Differential Ratios

[Krait]

Interesting way to get out of Mother's day Merv. Glad it all worked out in the end.

Cheers

[sambo]

Good result Merv. Do you know where the diff was sourced from?

[Merv and Sharon]

Thanks fellas. Took me all of 5 hrs on my own with some jacks, ropes, wooden blocks and a rubber hammer ... A hoist and three assistants would have been good.

Those solid ally bushes from Option 1 are good stuff.

The speedo now shows 80-82kms/hr at a true 100 (on the GPS), so re-calibration sounds sensible. I have a set of microswitches in the glovebox to play with to reset it.

Revs now are 2050 at 100kms/hr. Before was 2600. I was worried that I might lose some of the torque bonus of the Ford small block but it is there still, just in a lower gear now. Its great driving in first!

Not sure about the original source of the diff Paul, as I got it from Scott. There aren't too many 3.55's around I gather. I believe they come from the auto R33 RB25DE Auto, C33 Laurel RB20E Auto on the list that you posted earlier.

[Merv and Sharon]

Just to close this off and any who may do the same thing on their Harrison. The 3.55 diff and the aluminium bushes as supplied by Option 1.

[1 TUF AC]

I am in the process of collecting some parts to change my differential ratio on my Harrison. I have done a lot research and been to plenty wrecking yards and read this post at least a dozen times. The only part that I can't work out is what axles I need to buy!!! s13,s14 or s15 bolt six axles ?? I have GTS T rear end with a solid mounted 5 lug differential. I want to put a S 15 helical LSD with a 3.692 ratio. I know I need to buy a four bolt backplate and solid aluminium bushes to mount the diff. As well as shortening my tail shaft at least 20 mm to allow for the ABS sensor length on a S 15 diff. the only part I can't work out is what axles to get. I was going to buy S 13 axles but I read online that the GST t and the GTS wheel hubs have different splines. I'm pretty sure s13,s14 and r32 gts have the same hub spline but the GTS T has bigger axles because as the turbo model. Can anyone help

[sambo]

Hi mate. My Harrison roller was delivered with the viscous 4.11 GTS-T centre which comes with the 5 bolt half shafts as you've shown above. I picked up a 3.69 helical from the S15 and it has 3 flanges on the half shafts each with two bolts. So you need the S15 half shafts to go with the S15 centre. Make sure you get the half shaft bolts as mine shipped from Sydney without and the wrecker stuffed me around when I asked for them. Genuine from Nissan they weren't cheap! They're an odd design and I couldn't find a good alternative at the bolt shop.

Here are some photos from my gallery showing the S15 diff on the left, R33 on the right. Below that, the R33 half shafts are in the middle and S15 ones on the outside.

[1 TUF AC]

Originally Posted by sambo

Hi mate. My Harrison roller was delivered with the viscous 4.11 GTS-T centre which comes with the 5 bolt half shafts as you've shown above. I picked up a 3.69 helical from the S15 and it has 3 flanges on the half shafts each with two bolts. So you need the S15 half shafts to go with the S15 centre. Make sure you get the half shaft bolts as mine shipped from Sydney without and the wrecker stuffed me around when I asked for them. Genuine from Nissan they weren't cheap! They're an odd design and I couldn't find a good alternative at the bolt shop.

Here are some photos from my gallery showing the S15 diff on the left, R33 on the right. Below that, the R33 half shafts are in the middle and S15 ones on the outside.

so pretty much you're saying I need a S 15 diff with S15 axles. And the spline end of a s15 axle will slip straight in my r32 gst t wheel hubs with no problems at all. Do I need to put any spaces or anything like that or do they fit perfect?

[Rog246]

I think you be ok, & yes get the half shafts AND bolts-it will make life a lot easier for you

[1 TUF AC]

thanks for your help sambo. I will be off to the wreckers this week and if it's as easy as what you say my 4.11 nightmare will be over very soon.

[sambo]

Originally Posted by 1 TUF AC

And the spline end of a s15 axle will slip straight in my r32 gst t wheel hubs with no problems at all. Do I need to put any spaces or anything like that or do they fit perfect?

I can tell you the R33 GTS-t was a straight swap and I'd put money on the R32 being the same. There were differences with the GTR (twin turbo Godzilla) but we're talking about the single turbo GTS-t here, so you should be right. No spacers on mine.

You will probably also need adjustable control & camber arms as well as traction rods to get it all setup correctly in the Harrison.

Good luck!

[1 TUF AC]

I decided to put the diff in today and I have ran into some problems. The S 15 axles that I got from the wrecker are different length. The left side is okay but the right side is about 40 mm longer. I wonder if the car wreckers gave me the wrong ones. I tryed to put it in anyway but it won't Go in. The left goes in beautiful but the right one won't go in. If anyone's got a s 15 right hand axle laying around I'd be very grateful if they could measure it for me so I can see If the The wrecking Yard gave me the wrong one.

[Rog246]

Mate I had the same trouble when I was putting mine together. I swapped the 1/2 shafts from side to side !! They are not the same length either side.
I felt bit of a dill to be honest but fitted like a greasy stick in pig's bum when I swapped 'em over !!

[1 TUF AC]

Originally Posted by Rog246

Mate I had the same trouble when I was putting mine together. I swapped the 1/2 shafts from side to side !! They are not the same length either side.
I felt bit of a dill to be honest but fitted like a greasy stick in pig's bum when I swapped 'em over !!

I ended up getting them both in but the right hand side is very tight with only 15mm play. I definitely put them the right way. I think there's a possibility that the wrecker Gave me the wrong Axle. Or this conversion doesn't work on a r32 rear ends. Only r33 rear ends. Might have to get the axles shortened.

[renovationinnov]

just a question
why can you use the original shaft as by the pics I cant see any difference except the length
is the spline different course or is the flange mounting different pattern

[1 TUF AC]

I ended up putting the s15 axles in and took it for a drive and everything is all good. The right axle is a bit of a tight fit But once it's in it fits nice. What I noticed that the difference Was that the s15 axles collapse on both ends and the r 32 axles only collapse on one end. Am pretty sure the s15 axles have a different CV joint and they have a lot more give. The Car is a lot more better to drive and first gear is usable now. Bye-bye 4.11s and hello 3.9sssss

[sambo]

Good result mate. I don't recall having issues with shaft length (ha ha) but as mentioned, mine is R33 and the R32 could be different.

How are you finding the torsen centre? It behaves a little differently to the viscous 4.11 when you break traction.

Another thing I picked up from the Nissan forums is that you don't need LSD diff oil as the helical centre obviously doesn't have clutch packs. Just standard diff oil without friction modifiers. After a bit of research I filled mine with Redline Shockproof 75w90NS. The "NS" denotes non-slippery.

[Rog246]

" Non-slippery " Oil !
What' the point of that !???
You can't even use it in the bedroom if you're stuck !