Diff Ratios

[20SIX]

So my s13 has a 4:11 6x2 bolt diff in it, and has a new rear cradle in it also. ( under the assumption it's an r32 gtr diff and rear)

I've Damaged the diff or bearings, so will be removing and inspecting.

I did pick up a spare diff awhile back that have sitting there, it's also a 6x2bolt. It has stamped on it '38311' and 'A3'. Would this be the teeth count/ratio?

[GTSBoy]

1st thing. If by 6x2 you really mean 6 bolt flanges arranges in 3x2, then it's not GTR. GTR are evenly spaced 6 bolt. S chassis diffs and NA R chassis diffs are 3x2.

The ratio will be easily worked out by looking on the circumference of the crownwheel for the markings which will be some big number like 37 and some smaller number like 9 (for a 4.11 - other similar numbers for the other similar ratios like 4.08, 4.36, 3.89, etc). Inside the diff. Not on the housing. Anything on the housing can mean nothing about the internals.

[20SIX]

Okay great thanks for that info, I'll pull them both down and check it out.

And the gtr (32) 6 bolt single spaced diffs.. The shafts are stronger than the 3x2 assuming?

[GTSBoy]

Massively. The CVs more than the shafts.

[KiwiRS4T]

You could have a Stagea cradle too - they have a bolt pattern of 3x2 and a couple of final drives but the most common is 4.08 (close to 4.1) and people fit them to S13s.

[WARLORD]

Anyone know someone with 3.9 s

[20SIX]

Ahhh okay. Yeah I pulled my diff out and had a look it's a 4:11 (4:08) also has vicious lsd stickers on it

And it would be out of an abs model as it has the hole for the sensor at the front of it where tails shaft goes in.

I've smashed a tooth off the pinion..

So looking to source a replacement now.

I have another diff but it's non abs 3.91 and sounds abit worn, doesn't look like would fit anyway.

Any idea what my diff would be out of? Stagea only possibility? ( some stage before I bought mine someone has replaced the rear cradle with brand new genuine Nissan)

Also for a gtr diff, would I need to fit whole cradle, and what about hubs for the shafts?

Edited December 22, 2014 by 20SIX

[20SIX]

Oh and btw yes mine is an s13, so s13 hubs on rear

[GTSBoy]

4.08 is not 4.11. 4.08 is an auto ratio from Skylines and so on. 4.11 is the manual ratio.

If I had to guess I would say you have an auto turbo Skyline diff in there. The 3x2 halfshafts easily swap in for the Skyline 5 bolters.

[20SIX]

Weill it's 49:12 on the diff, has abs, and is viscious.

[WARLORD]

Do you have a pic of your diff handy 20six

[20SIX]

Hey mate, got it sorted.

Turns out I had the silvia diff r200 4:08's abs model. (3x2 6 bolt shafts)

Bought an r200 out of r33 4:11 abs 5 bolt shafts.

I changed the rear hat over from the silvia diff to the 33 diff (silvia one being 4 bolt rear and 33 2 bolt)

Then the 33 diff front mounts run bushes and longer bolts instead of being solid mounted like s13. So ended up buying some cnc machined solid bushes and aquiring the longer bolts to suit..

The 6 bolt Silvia shafts fit straight into the 33 diff and all is good.

[20SIX]

This is a picture of the same solid mounts I ended up using

[20SIX]

Also had the 33 diff pulled down, new bearings and shimmed and backlash set etc.

now I just need to save my money to do the one piece tailshaft ( my 2 piece is just about stuffed) and remove and rebuild the rb25 gearbox as syncros aren't happy in higher rpm. ( only on 13 psi also)