Mongoose
12-09-2004, 12:26 AM
I was going to post this in another thread but thought it would be best to start a new one
My Story:
My pinion seal had developed a very slight leak about 35K miles and about a dozen ¼ mile grocery runs after DR installed 4.10 gears so I had a dealer replace it. A week later the rearend started singing. Dennis graciously checked the backlash for me while I was in Fla. on a road trip. Backlash was OK. Singing continued to get louder. I couldn't be 100% positive what the problem was or what was the root cause. Dealer agreed to install new pinion bearings, pinion seal, carrier bearings, clutches, axle bearings and seals that I purchased from Ford Racing Parts. While the tech had the axles pulled, he noticed the parking brake shoes were shot on the passenger side and contacted me to get permission to replace @ $110. The day after the install, the pinion seal was leaking again worse than ever. Took the car back to the dealer to have the seal replaced. Five or so days later, the rearend starts singing again. Again I took the car back to the dealer. The service manager blamed the problem on defective parts that I had supplied and gave me an estimate of what it would cost to repair with him supplying the parts ($760, ring and pinion NOT included). He would not negotiate a compromise saying that they had done rebuilds like this many times and they never had a problem and were not at fault.
Now for the rest of the story:
With the help of a Helms manual and my friend Dave (you may have met him @ Indy), we rebuilt the rearend ourselves including installing a new 4.10 ring and pinion with all parts again being purchased from Ford Racing Parts. This was the first time for either of us. Being a machinist, I made the all the special tools needed for the job with the exception of the one that sets the clutch pack height that I had to get from SPX (maker of the special Rotunda tools). It's been almost 3 weeks now with no hint of a problem. I will be contacting the dealer for a refund shortly.
Facts:
To replace the pinion seal, the drive shaft yoke on the differential, which is secured by the pinion nut, must be removed.
When I went to pick the MM after the rearend had been rebuilt, the tech who did the work remembered he hadn't reconnected the ABS sensors and had me drive back into the service bay to reconnect them but "they had done rebuilds like this many times and they never had a problem and were not at fault". :bs:
As I was paying my bill for the rebuild, the tech mentioned he had a heck of a time getting the axles back in, but "they had done rebuilds like this many times and they never had a problem and were not at fault". :bs:
When I drove the car home after the rearend had been rebuilt, I heard a chirping noise coming from the rearend. I pulled the rear wheels and found that the tech had put a parking brake springs on backwards and had been almost worn in two by the ABS drums. The dealer ordered new springs and installed them the following day but "they had done rebuilds like this many times and they never had a problem and were not at fault". No wonder the tech had a problem getting the axles back in with the parking brake springs in the way. :bs:
The dealer charged me for 3 quarts of gear oil when the differential only holds 2 but "they had done rebuilds like this many times and they never had a problem and were not at fault". :bs:
You can ask for no better person than Dennis Reinhart to work on your MM. While he kept my car overnight, Dennis loaned me his personal MM so I didn't have to rent a car.
The parts purchased from FRP are exactly the same as the OEM with the exception of the pinion seal.
There is no warranty on parts purchased from Ford Racing Parts.
The Rotunda tool called out in the Helms manual for setting the clutch pack height is not the correct diameter tool. I ended up sending mine back for credit.
Opinion:
When replacing the pinion seal only, one should check how many inch-pounds it takes to rotate the pinion (the preload) before removing the pinion nut. This value is different from when you are setting up a new ring and pinion. When setting up a new ring and pinion, you would only be turning the pinion gear in an empty housing while setting its preload. When replacing the seal only, the wheels, disc brake calipers, axles, and differential add additional drag thus requiring more torque to rotate the pinion. Once the pinion seal is removed, the collapsible spacer (crush sleeve) should be removed and a new collapsible spacer installed along with a new pinion nut. The pinion preload should be constantly checked as the new pinion nut is torqued (approximately 200 foot-pounds) until the original preload is achieved.
I am of the opinion that both rearend failures were due to improper torquing of the pinion nut. Both failures appear to have been caused by over tightening of the pinion nut causing premature pinion bearing failure.
