rear diff fluid level
 

i put about 2 1/3 quarts in my rear diff, is this enough? when i stick my finger in i can't fel the fluid but i always have alot on my finger, i think i just can't feel the fluid.

Fill till it pukes out the hole slightly. Then stop.

Dealership calls for two quarts and 4oz of friction modifier

According to my Owner's Manual the proper level for the 1500 Series is from 5/8 inch to 1 5/8 inch below the bottom of the fill hole. No idea why so low?

A good way to measure might be to use an allen key or piece of wire bent to 90*. Just put it through the fill hole and lay it flat on the threads with the bent part pointing straight down. Haul it out and measure the level from where it is wet till the 90* bend.

All these guys that say fill it till it pours out the little hole obviously havent read the owners manual which is always a good idea. How much you put in there is fine if you have a limited slip you need to add the 4oz of friction modifer to it also.

i'll try the allen key, but i read the service manual and that is why i was wondering, i did add the limited slip additive.

I was under the impression the G80 didn't require friction modifier...?

I have the Mag Hytek cover on my truck and as per the instructions- using the covers fill hole, you add 2 quarts above the factory fill hole. I thought that was a bit much so I called Mag Hytek and was told this was to keep fluid in the tubes at all times and since there's no pressure, it's OK. No leaks from the axle seals yet.

I believe the Eaton limited slip requires 4 oz of GM friction modifier and 80w90 mineral based gear lube.

The G80 requires GM Synthetic 75w90 part #12378261 ( I think this # from my manual has been upgraded) and no modifier. I think Amsoil makes a Severe Gear 75w90 Synthetic gear lube that will work as well. I have read posts of other people using other synthetic 75w90 gear lubes and no modifier with no problems posted.

According to the local chevy dealership you have to add the friction modifier to the gear oil. If you dont you will get alot of rear end chatter and the G80 will be reluctant to unlock. When I did have the G80 in it started locking up on me and I added new fluid and the friction modifier and worked fine atleast until I did a nitrous assisted burnout on a damp road to a speedo reading of a 100. :devil: