RB26 S14 Transmission Options

[Scott Buwalda]

Fellas:

I have been following a few threads, and the issue I have facing me has been danced around, but not hit precisely on the head, so here goes.

I am using a Holden Commodore RB30 box. For one reason or another, it is grinding reverse terribly, and simply will not back up without chattering and lunging. Reverse gears are toast. So, what to do?

1. Do I pull the RB30 box and bring it somewhere to have it rebuilt, and rebuilt with what parts? It's not like I can go to the salvage yard and grab a Holden and pull the box for parts. Are there parts that share the RB20/RB30 format with other domestic Nissan models?

2. Do I yank the RB26 box out of the corner of my shop (thankfully I saved it, even when everyone swore the RB26 box would NEVER work in an S14 back a few years ago) and remove the front diff. and have the diff. casing welded up, and use that instead? it'd be stringer than the RB30 box I have.

3. Go find a good Z32 transmission, yank the bellhousing off the RB30 box, and install it (what implications am I to face...do I need an adapter plate of some sort to get the Z32 trans to mount to the RB bellhousing?) I am not worried about shifter placement, as I have a custom dashboard that can be easily modified.

Those with solid, first-hand experience please help! HELP!!

Scott

[SeVa-S13]

Not a fan of the RB25 trannies? Granted they feel like crap (like the Z32 TT's) but they can be had somewhat readily here...

[monkeyofdrift]

did it grind while the car was somewhat moving in reverse gear?? I notice if my car is moving alittle and if I drop it in reverse it grinds, so I wait for a complete stop then put it in gear. and the RB25 transmission is sweet.

[Stealth-Z]

A fourth option...?http://cgi.ebay.com/ebaymotors...ZWDVW

[REDLN]

man i wish i had the money to get that one cause i would pick it up quick

[240z4u]

Scott, do the RB30 and RB26 have the same bellhousing? If not, you have to use the rb26 bellhousing on the z transmission (I used a z31 turbo trans). It will move the shifter back a bit.

When you use a z transmission, the KA manual transmisson VSS bolts in.

That rb30 trans is the same as an rb20 transmission right? If so I do belive you can swap a KA trans onto the bellhousing from your rb30 transmission. I also recall hearing some internals are swappable.

Oh, and is the output shaft the same as an rb20 or 25 transmission? May wanna stay with the smaller trans if you dont wanna deal with another driveshaft.

If you have any specific questions about using a z trans, please email me. I did it myself.

Thanks - Evan

[Scott Buwalda]

Thanx guys, especially 240Z. Maybe I'll rephrase my question...

I have two RB transmissions already...an RB30 (which is basically equivalent to an RB20), and an RB26. I don't want to buy a third RB box, especially for the ungodly prices they're looking to get for one. Jeez, you'd think the gears were made of gold or something.

1. Do I rebuild the existing RB30 box, and with what parts? 240Z, do you have any idea what parts might be shared with any USDM transmisisons?

2. Do I modify the RB26 box by removing the diff. The benefit here is that the RB26 box will hold more power, the shifter will stay the same, and I can use the custom driveshaft.

3. Do I get a Z32 box? 240Z...I could take the RB30's bellhousing off, attach it to the Z32 box, and that would bolt right up? If so, that's going to be the way to go. A Z32 box can be had for cheap and they'll hold power. I am not overly worried about the driveshaft.

Scott

[StricNyne]

i will say this i talked to my mehcanic about using rb26 trans and he said its all on labor, of your doing the work yer self, its worth it to try, because you arent paying anything heh, but i was told its more than just welding the front diff up, like i heard the trans is too large and u need to modify the underbody in the front. Honestly thats wut scared me off the rb26 was transmission headaches, i really wish there was a way to use getrag trans from a supra...one day when i can afford one i will mess around with it

[Blown240sx]

26 and 25 trans are the same (outside) only difference is the mount style and the transfer case on the 26 trans. The modification your thinking of is probably the starter or what some people did to just use the 26 trans by cutting or banging out a hole for the transfer case to fit in.

[Evo_bill]

26 and 25 trans are the same (outside) only difference is the mount style and the transfer case on the 26 trans. The modification your thinking of is probably the starter or what some people did to just use the 26 trans by cutting or banging out a hole for the transfer case to fit in.

1+

if your up to tusk of working on the stock transmission, i.e removing gears and linkage, then cutting casing, and rewelding, then 26 transmission is the way to go.

[Kalypso]

1+

if your up to tusk of working on the stock transmission, i.e removing gears and linkage, then cutting casing, and rewelding, then 26 transmission is the way to go.

is there a write-up detailing this.. It cant be that difficult.

Im sure there's a pile of RB26 transmission's lying in a pile somewhere. lonely and neglected because no one is converting them.

[240z4u]

Scott, there is a great writeup on the transmission swap on hybridz.org of that trans swap over.

It can't get any damn easier, I apologize for not replying earlier. Drop me an email if you want, Ill be glad to help you out. I also have a z32 transmission on my bench I can snag photos of if you want.

Evan

[krayton]

rb26 transmission. ive seen it welded up. people are scarred of welding the cast. but i also know a bunch of people that are up for the challenge.

being that you already have the transmission. just try it. take the casing off and have it welded shut. you spend a few experimental dollars to have an awesome transmission.

im half tempted to swap my rb25 transmission for a rb26.

[74260zt]

The RB30 front half bell will not mate to the Z32 5 spd. as asked in earlier post above.

[HxC_Nismo]

the rb26 housing bolts up to the z32 transmission though, you might have to convert pull to push clutch or keep the pull style clutch you just have to use the rb26 flywheel and starter.

[240TT]

ive seen some rb240s with 6spd trannys. im just curious but where do they find those. ive seen some by greddy, hks, and hollinger but cant seem to find them. personally id rather have a 6spd over the 5 but if its really pricey id go with a rb25 transmission. i was also thinking about welding up the 26 transmission since it comes with the motor but i dont know much about doing that or where to even begin

[Kalypso]

rb26 transmission. ive seen it welded up. people are scarred of welding the cast. but i also know a bunch of people that are up for the challenge.

I own an SR, but i'd love to see this dont in a write-up with pics.

all this talk is here-say. so until then gentlemen... until then

[240z4u]

I have also seen the transfer case lopped off of an rb26dett transmission. I had one, and I did take it apart and I can confirm it is achievable.

I guess I can see wanting to use it if your stuck with it, but when it blows up and you need a new transmission you are much less likely to find 26 trans laying around. The driveshaft flange is different too.

Evan

[BoostFab]

this is pretty cheap

[nyc240sx]

i bought a rb26dett transmission just for the bellhousing i still have it laying around i bolted up the 300zx z32 bellhousing to it willing to sell it for super cheap

[S14eva1]

since we are on the subject....can some one tell me if this is a rb25 transmission ?

It doesn't look like it to me...what should I look for?

[240z4u]

Thats either a z31 turbo trans or RB25DET trans. Can't tell for certain.

Evan

[s14_sport]

Yes, it looks very similar to RB25DET transmission...but as state could be Z31 too..

[S14-NEO]

thats a S2 transmission and or a NEO RB25 transmission...looks exactly like the one i have behind my neo..