Gear install
02-14-2015, 06:10 PM
#21
3rd Gear Member
Thread Starter
Join Date: Jan 2010
Location: Louisiana
Posts: 738
Alrighty then.... Started working on it this morning, gears arrived around 2PM today along with the install kit. It only took me about an hour by myself with some tools to drop the rear and get it on a set of jack stands. I am very familiar with the breakdown at this point.
I took my time with the tear down, checking things as I went along (backlash, making sure everything was tight, checking wear pattern on the bearings, etc.). Got all the way down to the pinion with no problems evident. Check for walkout on the pinion and bingo. The pinion had a slight wobble to it, hardly evident unless you really checked for it. I am guessing I didn't put enough torque on the pinion nut to crush the crush ring enough and therefore didn't have enough preload on the bearing. I am amazed that I didn't because it was me and another full grown man wrenching on the nut as hard as we could. This would make sense though because the noise that made me want to tear it down made me think it was preload. Going from drive to coast side I would get a rumbling sound, like my car was going over a small rumble strip. It only made the noise on the transition from drive to coast and back, not while accelerating or decelerating.
Wear pattern on the gears doesn't look 100% perfect but it damn sure is in the list of acceptable wear patterns.
Gonna pickup a BIG torque wrench that can do 250+ lbs because apparently that's what's needed to crush the crush ring. Also gonna get a beam type in-lb torque wrench to double check for 4-5 in-lb of preload on the pinion this time.
Putting links to higher resolution pics:
https://i.imgur.com/CDYz7Cj.jpg
https://i.imgur.com/70i6AVG.jpg
https://i.imgur.com/Sunco7w.jpg
I took my time with the tear down, checking things as I went along (backlash, making sure everything was tight, checking wear pattern on the bearings, etc.). Got all the way down to the pinion with no problems evident. Check for walkout on the pinion and bingo. The pinion had a slight wobble to it, hardly evident unless you really checked for it. I am guessing I didn't put enough torque on the pinion nut to crush the crush ring enough and therefore didn't have enough preload on the bearing. I am amazed that I didn't because it was me and another full grown man wrenching on the nut as hard as we could. This would make sense though because the noise that made me want to tear it down made me think it was preload. Going from drive to coast side I would get a rumbling sound, like my car was going over a small rumble strip. It only made the noise on the transition from drive to coast and back, not while accelerating or decelerating.
Wear pattern on the gears doesn't look 100% perfect but it damn sure is in the list of acceptable wear patterns.
Gonna pickup a BIG torque wrench that can do 250+ lbs because apparently that's what's needed to crush the crush ring. Also gonna get a beam type in-lb torque wrench to double check for 4-5 in-lb of preload on the pinion this time.
Putting links to higher resolution pics:
https://i.imgur.com/CDYz7Cj.jpg
https://i.imgur.com/70i6AVG.jpg
https://i.imgur.com/Sunco7w.jpg
02-24-2015, 05:49 AM
#25
2nd Gear Member
Join Date: Sep 2009
Location: Ontario, Canada
Posts: 355
Just putting together a 1” per side shortened diff now. I hope you do not mind if a share some of my experience.
I bought an extra pinion bearing so I could open it up enough with a 1.5” sanding disk and a Dremel to be able to slip it on and off the pinion while determining the correct pinion shim depth required.
Made up a tool to hold the pinion flange when tightening the pinion nut.
Used a Park Tool model TW-1 Torque Wrench (1/4-inch drive, 0 to 60 Inch) for measuring bearing preload. I followed the FRPP instructions and achieved a bearing preload of 22 in-lbs measured with the Park Tool Torque Wrench (16 – 28 in-lbs recommended for new bearings).
Packed the left and right carrier bearings with shims until a achieved a .009 backlash. FRPP recommendation is .008 to .012.
And achieved the following tooth patterns.
Coast pattern:
Drive pattern:
I bought an extra pinion bearing so I could open it up enough with a 1.5” sanding disk and a Dremel to be able to slip it on and off the pinion while determining the correct pinion shim depth required.
Made up a tool to hold the pinion flange when tightening the pinion nut.
Used a Park Tool model TW-1 Torque Wrench (1/4-inch drive, 0 to 60 Inch) for measuring bearing preload. I followed the FRPP instructions and achieved a bearing preload of 22 in-lbs measured with the Park Tool Torque Wrench (16 – 28 in-lbs recommended for new bearings).
Packed the left and right carrier bearings with shims until a achieved a .009 backlash. FRPP recommendation is .008 to .012.
And achieved the following tooth patterns.
Coast pattern:
Drive pattern:
02-28-2015, 07:30 PM
#28
3rd Gear Member
Thread Starter
Join Date: Jan 2010
Location: Louisiana
Posts: 738
Slight change of plans. I'm gonna make sure the rear end is done right before I paint it, which means a re-install, making sure it's right, then tearing it back out and painting it then putting it back in.
I thought about it for a while and came to the conclusion that 4.10's are just too fun not to have so I threw the 4.10's back in with the same shimming and preloaded the pinion bearing to 25 in-lb's. Popped the RA back in and the backlash was at .020" so I swapped a shim at it ended up at .008-.009", .008" being the very lowest in spec. Got it back in, as I type this the only thing I have left to do is re-install the watt's link which is a task in itself because I removed the axle tube mounts and because of that I have to re-center the rear based on the fenders before I get up under the car and tighten the tube mounts. Hoping to have her back up and running tomorrow for some test runs in good weather.
I learned some stuff while the rear end was out though about ford racing gears. According to Ford you should never need to re-shim the pinion depth if you use FR gears. If you have .010" from the factory, the FR pinion should use the same shim and you should also use the stock shims for the RA (I broke mine in the process of re-installing so I couldn't). According to my pattern that info is dead on because I went back with .010" and it was perfect. Crossing my fingers for no whine and smooth running.
I thought about it for a while and came to the conclusion that 4.10's are just too fun not to have so I threw the 4.10's back in with the same shimming and preloaded the pinion bearing to 25 in-lb's. Popped the RA back in and the backlash was at .020" so I swapped a shim at it ended up at .008-.009", .008" being the very lowest in spec. Got it back in, as I type this the only thing I have left to do is re-install the watt's link which is a task in itself because I removed the axle tube mounts and because of that I have to re-center the rear based on the fenders before I get up under the car and tighten the tube mounts. Hoping to have her back up and running tomorrow for some test runs in good weather.
I learned some stuff while the rear end was out though about ford racing gears. According to Ford you should never need to re-shim the pinion depth if you use FR gears. If you have .010" from the factory, the FR pinion should use the same shim and you should also use the stock shims for the RA (I broke mine in the process of re-installing so I couldn't). According to my pattern that info is dead on because I went back with .010" and it was perfect. Crossing my fingers for no whine and smooth running.
02-28-2015, 09:51 PM
#29
3rd Gear Member
Thread Starter
Join Date: Jan 2010
Location: Louisiana
Posts: 738
Just went for a test drive. Gears are freakin silent now!
Now I have a new problem. For whatever reason my driver side rear brake is holding pressure on the disc. Need to figure it out. During the test drive it felt like my parking brake was on, when I got home I could smell burnt brake pad so I used the touch test and the only thing hot was the driver side rear disc. Probably gonna save that for tomorrow.
Now I have a new problem. For whatever reason my driver side rear brake is holding pressure on the disc. Need to figure it out. During the test drive it felt like my parking brake was on, when I got home I could smell burnt brake pad so I used the touch test and the only thing hot was the driver side rear disc. Probably gonna save that for tomorrow.
