G50 - 4.08 Rear Swap

[Clyons0203]

I am looking to do the Skyline GT-R 4.08 rear end swap very soon. I have located a few differentials and I am currenty checking to make sure they are the right ones. Now Nissan has several versions of the R200, with different final drives, and different output flanges. The output flanges range from 4,5, and 6 bolt. The G50 (torquey V8) has 6 bolt flanges.

From searching this forum, I need a Skyline GT-R rear vlsd diff. It has to have 4.08 final drive and a 6 bolt output flanges. The G50 requiers a R200 with 6bolt output flanges.

In order to fit in a G50 the companion flange (aka driveshaft flange) has to be swapped. G50 must use G50 flange.

Can I swap the flange or does a machine shop have to do it?? Why wont a Silvia (S14) R200 6bolt diff work??

This is a picture of a five bolt flange. (wont work on G50)

This is a picture of a 6bolt S14 Silvia Differential

[Clyons0203]

Hmmmm I did some more research. Looks like there are TWO TYPES OF 6BOLT DIFFs. One like the picture of above and one with 6 evenly spaced bolt holes. The G50 uses the evenly spaced one. So the Silvia diff looks like it wont work, dammit

[superuber]

[QUOTE=Clyons0203]Hmmmm I did some more research. Looks like there are TWO TYPES OF 6BOLT DIFFs. One like the picture of above and one with 6 evenly spaced bolt holes. The G50 uses the evenly spaced one. So the Silvia diff looks like it wont work, dammit

Your right it wont work. And no to your question about a machine shop.Listen, get a 300z non turbo rear diff take out the 4:08 ring and pinion gear and put it in your diff! It works! Depending on your tools and abilityyou can do it! I can post some pics of mine if any one cares?

[3Q Jay]

I can post some pics of mine if any one cares?

yeah we wanna see.

[rsiwicki]

Quote »yeah we wanna see.[/quote]yeah...I wanna see and also drive your car like I used to drive mine. You certainly would be an exception to the rule that just sticking in a 4.08 into the G50 diff would work.....then again there seems to be always exceptions if one looks hard enough.

Do a search on the 4.08 or contact Jamesmost (NICO member) and you will have plenty of knowledge to make an informed decision. Spend monies on other mods first unless you got monies to burn as it will not reduce your 1/4 ET's and also will make it more difficult to hook up from the stop light.

[superuber]

I know james has had issues with his traction control. My car doesnot have that. The only issue I have had is a leaking seal. As faras driving my car like you, I assume you mean hard. At times I driveit very hard, also I am putting a 100 nos shot to it. If thats not hard on itI don't know what is!! I can get the Q on the lift today and snap some pics. My rear is not apartbut I do have the old z diff and another Q diff. I can show what I did.

http://community.webshots.com/user/neheadsuperuber

[Jeff Williams]

Can I assume that the 300zx NA diff doesn't have to be VLSD?

Is there a difference in the automatic diff and the manual diff?

[superuber]

I think all 90 to 96 3ooz diffs are vlsd.They should all be 4:08's.

[Rex]

Can I assume that the 300zx NA diff doesn't have to be VLSD?

Is there a difference in the automatic diff and the manual diff?

Jeff, as I recall the 300Z AT diff has a lower (higher numeric) diff, that's what makes it more desirable.

[rsiwicki]

Non-Turbo Has 4.08Turbo Has 3.xx

You want a diff out of a non-turbo Z32

[superuber]

Non-Turbo Has 4.08Turbo Has 3.xx

You want a diff out of a non-turbo Z32

Thats what I said in my first post. I have the pics I amloading them now.

[superuber]

This pic is just the cases. The case on the right is the z case. The case on the left is a Q case(not mine) junk yard. This is a pic of the inside workings. The left is the Q. The right is the Z.You can't tell but the diameter of the ring gears are of course the same,but the axle holes are different. The Z is a little smaller.This is my stock ring and pinion.These are the infamous 6 and 5 bolt output shafts. Left Q, right Z.spacers. You have to move these around because of the taller 4:08.This is my rear diff in. I used the z rear cover. looks good!Because the gears are taller the diff is shifted inside to the right.this is the left (drivers)output shaft it sits right on the housing.This is the right side. It sticks out a little but still seals the gear oil in.ignore the abs sensors I used the other Q's.This is the most important part. Slide the boot clamp a little inward on theleft (drivers) side. (outside clamp)If you don't the axle pulls on the out put shaft and it can pull it out!I know it happened to me! There is a lot I left out, torque specs, other details. I would hope if you try this you know a little about cars! I did it, it does work, problem solved!



http://community.webshots.com/user/neheadsuperuber


Modified by superuber at 2:35 PM 6/7/2006

[3Q Jay]

thanks for posting pictures. good tip on not stretching the drivers side boot. of course the pass side is now compressed, not sure what all this will do long term to the 1/2 shafts. how did you rig your rear abs sensors-or does the non-tcs Q not utilise the rear sensors?

