diff shortening

yeprat1 · Post by **yeprat1** » Fri Jul 18, 2008 10:10 pm

ok guys this is something i nothing about .if u wanted to fit a diff thats not a banjo and it has to be shortened obviously the housing and the axles get shortened to suit fb/ek. so my question is why cant a standard axle be shortend and rejoined onto a hq stud pattern, are they the same thickness and would it be strong.

Post by **Blacky** » Fri Jul 18, 2008 10:20 pm

Having axles redrilled to whatever pattern is surprisingly cheap, around $150.
The trick with narrowing diffs is trying to use the short axle as your new long axle, therefore you only need to have one axle shortened.

yeprat1 · Post by **yeprat1** » Fri Jul 18, 2008 10:25 pm

forgot to ask if u were to join the two axles together what would happen with the brakes do they change

Leon B · Post by **Leon B** » Sat Jul 19, 2008 12:01 am

Generally (say you put a VP comonwhore diff in)
A good machine shop will cut down the diff to length, then take the VP stud plates off the end of the axel and weld plates to suit FJ-LJ pattern.
This is what happened when I had the 9 inch made for the HG Kinga
Cost around 700 to a grand, and you have to supply a diff.

yeprat1 · Post by **yeprat1** » Sat Jul 19, 2008 6:29 am

i really want to change the stud pattern so i can buy better wheels

EK283 · Post by **EK283** » Sat Jul 19, 2008 7:54 am

Yeprat,
I am assuming you only want the stud pattern changed?
To change stud patterns on axles the gurus will simply weld the old holes on the axle flange and redrill to suit. You then need the drum redrilled as well.
I have never seen a stock diff that has been drilled but it is possible if there is enough material on the flange.
Most people go the shortening of diffs with the correct stud pattern thinking the old bangos are no good I assume?
My diff at the moment has multi drilled axles so I can change the pattern from &*#@ to Holden simply by unscrewing the wheel studs and screwing them in the other pitched holes (Standard axles are pressed so you cant do this) The brake drums are also multi drilled.

Hope this helps.

Regards Greg

ben · Post by **ben** » Sat Jul 19, 2008 9:58 pm

Was in the same boat yeprat, but decided there was not enough meat on the flange to re drill hq pattern. Ended up re drilling hq front discs to early stud pattern and sticking with the 14 steelies. I'm currently going down the path if getting some moser axles made for my rally car. They cost around $800 and they will pretty much make up whatever you need. So i guess that's another option, obviously you would still need to re drill whatever drums you going to run.

kevin · Post by **kevin** » Sun Jul 20, 2008 10:51 am

think it may have finished but there was an early holden diff with HQ bolt pattern axles on ebay the other day
you can cut and weld axles but it's NOT very successfull
i think you're best option would be to shorten a commodore diff

yeprat1 · Post by **yeprat1** » Sun Jul 20, 2008 11:38 am

what model commodore diff is best

yeprat1 · Post by **yeprat1** » Sun Jul 20, 2008 4:58 pm

hey guys i have a chance to buy a 9 inch already shortend to fit eh is $800 to dear and would it be overkill seeing that i would have to shorten a commodore diff anyway

FB MAD · Post by **FB MAD** » Sun Jul 20, 2008 5:36 pm

I remember adds in old mid/late 80's Street Machine for a company called Diff Trans Spares and they were selling narrowed 9 inch diffs back then to fit HQ to WB's for approx $800 or so.

Since we are around 20 years on from those times you would expect prices to have at least doubled.

So I'd take a guess that $800 for a narrowed diff is not too bad in todays terms.

yeprat1 · Post by **yeprat1** » Sun Jul 20, 2008 5:55 pm

doesnt matter it has a eh stud pattern what im trying to avoid

yeprat1 · Post by **yeprat1** » Mon Jul 21, 2008 6:11 pm

got a price today on shortening a vn diff it was $650 to do the housing and $180 to do the axles and he makes new saddles so i dont have to wreck the old banjo

Sammy · Post by **Sammy** » Sun Aug 03, 2008 8:54 pm

do yourself a favour, offset the centre in the diff (commodore) so you can use two short axles from the commodore and not need to shorten any axles at all

mrs ratbox · Post by **mrs ratbox** » Sat Aug 09, 2008 10:12 am

there's a borg warner on ebay allready done to suit FB/EK item No 250278267842