Differential Repair -Genius or Dolt?
10-31-2013, 03:27 PM
#1
Junior Member
Thread Starter
Differential Repair -Genius or Dolt?
Well, I have had my second "incident" with a 4x4 differential coming apart. The first was with the GMC front, now with a 2000 F-150 8.8 rear. In both cases the bolts holding a ring gear backed out and punched through the housing, or in the case of the Ford, the differential cover.
I hate doing things more than once. So I never want this to happen again. My solution was a belt and suspenders approach. So you can be the judge. I am a genius for engineering a solution the factory should have done all along, or am I the dolt who's half baked idea is going to bite him in the rear (literally in this case) at some later date?
I had three bolts back out of the ring gear assembly. Two were rattling around loose on the left side of the differential. the third was half out and bent, a fourth bolt had the head sheared off, and another had to be filed down to fit in the 3/4" socket.
So now, ideally, I would replace all ten bolts, and this should be no problem given the historical popularity of the 8.8 rear end in Mustangs to F-150's for more than decade. Alas, it was not so. I could only find three bolts at each of 2 dealerships in the Minneapolis/Saint Paul area. One dealer could not find the three they thought were in inventory so I was down to three factory bolts. Not enough to do the job. So off to the hardware store for a full set of generic 7/16-20x3/4 grade 8 bolts.
Now to the genius part (at least in my mind). While at the hardware store, I grabbed some 1" wide brass stock and made 5 plate washers for each set of 2 adjacent bolts. After thoroughly degreasing the bolt holes and applying the reworkable version of thread locker, I torqued the bolts down over the brass plates.
Once the bolts were torqued, I used a chisel to bend up the edge of the brass plate against one of the flats on the bolt head. In order to back out now, the bolts will have to shear off a brass tab. My hope is that will not be likely.
I simply did not trust my ability to adequately degrease the bolt holes to rely only on thread locker. In addition, I assume the factory used a thread locker on the original bolts prior to spending 160k miles in an oil bath and that is what failed the first time.
So what do you think? I am I dolt
or genius 
?
I hate doing things more than once. So I never want this to happen again. My solution was a belt and suspenders approach. So you can be the judge. I am a genius for engineering a solution the factory should have done all along, or am I the dolt who's half baked idea is going to bite him in the rear (literally in this case) at some later date?
I had three bolts back out of the ring gear assembly. Two were rattling around loose on the left side of the differential. the third was half out and bent, a fourth bolt had the head sheared off, and another had to be filed down to fit in the 3/4" socket.
So now, ideally, I would replace all ten bolts, and this should be no problem given the historical popularity of the 8.8 rear end in Mustangs to F-150's for more than decade. Alas, it was not so. I could only find three bolts at each of 2 dealerships in the Minneapolis/Saint Paul area. One dealer could not find the three they thought were in inventory so I was down to three factory bolts. Not enough to do the job. So off to the hardware store for a full set of generic 7/16-20x3/4 grade 8 bolts.
Now to the genius part (at least in my mind). While at the hardware store, I grabbed some 1" wide brass stock and made 5 plate washers for each set of 2 adjacent bolts. After thoroughly degreasing the bolt holes and applying the reworkable version of thread locker, I torqued the bolts down over the brass plates.
Once the bolts were torqued, I used a chisel to bend up the edge of the brass plate against one of the flats on the bolt head. In order to back out now, the bolts will have to shear off a brass tab. My hope is that will not be likely.
I simply did not trust my ability to adequately degrease the bolt holes to rely only on thread locker. In addition, I assume the factory used a thread locker on the original bolts prior to spending 160k miles in an oil bath and that is what failed the first time.
So what do you think? I am I dolt
or genius ?
10-31-2013, 10:57 PM
#2
Senior Member
iTrader: (1)
Well, I have had my second "incident" with a 4x4 differential coming apart. The first was with the GMC front, now with a 2000 F-150 8.8 rear. In both cases the bolts holding a ring gear backed out and punched through the housing, or in the case of the Ford, the differential cover.
I hate doing things more than once. So I never want this to happen again. My solution was a belt and suspenders approach. So you can be the judge. I am a genius for engineering a solution the factory should have done all along, or am I the dolt who's half baked idea is going to bite him in the rear (literally in this case) at some later date?
