How can I tell which gear ratio is on my rear axel of my E350 van? The 3.7 or the 4.1? The book mentions both but I can't find it on the vehicle and I need to know to figure out how heavy a travel trailer I can purchase and pull behind. I have a 1998 E350 Clubwagon. V10 engine. Don't want to buy more than I can pull!

Mesa Vista

there is a little tag on your differential cover and if you cant figure it out bring the tag to a dealer and they will tell you .

WHAT ????? , wait ----- your suppose to leave those lil tags on there ?????:D

thats what spart people do lol!

You can look at the tag and write down the numbers on it or simply remove the bolt holding the tag on, remove the tag and replace the bolt. Either way, your local dealer can tell you what you have by the numbers on the tag.

Jack up your rear end. Mark your driveshaft with chalk. Turn your wheel one complete turn. Count the # of turns your driveshaft makes = ratio. i.e., just over 4 turns 4.10 etc.
1%er