I am wandering what grade of oil does my truck use in the rear end and in the tranny? i have a 2002 dodge 3500 with a 5 speed .. and the rear end has 3.55 gears dont know the size or number of bolts..... i am also looking to replace the rear end cover with one of those magtech covers ( i think thats the right name) lol well thanks

 

Well the cheapest route would be 80W90 Gear Oil to use in both. However if you want to help boost mileage a tiny bit. You could try either synthetic or get yourself some Amsoil Synthetic gear oil. Lots of fellas have really good luck with that oil.

Also, you have a Dana 80 rear end, if you need that to order a diff housing cover.

 

would that be the same wieght of oil with the synthetic???

 

Weight the same for syn gear oil. Use a GL-5 gear oil and add 1-2bottles of anti spin additive if a trackloc differential. Do not use GL-5 in 4500 tranny. Calls for Manual transmission fluid Dodge part #4874459. Other compitable fluids are avaliable from oil suppliers.