Page 1 of 1

Diff changeover help

Posted: Sat Sep 08, 2012 9:48 pm
by borgy11
Bought some 4:3 centres to replace my 3:9's. Got them in without any problems until the final step. Bugger. The tailshaft hole centres are different. Can anyone help with options. Heres what i thought could be the solution
A. Try to remove the flange from the old diff and put on new diff
B. not sure about compatability of running the old tailshaft one end and if possible rb30 other half.
I know this is a very common swap but havent seen any posts regarding this issue. What the hell should i do. Would prefer not to take the centre back out. Any help would be great

Re: Diff changeover help

Posted: Sat Sep 08, 2012 9:57 pm
by niss50
just change them over is wot i did with no prob

Re: Diff changeover help

Posted: Sat Sep 08, 2012 10:07 pm
by tas80
Change the pinion flange, had to do it on mine when I fitted 4.6 ratio centres from a 2.8 to my 4.2 coil cab.

Re: Diff changeover help

Posted: Sat Sep 08, 2012 10:23 pm
by borgy11
Does the big nut that holds the flange on have anything to do with pinion preload etc. i did have a quick try to get the pinion nut off my 3:9 but even with a breaker bar and a long pipe i couldnt get it to crack. I assume its right hand thread. Any tricks to it. Was gonna buy a impact gun tomorrow.

Re: Diff changeover help

Posted: Sun Sep 09, 2012 8:39 am
by joshy
Decent breaker bar and pipe then drive...

Re: Diff changeover help

Posted: Sun Sep 09, 2012 9:03 am
by blackmav
joshy wrote:Decent breaker bar and pipe then drive...
I've done that before and worked a treat but I recently had to do it and it was a no go. Snapped two bars and bent one.
I took it to a mates mech shop and he went through three sizes of rattle guns and still no good.
We then got a length of rhs and drilled two holes and bolted the flange to it from the back, other end on something solid. Takes the play out of it.

Re: Diff changeover help

Posted: Sun Sep 16, 2012 10:01 pm
by borgy11
Thought ide finish this off. Job done. I bolted a piece of 25mm shs across 2 of the flange holes for good leverage. Then with a 3/4 rattle gun and a 30mm socket rattled off no worries. 3 jaw puller to get flange off. Rattled flange back on lightly. Apparently the gq has a solid pinion spacer so preload is not affected. My vehicle manual seems to confirm this as it shows how to replace the pinion seal. I havent done the front diff yet so no 4wd yet. Drove on h2 car drives much better.