[rsiwicki]

thanks for posting pics....I must give you credit that you are certainly the first we have heard of going this route. I had mine custom built and it still needed "longer" carrrier bolts as I ripped one right through the metal when it broke loose. They also used a spacer so mine was pretty much dead center on, but that is small in comparison to ripping a carrier bolt through the casing like it was butter.

Congrats on doing this mod both cheaply and sucessfully.

[elwesso]

Looks pretty good... now go buy a few Q and Z diffs and make them for the rest of us!

[RobertsnewQ]

thanks for posting pics....I must give you credit that you are certainly the first we have heard of going this route. I had mine custom built and it still needed "longer" carrrier bolts as I ripped one right through the metal when it broke loose. They also used a spacer so mine was pretty much dead center on, but that is small in comparison to ripping a carrier bolt through the casing like it was butter.

Congrats on doing this mod both cheaply and sucessfully.

Rob - yours with the gear spacer is cleaner, but kudos to superuber for going where no Q has gone before.

Jay - the non TCS Qs have only 3-channel ABS so the pickup is on the input flange.

[Jeff Williams]

Does it matter if the 300zx diff is an open rear or does it need to be VLSD. Or are all non-turbo 300's open? I don't want to buy the wrong diff.

I know that I want the NA diff. I don't know if the Automatic or 5-speed NA diffs are different.

Thanks for the pictures they help a lot!

[elwesso]

you want the LSD

[superuber]

Rob - yours with the gear spacer is cleaner, but kudos to superuber for going where no Q has gone before.

Jay - the non TCS Qs have only 3-channel ABS so the pickup is on the input flange.

You're right, the abs sensor is on the front. You can't see it with the pics.Yes, it is much cleaner with the spacer. Who makes the spacer?As far as the boot being pushed in on the right side, it is 1/8 or maybe1/4 of an inch. It should not affect it at all. If a spacer could be had for this mod it would be alot easier!Yeah, having the shop to do it in is nice too! But if you had air tools it wouldn't be to bad. The diff is easy enough to get out.Good luck to all you who plan to do this!

[qsiguy]

What are the chances of getting a step by step write up on this Superuber? At least the basics. That would be great. So what's the estimated cost for this mod doing it this way? Seems like it should be a pretty inexpensive method.

[redmanfx]

I love this thread!! I actually get started back on my 4:08 project in the morning. How about I include some pics of the half axles of both a Q and Z along with the Z diff so some other people can see what we are chatting about. This time I'm trying to use the Z diff and make adapters, spacers or whatever else I may need. We'll see, I couldn't make it work once. I figure with pics like this other Q owners will get an idea of just how difficult (to me anyway) this really is to get to work right! Plus I've got my AC system to remove and the new one to reinstall. Makes for a good rest of my week.

[Jeff Williams]

you want the LSD

So the LSD ring and pinion gear is different than the non-LSD ring and pinion?

I ask this, because I can get a non-LSD free, but have to pay for the LSD, due to demand.

Free is better!

[jamesmost]

i have an extra r32 4.08

[elwesso]

james call me brotha.

[jamesmost]

I know james has had issues with his traction control. My car doesnot have that. The only issue I have had is a leaking seal. As faras driving my car like you, I assume you mean hard. At times I driveit very hard, also I am putting a 100 nos shot to it. If thats not hard on itI don't know what is!! I can get the Q on the lift today and snap some pics. My rear is not apartbut I do have the old z diff and another Q diff. I can show what I did.

http://community.webshots.com/user/neheadsuperuber

ur car does not have that problem or does not have TCS ??

[Clyons0203]

Do a search on the 4.08 or contact Jamesmost (NICO member) and you will have plenty of knowledge to make an informed decision. Spend monies on other mods first unless you got monies to burn as it will not reduce your 1/4 ET's and also will make it more difficult to hook up from the stop light.

I think this mod will reduce times. The gear ratio change will cause the Q to accelerate alot faster, but will also make the car spin more off the line. Some nice wide tires\rim should handle that.

[superuber]

I don't have tcs. Are you still having issues or did youswap back? Someone said about doing a write up on this. A good shop manual should give you all the info you would need to do a gear change. If you are not comfortable doing it with a manual maybe it's too much for you. I'm around this all dayeveryday. I'm not a Q45 master tech but being around cars allmy life has helped. My sugestion, find a local guy to do it.

[jamesmost]

did not swap back, still having issues w/ tcs/slip/abs have not had time to play around w/ it

[sheadee240]

did not swap back, still having issues w/ tcs/slip/abs have not had time to play around w/ it

So, It sounds like a tcs car will probably have issues with this diff ratio that need to be sorted?? ANyoneknow how to trick the tcs into seeing the wheel speeds that it wants to see?