I welcome any comments and contradictions.
Charlie
My Story:
My pinion seal had developed a very slight leak about 35K miles and about a dozen ¼ mile grocery runs after DR installed 4.10 gears so I had a dealer replace it. A week later the rearend started singing. Dennis graciously checked the backlash for me while I was in Fla. on a road trip. Backlash was OK. Singing continued to get louder. I couldn't be 100% positive what the problem was or what was the root cause. Dealer agreed to install new pinion bearings, pinion seal, carrier bearings, clutches, axle bearings and seals that I purchased from Ford Racing Parts. While the tech had the axles pulled, he noticed the parking brake shoes were shot on the passenger side and contacted me to get permission to replace @ $110. The day after the install, the pinion seal was leaking again worse than ever. Took the car back to the dealer to have the seal replaced. Five or so days later, the rearend starts singing again. Again I took the car back to the dealer. The service manager blamed the problem on defective parts that I had supplied and gave me an estimate of what it would cost to repair with him supplying the parts ($760, ring and pinion NOT included). He would not negotiate a compromise saying that they had done rebuilds like this many times and they never had a problem and were not at fault.
Now for the rest of the story:
With the help of a Helms manual and my friend Dave (you may have met him @ Indy), we rebuilt the rearend ourselves including installing a new 4.10 ring and pinion with all parts again being purchased from Ford Racing Parts. This was the first time for either of us. Being a machinist, I made the all the special tools needed for the job with the exception of the one that sets the clutch pack height that I had to get from SPX (maker of the special Rotunda tools). It's been almost 3 weeks now with no hint of a problem. I will be contacting the dealer for a refund shortly.
Facts:
To replace the pinion seal, the drive shaft yoke on the differential, which is secured by the pinion nut, must be removed.
When I went to pick the MM after the rearend had been rebuilt, the tech who did the work remembered he hadn't reconnected the ABS sensors and had me drive back into the service bay to reconnect them but "they had done rebuilds like this many times and they never had a problem and were not at fault". :bs:
As I was paying my bill for the rebuild, the tech mentioned he had a heck of a time getting the axles back in, but "they had done rebuilds like this many times and they never had a problem and were not at fault". :bs:
When I drove the car home after the rearend had been rebuilt, I heard a chirping noise coming from the rearend. I pulled the rear wheels and found that the tech had put a parking brake springs on backwards and had been almost worn in two by the ABS drums. The dealer ordered new springs and installed them the following day but "they had done rebuilds like this many times and they never had a problem and were not at fault". No wonder the tech had a problem getting the axles back in with the parking brake springs in the way. :bs:
The dealer charged me for 3 quarts of gear oil when the differential only holds 2 but "they had done rebuilds like this many times and they never had a problem and were not at fault". :bs:
You can ask for no better person than Dennis Reinhart to work on your MM. While he kept my car overnight, Dennis loaned me his personal MM so I didn't have to rent a car.
The parts purchased from FRP are exactly the same as the OEM with the exception of the pinion seal.
There is no warranty on parts purchased from Ford Racing Parts.
The Rotunda tool called out in the Helms manual for setting the clutch pack height is not the correct diameter tool. I ended up sending mine back for credit.
Opinion:
When replacing the pinion seal only, one should check how many inch-pounds it takes to rotate the pinion (the preload) before removing the pinion nut. This value is different from when you are setting up a new ring and pinion. When setting up a new ring and pinion, you would only be turning the pinion gear in an empty housing while setting its preload. When replacing the seal only, the wheels, disc brake calipers, axles, and differential add additional drag thus requiring more torque to rotate the pinion. Once the pinion seal is removed, the collapsible spacer (crush sleeve) should be removed and a new collapsible spacer installed along with a new pinion nut. The pinion preload should be constantly checked as the new pinion nut is torqued (approximately 200 foot-pounds) until the original preload is achieved.
I am of the opinion that both rearend failures were due to improper torquing of the pinion nut. Both failures appear to have been caused by over tightening of the pinion nut causing premature pinion bearing failure.
I welcome any comments and contradictions.
Charlie