Rear axle grease change out

[El Chapo]

Hi all.. I’m in the process of changing the gear oil in the rear axle of my 86 bronco. Vin tag shows axle H9 and the metal tag on the diff shows: S809P and 3L55886G28. I tried research it on. I just want to make sure I use the correct lubricant. The person at NAPA sold me 4 quarts of 80/90 Valvoline gear oil but looking closely it states it’s standard transmissions and I have an 4 speed automatic transmission so now I’m really confused. Can someone tell me what rear axle I have from the vin tag/metal tag as well as what lubricant I should be using. I plan on changing out the front soon so that info would be helpful🙏🏼 Thx

[Whisler]

H9 and 3L55 says you have a limited slip differential with 3.55/1 ratio. Not sure which differential you have, 9 inch or 8.8, but if it has a removable cover on the back it is not a 9 inch.  I believe that they gave you the right lube but you will also need to add friction additive for the limited slip. The reference to transmission type is that some manual transmissions also use this type lube.
Someone more knowledgeable may be along soon.

 

[El Chapo]

May God Bless you as well! Thanks for the info I will proceed and btw they did sell me the additive so I’m all set. Thank you!

[FuzzFace2]

If the 80/90 bottle said for limited slip then you may not need the extra bottle as it should already be in the oil.
Dave ----

[El Chapo]

Oh ok thank you! I’ll double check that.