Aluminum KR Differential Cover..?

[oldlugs]

Hey there folks, just wondering if both '08 and '09 KRs came with a factory cast aluminum diff cover. Is it only on the '09s? Were they used on any other Mustangs as a production part? I've looked around for some pictures/info. in other threads, but haven't seen it mentioned. My KR has the cast alloy cover with both fill and drain plugs, and I'd like to get one like it for my '08 Bullitt.

 

Thanks, Duane

 

[Dennis Brown]

Hey there folks, just wondering if both '08 and '09 KRs came with a factory cast aluminum diff cover. Is it only on the '09s? Were they used on any other Mustangs as a production part? I've looked around for some pictures/info. in other threads, but haven't seen it mentioned. My KR has the cast alloy cover with both fill and drain plugs, and I'd like to get one like it for my '08 Bullitt.

 

Thanks, Duane

 

 

My 08 came with it.

[Tob]

Duane, can you provide a better photo than that? The cover in that photo looks similar (but not identical) to an Explorer cover I modified for use on a Mustang chassis 8.8 axle assembly.

 

I cut the ears off

 

Trimmed a bit more from the casting

 

Cleaned everything up with the belt sander

 

Sandblasted it and clear coated (shown on left compared to the old SVO cover)

 

Looks like I see two plugs in your photo - one drain and one fill, similar to the Explorer unit as well.

 

Tob

[oldlugs]

Duane, can you provide a better photo than that? The cover in that photo looks similar (but not identical) to an Explorer cover I modified for use on a Mustang chassis 8.8 axle assembly....

 

Looks like I see two plugs in your photo - one drain and one fill, similar to the Explorer unit as well.

 

Tob

That looks like a good source for an inexpensive cover with a drain. I'll have to take a looks at some junkyard Explorers. Nice work on that!

 

I'll get a better picture of my diff cover when I get a chance. That one was taken with my car on the ground, and me crawling under with my SLR, and a fixed 55mm lens on it... It's a pretty bad picture. This cover doesn't have a bunch of ribbing, and I think I saw FoMoCo and a part # on it. It's apparently not a FRPP cover though. I'm wondering if this cover may also have been used on something like a Crown Vic or Grand Marquis.. Also wonder if it was put on before leaving Ford, or at Shelby Autos. Odd that it uses common looking grade 5, cad plated hardware to hold it on, instead of the black finished, unmarked hardware on my Bullitt's cover.

[Tob]

I noticed the hardware as well, as it just doesn't look up to OE Ford spec. The factory Explorer bolts were at least black oxide pieces.

 

The cover you show is definitely not anything ever offered by SVO, Ford Motorsport, or FRPP. My understanding regarding the KR rear axle assembly is as follows:

 

- Ford installed a 3.73 geared axle assembly that wasn't offered on any other V8 Mustang, except for the Bullitt. It utilized the unique large pinion bearing as well as carbon fiber clutch discs. The KR axle assembly is identical to the 'Special Edition' assembly currently sold by FRPP

http://www.fordracingparts.com/parts/part_...tKeyField=10353

 

The hardware leads me to believe that the cover was installed by CS employees/contractors and not on the line from Ford.

 

I'd definitely like to see some clear shots of this thing as I have never heard mention of it before this thread!

 

Tob

 

On edit...more can be found on the KR/FRPP axle assembly at the link below

 

http://www.teamshelby.com/forums/index.php...1-A373&st=0

[shel-b001]

Duane, can you provide a better photo than that? The cover in that photo looks similar (but not identical) to an Explorer cover I modified for use on a Mustang chassis 8.8 axle assembly.

 

I cut the ears off

 

Trimmed a bit more from the casting

 

Cleaned everything up with the belt sander

 

Sandblasted it and clear coated (shown on left compared to the old SVO cover)

 

Looks like I see two plugs in your photo - one drain and one fill, similar to the Explorer unit as well.

