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diff ratio install

Posted: Fri Nov 11, 2005 2:04 pm
by jacka
Is it difficult to change ratios from 3:7 to 3:9 on a w/t sierra. I am of little mechanical aptitude, wondering if I could do it myself. Is there specialist tools required?

Posted: Fri Nov 11, 2005 9:27 pm
by Gutless
If you have complete 3.9 centres, then you can just unbolt the 3.7 WT centre, and bolt in the 3.9 NT centre. straight swap!

You will ofcoarse have to pull the axles out first etc etc, but there is no need to play with the R&P's if you don't need to.

Posted: Fri Nov 11, 2005 9:42 pm
by munga
removing the axles is (potentially) the hardest part.
some pop right out, some require a few beers and many words your mother wouldnt like.

i tried inverting the drum and using it as a slide hammer of sorts
that didnt work
i tried refitting the wheel and belting it with a bfh
that didnt work
i tried snatching it out
that kinda worked but didnt do my axle any good
i then put a jack behind it and that was enough pressure to pop it out.

if you need the car for monday, get stuck into it friday arvo / night coz those pesky axles can give you grief.

diff ratios

Posted: Sat Nov 12, 2005 5:51 am
by jacka
I think I'll just pay someone to do it!

Posted: Sat Nov 12, 2005 9:19 am
by munga
oh dont be put off because of me..
once youve done it a couple of times, you can do an axle in about 20mins

all you need is a manual, some gasket goop (or a gasket for the centre)
and some non-lsd diff oil

drain the oil
drop the tailshaft
remove the wheels and brakes
(no need to undo the brake lines)
undo the 4 bolts holding the axle to each wheel hub
slide out the axles from the axle tubes
undo the centre
remove.
place ad on outers for sale of old centres.

guys, have i forgotten anything?

(dont forget to refill the diff with fresh oil)