RB25 Boxes

[masTers]

Hey guys, I have access to a decent series 1 R33 RB25-DET gearbox. Just curious as to if there was alot of diffrence between the 3 RB25-DET boxes? I know cubes guide touches on it a bit, and im not talking about clutch differences. Can they all handle the same power?

Also what is invloved in fitting one to a R32? It will be behind (eventually) a RB30-DET

Steve

[dangerous_daveo]

If anyone tells him to do a search, do it yourself first, there isnt a lot of info really, not in the one topic at least.

Maybe the few people who have done the conversion, and actually know what they are talking about post it in here and we make a sticky topic?

[Bl4cK32]

ok....here we go

r33 box bolts up to rb20/25/30 motor and gearshift is in same spot.

U need : rb25det gearbox, rb20det tailshaft end that bolts to diff, r32 gtr speedo sender, r33 red cog off speedo sender in r33 box u have, custom tailshaft, custom gearbox mount, r33 gearbox yoke.

R33 gearbox is longer so using a auto x member only works if you have an auto chassis to begin with (bolts in).

Cut the brown r32 gtr cog off the sender, and swap it for the r33 red cod (do a search i showed pics on "speedo sender fixed")

Any other q's lemme know

[dangerous_daveo]

Does it matter which RB25 box is used? IE s1 or s2 box, does it make a difference. As doing the searching I found conflicting views on this.

[masTers]

Thats what id like to know. The cost difference between the S1 R33 box and a S2 R34 box is minimal, but i'd like to know more about them.

[R31 POWER]

One box has a "push" clutch set up and the other "pull" I can't remember which one is which.

[DCIEVE]

He knows they run the different clutch types, pull type from the later versions being better but more expensive. Any difference in strength though?

[Bl4cK32]

Earlier r33's like 92-93 use the push, later ones use the pull.

I wouldnt worry about which one is internally stronger. If you are that worried, get an OS gearset, or dogbox.

There is a conversion to make push to pull, or pull to push....i just used the push to keep it the same as the r32 setup.

[DCIEVE]

im not talking about clutch differences. Can they all handle the same power?

Steve

From the original post...looking for differences in STRENGTH

[masTers]

Thanks mate, was begining to wonder if id written the original question in something other than plain english.

[masTers]

I wouldnt worry about which one is internally stronger. If you are that worried, get an OS gearset, or dogbox.

Thats the whole reason for the conversion. If I wanna know if i can get away with a series 1 box, as its easier.

Realisticly i need this box to hold 450ish rwhp daily, which ive heard the 25 boxes can handle.

[Bl4cK32]

Thats what i got sitting behind my rb30det atm....Id say it should be ok....

[masTers]

And thats what will be behind mine.

For arguments sake. How much is it to rebuild or tuffen up a 20 box? I'd say it would be horribly expensive because of the popularity of the 25 box conversions.

[Bl4cK32]

I didnt think you could "beef up" a manual gearbox....Only modify auto g-boxes.

$500ish will rebuild a rb20det box, $950 in parts + $600 in labour say to rebuild the r33 box.

[R31 POWER]

Opps my bad

Looking at the guts of my broken 20det box i would'nt spend 1c on it.Gear faces are so narrow and they are only good for paper weights!

[dangerous_daveo]

The reason I was asking about which had which type of clutch so we can make the one thread and sticky it. So we dont have to go thru like 20 others to try and find the info. I think as people use the RB20 more as its a cheaper motor, they will want to be using the rb25 box. So to save the hassles, one thread with all info would be much easier yeah?

[jnr32r]

ok....here we go

r33 box bolts up to rb20/25/30 motor and gearshift is in same spot.

U need : rb25det gearbox, rb20det tailshaft end that bolts to diff, r32 gtr speedo sender, r33 red cog off speedo sender in r33 box u have, custom tailshaft, custom gearbox mount, r33 gearbox yoke.

R33 gearbox is longer so using a auto x member only works if you have an auto chassis to begin with (bolts in).

Cut the brown r32 gtr cog off the sender, and swap it for the r33 red cod (do a search i showed pics on "speedo sender fixed")

Any other q's lemme know

Hi there,

when u say speedo sender u mean the whole speedo cable?

[Skyrine-Dave]

I would say that all the RB25det boxes are of same strength, Possibly newer ones might hold up a bit better if they arent as fatigued as old boxes...

A cheaper alternative to the GTR speedo sender is the Nissan Navara speedo sender, Ive posted the part number numerous times here. It should only cost you $24 and readily available at your local Nissan Parts dealer. I think the GTR speedo sender is around $150 and has to be brought in from Japan

[Bl4cK32]

Hi there,

when u say speedo sender u mean the whole speedo cable?

No, the part the speedo cable screws into on the actual gearbox. Its held in by a little clip which has a phillips head screw. Then it pulls out (its sealed by an o ring)

[masTers]

Any pics?