 

Tob

 

Is that off a four wheel or two wheel drive?

[Tob]

That cover came off of an AWD Ford Explorer with an 8.8 rear differential.

 

Here's a comparison of a stock tin cover, SVO cover, and the Explorer cover (inverted)

 

A sweet, machined groove to capture a portion of the rtv sealant used at the factory and provide a leak free seal, something that should have been used on the FRPP covers as well

 

A plan view shot

 

Note the thick and very beefy flange

 

A cut of the difference in elevation between the SVO cover and the Explorer unit

 

Casting/engineering number

[oldlugs]

OK - got under the car again, this time armed with a light so I could see, and my wife's little pocket camera.

Here are a couple more pictures of the diff cover, and the numbers on it, and my axle code label.

 

 

 

 

 

 

I sure wish Ford had spent the extra $ to paint this thing...

Anyone recognize that cover as being used on another car..?

[Tob]

Lugs, I've been looking everywhere and am seeing mention of this nowhere! Comparing the KR cover to the Explorer I see many similarities.

 

There is no way that Ford tooled this piece up just for a limited production run of KR Mustangs. It is obviously a Ford part and not some CS piece either.

 

Tob

[sprint200]

Tob,

 

I do remember some discussion back in '07 (maybe just after the start of Job 2) about diff covers. Most of Job 1 had received stamped steel covers, like mine. But some '07's did come with aluminum covers. Idon't specifically remember any pictures, but remember reading the threads. Sorry, I haven't searched yet (I will) but thought I'd give a quick response first.

[sprint200]

Found the thread.......................Here It Is

 

 

From the few remaining pictures, it appears that the regular GT500 aluminum Diff covers had a similar profile to the stamped steel covers. Maybe someone could track down some of the missing pictures??????

 

 

Off Topic, Tob, this thread is where most of the "rusty rear end" crap started..............

[LuckySnake]

Found the thread.......................Here It Is

 

 

From the few remaining pictures, it appears that the regular GT500 aluminum Diff covers had a similar profile to the stamped steel covers. Maybe someone could track down some of the missing pictures??????

 

 

Off Topic, Tob, this thread is where most of the "rusty rear end" crap started..............

At least some of the early GT500s came with stamped aluminum covers. Either stamped aluminum or steel with paint on a GT500.

I did notice the diffs with the aluminum are painted from Ford but the tubes aren't painted. Here is a pix of the one on coupe #489 hiding behind the Fays2, it's original.

[LuckySnake]

Hey there folks, just wondering if both '08 and '09 KRs came with a factory cast aluminum diff cover. Is it only on the '09s? Were they used on any other Mustangs as a production part? I've looked around for some pictures/info. in other threads, but haven't seen it mentioned. My KR has the cast alloy cover with both fill and drain plugs, and I'd like to get one like it for my '08 Bullitt.

 

Thanks, Duane

 

Here is a pix I saved of a members 08 KR diff. To me the 08 the hardware looks different than yours (09)

Edit: Could just be lighting making the hardware look different?

[Tob]

Off Topic, Tob, this thread is where most of the "rusty rear end" crap started

Threads here seem to run off topic rather quickly, among other things. I gouged my left eye out by the third page and feel much better now.

 

The early GT500s came with stamped stainless covers.

That is incorrect. Sterling axle has used three different types of covers over the years on 8.8 (and 7.5) equipped axles. Stamped steel, stamped aluminum, and cast aluminum. Never stainless. It may look like it to some but it is not.

 

Unfortunately, Sterling uses whatever they have on hand for stick axles. That is why the cast cover is so interesting. It was no doubt, more expensive than either a steel or aluminum stamping.

 

The shot of the cover you linked, from coupe #489, is aluminum. If you look closely, you can see where it is oxidizing already, directly underneath the bolt heads.

 

In the last photo you linked, that is the correct hardware, plated bolts with an integral washer.

