Jump to content
SAU Community

Recommended Posts

Ive picked up a D22 gearbox as they are the same gearset as the rb25det box etc

Has any one done this before?

Im looking at this as this box cost me $250 nzd and a 25det big box sells for 2.5k

If i can source a rb bellhousing from a big box it appears it will bolt on but i think I will need to space it out as it appears the input shaft sits out further but the gearbox in total is shorter then the rb, so maybe the difference is in the bellhousing or maybe a spacer at the center plate will be enough

  • Like 1
  • 2 weeks later...

im just doing this conversion on s15 with rb26 and ive got it all bolted up just waiting on drive shaft to be made to put it to the test i machined down the input shaft to same length and diameter as rb box and used rb25det bellhousing and needed to make up a dogleg gear shifter and thats all ive needed to do

  • 4 weeks later...

the front half of the box is the same length apart from the input shaft which you can machine the end of it back a bit to fit.

The rear half is shorter.

If your going to run one in a new conversion, you should strip the box and do the bearings and also machine the input shaft. Then reassemble with a gtr or rb25det bellhousing.

Your going to have to make a diveshaft anyway, so make it longer to suit the d22 box.

You cant use a RB input shaft because the tooth count is different.

You can buy a broken 25det or 26 box cheap for the bellhousing only.

If you can get a big box with a blown 3rd gear for cheap, and a diesel box, you can make 1 out of 2 that will fit inside the RB case.

I have done a few for mates. Most recent one is behind a 330rwkw rb25det neo. going well so far

  • 1 year later...
  • 2 months later...
On 16/04/2016 at 7:27 PM, fletch rb30 said:

the front half of the box is the same length apart from the input shaft which you can machine the end of it back a bit to fit.

The rear half is shorter.

If your going to run one in a new conversion, you should strip the box and do the bearings and also machine the input shaft. Then reassemble with a gtr or rb25det bellhousing.

Your going to have to make a diveshaft anyway, so make it longer to suit the d22 box.

You cant use a RB input shaft because the tooth count is different.

You can buy a broken 25det or 26 box cheap for the bellhousing only.

If you can get a big box with a blown 3rd gear for cheap, and a diesel box, you can make 1 out of 2 that will fit inside the RB case.

I have done a few for mates. Most recent one is behind a 330rwkw rb25det neo. going well so far

Hey mate, I'm doing a rb25 conversion in my d22 (keeping it 4x4) done some research and a few people have said the navs input shaft spline is shorter than the rb. So apparently the clutch only uses a third of the spline? Just want to know how your mates cars are going as I don't want to replace the shaft if it shears off the splines haha cheers

  • 3 years later...

I am looking at this option, as big boxes are stupid prices these days. 

How would I find out how much is needed to shorten the input shaft. Or more accurate details.

Cheers

14 hours ago, elohim_imanu said:

I am looking at this option, as big boxes are stupid prices these days. 

How would I find out how much is needed to shorten the input shaft. Or more accurate details.

Cheers

Is $3.5k a stupid price for a brand new complete RB25DET box ? Seems pretty reasonable to me for what they are without all the bullshit required to split a box apart and retrofit parts - assuming you even have the capability / tooling required to rebuild and assemble a transmission yourself.

At the end of the day either gearset is still just essentially a poxy standard GTR gearset inside anyway - not exactly the pinnacle of strong gearboxes by any means.

8 hours ago, BK said:

At the end of the day either gearset is still just essentially a poxy standard GTR gearset inside anyway - not exactly the pinnacle of strong gearboxes by any means.

Careful. You are showing your snobbery. Not all of us have the budget for 3 GTRs.

No I'm not trying to be like that at all. Just the facts - a factory box is still just a factory box. Converting could cost easily the same as just purchasing a new one if required.

Yuh, what's the point unless you're broke-arse and have access to free Nav parts and capable of the required work?

New box is new.

If I were going to put time and energy into f**king about with alt Nissan gearboxes, it would be to go CD009 and get the extra gear.

  • Like 2

Yeh, well. I am running a 25de auto, probably going to do a stock +t to it. So I don't need much in the way of gearboxes, just something reliable and can handle a bit of power and do not want to sink a bunch of cash into it. I am not your average Skyline owner who does burn outs at KFC or drifts.

I enjoy working on cars (built not bought). I am a fitter and turner, so know a few things about machinery. Nav gearboxes are relatively cheap. Was just asking, from people who know, if there are some specifics around it. I may just end up just using a 20det box. 

I am interested where I would buy a new box for $3.5k though. I am in NZ and that is a 2nd hand price.

Well the R33 box is probably hard to get. It's OOS at JustJap for example. The R34 box is available there for >$4k now. Same same, but different. These or the R33 may be available at overseas Nissan parts people (all the usual suspects) for $3.5k but would have additional costs to get them into the country. Doesn't really matter. $3.5k. $4.5k. It's all about the same amount of money. If you want to play, you have to be ready to pay.

