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9 inch carrier problem

tarafied1

tarafied1

Well-Known Member
The 9 inch carrier I had in the Mustang with the 2.79 gears had a major problem. The carrier bearing adjuster on one side blew out. Looks like the threads just stripped. The locking tab was still holding it so I know it didn't unscrew itself. I noticed this horrible noise after stomping on the throttle pretty hard one day. I've been running the carrier for a while. I had 4.11 traction lock diff in it but put this 2.79 open diff in well before Power Tour last year and just left in. I've switched to a 3.73 I got from Rick because it's better than the 4.11's but I think I'm going to put different ring and pinion in the 4.11 carrier with the limited slip diff.
Anyone ever seen a 9 inch do this? Just too much torque from the 429?
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If the inside thread is OK , it had unscrewed itself by a blocked bearing ????
Seems it is the left side of the carrier, so unscrewed itself is possible , I think. IMHO.
 
the tab that bolts on (you can see it in the picture) was still in the hole so it couldn't have unscrewed. The bearings look okay, no galling or bluing. The threads are shot on the adjuster and the carrier. The photo is exactly how I pulled it out.
It appears that the whole ring carrier pushed to the left and forced the adjuster out of the diff???
 
"tarafied1" said:
Just too much torque from the 429?
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Guys are putting way more torque than that through stock type 9" set-ups so it's not simply a matter of too much torque.
 
I have never seen that happen, very strange. They can be fixed the same way you would line boor mains or resize the big end of rods. May be more cost effective to replace the center section unless it is a nodular unit.
 
it was nothing special. I'll just scrap it.
My wife couldn't stand the noise and was worried about gas mileage so I bought a junkyard 9" diff with 2.50:1 gears. swapped it in this afternoon. I will run that on the Power Tour. I'll build a 3.50 or another 3.70 to swap in after the tour. The 3.70 I took out was a nice ratio but just loud!
 
Ahhhh...another blue-hair on the roads! Welcome to the slow side!
 
2.50:1??? never knew they went that low, you'll have to get Tara to push start you at the beginning of every event...
 
oh that 429 has plenty of grunt, it does feel different but with the 3.70's it would get sideways. Now it is a little more controlled. I think I can live with it for the tour but it won't stay in there!
 
With that torque of your engine , you gonna put alot of load on that third member !!!!! 2.50 or 2.79 :hide

Maybe that was the problem with the busted one ?? :confu :confu
 
"SELLERSRODSHOP" said:
2.50 was the standard gearset in the lincoln versailles disc brake 9" everyone used to covet.
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My Versailles 9" had the 2.79 but I had heard 2.50's were common in them. This diff came out of a truck I think because the yoke was huge and very long with a big shield on it.
Anyway, I drove the car over 300 miles this weekend with no issues. It's not gonna win most drag races but on the highway at 70 - 75 it was only turning about 2,000 rpms with no OD.
 
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