Rear differential cover leaking
Thread Starter
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Posting Guru
Joined: Apr 2003
Posts: 1,089
Likes: 1
From: Michigan
Rear differential cover leaking
Hey. My rear diff is leaking at the bottom of the cover. Being in Michigan, there is a bit of rust and I suspect that and corrosion are the cause (I think I've heard that this is a known issue). As I will probably need a new cover anyway, does anyone know the Ford part number of the nice aluminum one on the newer SD's? I would like to replace it with that one. Also, I see from reading here-> Welcome to guzzle's Rear Differential Maintenance Web Page that I will need 3.5 qts of 75W-140 synthetic gear oil. I will be using Mobil one. Does that already have the friction modifier in it or do I have to find the Ford stuff?
Thanks!!
Thanks!!
Hotshot
Joined: Oct 2005
Posts: 12,237
Likes: 22
From: Florida
I installed the '08 finned cover...
Part #8C3Z-4033-A
You will need 12 longer bolts (5/16-18 x 1.25)...I went stainless with lock washers
Here is a photo of mine after install...
I do not have a LS rear end but I think you need to add friction modifier to the fluid but some will confirm that I am sure...
Hope this helps...
I was able to get the cover from my local dealership for $45ish if I remember right...just ask for a discount and you may get it like I did...otherwise order from Ed the FTE parts guy on here...he has great prices...
Good luck,
Joe.
Part #8C3Z-4033-A
You will need 12 longer bolts (5/16-18 x 1.25)...I went stainless with lock washers
Here is a photo of mine after install...
I do not have a LS rear end but I think you need to add friction modifier to the fluid but some will confirm that I am sure...
Hope this helps...
I was able to get the cover from my local dealership for $45ish if I remember right...just ask for a discount and you may get it like I did...otherwise order from Ed the FTE parts guy on here...he has great prices...
Good luck,
Joe.
Thread Starter
|
Posting Guru
Joined: Apr 2003
Posts: 1,089
Likes: 1
From: Michigan
I installed the '08 finned cover...
Part #8C3Z-4033-A
You will need 12 longer bolts (5/16-18 x 1.25)...I went stainless with lock washers
Here is a photo of mine after install...
I do not have a LS rear end but I think you need to add friction modifier to the fluid but some will confirm that I am sure...
Hope this helps...
I was able to get the cover from my local dealership for $45ish if I remember right...just ask for a discount and you may get it like I did...otherwise order from Ed the FTE parts guy on here...he has great prices...
Good luck,
Joe.
Part #8C3Z-4033-A
You will need 12 longer bolts (5/16-18 x 1.25)...I went stainless with lock washers
Here is a photo of mine after install...
I do not have a LS rear end but I think you need to add friction modifier to the fluid but some will confirm that I am sure...
Hope this helps...
I was able to get the cover from my local dealership for $45ish if I remember right...just ask for a discount and you may get it like I did...otherwise order from Ed the FTE parts guy on here...he has great prices...
Good luck,
Joe.
Hotshot
Joined: Oct 2005
Posts: 12,237
Likes: 22
From: Florida
Rob,
I swapped to the '08 finned cover for any benefit I may get from cooling capacity of the thicker finned cover over the factory stamped steel one...the original one is very thin steel and I assumed that the peeling paint meant the rear end gets pretty hot from my long hard pulls I subject my Ex too each summer...
So my thoughts were functional due to my mostly towing use of my Ex...I'm not sure how much cooling capacity I actually get out of this finned cover but it has to be more than the factory one (in my mind at least)...
If you do any serious towing...and you have to swap the cover anyway...I'd check into the '08 finned one...it can't hurt cooling any...that's for sure...plus since I had less than ~$60 in mine with fasteners...it wasn't that bad price wise either...plus it looks nice too!
Good luck,
Joe.
I swapped to the '08 finned cover for any benefit I may get from cooling capacity of the thicker finned cover over the factory stamped steel one...the original one is very thin steel and I assumed that the peeling paint meant the rear end gets pretty hot from my long hard pulls I subject my Ex too each summer...
So my thoughts were functional due to my mostly towing use of my Ex...I'm not sure how much cooling capacity I actually get out of this finned cover but it has to be more than the factory one (in my mind at least)...
If you do any serious towing...and you have to swap the cover anyway...I'd check into the '08 finned one...it can't hurt cooling any...that's for sure...plus since I had less than ~$60 in mine with fasteners...it wasn't that bad price wise either...plus it looks nice too!
Good luck,
Joe.
Thread Starter
|
Posting Guru
Joined: Apr 2003
Posts: 1,089
Likes: 1
From: Michigan
Rob,
I swapped to the '08 finned cover for any benefit I may get from cooling capacity of the thicker finned cover over the factory stamped steel one...the original one is very thin steel and I assumed that the peeling paint meant the rear end gets pretty hot from my long hard pulls I subject my Ex too each summer...
So my thoughts were functional due to my mostly towing use of my Ex...I'm not sure how much cooling capacity I actually get out of this finned cover but it has to be more than the factory one (in my mind at least)...
If you do any serious towing...and you have to swap the cover anyway...I'd check into the '08 finned one...it can't hurt cooling any...that's for sure...plus since I had less than ~$60 in mine with fasteners...it wasn't that bad price wise either...plus it looks nice too!
Good luck,
Joe.
I swapped to the '08 finned cover for any benefit I may get from cooling capacity of the thicker finned cover over the factory stamped steel one...the original one is very thin steel and I assumed that the peeling paint meant the rear end gets pretty hot from my long hard pulls I subject my Ex too each summer...
So my thoughts were functional due to my mostly towing use of my Ex...I'm not sure how much cooling capacity I actually get out of this finned cover but it has to be more than the factory one (in my mind at least)...