Just Jap, JDM garage etc. The boxes from somewhere like Amayama or Nengun are way under $3k AUD new but you gotta ship it and duty, taxes. If I were to be getting a new one I'd be talking to Darron at Just Jap.

Forget the RB20 box idea

  • Like 1
5 minutes ago, BK said:

Forget all above and CD009 like previously mentioned 👍

Yeh, like I say. >$4k is more than what I want to spend on a gearbox for this project. But thanks anyway.

10 hours ago, GTSBoy said:

The R34 box is available there for >$4k now. Same same, but different.

Never pulled a 34 GTT box down but do you know how they are different ? The 33 RB25 box is the same as the 89 - 96 model GTR boxes inside as far as input shaft, main shaft gears, synchros, selector forks and counter shaft goes.

I was under the impression the only change to the 34 rwd box was on the 2nd and 3rd gear main shaft gears, selector fork and synchro revision to match the series 3 R33 GTR gearset changes. Obviously released as a pull in the the 34 GTT box too but that's also easily changeable.

41 minutes ago, BK said:

I was under the impression the only change to the 34 rwd box was on the 2nd and 3rd gear main shaft gears, selector fork and synchro revision to match the series 3 R33 GTR gearset changes. Obviously released as a pull in the the 34 GTT box too but that's also easily changeable.

Yuh, I think that's pretty much the extent of it. I should have bought a 33 one when they were only $3k. Now I wish I bought a 34 one when they were <<$4k. Expensive future proofing shed ornament .

Some pretty harsh opinions of a gearbox that regularly takes double and often triple the power it was engineered for.

3.5k is a lot of money for a gearbox for a near stock engine and it's great to see cheaper options being looked into. Even the 350z box itself might be cheap but trans adapter etc mean total cost isn't.

1 minute ago, Duncan said:

Some pretty harsh opinions of a gearbox that regularly takes double and often triple the power it was engineered for.

3.5k is a lot of money for a gearbox for a near stock engine and it's great to see cheaper options being looked into. Even the 350z box itself might be cheap but trans adapter etc mean total cost isn't.

Exactly. There is not much in between. R33 GTR gearboxes are cheaper, about $2k. But a lot of mucking around making them 2wd. Even a 350 2nd had box is $3k. I know this has been thrashed around here a lot, but is the 20det good for up to 300hp? They are about $1k. Like I said, don't intend to thrash it.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Echo the awesome sentiment 👍 Definitely a car worth saving. Looking forward to seeing updates as well. 
    • Scenic roads, stunning skylines, and Chickos to finish it off! Join SAU NSW as we cruise through the Royal National Park and along Lawrence Hargrave Drive to Figtree! Sunday 26th October 2025 4:30PM Meeting Waterfall Station Parking 5:00PM Cruise Departure Royal National Park > Lawrence Hargrave Dr > Memorial Dr > Sid Parrish Park 6:15PM Arrival at Sid Parrish Park Figtree Meet Location: Waterfall Station Parking Final Destination: Sid Parrish Park RSVP: https://forms.gle/E4s5SiRKQfDdypky8 *Disclaimer* There will be a lead and follow car so no one should get lost. If you would like to attend or bring others along please put your name down and a +1 as numbers will be needed prior! This is NOT a race and we will all be adhering to all road rules. If this is what you want please come to one of our many track days. This is an official SAU:NSW event and will be run under a CAMS permit. One of the things that really sets our club apart is our commitment to being true enthusiasts. When on normal roads we strive to maintain good relations with the authorities as well as the public in general. When attending one of Skylines Australia NSW events please try to: • Be aware of surrounding environment and act accordingly. • Drive courteously on the state’s roads as a true enthusiast should. • Understand how important it is to maintain the good name of SAU NSW and thus, treat others accordingly. • Any misbehavior will not be tolerated and you will be asked to leave.
    • It's funny, as Ive seen plenty of people use them in cheap builds on YT. And they actually go okay, even though a lot of other maxspeedingrods stuff is terrible. Those turbos seem reliable enough, the only part being, a good quality turbo that is "identical" to it, will out perform it day in and day out. In both a lower boost threshold, and the ability to flow more air at the same boost pressure. As a cheap cheap replacement, not a terrible choice. For cheap and shouldn't blow in a day, not terrible (like other eBay/Temu turbos) for low cost and still decent performance, that's where the question comes in to play from the results I've seen. I'd actually find it hilarious to buy one, and strap it to a paddock basher or some other cheap as POS originally NA car, and send it to the moon!
    • The maxpeedingrods turbo is cheap and bolts on to stock parts. I think you just need a bigger silicone coupler for the intake. Its a cheap china turbo, but it's been running on mine for almost 3 years at 16-19 psi.
    • What do they look like right after you've tried to start it with everything connected? Also post photos of what they actually look like.
×
×
  • Create New...