I am pretty new to this but learning allot as i go here. I have been building up a 460 efi on my 89 f-150 and today apparently I put a little too much torque down the drive shaft. The shaft did not twist but the differential end of the joint broke sending the drive shaft to the ground. The Ujoint on the drive shaft seems ok but I need to replace the part on the differential that it connects to and I ,embarrassed, cannot figure out what the name of that is to find/order the part. Here is a pic.

 

It's called a half round companion flange.
The torque on the nut is around 160 ft. lbs.

Before you remove the pinion nut.

You need to jack the rear up and remove the rear wheels and brake drums.
with an inch lb. torque wrench measure the torque required to turn the pinion nut in either direction. Record that value. Remove the pinion nut and purchase a new one. When you install the new nut tighten it until the torque to move the nut is the same as what the value you recorded was. Then tighten then the nut a little bit more.

The ring and pinion back lash is set by crushing a sleeve on the pinion gear which is why it's critical you install a new pinion nut this way.

 

what's this 460 got a damn blower?

 

Wow! I've never seen that before. That's got to be a bummer. Good luck on fixing it and getting your truck back on the road. Maybe you ought to upgrade to a 10.25 sterling to handle the 460. Of course, I don't really know if that particular part is any different from a stock F150 rear to a 10.25 sterling.

 

I followed everything you said except
"The ring and pinion back lash is set by crushing a sleeve on the pinion gear which is why it's critical you install a new pinion nut this way."

What do you mean by this and also any idea where i can get a replacement flange?

 

In other words you NEED to torque down the nut. It will crush the sleeve to give it the proper 'setting'. The backlash is the amount the pinion can move back and forth. You dont want it too tight cause itll cause major problems and you dont want it too loose cause thats not good either. Torquing it to specs you wont have a problem.

 

Got it thanks! Any idea where i can get a replacement flange and nut? Do I need to get the sleeve also or use the existing one? Sorry for all the questions im still learning.

 

No do not simply retorque the nut back on to 160flbs, if you crush that sleeve much beyond where it is now you'll have to replace it and start from scratch.

Do it just as F150xlt described it. Technically should pull the axles too but simply removing the drums should work fine. If the torque required to turn it exceeds a inch torque wrench's capacity just pull the axles to reduce the load a little more (doubt it will but just in case it does).

You can reuse the same nut in a pinch but only if its self locking feature is still viable, if not make it so it is or find a replacement.

 

Jeff's Bronco Graveyard sells a forged rear pinion yoke. (Ford calls it a half round companion flange). You might as well replace the pinion seal which they also sell along with a pinion nut for a 8.8 rear.

Link for rear pinion yoke
http://broncograveyard.com/bronco/i-...inion_yoke.htm


Link for pinion nut and pinion seal. Scroll down to find the parts.
http://broncograveyard.com/bronco.ph...cending&page=5

 

Pinion crush sleeve or pinion seal?

sleeve:http://broncograveyard.com/bronco/i-...ush_sleeve.htm

Seal: http://broncograveyard.com/bronco/i-...d_8_8_inch.htm

 

You don't need a pinion crush sleeve.

Everyone is trying to explain why it's important you tighten the pinion nut a certain way.

When the rear end was set up from the factory, the ring and pinion gear back lash was set to a certain spec. When the pinion nut was tightened, it crushed a metal sleeve mounted on the pinion gear shaft.

When you loosen and remove the pinion nut to replace the pinion yoke the crush sleeve will have slack in it. So when you reinstall the pinion nut you want to take the slack out but not crush the sleeve any more than it was because that will change the gear back lash between the ring and pinion gear. That's why you need to measure the torque required to rotate the pinion shaft and set it back to the original torque or a tiny bit more.

You can't see the pinion crush sleeve unless you remove the pinion gear which requires you to take the differential apart.

 

aaahhhh lightbulb! I get it now. Thanks for taking the time to put up with my noobness lol. :P

 

So ya this is interesting. I went to take the pinion nut off and there was no torque on it. I grabbed the nut and it came off by hand... For some reason it was loose well before the yoke broke which explains why the nut and pinion yoke was covered in differential oil. It must have been leaking the whole time. The new yoke, seal, nut, and u clamps will be here tomorrow so that should close everything back up. I will use some locktite on the pinion nut when i torque it down to insure it stays that way. Should be fine when im done. I think i will change out the differential lube while im at it in case it lost too much from the pinion nut leaking.

 

How do you properly change the pinion seal? Is it just past the yoke inside the rearend there?

 

Yea, the seal rides on the yoke. While this is a pic of a full floater yours will be very similar at the pinion seal area.



Oh and like them air bags too!