I had three bolts back out of the ring gear assembly. Two were rattling around loose on the left side of the differential. the third was half out and bent, a fourth bolt had the head sheared off, and another had to be filed down to fit in the 3/4" socket.
So now, ideally, I would replace all ten bolts, and this should be no problem given the historical popularity of the 8.8 rear end in Mustangs to F-150's for more than decade. Alas, it was not so. I could only find three bolts at each of 2 dealerships in the Minneapolis/Saint Paul area. One dealer could not find the three they thought were in inventory so I was down to three factory bolts. Not enough to do the job. So off to the hardware store for a full set of generic 7/16-20x3/4 grade 8 bolts.
Now to the genius part (at least in my mind). While at the hardware store, I grabbed some 1" wide brass stock and made 5 plate washers for each set of 2 adjacent bolts. After thoroughly degreasing the bolt holes and applying the reworkable version of thread locker, I torqued the bolts down over the brass plates.
Once the bolts were torqued, I used a chisel to bend up the edge of the brass plate against one of the flats on the bolt head. In order to back out now, the bolts will have to shear off a brass tab. My hope is that will not be likely.
I simply did not trust my ability to adequately degrease the bolt holes to rely only on thread locker. In addition, I assume the factory used a thread locker on the original bolts prior to spending 160k miles in an oil bath and that is what failed the first time.
So what do you think? I am I dolt or genius ?
I hate doing things more than once. So I never want this to happen again. My solution was a belt and suspenders approach. So you can be the judge. I am a genius for engineering a solution the factory should have done all along, or am I the dolt who's half baked idea is going to bite him in the rear (literally in this case) at some later date?
I had three bolts back out of the ring gear assembly. Two were rattling around loose on the left side of the differential. the third was half out and bent, a fourth bolt had the head sheared off, and another had to be filed down to fit in the 3/4" socket.
So now, ideally, I would replace all ten bolts, and this should be no problem given the historical popularity of the 8.8 rear end in Mustangs to F-150's for more than decade. Alas, it was not so. I could only find three bolts at each of 2 dealerships in the Minneapolis/Saint Paul area. One dealer could not find the three they thought were in inventory so I was down to three factory bolts. Not enough to do the job. So off to the hardware store for a full set of generic 7/16-20x3/4 grade 8 bolts.
Now to the genius part (at least in my mind). While at the hardware store, I grabbed some 1" wide brass stock and made 5 plate washers for each set of 2 adjacent bolts. After thoroughly degreasing the bolt holes and applying the reworkable version of thread locker, I torqued the bolts down over the brass plates.
Once the bolts were torqued, I used a chisel to bend up the edge of the brass plate against one of the flats on the bolt head. In order to back out now, the bolts will have to shear off a brass tab. My hope is that will not be likely.
I simply did not trust my ability to adequately degrease the bolt holes to rely only on thread locker. In addition, I assume the factory used a thread locker on the original bolts prior to spending 160k miles in an oil bath and that is what failed the first time.
So what do you think? I am I dolt
or genius ?Im going to go with the only time will tell approach but im hoping for the best for you man
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BrusselsSprout (11-01-2013)
11-01-2013, 11:09 AM
#3
Junior Member
Thread Starter
Tell me something I didn't know....
Yeah, that is exactly where I am as well, time will tell. I am hoping to draw a consensus from the community on this one. Thanks for playing
!
11-01-2013, 05:37 PM
#4
Have seen it done with steel strips or drilled and wire ties. I would have used Loctite Red and Loctite cleaner. I worry that the brass will give with time.
11-01-2013, 08:10 PM
#5
11-03-2013, 08:07 AM
#6
Junior Member
Thread Starter
What did the factory do?
Yeah, but I assume the factory assembled this with threadlock to begin with. Further, the Ford factory had ideal starting conditions with the ability to assemble this with clean oil free surfaces. Yet 130k mles later it is dissembled all by itself.
I am a specialist in precision cleaning by trade and did my best to clean the ring gear throughly, but it has spent 130k miles saturating the metal pores in gear lube; so I have little confidence I am able to clean this completely without soapy water, solvents and a big ultrasonic tank.
So what did the factory do when they assembled it originally?
I am a specialist in precision cleaning by trade and did my best to clean the ring gear throughly, but it has spent 130k miles saturating the metal pores in gear lube; so I have little confidence I am able to clean this completely without soapy water, solvents and a big ultrasonic tank.
So what did the factory do when they assembled it originally?
