Jag diff - Dana 44 CWP conversion

Technical advice Q&A

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Sirjames
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Joined: Thu Mar 15, 2018 10:41 pm
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#1 Jag diff - Dana 44 CWP conversion

Post by Sirjames » Fri Feb 01, 2019 3:07 pm

Hi everybody.

Apparently the crown wheel and pinion in a Jag diff are identical to the American Dana 44.
There are more splines for the flange, and the bolts holding the crown wheel to the carrier have a different size.
These differences can be solved.

Has anyone tried fitting an American Dana 44 CWP to a Jag diff? Any problem?

I just got a E type diff rebuilt with brand new CWP by a very welknown company, it whines and the oil is super black after 3000Km only. I got the oil analysed: a lot of steel in it...
Off course they deny any responsibility, the diff rebuilt only cost me 2000£. I did all the rest.

Apparently getting good gears becomes a problem, and I'm really fed up with these "specialists"
I can do Jag engines, my dad can do Astons etc...engines so we should manage a diff!
I decided to do it myself, so advices welcome please!!!
James 67 OTS, 73 OTS 6.0L, and other makes

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Philk
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#2 Re: Jag diff - Dana 44 CWP conversion

Post by Philk » Fri Feb 01, 2019 3:41 pm

Sirjames wrote:
Fri Feb 01, 2019 3:07 pm

Has anyone tried fitting an American Dana 44 CWP to a Jag diff? Any problem?
By coincidence, I've just had our IRS overhauled. The diff had been converted to 3.07 in the USA back in the mid 1990s and, on opening the diff up for the seals to be done, we noted it was a Dana 44 crownwheel/pinion (with a 26 spline shaft). The car had done only 10,000 miles since that time but there was no sign of wear. It was also very quiet (which we were keen not to undo).
Phil
1964 S1 3.8 OTS

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Sirjames
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#3 Re: Jag diff - Dana 44 CWP conversion

Post by Sirjames » Fri Feb 01, 2019 4:09 pm

@ PhilK : Are you not a friend of Steve (Southern Classics in Twickenham) ?
Yesterday I asked him about that subject and he told me a story very similar to yours.
James 67 OTS, 73 OTS 6.0L, and other makes

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mgcjag
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#4 Re: Jag diff - Dana 44 CWP conversion

Post by mgcjag » Fri Feb 01, 2019 4:18 pm

Hi....quite a bit of info on the JL site in US if you search...one link here.... https://forums.jag-lovers.com/t/e-type- ... a-44/65218 ..also copied this text from one post "To install Dana 44 gears you need a special installation kit that
has shoulder bolts to match the larger bolt holes to the size of
the Jag carrier (or have a machine shop drill and tap the carrier
for the bigger bolts) and special bearings to mount the D44 pinion
in the Jag housing. Of course you need the yoke for the pinion
shaft too. CWI (http://www.cwiinc.com/index.html) has yokes to mate
with the Jag driveshaft flange, or you can use a standard D44 yoke
and change the driveshaft.’’
Hope it helps....Steve
Steve
1969 S2 2+2 & Building a C type replica

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Philk
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#5 Re: Jag diff - Dana 44 CWP conversion

Post by Philk » Fri Feb 01, 2019 4:52 pm

Sirjames wrote:
Fri Feb 01, 2019 4:09 pm
@ PhilK : Are you not a friend of Steve (Southern Classics in Twickenham) ?
Yesterday I asked him about that subject and he told me a story very similar to yours.
He may well have been referring to my car (which Southern Classics has just done an IRS overhaul on). The firm he used to refurbish the differential noted it had a Dana Crownwheel and Pinion (which meant it had a 26 Spline Yoke at the end of the Crownwheel shaft). Given the diff was running so quietly and the 3.07 Crown Wheel and Pinion were virtually unworn, we decided to leave it in-situ and just replace the seals. Steve then managed to source a superb 26 spline Flange of the correct size and hole spacing. See picture below.

Image
Phil
1964 S1 3.8 OTS

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64OTS
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#6 Re: Jag diff - Dana 44 CWP conversion

Post by 64OTS » Mon Feb 04, 2019 1:20 am

Using Dana 44 3.07:1 parts is the way I am going. The rear suspension is still in the car but I was lucky enough to source a new Spicer gear set from Amazon (before the Aus version took over here!) for about $150. Instead of shoulder bolts I have hardened spacers to fit over the 3/8 Dana bolts which are narrower than the 7/16 carrier holes. I sourced a 26 spline input flange from Northern Drivetrain for just over $100. I compared bearing part numbers and sizes with the various data available online and I think the bearings in the kit should mostly fit OK. My local specialist will put it all together and says he can source anything needed including an input shaft spacer/ crush sleeve/ bearings if needed. Cost will be about $1500 for the change, so all up should be under $2000 (about gbp 1400). Some Spicer part numbers are CWP kit (706017-X) input flange (2-1-1881-X or NDT00113) bearings (706031X & 706030X) seal (CR15788). I hope that helps.
Tim 1964 4.2 OTS

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Sirjames
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#7 Re: Jag diff - Dana 44 CWP conversion

Post by Sirjames » Mon Feb 11, 2019 9:27 am

Thank you all for the messages, even if I'm still not sure 100% it helps.

Just talking to someone I recently learned that there are 4 types of input shaft bearings!!
We always learn.
So I'll order a Dana Spicer set of gears from the US and see what I can do with it...
James 67 OTS, 73 OTS 6.0L, and other makes

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