New Gears for a Ford 8.8

#1
Gear installs seem to be the redheaded stepchild of the automotive industry. No one wants to mess with them, and everyone has some interesting stories to share. While the installation of gears may seem like rocket science if you have read through some of the installation instructions, with the proper tools and techniques it can be done. These proper techniques are perfected with experience and as easy as it may sound, you probably won’t want your first try to be on something you daily drive.

An improperly setup ring and pinion can have a variety of problems ranging from excessive noise to gear damage and failure. These unfortunate side effects are something I just couldn’t take a chance on in my daily driven trail rig, so when it was time for new gears in the Ford 8.8 in my TJ I decided to let the pros do what they do best. I enlisted the guys at CFS Off-Road in Columbia, SC to do the install while I took some pictures to let yall see how it’s done.



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After doing most of the work to my jeep on my back on the ground laying in the dirt,
the first step for this install made the process that much nicer as we put the jeep on the lift and raised it up.​



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After draining the gear oil, the tires, wheel spacers, and brake calipers were removed.



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Because the Ford 8.8 is a c-clip axle we removed the cross pen and clips inside the ARB in order to remove the shafts.
On a non c-clip axle such as a dana 44 or 60 you would need to remove the four bolts on the bearing retainer on each side of the axle housing.




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The ARB line was disconnected and the carrier bearing straps were removed in order to pull the carrier from the housing.



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Once the carrier is out you can clearly see the pinion gear huddled up in the housing.
 
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#2
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After removing the old ring gear from the carrier we got the near gears ready to go.



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Always use thread lock on the ring gear bolts when installing the ring gear onto the carrier.
Back in college I remember riding with a roommate on 123 coming back into Clemson when
some of his backed out after the installer didn’t threadlock and torque them properly.
Threadlock is cheap insurance, so use it.





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The pinion was then removed using an impact wrench.




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After seeing my 8.8 driveshaft flange I’m surprised I’m not having leaking issues, mud and grit has worked
with the seal to grind grooves into the flange. Unfortunately I didn’t have another flange on hand,
so we reused the old flange. In this picture you can see the burnt gear oil sludge from the extreme
heat the old gears were creating.




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Here you can see the new ring gear on the carrier and the old pinion
before the old bearing and shims are removed.
 
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#3
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Here is the housing without the internals almost ready for the new parts.



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One of the important tools needed for setting up gears is a bearing puller. While you can avoid this by
buying or making setup bearings for your specific axle, being able to remove bearings that have been
pressed on makes the process much simpler. Here Jason explains how to adjust the preload on the
bearing puller collar and then remove the bearing.




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The new pinion bearing races were tapped into the housing. And the new pinion was installed
for the first time. The old shims were removed from the old pinion, measured and used as a
starting point, then .015” were added to the pinion shim stack to bring it up to .031” to
achieve proper pinion depth.



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Jason attached an interesting custom tool to hold the pinion flange. Then he used an impact
wrench to tighten the pinion nut until he reached the appropriate pinion bearing preload of
between 20-25 inch pounds.
 
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#4
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New pinion in its new home, ready for the carrier.



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After installing the carrier with the initial shim set, Jason checked the backlash.
He explained that as he got close to the appropriate gear pattern he would up
the shims to tighten the carrier preload, then check for proper backlash again.




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Jason changes the shims on the carrier to adjust the backlash. One thing about using
an ARB in a Ford 8.8 is that the shims actually go on the outside of the bearings, so each
time you adjust the carrier shims you don’t have to remove the bearings from the carrier.



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Mike preps the cover and housing while Jason reinstalls the Carrier.



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After checking backlash a second time we got .008 which for an 8.8 should be between
.006 and .015 depending on the application. With the correct backlash on the carrier
Jason applies some gear marking paint to check the pattern on ring gear.
 
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#5
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While checking the pattern make sure you apply ample resistance to the pinion in order to
get an accurate reading. This is the first attempt and from the pattern we could tell that
we needed to change the carrier position a bit.




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Jason checking the shim thickness on the new shims before
putting the carrier back in for another attempt.




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After checking backlash again, Jason applies more marking paint and checks the pattern.
This one looked much better and we decided to run with it.





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Jason checks the torque on the carrier bearing straps before continuing with reassembly.



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Shafts installed along with the c-clips
 
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#6
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After putting in the c-clips, the Cross pin is put back into the ARB and this picture was
right before tightening the retaining pen. The ARB is hooked back up as well. After
this we tested the ARB to make sure it would lock and unlock and wasn’t leaking
and it was time to seal it up.

Note: you can barely tell in this picture, but one ring gear tooth was filed down in
order for the cross pin to go into the carrier. This is a common modification needed
with gears lower than 4.10 in many axles.




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With it all buttoned up and full of gear oil I headed back down the road.



Thanks to Jason and Mike at CFS Off-Road for doing the install and letting me
peak over their shoulder and take pictures as they worked.





SOURCES

CFS Off-Road
1614 Barnwell Street
Columbia, SC 39201
803-550-9411

East Coast Gear Supply
6508 Mt Herman Road
Raleigh, NC 27617
919-672-2705
 
#7
One thing you forgot I mention is the bearing carrier straps or whatever they are called are specific to why side try need to be on, so they need to get marked with something so that they are in the same orientation they were when the axle was stock.


And just to be knit picky all 8.8s you put the shims on the outside and do not press the bearings on like you would with a Dana 30.


Hope those gears hold up well, the pattern looks pretty good!
 
#8
Thanks Mason, I tried to include a few details, but there are so many things to keep track of I just listed the major stuff.

And I didnt know about that for all 8.8s shims. interesting.
 
#9
It may not be that way for the open carrier, but that is how it was for my LSD. And yeah you did a real good job on the right up.
 
#14
Yea I think he had some gear whine due to manufacturing error that was warranteed but he had to wait 10 yrs before they would warranty it.
 
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