 

Jeff, I'll post this at CC and see if Jeff F (a factory FRPP engineer) or any of the parts gurus can explain what the original application of it was.

 

Tob

[LuckySnake]

Threads here seem to run off topic rather quickly, among other things. I gouged my left eye out by the third page and feel much better now.

 

 

That is incorrect. Sterling axle has used three different types of covers over the years on 8.8 (and 7.5) equipped axles. Stamped steel, stamped aluminum, and cast aluminum. Never stainless. It may look like it to some but it is not.

 

Unfortunately, Sterling uses whatever they have on hand for stick axles. That is why the cast cover is so interesting. It was no doubt, more expensive than either a steel or aluminum stamping.

 

The shot of the cover you linked, from coupe #489, is aluminum. If you look closely, you can see where it is oxidizing already, directly underneath the bolt heads.

 

In the last photo you linked, that is the correct hardware, plated bolts with an integral washer.

 

Jeff, I'll post this at CC and see if Jeff F (a factory FRPP engineer) or any of the parts gurus can explain what the original application of it was.

 

Tob

Hi Tob, what you see under the bolt heads is gray RTV, I reinstalled the cover when I put the Watts links on. I help install stainless components to aircraft water systems from time to time and most jets are mostly aluminum and CF, so I'm pretty sure I'm correct on this one. There is always a first time and and if I'm wrong I'll be the first to admit I'm wrong.

Edit:Tob straitened me out on this subject , thanks Tob.

[Tob]

Same here, Lucky. I could use a shocker this morning.

 

A quick plink with a finger is a good giveaway, as is cutting through it (which I doubt you intend on doing:))

 

You could also try shaving the flange with a razor knife.

 

On edit...the tag won't give you any written confirmation either way as to the cover material.

 

Here are some other aluminum covers..

http://www.p71interceptor.com/suspension/s...PICT0069-vi.jpg

http://www.p71interceptor.com/suspension/s...ar/PICT8593.jpg (PI Crown Vic)

[LuckySnake]

Same here, Lucky. I could use a shocker this morning.

 

A quick plink with a finger is a good giveaway, as is cutting through it (which I doubt you intend on doing:))

 

You could also try shaving the flange with a razor knife.

 

On edit...the tag won't give you any written confirmation either way as to the cover material.

I don't mind giving an inconspicuous edge a shave test, for the sake of knowing what is installed. I'll check it out and get back.

[07-2937]

It is a KR only cover(at least at the time) It was installed during the upfit to strengthen the housing and most of all to reduce gear whine.... It is a FORD part. It was a mid run change some have it and some dont...

[LuckySnake]

Hi Tob, I'm wrong! I hate it when that happens. It's an aluminum cover. I always thought it was stainless because of how heavy the cover is. But after lookin closer it's just because of how thick it is. I apologize.

[Tob]

Its all good, brother! At least you have one of the lightest covers installed, allowing you to go the fastest!

 

07-2937, obviously, it is a factory OEM part. I have a feeling it was/is used in another application. Besides, why wasn't it used at the end of the production run if there was a known whine issue at CS?

[07-2937]

It was used on all KR upfits on site at the time and all new arrivals Not all 3:73 sets whine but they do somewhat when they are new and quiet down like a 3:55,3:23. I have not seen this cover on anything else yet maybe on police cruisers? Hope that cleared things a little

[twicebitten]

if it is steel it will be magnetic and aluminum is not

[mdwayne]

if it is steel it will be magnetic and aluminum is not

My 09 definitely is steel.

[Dennis Brown]

Here is a pix I saved of a members 08 KR diff. To me the 08 the hardware looks different than yours (09)

Edit: Could just be lighting making the hardware look different?

My 08KR looks just like that.

