Yoke bolt too tight on 3rd Member?

[sharpstang72]

Hey Guys, hope everyone is doing well after a Fathers day weekend.

I have a question about the 3rd member I just installed with a buddy of mine who is a very good Mechanic. I had a non-posi with 3.50 gears, and 28 spline. installed a new one with a posi-traction 3.50 gears. He was going to come back a week later to finish up the work. I couldnt wait, so I went ahead and changed the Yoke myself and tightened the Big bolt for the yoke with the impact gun. I only went as far as the old Yoke was on the 3rd member and didnt really know it had to be torque. When I turn the rear wheels by hand they turn ok, I have not added any oil to the 3rd member yet (Car still up on ramps, trying to finish up the rust issue on battery apron and frame rail next to it) still waiting for him to stop by and check for any damage that may have occurred. Is it possible that I may have damaged the preload spacer bearing, seal or any other parts that yoke can damage? I dont know much about gears, or 3rd member parts. He thinks I may have damaged the preload bearing seal, or what ever. The last time we changed it, it was hand tightened in increments to push the yoke back and drove the car & had no issues. Is there anything I can do to make sure nothing is wrong or can be fixed since the car is still up on the rams and has easy access?

Thanks and as always, any help or diagrams/pics would be greatly appreciated.

 

[72HCODE]

"I couldnt wait, so I went ahead and changed the Yoke myself and tightened the Big bolt for the yoke with the impact gun."

No, No, No.

you will need to take the yoke apart, replace the crush sleeve and retorque the yoke nut to spec:

8-14 Lb-In for a used bearing, or 16-29 Lb-in for new REMEMBER Inch pounds not Foot pounds.

you never EVER use a impact gun on the yoke i just hope you didn't destroy the bearings.

see my wiki entries:

http://www.7173mustangs.com/thread-how-to-rebuild-a-ford-9-inch

http://www.7173mustangs.com/thread-how-to-rebuild-a-ford-9-inch-part-2

 

[homelessmexican]

sorry to hear man, 72HCODE i have to say very funny pic made me laugh. and 1 quick question on 9" how many quarts does it hold of that horrid smelling rear end fluid?

 

[sharpstang72]

Hey Hcode, is there a way to tell whether the bearing is damaged for sure w/o removing the yoke? I installed it the same way last time, except it was torqued in increments as we turned the drive shaft in between to make sure it wasn't too tight. I can turn the wheels with no problem, is that a good sign or should just take off the yoke? Thanks

 

[72HCODE]

sorry to hear man, 72HCODE i have to say very funny pic made me laugh. and 1 quick question on 9" how many quarts does it hold of that horrid smelling rear end fluid?

If you have a locking rear make sure you get a bottle of friction modifier.

every rear is a little different but you should have 3 bottles on hand. i believe i put 2.5 quarts in mine. Pop off the side fill hole on the driver's side next to the yoke and fill up the rear until the fluid starts to come out the fill plug hole.

you want it level with the plug hole basically. with the car jacked up and the drivers side rear tire off it will be pretty easy to get to it. i used a long funnel and just checked it as i poured the fluid and modifier into my 9"

Hey Hcode, is there a way to tell whether the bearing is damaged for sure w/o removing the yoke? I installed it the same way last time, except it was torqued in increments as we turned the drive shaft in between to make sure it wasn't too tight. I can turn the wheels with no problem, is that a good sign or should just take off the yoke? Thanks

even a rear end with blown bearings can be turned you can't go by feel, it needs to be measured accurately. the parts are very heavy you can tell when its extremely tight since the rear will feel like the brakes are locked up. you can tell when its lose because you can jiggle the yoke. But if you want a 100,000 miles out of the refreshed rear then you want to make sure its right.

too much preload and the bearings will wear out and give you metal flakes in the fluid which will then wear out all the other bearings and the gears and the spider gears inside the diff or wear out the clutch plates in a locker. it won't happen over night, but in a few 100 or 1000 miles that rear may start rumbling. incorrect preload is the biggest mistake people make next to setting the gear tooth pattern. you don't want to have to take that rear apart over and over and just hope you get it right.

the best is remove the 3rd member and get it on the bench for a complete inspection, pulling the nose off, will allow you to replace the seal and set the pinion preload but doesn't give you the ability to double check the gear backlash which can change as well.

an impact wrench has too much power and the knocking can damage to bearings and chases. too much preload may cause flat spots on the roller bearings or indent the chases. you will never be able to feel this damage but you will see it later on during a fluid change or when the rear end starts to fall apart.

