it so I don't have to worry about it. As many members have done the fluid swap with the additive added and reported no noise from the diff.

LS WON

VETRYET

Just did the change on a 2005, 16,000 miles. Used a lil less than two quarts of Amsoil Severe Gear 75W-90 Synthetic Extreme and one 4oz bottle of Amsoil Slip Lock Differential Additive. The two quarts of 75W-90 were $19.06 (for both) and the bottle of Slip Lock was $8.16. For the 2005 you DO need a 10mm Allen wrench (L) which works for the drain plug and the filler plug. Purchased the Allen wrench at local hardware store for $2.63. I also used a "FloTool MixMizer" from WalMart to suck the fluid from the bottles and inject into the trans axle. Cost for this item (in auto dept near gas cans) is under $4. It's basically a syringe with a clear tube extension. Once fluid in the bottles got too low, I cut off the top of the bottle with a utility knife to gain access to remaining fluid. Once buttoned up, did the recommended 8-10 figure eights. The rear chatter has completely disappeared. Night and day difference. This was an easy do it yourself project. And no, I am not a gearhead. I am a biotech rep. I did jack the car up some to do the initial plug removals but set it back on level ground for the fill up. Probably did not need to jack it up but did provide a little more elbow room on the first go-round. As someone recommended earlier, make sure you take the filler plug out first, otherwise you are in deep bovine feces if unable to refill.

SnapperDragon

I'd like to thank Vet for posting this DIY. I just did this today on my 07 and everything went smooth. Sure, I could have taken it to the dealer, but this helps me feel a bit more connected to the car. I used the wood ramps that I made with the measurements given in another thread to get the front off, jacking pucks to lift the car with, jackstands in the preferred location, and the procedure to drain and fill (using a manual pump). Ran the car while in the air and then topped off the fluid, then went out for the figure 8's to get the clutch packs all nice and slick.

Next project: z51 sways.

calemasters

2006 Access:


On the 2005 MY C6, the differential drain plug can be difficult to access due to the leaf spring. I made this tool so I could access the drain plug on the '05.

PAVette

Superb post. Thanks for taking the time to provide us this important information in such a clear manner.

LS WON

Pretty clever. You can also use the Allen L wrench on both plugs.

Vet

RAT

Well, that was easy! Off to run some figure 8 now.

Thanks for the information.

LS WON

How easy was it?

siffert

Thanks for the DIY. I had a bit of clunking when my '07 (13K miles) was cold in the morning leaving my garage while backing out, then turning. I just changed it with the Dexron LS. Had a pump and used almost 2 full quarts while on a lift. Printed out the DIY, install worked like a charm. Oh, no more clunking, worked like magic!

Njttz

This is hands-down no BS the most informative post of any kind for any vehicle that I have read. My thanks to all who contributed! This one is getting filed for future use.

My car doesn't have the chatter (yet?) but I like to change diff and tranny fluids; I've seen some awful looking stuff come out after the factory fill and several tens of thousands of miles of service. As long as I have the car raised and under there I would like to do the tranny. Is there a similar post for doing the tranny along with various fluids people have used?

Thanks!