Swapping differentials

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dmoody

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Nov 4, 2002

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Winston-Salem, NC

Sep 13, 2004

#1

• Sep 13, 2004

• #1

Hey guys,
I'm swapping in a 1980 Ford Granada 5-lug 8" rearend into my II. There is only one thing I'm not sure about... the gear ratio is 2.5:1... can I swap in my II diff (3.00:1) so I'm not running such a miserable gear ratio?

d

 

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a351Must2

Windsor II

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Mar 12, 1999

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Snohomish, WA

Sep 13, 2004

#2

• Sep 13, 2004

• #2

yes

 

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mustang2

New Member

Apr 29, 2004

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NC

Sep 13, 2004

#3

• Sep 13, 2004

• #3

I thought I heard on here once the Granada had a 9 inch rear?

 

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dmoody

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Nov 4, 2002

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Winston-Salem, NC

Sep 13, 2004

#4

• Sep 13, 2004

• #4

Not my donor Granada.. of course it has a six banger. I think the bigger 351 powered Granadas had a 9 inch.

d

 

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mustang2

New Member

Apr 29, 2004

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Sep 13, 2004

#5

• Sep 13, 2004

• #5

Ok, " duh". I guess that would make sense would'nt it.

 

Blue Thunder

15 Year Member

Mar 20, 2004

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Upstate New York.

Sep 13, 2004

#6

• Sep 13, 2004

• #6

2.50s are good if you ever plan on racing on the salt flats.

 

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dmoody

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Winston-Salem, NC

Sep 13, 2004

#7

• Sep 13, 2004

• #7

Blue Thunder said:

2.50s are good if you ever plan on racing on the salt flats.

Click to expand...

I'll keep that in mind if I can ever get the car out of the garage.

d

 

TheEvII

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Sep 8, 2004

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Lakemoor Il.

Sep 13, 2004

#8

• Sep 13, 2004

• #8

The 2.50 will also be good to keep around in case you'd like to take a long trip like to a show or to Ok. to spank Megan, you could always easily swap in the 2.50 and hit the road.

 

Wart

I'm Mad as HELL and I'M not Gonna Take it ANYMORE!

Founding Member

Sep 1, 1998

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NE Ohio

Sep 13, 2004

#9

• Sep 13, 2004

• #9

Are you sure it's an 8"? Or a 2.50?

I remember the 2.50 as a 9" gear. The popular 8" gear in a mid size is a 2.79.

{edit}

I've only seen 7.5 (?) integral carrier rears behind sixes. Engine swap?

 

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dmoody

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Winston-Salem, NC

Sep 14, 2004

#10

• Sep 14, 2004

• #10

I'm sure it is the original engine. It looks just like the 8" in my II from the back. In the front it has this strange clamp that is in front of the differential case. It is about 8" x3". I don't think it is a 9" rearend because it doesn't have the hump in the back. What does the 7.5 look like? I measured the axle housing where the u-bolts attach and it is a little over a quarter inch wider than my II. So I'll have to elongate the holes in my leaf spring mounts, etc. Also it is a 5 lug rearend. The engine I think is a 250 inline six cylinder. That is really all I know. I hope it is the 8"... I've done a lot of work dragging this thing where I can get underneath it and cut the brackets off. :-( Oh one last thing, I measured from drum to drum and it is about an inch wider than the rearend in my II. I didn't think that was a big deal.

d

 

Wart

I'm Mad as HELL and I'M not Gonna Take it ANYMORE!

Founding Member

Sep 1, 1998

408

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NE Ohio

Sep 14, 2004

#11

• Sep 14, 2004

• #11

Ford is well known for doing 'assembly line upgrades'. Definate possability you got a 8 behind a 6.

The 2.50 gear? Are you sure? I went looking , no 2.50 ratio listed for the 8.

 

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dmoody

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Winston-Salem, NC

Sep 14, 2004

#12

• Sep 14, 2004

• #12

I'm probably wrong about the gear ratio. I looked all over the Internet for information on the Granada and couldn't find much on them. I came upon another car that had the six in it with a 2.50 gear ratio. That is something I didn't look at, the gear ratio that is, so I asked if I could swap my 3.00:1 out of the II in case I run into this problem.

d

 

Camshaft78

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Sep 1, 2004

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Sep 14, 2004

#13

• Sep 14, 2004

• #13

Wait, you can't fit a 9 inch? What about an 8.8 inch?

 

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dmoody

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Winston-Salem, NC

Sep 14, 2004

#14

• Sep 14, 2004

• #14

Sure, I mean there are 9-inch rearends out there that have a suitable width for the look I'm going after. However I can't find one of those rearends (65-66 Mustang would work). The 8.8 inch is everywhere in junkyards but they're all too wide... I'd prefer an old style dished rim on the back when I'm finished. I don't like these newer rims that are flat. Just my preference though. Also with the 8" it would be easier to reuse my existing brackets since the axle housing is a little smaller in diameter.

d

 

Blue Thunder

15 Year Member

Mar 20, 2004

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Upstate New York.

