First Attempt to install Z32 NA 4:08 differential on the Q failed......

[redmanfx]

......but I'm trying again. The failed first attempt was my fault because I didn't take my time and make sure everything was perfect. I used the Z32 half axles and the set up was short about 2 inches but I pressed on and paid the price when, after two days I shredded the project. I started feeling vibrations, but ignored them thinking I'd get to check them out the next day, but the problem didnt' wait until then.

Considering I did this myslef with little help my patients was my downfall. My installation was patchy at best because things didn't fit quite right. Instead of working with it, I more or less jerry rigged it. Terrible I know, but I was just too excited and didn't intend to leave it that way.

So..... This time I'm going to use the Q's half axles and fabricate a spacer/adapter to hook them up with another Z32 NA differential. I will not be doing the install as I'm leaving that to the professionals. I'm sure we can get it to work this time and have it documented as well. Pictures to be included with a write up as it's about time I start doing some write ups instead of being lazy about that. I'm bidding on another differential now so it will be about five weeks or so most likely.

This was really the first time I screwed a DIY project up, but hey you don't get anywhere "wishing" it would get done. Thankfully I didn't mess my Q up.

To be continued....

red

[Jeff Williams]

You're my hero.

I hope you didn't ruin anything more.

Keep us posted, and take a lot of pics, please. (I know I never think if the camera, until I am 2 hours into the project).

[superuber]

I have a 95 and I built my 4:08 set up myself at my shop. It's been almost a year and I haven't had any problems. I used my oe caseand threw the gears into that. The gears are steeper and it sat a little offset, but the set up has been great. I had some initial problems but it's very easy. If you are interested in more info let me know. I had the rear diff in and out alot, but with a lift it does make it easier. What year are you dealing with?

[RobertsnewQ]

Did you have to use a spacer behind the ring gear?

[superuber]

Actually, no. I got a rear diff out of a 90 z and took out the pinion and ring gear. Threw it in mine. Without the spacer it was shifted to the right, but the axles took up the small difference. The drivers axle sits a little further in the rear but other than that it works great. Of course i put all new seals in,and tore it down after 5,000 miles and all is well! It's held up great even with a 100 shot NOS!

Modified by superuber at 1:19 PM 5/4/2006
Modified by superuber at 1:19 PM 5/4/2006

[Jeff Williams]

Alright, superuber I am gonna have to see some pics and a write-up of this job.

I have done some diff work in my racing past. I started out swapping the gears in a GM rear end, and then went to For 9" which are super easy, just swap the pumpkin. I then switched to Halibrand quick changes for the short tracks, and used the 9" on the larger ovals.

I have heard a lot from people on this board trying the gear swap, and blowing up the diff. A few have succeeded.

The spacer is mentioned a lot, but I don't know if anyone has made one.

Richmond made a few sets of gears for the 300ZXtt rear diff, but they are really expensive, and hard to find.

I have wanted to try this swap several times, but just can't find the time. I used to have 2 Q's but had to let one go.

If you are up to it, I bet a lot of people would love to have the 4.08 gear set in their Q. Do you have the time to build about 10 of these?

[Flagship-Q]

Amen! I think I just soiled myself thinking about this. I didn't realize (or read enough I guess) that the diff or gear swap was possible. @nd keeping us updated as there will be guys here a mile deep interested in this.

[AZhitman]

Mine required a ring gear spacer (and longer bolts).

[jamesmost]

Mine required a ring gear spacer (and longer bolts).

thought u had an r32/33 rear ??

[superuber]

I did this mod a while ago. I'm trying to remember all of it. I can give you a little info but it's going to take me some time to recall it all. It's not a difficult mod but for me there was a lot a thinking and trying things out.I have only had my Q for a couple of years now. I started reading about all the mods I saw on Q45.org and here. I thought the 4:08 conversion was standard, easy. So I got a 90 300 nonturbo rear diff from the local junk yard and started looking at it. I also got a 92 Q rear diff because I wanted to keep my stock one. As you know the axle hook up has 6 bolts the z has 5. So I knew I had to use the Q diff and steal the gears from the z. Another problem was the abs hook up. The 92 Q hook up was different from my 95.The 92 has the sensors on the axle's. My 95 had it on the input of the pinion. I did get it to work but can't remember what I did. But thats not really that important I drove it with my abs light on until I fiqured it out. Like I said it shifted the whole diff over. But I threw the axles on. The right side sticks out a little more than stock but snapped in. The left side sits in closer, that is where I had some problems. Listen, I'm not a nissan guru, never claimed to be. I was raised in an auto repair shop. Never got into speed or racing. I thought from reading that every one was doing this thats why I took it on. The other thing to consider is these are not highway gears. The Q revs higher on the highway. You may not notice it much, but you start cranking 30 to 40k a year and you may have premature engine wear. I drive my car 20 miles a day to work and it pretty much sits on weekends. I put on 5k a year. not your daily driver. Keep that in mind if you want to do this. As far as building diffs, i'm not really interested in any extra work. You can do this. I can't believe some of you haven't done this already. like I said I had no idea I was "doing a new thing". Nico certainly has greater car minds than me.

