somis13

on my way home today my truck sounded like someone hit the back end with a sledge hammer a couple times. not being a retard I knew something was not rite so I pulled over to check for any obvious problems. it only took 1 second to see the hole in the diff cover that was obviously made from parts hitting it from the inside. my question is this. now that I need to buy new gears, what size will make it rite if my stock tire size was 265 and I'm running 315's. the stock gears are 3.54's thanks

98whitelightnin

i would go with a 4.10 or at the lowest a 4.56 and remember you will have to change the front gears too. i dont know which one would make it right with the speedo but i would go with a 4.10, i have heard that they are very strong gears because of there size

somis13

yeah thats what I came up with. I used an online calculator and came up with 4.11 I am leaning towards 4.56 because this truck tows all the time and never sees speed over 75 mph. thanks. I would still like to hear from others that have swapped theres out

braxton357

I'm running 4.10's with 315's and love it. With stock sized tires it sucks. Just remember you're going to have to regear both axles, and the carrier break for d60's and 70's is 4.10 and down or 4.56 and up...meaning if you go with 4.56's you will have to buy/install new carriers for both axles as well.

trksrfun

i wouldnt go as tall as 4.56, me personally i would go with 4.10 and keep the 315's, i had 4.88 with 35's on my ferd and it wasnt bad if you dont mind shifting..

chainzaw

sosmis13 how can you post a thread with such a cool subject title with no pictures!!!

BRO

Sorry to hear about your about your rear end (that don't sound right, but you know what I mean). What do you think caused the problem? The last time you changed the gear oil did everything look ok? I'm curious for the sake of learning from it for my own use, so I hope you don't mind me asking questions.

dozer12216

So what are you trying to tow??? 8,500 is not that much of a load as long as driving reasonable. I would think the auto tranny would be weak link. The 4.1 gears will cost much fuel. The teeth cracked several days earlier or maybe 6 months ago from vigrious excerise and finally gave it up by exiting through cover.

need12v

With an auto 4.10s are almost a necessity with 315's because the over drive is so deep.

With my 6 speed I love my 315's & 3.55's. Cruising legal speed is about 1700 rpm.

somis13

ok, I did the swap to the 4.10 gears front and rear, thanks for the replies guys. I will try to upload a picture of the pinion gear to day and post it on this thread. I tow the biggest pea gravel concrete pump they make, and I drive my truck like I stole it.

somis13

here it is: 8 teeth broken off and the 5 that were left had cracks as if they would have made it 2 more feet of driving, before they let go.

bullfrog5.9

cool add the pic to the carnage pic thread