I have a 90 F150, 4x4, 5.0 lt truck, and when i first got it, i replaced the tranny... I thought the rear diff had an issue, cause i had opened it up, and seen a few chunks out of one of the spider discs missing.



Now a few months later, when i'm driving with lots of weight in the truck bed, or have a large boat attached, and i'm making sharp corners... it goes CLUNK, CLUNK. Some times it does it, some times it doesn't...

Oviously i need new spider gears... Are these easy to replace just those gears, since my pinion gears look fine...

Or do i need to replace the whole rear diff internals ?

Also, if i don't replace the rear diff, (assuming all the spiders will break off) will the car just not have power while turning... it will only have forward and rev power?

 

Considering the amount of labor, special tools that may be required to set gear backlash, and how long it would take repair that rear end, you may be better off finding a used rear end and swap them out. If you go with a used rear end replace the pinion shaft seal and wheel bearing seals before you install it (personal experience).

 

When you say replace the rear end with a used one, are you talking about the entire unit, including internals... or do the internals all come out as one?

 

The entire unit. Check your junkyards, classifieds, Craigslist.org

 

you don't need and entire rear end! remove the center shaft, push the axles in, pull the c-clips, pull the axles out. unbolt the main caps, pull the shims out from each side and lay them left and right of you with the correct side, do not mix them up at all. pull entire carrier out. mark the carrier and ring gear across. unbolt ring gear. pull out the side and spider gears, reinstall new ones. put the ring gear back on, lining up your mark so its in the same exact spot. pop the carrier back in with the same shims on the same side. main caps, c-clips and the center shaft and you'll be good. 2hrs max! no need to worry about back lash and whatnot as long as yours doesn't feel excessive. only thing special you need is a torque wrench.

 

So what kind of parts/kit all should i replace ? I think the rear is a 8.8, with 4.10 gears.

 

SUPER LAME !

I let my brother borrow the truck today to get "some wood" from home depot for a home project... he loaded up about 700lbs of supplies, and was turning a corner, when POP ! And now, even in forward and rev, its making loud clunks... i think one of the spiders exploded, i hope now i don't have to replace the pinion and other main gear sets =( What could i expect to pay for a replacement entire internal gear setup?

 

it depends on the gear ratios. You'll want to be sure to match up the front axle or plan on doing both. Did you want to change gears? Now would be a good time. If you need 3.08s and don't mind used, you can have mine for the cost of shipping. I found there's good options for the rear axle on Ebay since we share the rear axle with our mustang friends.

 

If i have 4.10's now in the rear, and switch to a 3.08, then i would have to change the front ?

I would like to keep it as simple, and low budget as possible, i just want to get the truck running again, so it can serve its purpose of purchase, to tow my boat LOL... But right now, i have to borrow a truck, just to go fishinig =(

 

yes you would have to replace the front, if u want to use 4 wheel drive, and IF your ring or pinion is messed up u can get a brand new set for under $100 on ebay, or like $180 for ford racing. this same thing happened to me, but from the first time i heard it pop, it took a day and i had two spiders explode, and took a chunk out if the pinion, to i found a 355 traclock rear end for $100 on ebay