[Flagship-Q]

Just curious, why did you use the Z32 half shafts instead of the Qs if you were using the Q diff. anyway? So, if you just put in the gears from the Z32 diff. (spacer, longer bolts or whatever) into the Q axle, no other mods are needed? If the Z32 half shafts are needed, couldn't they be shortened or lengthened to the correct length? Pretty interested in doing this. Also, any idea what RPMs you were doing on the highway as a result of the new gearing? Thanks!

[Rex]

... Also, any idea what RPMs you were doing on the highway as a result of the new gearing? Thanks!

I see about 15% more, give or take.

[elwesso]

thought u had an r32/33 rear ??

Probably this was before he had this rearend.....

[Mark86T]

Maybe these would work. Doesn't the Q have the same diff. housing as the z32 TT? This is what the TT guys use now. Not cheap though.

http://www.specialtyz.com/gears.htm

[elwesso]

I would think thatd work, howeverthats about what the assy costs from Nissan, so its not overpriced...

I agre,e i think the Q45 hsa the R230 not the R200

[superuber]

All I used from the z was the ring gear, pinion. I put those in the Q diff. I could not use the z axles because they will not work. So basically I got the 300z diff just for the gears. I did not use a spacer that is why it was sitting to the right. A spacer and longerbolts would be the perfect setup. I could not locate them, so I just went ahead with what i had. Also, the speedo is off. How much? Maybe 10 mph. It made a huge difference. Even at highway speeds it pulls hard. Can you do this? depends on your skill and tools. Will it work for you? I don't know. It worked for me, it's got 5k on it and I am not easy on it. It seems to be holding together even considering I use the nos daily. The gas guys love me, got my own account!

[redmanfx]

I have a 95 and I built my 4:08 set up myself at my shop. It's been almost a year and I haven't had any problems. I used my oe caseand threw the gears into that. The gears are steeper and it sat a little offset, but the set up has been great. I had some initial problems but it's very easy. If you are interested in more info let me know. I had the rear diff in and out alot, but with a lift it does make it easier. What year are you dealing with?

What I'm going to do is actually use the Z32 differential and use adapters & spacers to hook up the Axles and anything else. I want to avoid the swaping of gears inside the casings due to the ring and pinion wear on the original casing. This has caused huge problems in the past to swaps using the same casings. Plus if you relax and slack up on anything you'll blow the differential. You don't want to use the same bolts for example. I have a 92 Q and the Z32 and my 92 have the same size diff's. After experiencing the shredding of my work I don't won't to have much that doesn't fit right like I just did. ONce bitten twice shy for sure. I want to deal with adapting what I know works to what I have to work with.

I also want to aviod any Whining from the diff after it's all done. I know that is also a side affect of the swapping of gears. Joe has told me he has all the gears available for aroung $800, but I don't want to go that rout. Ask Greg if he likes the whining. Just something to consider. I've also contacted AAACOMP about this a year ago and I want to got this way since I failed and shredded my last attempt.

Our buddy John at IPT said they would install the gears into an existing Q differential, so some of you guys may want to go that rout. Get the Gears and a spare casing, send it to IPT and have them put in the 4:10 or 4:08 in the Q's casing. They haven't done it yet, but there's aways a first. Your talking around $1500 for that since you have to get the gears(New) and pay for labor and shipping. [email protected]

superuber- It sounds like you have had great success at doing this and I'm sure if your set up worked others will be willing to try. Great job in getting everything to work correctly. I do drvie my Q allot and wear would be a concern for me. Can take any pics of the placement of everything since you said some things stick out a bit and such. Just curious because I had the same thing except it was a bit short and didn't hold up like I wanted. I didnt use any spacers either.

Anyway we do it I'm going this way and will share my success or failure with everyone again. Either way we go it can be done. It's just what way is most economical and commercially successfull to make it worthwhile for us. I've heard once you have a 4:08 you won't ever want to go back..

red

[redmanfx]

This is what I'm bidding on so please don't bid against me.

http://cgi.ebay.com/ebaymotors...%3A11

red

[RobertsnewQ]

Good for you guys for trying it. I spent some time looking at the options and decided that the only one worth the cost was the R32/R33 swap.

