so to get this right...
if one is to do a diff fluid change...
what fluid and how much of it does one need? how often should the fluid change be done? how much should parts & labor be?

 

the diff takes .78 quarts and the transmission is almost 1.8 qts. if they put that GL-5 fluid in your transmission, say bye bye to your brass synchro's in the transmission.

 

you will need a 1 quart bottle. Do it every 15-30k miles. about $35 in labor and a $1 for the crush washers

 

xviper's the man, do as he said. Although I like the "take you manual in, show them the correct amounts and then hit them with it" idea as well.

 

hell hath frozen over.

 

Just do it yourself it doesnt take that long to change fluids tranny, diff, or engine oil trust me i did all 3 in under an 1hr just make sure you have all the tools and jacks . at least that way you know what your putting in your engine. i put mobile 1 75/90 in my diff. and gm synchro. friction modified for tranny. and 10/30 royal purple for engine i have used mobil 1 for engine and it seems the royal purple is smoother runs imo.

btw 1qt is enough

 

i took a look in my manual last night so i could prove them wrong, and thing is, it doesnt say the needed ammount! it just says to fill it until it is level to the fill bolt. does the helms manual say the ammount needed?

 

I personally have filled my diff and it took 1 bottle only and when the car was leveled out, some fluid came back out, just like it said it would in the FAQ tech. section on how to change your fluid in you diff.

 

The Helm manual states in very specific terms what the exact volume of fluid all the casings take. For the diff, it reads 0.78 US qts. at oil change.

 

appreciate the help guys