Stranger in the Black Sedan
05-04-2008, 08:13 PM
I have been chasing slight axle howl above 40 mph with my MM since I have owned it. I had the dealer do the TSB axle kit about 7,000 miles ago. I have been assuming the howl was ring and pinion related. I bought a rotunda/OTC tool and I have literally been through 3 different brand new genuine OEM gear sets, which all set up perfectly, trying to figure out the rear axle noise. I just spent the better part of a week w/ the rear apart again double checking the Ford 3.73s, and replacing the carrier. I checked axial and lateral runout on the carrier and it was less than 1 thou each. Just for the heck of it, I replaced the carrier anyway with another unit. No difference.
One thing I noticed this time I had the rear apart, was that the passenger's side axle shaft bearing journal has a groove starting to form where the wheel bearing rides. The groove does not catch a fingernail yet but it is very narrow and very noticeable. I can't figure out why a cylindrical roller bearing is leaving such a concentrated narrow groove in the new TSB replacement axle shaft. The driver's side axle shaft is starting to make a similar narrow groove, but it is nowhere near as bad as the passenger's side (powered) axle shaft. Also--- If I grab the pass side wheel flange and rock it vertically, there is a very small amount of play. The driver's side shaft has no play I can tell of.
Have a look
http://s134.photobucket.com/albums/q116/shylin01/2003%20Mercury%20Marauder/Resetting%20the%20373s/?action=view¤t=resettingthe373s018.jp g
Does this look like "normal" wear on a 7,000 mile TSB replacement axle shaft? I need to know from someone who has a lot of experience dealing w/ the junk soft axles in these cars, and what type of wear is bad wear on the journal.... I am thinking either the dealer did not seat the new wheel bearings properly and they are cocked in the housing, or the TSB axle kit axles are also soft and not heat treated properly.
If this is really the source of the slight howl at speed, and I have wasted $1500 changing out gear sets (cost of tons and tons of bearings, I had to buy the OTC/Rotunda tool kit, and 3 Ford new gear sets), I will be furious. But at least maybe I am on to something finally.
If there were an easy swap, I'd put a 9" in this car at this point. This is getting really, really ridiculous for such a low power application.
One thing I noticed this time I had the rear apart, was that the passenger's side axle shaft bearing journal has a groove starting to form where the wheel bearing rides. The groove does not catch a fingernail yet but it is very narrow and very noticeable. I can't figure out why a cylindrical roller bearing is leaving such a concentrated narrow groove in the new TSB replacement axle shaft. The driver's side axle shaft is starting to make a similar narrow groove, but it is nowhere near as bad as the passenger's side (powered) axle shaft. Also--- If I grab the pass side wheel flange and rock it vertically, there is a very small amount of play. The driver's side shaft has no play I can tell of.
Have a look
http://s134.photobucket.com/albums/q116/shylin01/2003%20Mercury%20Marauder/Resetting%20the%20373s/?action=view¤t=resettingthe373s018.jp g
Does this look like "normal" wear on a 7,000 mile TSB replacement axle shaft? I need to know from someone who has a lot of experience dealing w/ the junk soft axles in these cars, and what type of wear is bad wear on the journal.... I am thinking either the dealer did not seat the new wheel bearings properly and they are cocked in the housing, or the TSB axle kit axles are also soft and not heat treated properly.
If this is really the source of the slight howl at speed, and I have wasted $1500 changing out gear sets (cost of tons and tons of bearings, I had to buy the OTC/Rotunda tool kit, and 3 Ford new gear sets), I will be furious. But at least maybe I am on to something finally.
If there were an easy swap, I'd put a 9" in this car at this point. This is getting really, really ridiculous for such a low power application.