Supergruber - I'm surprised there was enough adjustment range in the diff support bearings to get the ring gear over that far. Cool. Now, did your right axle flange snap in, or was the groove too deep? Has that caused problems?

Redman - Make sure you have a VERY good shop make those adapters. You could probably sell quite a few since that route might be cheaper than the R32 swap or gear swap. I could have told you the axles don't have enough plunge, though! If just the CVs came apart, why are you looking for another pumpkin?

And Wes, the R230 gears will not work in the R200. The numbers are the diameter of the ring gear in mm - 200mm vs. 230mm. Q45 has the R200, but a weird variant of it.

[irax]

so does any one know with prof with pic that R33/32 GT-R rear diff works? or if you guys want to pitch in, ill buy it and tell you all but i wont know if any sensors work cuz its a track car only.. so i dont care

[superuber]

my right axle did snap in. Like I said my left axle just sits a little closer to the diff because of offfset. but only the width of the ring gear spacer, so its like a 1/4 inch or less. If I had that ring gear spacer it would be a perfect fit because that would push it over. I don't know how to explain this but inside the diff there are spacers too. because of the steep gearing I also moved one over. If you have seen the inside of a diff you would understand what i'm talking about. As far as whining, none, quiet! If I could do it again I would do exactly the same thing. I would be leary about using the whole z setup. we had it all here, axles and all from the z and they seemed less beefy. the diameter of the axle shafts looked thinner. Atleast thats how I saw it. maybe it was the year I had? $1500? Seems steep. Here is what money I have into it .300z rear diff 200.00 junkyard92 Q45 rear diff 200.00 junkyardPlus I have my oe diff plus the rest of the z diff. i'll try to get pics together.

[redmanfx]

That's great! You're the only person I know of that's done it that cheap and the fact you don't have whining or any other problems is just super news for me given you did it with all used parts! Way to go!

$1500 is based on brand spanking new gears and labor with shipping, plus it's a guestimate. Most of the Z setup is less beefy to be sure, but I'll only be using the Z Differential and I'll be sticking with the Q half axles. The adapters are the key thing plus some sensors that I believe I have figured out, but I guess we'll see.

If this doesn't work I'm going to try exactly what you did, but with the spacers. I'm at $160 with the diff from ebay with shipping and $80 for the spare Q half axles and who know how much for the fabricated adapters and spacers, but it shouldn't be to much. Keeping the expenses down is the key part for me. Plus I'll be doing my exhaust, AC system and painting my O.Z wheels so I'm getting all excited. I paid $300 for Z diff that I shredded and $100 for the Z half axles.

red

[irax]

anyone ever thought of just using different axles ? or just adapting them? i mean you can use a 300zx NA diff with j30 axles in a 240sx or just use the inner cv-joints from a 300zx or j30 on 240sx axles too... soo just something to consider.

[RobertsnewQ]

Q45 splines aren't the same as 300zx/j30, unfortunately. The bigger bolt pattern is for a bigger CV.

Redman (if I understand his post correctly) used 300zx axles, but they're too short.

I still don't understand what broke inside the diff, though.

[superuber]

It sounds like that should work for you. If I can be of any help you can email me with any questions. As long as the flange fabrication goes well I think you will be alright. I thought of that when I was working on mine, but I just tried changing the gears and it worked! But if thats what you feel comfortable with, go for it! Like I said before I don't want to come off as a know it all. I have learned many things from this site and I am thankful for all of it. good luck!

[redmanfx]

The Top of the axles where they bolt into the diff and the diff itself were ripped apart. Don't ask me how they just were. Yes they were short and I tried to make it work. The result was failure.

red

[irax]

SideTopic: does it have to be an R33 GT-R rear diff or can any R33 diff work? cuz a friend of mine can ship me an R33 GTS-T type M rear pumpkin ill see if i can have him take pics...
Modified by irax at 5:15 AM 5/6/2006

[RobertsnewQ]

SideTopic: does it have to be an R33 GT-R rear diff or can any R33 diff work? cuz a friend of mine can ship me an R33 GTS-T type M rear pumpkin ill see if i can have him take pics...

Modified by irax at 7:23 AM 5/4/2006

GT-R only. GTs-t has the 5-bolt axles.

[superuber]

With the axles stretched it put stress on the joint. Maybe stretching them did it in. Also if you pulled on the shaft it could have pulled the axle out of the diff. If that happens the splines get trashed.


Modified by superuber at 12:42 PM 5/4/2006

[redmanfx]

I'm blaming Slim for this!

red