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View Full Version : Can I put Q45 gears and LSD into S13 diff?

Fred Allen Burge
09-30-2011, 08:09 AM
Hi,

I need a lower gear ratio (numerically) for my LS1 swap and I want LSD while I'm at it. I'm wanting to use the 3.54 gears and LSD out of an early 90's Q45 diff and put them into my stock S13 diff housing. I need to stay 4 lug since I already have my wheels bought.

Can I put the Q45 guts into my S13 housing and keep 4 lug? If not what's the best route to go to get lower gears (numerically) and limited slip?

I've searched around a lot and this info is surprisingly hard to get a straight answer on.

Thanks!
Fred
whitey240
09-30-2011, 08:14 AM
Just curious... Why are you looking to put a lower gear in? I have a 4.86 gearset right now in my 240 and I couldn't image it any other way. I cruise along the highway at 2-3K in 6th gear.
Flicktitty
09-30-2011, 10:13 AM
I've read you can, but you need one Z32 Axle and one Q45 Axle. and i believe someone said you can still use the 4 lug hubs.

Install Guide: Q45 Differential swap into 240SX subframe : 240SX Technical Forum (http://forums.nicoclub.com/install-guide-q45-differential-swap-into-240sx-subframe-t267924.html)

www.ka-t.org :: View topic - Q45 Diff to S13 and Keep 4 Lug? (http://www.ka-t.org/forums/viewtopic.php?t=47889&sid=1cb6f8b30825cc7a690c4db91f23ad3f)
Fred Allen Burge
10-01-2011, 07:34 AM
Just curious... Why are you looking to put a lower gear in? I have a 4.86 gearset right now in my 240 and I couldn't image it any other way. I cruise along the highway at 2-3K in 6th gear.

I need my rear end to match a GTO's rear end or as close as I can get it so it will shift and drive like a stock GTO since I'm using a GTO engine/auto tranny.

The GTO has about a 3.4 ratio roughly, the early 90's Q45 has about a 3.5 which is what I was wanting but they require 300z and Q45 axle mixing and matching and thus 5 lug hubs to go with the bigger axles apparently.

The 97+ Q45 is about a 3.6 rear end, close enough for me, and only requires using 93-94 J30 axle shafts which means I can keep my stock 4 lug hubs and wheels, etc. So that's the route I'm going, bolting in a 97+ Q45 complete diff along with 93-94 J30 axles, using my S13 rear diff cover and front pinion flange. I'll make a post once I get it all together.