a lot of people have done it just like you in the past, trying to cut a corner and make a repair easy, it doesn't make it right. If you want to do it correctly then you have to take it apart and start over and inspect for possible damage.

at the very least, install a new crush sleeve torque the yoke and check preload on the bearing making sure its in spec and do not over shoot it, or you will need to start over again with another crush sleeve.

earlier ford 9" used a solid spacer in place of the crush sleeve, These solid spacers could be Torqued down heavily as long as the correct preload was obtained. i think that is where a lot of old school mechanics got the idea of using the impact wrench from, you can convert a 9" to use the solid spacer, in fact many drag racers do this because the soild spacer is stronger then the sleeve which is collapsible. the impact wrench was still a bad idea since the knocking was bad for the bearings but i can understand it for the sake of speed. With a collapsible sleeve its so easy to over torque the preload and ruin the rear.

 

[sharpstang72]

thanks Hcode, I'll go ahead and take your advice .

 

[FastE]

sorry to hear man, 72HCODE i have to say very funny pic made me laugh. and 1 quick question on 9" how many quarts does it hold of that horrid smelling rear end fluid?

If you have a locking rear make sure you get a bottle of friction modifier.

every rear is a little different but you should have 3 bottles on hand. i believe i put 2.5 quarts in mine. Pop off the side fill hole on the driver's side next to the yoke and fill up the rear until the fluid starts to come out the fill plug hole.

you want it level with the plug hole basically. with the car jacked up and the drivers side rear tire off it will be pretty easy to get to it. i used a long funnel and just checked it as i poured the fluid and modifier into my 9"

Hey Hcode, is there a way to tell whether the bearing is damaged for sure w/o removing the yoke? I installed it the same way last time, except it was torqued in increments as we turned the drive shaft in between to make sure it wasn't too tight. I can turn the wheels with no problem, is that a good sign or should just take off the yoke? Thanks

even a rear end with blown bearings can be turned you can't go by feel, it needs to be measured accurately. the parts are very heavy you can tell when its extremely tight since the rear will feel like the brakes are locked up. you can tell when its lose because you can jiggle the yoke. But if you want a 100,000 miles out of the refreshed rear then you want to make sure its right.

too much preload and the bearings will wear out and give you metal flakes in the fluid which will then wear out all the other bearings and the gears and the spider gears inside the diff or wear out the clutch plates in a locker. it won't happen over night, but in a few 100 or 1000 miles that rear may start rumbling. incorrect preload is the biggest mistake people make next to setting the gear tooth pattern. you don't want to have to take that rear apart over and over and just hope you get it right.

the best is remove the 3rd member and get it on the bench for a complete inspection, pulling the nose off, will allow you to replace the seal and set the pinion preload but doesn't give you the ability to double check the gear backlash which can change as well.

an impact wrench has too much power and the knocking can damage to bearings and chases. too much preload may cause flat spots on the roller bearings or indent the chases. you will never be able to feel this damage but you will see it later on during a fluid change or when the rear end starts to fall apart.

a lot of people have done it just like you in the past, trying to cut a corner and make a repair easy, it doesn't make it right. If you want to do it correctly then you have to take it apart and start over and inspect for possible damage.

at the very least, install a new crush sleeve torque the yoke and check preload on the bearing making sure its in spec and do not over shoot it, or you will need to start over again with another crush sleeve.

earlier ford 9" used a solid spacer in place of the crush sleeve, These solid spacers could be Torqued down heavily as long as the correct preload was obtained. i think that is where a lot of old school mechanics got the idea of using the impact wrench from, you can convert a 9" to use the solid spacer, in fact many drag racers do this because the soild spacer is stronger then the sleeve which is collapsible. the impact wrench was still a bad idea since the knocking was bad for the bearings but i can understand it for the sake of speed. With a collapsible sleeve its so easy to over torque the preload and ruin the rear.

+1 Hcode is dead on!Get yourself a shop manual and follow it step by step! Don't cut corners.I have set up three of them so far and each one has been a learning experiance.I finaly got it right on my third one (no noise). Read all you can,but be careful ! There are guides out there that leave out some very important steps that will make all the differance. Hcodes guide is a very good one! He pointed out a step that most over look as did I on my first two builds.I went back and re-read the Ford manual and found the step in another section.The point I was missing was where you spread the case.It made a differance in all my other settings.The crush sleeves are tricky the first time.After I ruined my first two I got it down. You have to go VERY slow and sneak up on your setting, and I do mean sneak! Buy extras when you buy one.