glw165

just bought truck noticed rear axle studs are bigger than front studs? i need a rear wheel bearing and what do i tell them i need being they are diff size? they are all 5 lug but bigger studs in back, why is that?

ColtRice17

It could be the fact that there are differand rear axels like I have an 8.8" then there is a 9.75" and a 9.756" so you need to know exactly.

glw165

how do i determine that? and surely they wouldnt have changed the ratio, it is 4wd, supposed to be 355

ColtRice17

You are correct in that. When you open the rear differential there should be a tiny metal tag on one of the bolts. If you can find that then oreillys can tell you which one it is. So can ford

glw165

there is a tag but its just letters, noone was able tell me what ration by thatm but dealer told me with my vin that was equipped with 355, as door tag says h9=355, but then when seen rear diff had bigger studs i was throwed for a loop as to why, and it needs rear wheel bearing so when i tell them 2000 f150 4x4 but yea the rear studs are bigger than front then something has been changed clearly

ColtRice17

Previous owner pay have swapped out the stock 8.8" axel for another 9.75 for who knows what reason. Pull out the barring and get some digital calipers and go to oreillys and make sure you get the right one.

glw165

your correct i went outside got numbers off tag, then found a chart online the s919f is a 9.75 355 gear, so at least same ratio as front thank god, lol, so im assuming it came with 8,8 now 9.75 which is y bigger studs

akdoggie

The bigger studs were used in the 99 and up model years. They replaced the 12 mm studs with 14 mm. Some 99's have 12mm and some have 14mm also. It all depended on the production date.

You are better off with the heavier axle. You should also have rear disc brakes with the 9.75 axle. That may be why the change of rear axles. At least you have matching 3:55's so nothing there to worry about.

glw165

Just gotta figure how change wheelbearing now on pass rear

ColtRice17

Its easy. When you go to the parts house ask to borrow or rent a slide hammer and a barring puller. Jack up the back axel on a lvl surface insert jack stands crawl under and remove bolts from differential cover. Look inside and take a good picture. ( should have wheels and tires off by now also) after taking picture pull out gear that is on the end of your passenger axel. Your gonna have to figure how to get everything out and back in again. Make sure the shims are exactly where you found them when you finish.

Once gear is off of internal axel half shaft go to the other end and pull the axel out. Thwn sex it somewhere clean like a trash bag. Then use slide hammer to remove old barring. ( be careful mine broke when I was removing it and I got the race stuck) then put it all back in straight. Then the wheel seal axel. Differential internals silicone seal the differential cause the gaskets suck. Put wheels back on let it down and drive easy for a while.