If you do any serious towing...and you have to swap the cover anyway...I'd check into the '08 finned one...it can't hurt cooling any...that's for sure...plus since I had less than ~$60 in mine with fasteners...it wasn't that bad price wise either...plus it looks nice too!
Good luck,
Joe.
Hotshot
Joined: Oct 2005
Posts: 12,237
Likes: 22
From: Florida
Rob,
I did not do this mod by myself...the shop that installed my 4.30's installed this cover after the original cover started leaking (they didn't use enough permatex I guess)...so when they had to fix the cover due to their error I had them simply install this one...they used permatex...
Torque values are different between the steel one and the aluminum one (aluminum one is lower)...aluminum one I believe is 28ft-lbs?...I cannot remember exactly so ask the parts guy for sure what the proper torque value is...
The aluminum cover actually has a groove cut into it for the permatex whereas the steel one is simply a flat one with no groove...
I also had to 'snug' my bolts up after a few miles because I got a very slow drip...but a little snug of the bolt and all has been well...
Good luck...and share some photos when you get it done.
Joe.
I did not do this mod by myself...the shop that installed my 4.30's installed this cover after the original cover started leaking (they didn't use enough permatex I guess)...so when they had to fix the cover due to their error I had them simply install this one...they used permatex...
Torque values are different between the steel one and the aluminum one (aluminum one is lower)...aluminum one I believe is 28ft-lbs?...I cannot remember exactly so ask the parts guy for sure what the proper torque value is...
The aluminum cover actually has a groove cut into it for the permatex whereas the steel one is simply a flat one with no groove...
I also had to 'snug' my bolts up after a few miles because I got a very slow drip...but a little snug of the bolt and all has been well...
Good luck...and share some photos when you get it done.
Joe.
More Turbo
Joined: Jun 2004
Posts: 634
Likes: 8
From: Southern Tier New York
I did the swap too... Use Royal Purple and you do not have to add the friction modifier... Royal Purple's formula includes the friction modifier.
Here's a easier way to do the swap...
With a floor jack, lift the rear of the vehicle from under the hitch receiver (I also put 2 pieces of 2x10 between the receiver and the jack) until just before the rear wheels come off the ground... then jack stand the frame just before the rear wheels (always use jack stands!!!) (do both sides).
Lifting the vehicle this way, you'll have plenty of clearance to get at all your diff bolts and lots of space to move.
Have fun!!!
Here's a easier way to do the swap...
With a floor jack, lift the rear of the vehicle from under the hitch receiver (I also put 2 pieces of 2x10 between the receiver and the jack) until just before the rear wheels come off the ground... then jack stand the frame just before the rear wheels (always use jack stands!!!) (do both sides).
Lifting the vehicle this way, you'll have plenty of clearance to get at all your diff bolts and lots of space to move.
Have fun!!!
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Thread Starter
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Posting Guru
Joined: Apr 2003
Posts: 1,089
Likes: 1
From: Michigan
I did the swap too... Use Royal Purple and you do not have to add the friction modifier... Royal Purple's formula includes the friction modifier.
Here's a easier way to do the swap...
With a floor jack, lift the rear of the vehicle from under the hitch receiver (I also put 2 pieces of 2x10 between the receiver and the jack) until just before the rear wheels come off the ground... then jack stand the frame just before the rear wheels (always use jack stands!!!) (do both sides).
Lifting the vehicle this way, you'll have plenty of clearance to get at all your diff bolts and lots of space to move.
Have fun!!!
Here's a easier way to do the swap...
With a floor jack, lift the rear of the vehicle from under the hitch receiver (I also put 2 pieces of 2x10 between the receiver and the jack) until just before the rear wheels come off the ground... then jack stand the frame just before the rear wheels (always use jack stands!!!) (do both sides).
Lifting the vehicle this way, you'll have plenty of clearance to get at all your diff bolts and lots of space to move.
Have fun!!!
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More Turbo
Joined: Jun 2004
Posts: 634
Likes: 8
From: Southern Tier New York
I had no issues with cover bolts or fill plug.
Here's a pic of mine... notice how the underside is significantly cleaner than Joe's...
Sit. Stay.
Joined: Oct 2001
Posts: 18,308
Likes: 20
From: Washington State
You're allowed to drive your truck, ya know. 
Use the black RTV. There's a groove in the pan for you to apply a bead all the way around. Let it skin over before you install it.
Don't use the gasket that comes with it. It is useless!
Hotshot
Joined: Oct 2005
Posts: 12,237
Likes: 22
From: Florida
Mine now has black permatex as Monsta suggests...that blue stuff leaked and the shop had to redo it yet again (about 2 weeks after this photo was taken)...
I had suggested the shop keep my truck over night since I didn't need it so they could let the RTV set up before filling the diff...but they said no need...if you have the option...I'd personally let it set up before filling...mine had another slight leak after the last time but that is where I snugged the bolt and leak stopped...
Joe.
I had suggested the shop keep my truck over night since I didn't need it so they could let the RTV set up before filling the diff...but they said no need...if you have the option...I'd personally let it set up before filling...mine had another slight leak after the last time but that is where I snugged the bolt and leak stopped...
Joe.
Post Fiend
Joined: Mar 2009
Posts: 11,798
Likes: 14
From: Mt. Shasta California
Mobil 1 has 2 oils. One has an LS after Mobil1 with modifiers in it but you don't need it and shouldn't use it. Use the regular Mobil1.
Elder User
Joined: May 2003
Posts: 858
Likes: 1
I used "The Right Stuff" sealer when put my cover on. It is more expensive but I believe it says it is OEM stuff. Cures fast so no wait time to put oil in. Get the caulking gun style not the cheeze whiz can style.