2005 4.6 2WD Differential noise - plan of attack
10-31-2022, 05:01 PM
#1
2005 4.6 2WD Differential noise - plan of attack
Working on a 2005 4.6 I got cheap for the land to run around on. Previous owners said bad differential or calipers (what?). Basically horrible noise from the back. I tore into it and found the root cause, parking brake shoe had come loose and knurled around the hub and grenaded inside the rotor. Huge mess. Fixed all that, wheels spin easy and it’s driveable. However, lot of noise at about 10mph and increases with speed / RPM. Shifting to neutral makes no difference. Quiet at a stop and reviving, definitely from the tailhousing back. I’m thinking bearings, maybe ring and pinion. No leaks, it’s full of fluid. H9 axle, LSD with 3.55’s.
Trying to avoid a FULL diff rebuild with gears, clutches and bearings.
I’m guessing fluid has never been changed but I’m not sure fresh fluid would fix any issue if damage is already done.
Trying to avoid a FULL diff rebuild with gears, clutches and bearings.
I’m guessing fluid has never been changed but I’m not sure fresh fluid would fix any issue if damage is already done.
10-31-2022, 05:45 PM
#2
Working on a 2005 4.6 I got cheap for the land to run around on. Previous owners said bad differential or calipers (what?). Basically horrible noise from the back. I tore into it and found the root cause, parking brake shoe had come loose and knurled around the hub and grenaded inside the rotor. Huge mess. Fixed all that, wheels spin easy and it’s driveable. However, lot of noise at about 10mph and increases with speed / RPM. Shifting to neutral makes no difference. Quiet at a stop and reviving, definitely from the tailhousing back. I’m thinking bearings, maybe ring and pinion. No leaks, it’s full of fluid. H9 axle, LSD with 3.55’s.
Trying to avoid a FULL diff rebuild with gears, clutches and bearings.
I’m guessing fluid has never been changed but I’m not sure fresh fluid would fix any issue if damage is already done.
Trying to avoid a FULL diff rebuild with gears, clutches and bearings.
I’m guessing fluid has never been changed but I’m not sure fresh fluid would fix any issue if damage is already done.
you’re not out much (time or money) by opening it up to look, clean it out and give it new fluid (and MC friction modifier).
10-31-2022, 05:47 PM
#3
True. 75W140 seems to be the standard but also seen 75W90. I may grab 3 quarts and the MC FM and try it. Do these covers have a gasket or just RTV?
11-01-2022, 05:17 AM
#5
Mark
iTrader: (1)
RTV.
11-01-2022, 06:45 PM
#6
Senior Member
The original fluid spec in 2004 was 75w90 but somewhere in 2005-2006 I believe it was they changed it to the 75w140 spec going forward and recommended it for the 04-05 if work was done or fluid changed as well.
the factory used rtv to seal the cover on as already noted.
Personally i sort of doubt new fluid would reduce any noise except for limited slip clutch chatter, but it certainly can't hurt to change it and take a look around in there. Inspect gear teeth for wear, measure backlash if you have a dial indicator, check the pinion yoke for in/out and side to side play that would indicate loose pinion bearing.
You could pull the axles out and inspect the wheel bearings and mating surfaces on the axles for any signs of spalling or wear.
the factory used rtv to seal the cover on as already noted.
Personally i sort of doubt new fluid would reduce any noise except for limited slip clutch chatter, but it certainly can't hurt to change it and take a look around in there. Inspect gear teeth for wear, measure backlash if you have a dial indicator, check the pinion yoke for in/out and side to side play that would indicate loose pinion bearing.
You could pull the axles out and inspect the wheel bearings and mating surfaces on the axles for any signs of spalling or wear.
11-03-2022, 11:20 AM
#7
will be curious to hear your results. May not work, but worth the try IMO. Good luck.