Sep 14, 2004

#15

• Sep 14, 2004

• #15

I really dislike the 8.8s.

 

Wart

I'm Mad as HELL and I'M not Gonna Take it ANYMORE!

Founding Member

Sep 1, 1998

408

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NE Ohio

Sep 17, 2004

#16

• Sep 17, 2004

• #16

Blue Thunder said:

I really dislike the 8.8s.

Click to expand...

I've never played with one.

Never had the desire.

Something about having multiple chunks that can be easily set up on a bench and ready to drop in.

Verses having to dick with gears while laying under the car.

They say the 8.8 has the strength of the 9 without the weight penalty .... good for them, some day I'll have to worry about unsprung weight, not today though.

 

Wart

I'm Mad as HELL and I'M not Gonna Take it ANYMORE!

Founding Member

Sep 1, 1998

408

3

58

NE Ohio

Sep 17, 2004

#17

• Sep 17, 2004

• #17

dmoody said:

Sure, I mean there are 9-inch rearends out there that have a suitable width for the look I'm going after. However I can't find one of those rearends (65-66 Mustang would work).

Click to expand...

Versialles (sp?) have what your looking for without the $$$ penalty of being for the Classic (pre '71) Mustang. OTOH, Versialles rear ends are becoming really rare thus driving upthe cost, and the brake parts are big jing.

Another source is the early Bronco. Unfortunately they're 5" x5, but can be ... resized.

But do you really need a 9" ?

I'd prefer an old style dished rim on the back when I'm finished. I don't like these newer rims that are flat. Just my preference though.

Click to expand...

Form follows function. Dished, flat ... they are what they are. Least for me.

The Granada (and Versialles) rears hold 205/70/ 14 tires on steel wheels inside the wells well. Wider tires will probably need wider rims with a greater offset. Whatever they turn out to be will be fine for me.

Also with the 8" it would be easier to reuse my existing brackets since the axle housing is a little smaller in diameter.

Click to expand...

2 7/8 I believe.

Don't even think of (re)using the II U-bolts. They will need rebent which is a PITA, it's even a bad idea. And U-bolts are cheap. Last 7/16" set I got for 2 7/8 inch tube cost under $20 with tall nuts and washers.

Did the Granada have rubber mount or solid perch? If it had rubbers and you want to retain the rubber mounting you had best gotten the related parts, the terches are more than likely different than the perches on the II, the perch parts don't really interchange.

I would like to ramble on but I got a call and have to leave.

Final note (for now) I have a '78 (?) Granada 8", I'm doing the same as you except this is my 5th, 6th or 7th time I've done this.



d

 

Blue Thunder

15 Year Member

Mar 20, 2004

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Upstate New York.

Sep 17, 2004

#18

• Sep 17, 2004

• #18

Wart said:

I've never played with one.

Never had the desire.

Something about having multiple chunks that can be easily set up on a bench and ready to drop in.

Verses having to dick with gears while laying under the car.

They say the 8.8 has the strength of the 9 without the weight penalty .... good for them, some day I'll have to worry about unsprung weight, not today though.

Click to expand...

The biggest thing that pissed me off about the 8.8 was that the axle bearings run directly on the axles without an inner race, so when the bearing wears out, so does the axle surface. (Though they do make offset wheel bearings, to avoid having to replace the worn axles, at least the first time) Also, C-clips suck, because for some strange reason, I like keeping my wheels attached to my moving car at all times.
I'd be willing to bet that an 8.8 is nowhere near as strong as even a stock 9" with 28 spline axles, nor does the 8.8 have the availability of parts that the 9 enjoys. (for good reason!)

 

TheEvII

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Sep 8, 2004

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Lakemoor Il.

Sep 18, 2004

#19

• Sep 18, 2004

• #19

The 9 inch is the strongest rear end available. I have an 8.8 inch in mine but had the cost for a new 9" not ben so high I would have gone with that. Don't get me wrong the 8.8" is strong and is just fine but like someone else pointed out on another site and here as well, with the 9", it's easier to service and if you'd like to take a long trip, it's easy to swap in a pumkin with a lower gear. I should point out that my 8.8 has 31 spline axles as well. I don't know how strong the 26 spline axles are, although you don't see many fox bodys with bad rear ends and they take a serious beating most of the time.

 

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dmoody

Founding Member

Nov 4, 2002

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Winston-Salem, NC

Sep 27, 2004

#20

• Sep 27, 2004

• #20

Ok guys, I dug deep into the muck this weekend and instead of pulling the whole rearend out of the Granada I pulled the axles. They are exactly the same as my II axles! I couldn't believe it... I figured since the rearend is not the same width and also since the II 8" housing tapers on the end when it reaches the brake drum I thought at least the bearings would be different. Not true at all. The only difference other than the lug count is the bearing retaining plate. For some reason the II uses a smaller bearing retaining plate. I'm having the plate on the Granada axles pressed off and having the II plate pressed back on... and voila I should be done with the 5-lug conversion.

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