[defibros]

Hi, just wondering if a SJ70 (1994) rear centre diff will fit my 1989 Sj50 sierra? mine is leaking badly from the centre diff and i thinking what options i have ...

[Scrawny]

Are we talking transfer? There's a good chance it will bolt straight in. There's also a slim chance the flanges are different, someone else may be able to confirm

[zooky08]

Flanges are different and ratio is different.
Yes it will go in but you Need to change the front as well as it is different ratio.
Youll need to swap your flanges over as well.
Sj50 are 3.9
Sj70 are 3.7

Or you could change your pinion seal in the third member that is leaking.

[defibros]

Thanks guys, i am talking about my Rear Centre diff is leaking a lot from the pinion seal. I try to turn it and it feels like the bearings are buggered as well..

i always thought the SJ50 diffs are 3.7? Mine is a 1989 WT sj50 if it helps to clarify things

Cheers

[royce]

Mate stop saying centre diff, that means something totally different in 4wd's!

Assuming you mean the diff centre, being a 1989 it might be 3.7 ratio or it might be 3.9, likewise the flange might be the smaller NT 1.3 size or the larger WT size (likely its the NT though)

youll have to pull yours out and confirm what you have first

[defibros]

Thanks
I mean the REAR diff guys.. Sorry about it..

royce wrote:

Mate stop saying centre diff, that means something totally different in 4wd's!

Assuming you mean the diff centre, being a 1989 it might be 3.7 ratio or it might be 3.9, likewise the flange might be the smaller NT 1.3 size or the larger WT size (likely its the NT though)

youll have to pull yours out and confirm what you have first

[zooky08]

It is called a third member

[defibros]

so will a sj70 third member fits mine?

zooky08 wrote:

It is called a third member

[Scrawny]

defibros wrote:

so will a sj70 third member fits mine?

zooky08 wrote:

It is called a third member

You need to confirm what ratio you have, could be either 3.7 or 3.9

[defibros]

is there a marking somewhere on mine to see or i have to remove the rear centre diff to see?

Scrawn wrote:

defibros wrote:

so will a sj70 third member fits mine?

zooky08 wrote:

It is called a third member

You need to confirm what ratio you have, could be either 3.7 or 3.9

[zooky08]

Yes it will bolt in, but like Royce has said.
You'll need to pull yours out To see if you have the same ratio.
If being different ratio, you'll have to get two third member with the same ratio and swap your flanges over.
You need to confirm what ratio and flange bolt pattern before you get another third member.

[royce]

Piss off with your American Third member Pumpkin bullshit, its called a friggen diff centre

[want33s]

Being an 89 SJ50 I would put money on it having 3.7 ratio and 10mm bolts in the tailshaft/diff flanges.
Your 94 SJ70 centre should go straight in and work fine.

To check the ratio in your car without disassembly:
Chock front wheels.
Jack up both rear wheels.
Place axle stands under diff.
Put car in neutral.
Release handbrake.
Get under car and turn the tailshaft counting how many turns it takes to make a tyre do one full revolution.
It will be 3.7... three and three quarter turns
OR
3.9... four turns roughly.