I have a 93 f150 that needs the back right seal replaced.. it is model 18 axle.
I was wondering if i should do both seals. should i also replace the bearings while i am at it? also what gear oil should i use? should i buy the dealer gear oil. and lastly i read where i need to use friction modifier. is that for limited slip axle only? Are there any tricks i should know ahead of time?
Thanks for any info....
Danny

 

Axle code 18 (on the door jamb sticker) is a 3.08 non limited slip. No modifier needed, and the correct gear oil is standard 80W90, you may use synthetic 75W90 if you prefer. As long as it meets GL-5 specs you are fine, no need to buy it from the dealer.

 

if u dont have a seal puller when u pull the axel when the splines get to the seal if u push the axel to one side it 90% of the time pulls the seal for u

 

Do both axle seals while you are in there, or you will be kicking yourself when the next one starts to leak, it's a cheap, but time consuming fix.
I would consider getting a new cross shaft locking bolt when you get parts, I didn't and next time I need the axles out, I'm gunna have to cut the bolt.
I did not need to do bearings, 247k or so when I did this and they looked brand new.
Take a look at the bearing and the surface where the bearings ride on the axle, if they are clean then proceed. If the bearings are loose or worn a lot replace em. If the axles are gouged, replace those too.
Worse case scenario, axles and bearings, bronco graveyard has the shafts bearings and seals in a kit for relatively cheap.

 

Click my black Bronco in my signature & read the captions in the 8.8" Axle album.

 

Thank you all for all the info!!!

 

I tried replacing my seals today.. When i got to the Cross-Pin Bolt i couldn't get it out. i didn't have a six-point wrench. i it started to strip. i also didn't have a Cross-Pin Bolt to put back in. it is Sunday and the dealer is closed. so i put everything back together. the leak wasn't as bad as i thought. but i still want to do it. i am going to get a new Cross-Pin Bolt and a six-point wrench... i am afraid i might of stripped the bolt head too much. does anyone have an idea/trick how to get this out?
Thank you!

 

I've always used a small cutting wheel to put a slit in the bolt so you can then use a screw driver to get it out.
Or try vice grips, but if it's lock tited in there, good luck.
Oh and if you do cut the bolt make sure you get the housing really clean after so there aren't any metal shavings in there with the new oil.

 

Would heating it up with map gas help?..also Should i even try to heat it up? haha I don't want to burn it up! haha

 

I'd imagine you can heat it up, just don't get any of the seals hot.

 

Don't cut or heat it - those bolts are infamous for breaking even when they're NOT mistreated. Get the right socket (preferrably a 6-point impact 8mm) and GENTLY try to remove it. If the head or tip breaks off, try to find the extractor kit shown in my album.