Jag IRS diff mod, help needed.

[puttputt]

Hi,
I wonder if anyone can advise. I am in Western Australia and building
a G-Force Cobra, with GM LS3 6,2 Litre engine, and Tremec Magnum
6 speed with wide ratio (0.50 6th ratio).

I have an open 3.31 jaguar 19 spline IRS diff.

I want to upgrade to a LSD 3.92 30 spline setup. I have ordered new
3.92 gearing, and Dana 30 spline locker, with overhaul kit from The USA.
But cannot locate a supplier for new 30 spline short shafts(half shafts).
Can anyone suggest where I can buy these ?

I can get a pair of used 30 spline half shafts from a 2.88 diff, will these be
correct for my application as I believe a 2.88 cannot be retrofitted with 3.92 or
any 3.xx ratio as it has a different casing, whereas all 3.xx ratio diffs can be
upgraded as all use the same casing.

Correct me if I am wrong with any of the above.

Thanks.

[just dreamin]

My understanding is that all standard length Jag shafts are too long except the E and S type. As such they are usually shortened to the reqd length by someone like Hardy Spicer. Does that help?

[kyleb]

These guys may be able to help. V&A Spiteri Jaguar - Independant Jaguar Specialists
Cheers

[puttputt]

1)Thanks very much Kyleb, that looks promising, they have axles on their website, I will contact them as soon as possible.

2) Reply to Just Dreaming: the half shafts I need are the pieces that fit into the diff, and need to be correct to work, I think it the other outer half is what is modified.

[joyridin']

If you do a search, there are a couple of vendors that appear int he threads. Here are the links:

Summers Brothers - Manufacturer Of High Performance Axles For All Of Your Racing Needs!
Reiderracing.com
Mark Williams Enterprises- Home Page

[puttputt]

Originally Posted by joyridin'

If you do a search, there are a couple of vendors that appear int he threads. Here are the links:

Summers Brothers - Manufacturer Of High Performance Axles For All Of Your Racing Needs!
Reiderracing.com
Mark Williams Enterprises- Home Page

Thanks Joyriding, I will follow these up.
I am also going to open a thread in general section, as I struggle to find this, meaning it is not easily seen.

[mickmate]

I believe there is an early and late Jag diff. It looks like if your inner axles are the same bearing sizes they will interchange.

[justcobra]

Gentleman your guidance is required! I got a jaguar 3.31 LSD diff and in the process of fitting it to RMC .
Instead of cutting and welding would a S type lower and upper half shafts be a better alternative.
The S type track width is 55 inches and I will be using Trigo wheels with adapters/spinners.
Has any body got a spare set of S type Jag upper and lower control arms for sale at a reasonable price?

[RICK LAKE]

puttputt The best info I have is that CWI used to get their 30 spline axles from your country. Problem was they twisted. The axle was not a chromemoly. I got the kit from CWI and have been racing these axles for 14+ years and no problems. Mark williams is the ONLY company I would trust for these axles. They where making them for CWI as replacments when the problem of these axles showed it's failures.
Side notes, the best info I have on a 2.88 jag rearend is only the ring gears and carrier are different. 307-4.09 are the same carrier and 410 on up is the last. There are 4 different carriers.
Same for axles, 2 different splines, 19 and 27. aftermarket is a 30 spline.
bearings and seals are the same. Bottom line is these axle are good for about 450 hp and torque. If you run a soft wear tire this rating goes down. Forget the 5,000 rpm hole shots.
Rear support cover, BUY ONE. They stop the different caps from walking and control the carrier too. Been running one for 14 years.
I have a 30 spline setup and was told from CWI this will take 600/600 hp and torque. I did replace the jag carrier with a Detroit locker. Dana 44 and Jag use the same parts basicly. I did have to do some machine work for the carrier so the ring gear work fit. ( Enlarged the holes for the bolts) If you run into a bind look for jeep parts of the 70's They all came with dana drive trains. Over build is the best thing you can do. Good luck. Rick L.

[mickmate]

Precision Gear - Ring and Pinions, Differentials Installation Kits and more!
has the 30 spline stub axles to fit a Dana 44 carrier.

[Tom Wells]

puttputt,

Here's a bit more Jag diff info for your reading pleasure: First Coast Cobra Club • View topic - Jaguar differential decoding

Enjoy,

Tom