Strange diff center markings

Includes clutch, transmission, propeller shaft,
universal joints, differential and rear axle.

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Rapps
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State: NSW

Strange diff center markings

Post by Rapps »

Hello All.
I have just pulled the diff center from the EK ute to fit a 3.55. The center I removed had no stamp on the front collar and I just found these numbers after HOLDEN 740395 MN can anyone identify this center?
Blacky
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Re: Strange diff center markings

Post by Blacky »

If the centre is out just read the ratio off the crown wheel ???
When you're faced with an unpleasant task that you really don't want to do, sometimes you just have to dig deep down inside and somehow find the patience to wait for someone else to do it for you.


Foundation member #61 of FB/EK Holden club of W.A.
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Craig Allardyce
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Re: Strange diff center markings

Post by Craig Allardyce »

What where the numbers actually stamped in? The case or crown wheel gear? I think your a digit short too.
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Rapps
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Re: Strange diff center markings

Post by Rapps »

it is stamped on the crown wheel 7407395 MN
ek diff.jpg
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Harv
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Re: Strange diff center markings

Post by Harv »

If I read that part number as 7407395, then the Master OldFarts Dogologue indicates that it is a differential pinion flange slinger for FJ from engine number 136885.

Cheers,
Harv
327 Chev EK wagon, original EK ute for Number 1 Daughter, an FB sedan meth monster project and a BB/MD grey motored FED.
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Craig Allardyce
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Re: Strange diff center markings

Post by Craig Allardyce »

Yeh I read that too Andrew.
The part number pictured does match what I have here for a 3.89 crown wheel. The number is pretty much useless as a reference in the master cat as it only lists matched set crown wheel and pinions by different numbers. The part number stamped on the crown wheel would have been for identification prior to lapping and setting with its mating pinion gear. After that both gears would have been stocked as a set under another number. No other numbers are on the crown wheel apart from engraved serial number and pinion positioning dimension.
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Rapps
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Re: Strange diff center markings

Post by Rapps »

thanks Gents that explains the old girl howling its head off at 60mph with 185/75/13's
It will now have a 3.55 and 185/65/14 's
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Errol62
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Re: Strange diff center markings

Post by Errol62 »

My calculations say you would be reducing your revs at a mile a minute from 3279 to 3051. Equivalent to 7.5% overdrive.

If you were to stick with your current wheel tyre combo and just change the centre you would achieve a 10% overdrive. Something to think about.


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Rapps
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Re: Strange diff center markings

Post by Rapps »

OK thanks Errol. We are going to Gosford next week and will try both sets.
Going to that museum with our car club on Saturday
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Rapps
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Re: Strange diff center markings

Post by Rapps »

Here is the update on the Ute. This past weekend we traveled just over 500 miles round trip and it ran just great (saw a black sedan heading north at Port Maquarrie and just thundering )
She has stopped howling at the 60 mph now. I agree that the 13's may be better so will try that again.
This is it's second large trip since I got it out of a shed No problems
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In the Shed
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Re: Strange diff center markings

Post by In the Shed »

Good stuff, do you know what the engine rpm is at 60 mph?

Regards
Stephen
A day in the shed beats a day at work!
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Rapps
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Re: Strange diff center markings

Post by Rapps »

Thanks Stephen , I don't have a tach in it but it is easy on the ears now and cost around $80.00 in fuel for the 500 miles at around $1.45 per litre.
I am very happy with it
Regards Lindsay
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FireKraka
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Re: Strange diff center markings

Post by FireKraka »

Hi Rapps;
Now that it is running really well you can plan to come to Perth for the Nationals next year :yeahhh: :grinnn:

Regards
Neil H
Member of WA FB/EK Car Club
Frankenstein EK V6 Ute
FB Station Wagon Project
1950's Commer Light Truck (2.5 Ton)
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Rapps
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Re: Strange diff center markings

Post by Rapps »

Yes that could be an idea.
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