Blown Rear End

[FullBlownModz]

Welp, blew up my 8.8 once again! I need help from yall though. The spider gears and cross shaft are toast, but only one tooth on the pinion gear is damaged. Normally, I would just replace the pinion and regear, but I am about to throw in a ford 9 inch within the next month or two. I am only concerned because I have a 3 hour drive to make in this thing in a month. What do yall think?
1) replace the pinion gear and regear with new bearings
OR
2) just replace the spider gears and cross shaft until I can regear and assemble my 9 inch

 

[imp]

Welp, blew up my 8.8 once again! I need help from yall though. The spider gears and cross shaft are toast, but only one tooth on the pinion gear is damaged. Normally, I would just replace the pinion and regear, but I am about to throw in a ford 9 inch within the next month or two. I am only concerned because I have a 3 hour drive to make in this thing in a month. What do yall think?
1) replace the pinion gear and regear with new bearings
OR
2) just replace the spider gears and cross shaft until I can regear and assemble my 9 inch

@FullBlownModz
Depends on one important thing. If you turn the pinion by hand, can you feel the damage to the tooth? Does it make noise when running normally? If no, drive it as is. If yes, further chipping of teeth is likely, with complete disastrous failure possible. a large piece of tooth trapped against the ring gear will break the teeth off, then jam the next in line, breaking them, and so on. At best, gears wrecked. At worst, the entire center section casting can be broken in two. I saw one split from top to bottom, clean in two, and was a 9-inch. 1963-1/2 427 fastback. imp

 

[Mr. Alligator]

Just do what you can to get by, and rent a car for the trip.

Just an idea.

 

[koda2000]

When I discovered the rear diff in my '01 Sport Trac was trashed, I went to the salvage yard and bought a complete rear diff out of a 4 door Explorer with the same gear ratio. It came with a 30 day warranty. I removed the cover and found everything to appear to be in good order and it appeared the diff had been recently serviced. I replaced the axle seals before installing the used rear.

Installing the replacement diff was straight forward. Cost me $300. Used parts can save you big-time, but it's a crap shoot. Having a rear end professional rebuilt can run you $1500 and it's a job that is above the capabilities of most DIY'er's.

 

[FullBlownModz]

Depends on one important thing. If you turn the pinion by hand, can you feel the damage to the tooth? Does it make noise when running normally? If no, drive it as is. If yes, further chipping of teeth is likely, with complete disastrous failure possible. a large piece of tooth trapped against the ring gear will break the teeth off, then jam the next in line, breaking them, and so on. At best, gears wrecked. At worst, the entire center section casting can be broken in two. I saw one split from top to bottom, clean in two, and was a 9-inch. 1963-1/2 427 fastback. imp

Unfortunately, it does make a noise when the ring and pinion mesh together at the damaged pinion tooth. I replaced the spider gears, and we will see what happens since the ring and pinion already need to be replaced. I was thinking about grinding down and smoothing out the damaged tooth, but i dont have an extra crush sleeve. They come from ford with crush sleeves or solid spacers?

Just do what you can to get by, and rent a car for the trip.
Just an idea.

Im doing what i can for the time being. I have 2015 mustang i can borrow for the trip, but i don't think it would hold up well since its a 4 day camping trip haha

 

[imp]

Unfortunately, it does make a noise when the ring and pinion mesh together at the damaged pinion tooth. I replaced the spider gears, and we will see what happens since the ring and pinion already need to be replaced. I was thinking about grinding down and smoothing out the damaged tooth, but i dont have an extra crush sleeve. They come from ford with crush sleeves or solid spacers?



Im doing what i can for the time being. I have 2015 mustang i can borrow for the trip, but i don't think it would hold up well since its a 4 day camping trip haha

@FullBlownModz
You CAN smooth off the chipped tooth area. What matters is HOW MUCH of the entire face of the gear tooth has been damaged. If over half, it's likely under severe strain the entire tooth will break off, with possible results I described above. Any sharp edges intersecting the mating tooth faces will produce noise. This is especially true if bearing preloads are not adequate.

Ford used solid spacers only on production high-performance options, cop cars, and taxicabs, years back. Now, I dunno. Much harder to set up, especially on a production line basis. Re-using a crush washer is tickling the dragon's tail. Best is a new crush washer, but if a thin steel washer of correct inside diameter and about 0.010-0.020 thickness can be found, it will serve to further crush a used crush washer, making the assembly acceptable. Pinion bearing preloads MUST be correct, or noise and failure will come about quickly. imp

 

[FullBlownModz]

You CAN smooth off the chipped tooth area. What matters is HOW MUCH of the entire face of the gear tooth has been damaged. If over half, it's likely under severe strain the entire tooth will break off, with possible results I described above. Any sharp edges intersecting the mating tooth faces will produce noise. This is especially true if bearing preloads are not adequate.

Ford used solid spacers only on production high-performance options, cop cars, and taxicabs, years back. Now, I dunno. Much harder to set up, especially on a production line basis. Re-using a crush washer is tickling the dragon's tail. Best is a new crush washer, but if a thin steel washer of correct inside diameter and about 0.010-0.020 thickness can be found, it will serve to further crush a used crush washer, making the assembly acceptable. Pinion bearing preloads MUST be correct, or noise and failure will come about quickly. imp

I ended up just not messing with anything besides replacing the spiders. There was one sharp spot that was making noise when it meshed with the ring gear. I should have knocked it off, but im buying a new set of 4.10s (Motive brand) soon. I drove up to 50mph and floored it from a stop going up a hill, and everything seemed alright. The noise was loud at first, but after driving a few miles, it quieted down. I mainly hear it louder when im coasting vs gassing it. Could this mean the coast side of the damaged tooth was more damaged than the drive side?

 

[imp]

I ended up just not messing with anything besides replacing the spiders. There was one sharp spot that was making noise when it meshed with the ring gear. I should have knocked it off, but im buying a new set of 4.10s (Motive brand) soon. I drove up to 50mph and floored it from a stop going up a hill, and everything seemed alright. The noise was loud at first, but after driving a few miles, it quieted down. I mainly hear it louder when im coasting vs gassing it. Could this mean the coast side of the damaged tooth was more damaged than the drive side?

@FullBlownModz
Yes, of course. But the coast side of the gear teeth impose far less load upon the gearset than the drive side, due to the amount of torque being transmitted. imp