Diff shortening

[66STNG]

Hi,
Looking at shortening the AU diff I have by 25 mm either side.
1. Has anyone done this.
2. And how do you pull the tubes off, they appear to be plug welded in,
Any advice..

[Shayne93]

Drill the plug welds out on the cradle.
I went with the R31 diff for this reason, as I said before.

[66STNG]

Cheers shayne,
Will give it a crack

[Shayne93]

Just make sure it's bang on straight.
There are some gains by working in camber etc but will wear the inner bearings (the expensive ones to replace)

[ozbilt]

Cheers shayne,
Will give it a crack

Get it done professionally. The dollar you save by doing it yourself will be eaten up tenfold by getting it fixed later.

[Shayne93]

I personally don't think it's worth shortening them. The cost outweights that too, compared to buying an 8 or 9 inch.

Falcon diff, you'll have to get the housing and axles shortened. Big dosh.

A new complete 9 inch in the states is 2k with disc brakes.
You could also get an 8 inch, throw a new LSD carrier and gears in, done deal.

If you're set on an Aus Borg Warner diff, R31 is probably the much cheaper option. Get the axles redrilled to 5 stud (Cost me $200), have the falcon centre put into it and put leaf spring perches on.

Or... get wheels with an inch extra backspace on the rear.

[scott66stang]

I cant remember the exact measurements but with a 67 onwards you can use the EB-AU axles as there is enough on the spline. I found that the narrower 65-66 requires the use of the original or after market axles but then to use the AU tapered roller bearings to suit the diff the axle needs some lathe work to sit the bearing closer to the hub otherwise the disc brakes will be out of wack.
Or you can get the AU axles shortened and resplined which i have been told is not recomended, but i think that depends on how much power you intend to use.

[66STNG]

I am getting some quotes this week to shorten it, however I think it will be cheaper to start again and buy an 8" .
I'm just going through the motions at present to see which is more cost effective, as I have the diff it's an LSD and been rebuilt.
I was trying to keep the driveline all falcon, but not if it's not cost effective.
Anyone want an AU diff,

[scott66stang]

I kept the 8" and did the disc brake conversion due to the extra cost of shortening the diff that i didnt want to spend at the time.
But i still want to attempt doing the EB-EL diff as i have about 4 to play with, i have recently purchased a lathe (another Toy) that will handle the axle lengths, i just have to learn how to use one again, its been 30+years

[Shayne93]

Guy,
Why not use the AU diff as is and use AU offset wheels on the rear.

I think the later GT's run the same size wheels all round, 36mm offset on the front and 28mm on the rear, for a wider stance.

If the diff needs 25mm off each side, that will be an offset of roughly 31mm on the rear wheels.

Could work well if you plan on wider wheels for the rear end. Food for thought!

[ozbilt]

Guy,
Why not use the AU diff as is and use AU offset wheels on the rear.

I think the later GT's run the same size wheels all round, 36mm offset on the front and 28mm on the rear, for a wider stance.

If the diff needs 25mm off each side, that will be an offset of roughly 31mm on the rear wheels.

Could work well if you plan on wider wheels for the rear end. Food for thought!

His car is a 66, not 67 or later.

[Shayne93]

I'm only going off the original post of 25mm per side, Kerry.

I just did a few quick calculations on the AU diff width and the AU diff would be about 80mm too wide each side for a 66.

XA - XF and EA- EL would be 45mm too wide each side I would think.

I saw a ford 8 inch diff out of a compact fairlane (is this the same width, Kerry?) for sale on gumtree today for $800, I know guy was looking for an 8 inch.

[Shaunp]

Just get the correct size 8" for it, cost you like $500

[ozbilt]

Just get the correct size 8" for it, cost you like $500

I believe Guy has one lined up to buy. We discussed ratio's today.

[ozbilt]

I'm only going off the original post of 25mm per side, Kerry.

I just did a few quick calculations on the AU diff width and the AU diff would be about 80mm too wide each side for a 66.

XA - XF and EA- EL would be 45mm too wide each side I would think.

I saw a ford 8 inch diff out of a compact fairlane (is this the same width, Kerry?) for sale on gumtree today for $800, I know guy was looking for an 8 inch.

It would have needed that 25mm off each side running the wheels the ute had on it. It would still have needed massaging of the rear fender wells.

All good now (read my post before this) ......