[Tob]

As far as I can tell so far, 7L2W (first lettering group on one of the cast aluminum cover photos previously posted) breaks down as follows:

 

7 = 2007

L2 = Explorer

W = Axle and Driveline

 

My wife has an '07 V8 equipped Mercury Mountaineer, but it came with IRS (and AWD). Since I'm pretty sure these vehicles don't use an 8.8 up front, that would only leave a solid axle for this cover to have come from. Does anyone know if Explorers or Mountaineers were/are available in 2WD? That would be the source if there is. Interesting especially, since the cover is so similar to the one I show in my earlier photos (from an AWD Explorer).

 

I didn't think this was unique to the KR. This would be a nice find if it holds to be true. I just wonder if Ford pricing would be ridiculous on it (there's always the wrecking yard if so).

 

Here's the chart I used to break down the number.

 

Tob

[oldlugs]

I'll be hitting the local junkyards when I get the chance. I want one of these covers for my Bullitt axle.

Thanks to all for your input on this. I was worried that my KR may be a strange deviant (actually that maybe the dealer did something fishy..).

 

Duane

[Tob]

Thanks to all for your input on this.

 

Actually Duane, any and all thanks goes to you. If you hadn't brought this up many would have never believed it.

 

I spent some time at my local Ford dealer today. I've grown close with their parts guys and they always go out of their way to find unique stuff for me. This one had them going for quite some time. They found a match for the engineering/casting number, but can't confirm it'll be the right one. They'll have it tomorrow afternoon. If it is the right one I'll pick it up, for sure.

 

My fingers are crossed, as the price wasn't bad at all...

 

Tob

[Tob]

Duane, I'm going to ask for a favor. Could you please provide some more shots of your cover, particularly of the uppermost portion - on each side. There is also a vent hole on the upper right corner that would fall somewhere between 1 and 2 o'clock. I'd like to know if the factory plugged it (did they thread the hole, use a rubber plug, ...?) or if they vented it.

 

It would appear that Ford may have contracted out the modifications to a factory Explorer cover and not cast a unique cover for the KR. I have the corresponding cover in hand (I picked it up earlier today) and I think I can prove exactly what Ford did to make this work.

 

I'll keep digging, but I suspect that Ford used someone like Watson Engineering to prep 'x' number of these for installation on the assembly line.

 

Duane, I also need you to confirm the last two letters of the part number. I am 99% sure that they will show as AB. If so, this may turn out to be 'the' most exclusive KR part out there.

 

I'll post more photos tomorrow.

 

Tob

[oldlugs]

Duane, I'm going to ask for a favor. Could you please provide some more shots of your cover, particularly of the uppermost portion - on each side. There is also a vent hole on the upper right corner that would fall somewhere between 1 and 2 o'clock. I'd like to know if the factory plugged it (did they thread the hole, use a rubber plug, ...?) or if they vented it....

OK - here are a couple more shots. It appears that it has had some ears or part of the casting ground off (?), and the right side vent hole is plugged. I can't tell if if the plug was threaded, or a pressed/hammered interference fit. It looks to be made of aluminum bar stock and ground flush, but no way for me to know until inspected from inside the cover. It doesn't feel like rubber with a fingernail. An interesting modification for someone wanting a correct appearing aluminum cover with a drain for their KR.

 

Tob, how much does the unmodified Explorer cover go for over the counter..? Two of four wheel drive Explorer?

 

Duane

 

 

 

[Tob]

Duane, you are a gentleman and a scholar. Once again, thanks for climbing underneath and capturing some critical shots.

 

Here is my receipt from yesterday.

 

Here is a shot of the 2001 Explorer cover that I previously cut down next to the 2007 Explorer cover, which matches what Ford used on your KR (note here that the older cover can be used as well).

 

The '01 cover used the 'AC' revision...

 

The '07 cover, and KR piece, uses the 'AB' revision. Thanks for confirming!!

 

This gives you an idea of what needs to be cut off...

 

Note the 'AC' drain plug...

 

And the newer 'AB' drain plug...

 

This shot shows what I did (some four years ago) to the vent hole on my '01 cover. I cut threads and put a pipe plug in its place...

 

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