rb25 transmission rebuild

[b00stinbmx]

so im interested in rebuilding my rb25 transmission this winter, im wondering if anyoine has any information on this. i don;t feel like sourcing a used z32 transmission so don't suggest that. the only real problem is im getting some grinding now going into 3rd and 4th gear and it seems to be making some noise, possibly a bad bearing... if anyone can help id appreciate it! thanks
-tyler

[240z4u]

You are embarking on one of the few things I just won't touch in a car. Good luck.

[RRRRB]

Im in the middle of doing this now, you will need a long puller set such as this http://www.urreaprofessionaltools.com/p ... d3305.aspx

a smaller puller for bearings, bearing seperaters etc just to get it half way apart, everything is pretty much pressed together, i WOULD NOT recommend this to someone who hasnt had a transmission apart before... Ive built Multiple honda transmissions and installed LSD's straight cut gears, built custom shims etc to get those all to work. The RB25 trans seems much more intense thus far then anything i have messed with..

you WILL also need a good press and other things to get it done

The Rb25 transmission is a PITA cause everything is pressed on...

i bought a new synchro and bearing kit from Ebay, looks like a good kit.

however the sliders, insert springs etc, have been updated to newer parts so if you have a bad slider or insert springs you wont be able to buy new from nissan unless you buy 900 dollars worth of parts to update the trans to take the newer style sliders and synchro setup..

Chances are your sliders are beat up everytime it grinds the slider is whats taking the beating.. so before doing this id either soruce the sliders from a good used trans or prepare to spend the money to update the gearbox...

Keep us posted id like to know your progress as im in the middle of doing mine too, just waiting for my puller set to show up..

[RRRRB]

i just finished the hard part of the rebuild today, i replaced all synchros, 3rd gear and the 3-4 slider with good used componets, i also replaced all bearings, everything is back together just have to put the case on..

This isnt hard to do, but you have to be a ready for things to not go perfectly, nissan has alot of speicalty pullers/tools to work on this trans, so using the common pullers etc dont always work as good as a factory tool, you can get the job done if you improvise, and take your time. I spent about 5 hours working on this trans today and its not completly done yet... its a big job with a lot of pressing/pulling and much easier with someone helping..

After buying the pullers and bearing kit and sourcing good parts i have about 700 bucks into doing this, could i have bought another trans for that, probably, but i will now be able to repair this thing next time something happends and its always nice to have tools...

i will also add that the big snap on set listed in booztedZ's rbz32 bell housing swap wont work on the rb25 trans due to the main shaft being a few inchs longer.... it only works on a z32 trans... however with a few peices of metal and a drill it could be made to work...

If you have any other questions let me know ill try my best to help..

[Bluefire]

As RRRRB said, you will need a lot of tools to properly do your own transmission rebuild, specifically bearing separators and a press with different adapters. After messing with some SR transmissions, I find its easier to have some else do it thats equipped with the proper tools.

[BoredEE]

The worst part about rebuilding an RB transmission is parts availability I've waited 4 months for simple C rings. If you need to replace gears you're SOL.
Based on a 300zx transmission new from nissan being ~2k I'm sure a RB is about the same, I read somewhere on this forum that you can get one if you call up nissan north america 1-888-833-3225

I've been meaning to post a write up on this. My first attempt was a failure 2nd gear grinded. I'm going with a rb20 trans so much easier to pull/install with engine in.

The specialty tools list isn't too bad, this is what I used:

Press, this is cheapest press I've seen that can accept the length and width of the RB transmission and the press head is movable which helps when pressing out the main and counter shaft.
http://www.northerntool.com/shop/tools/ ... _200332759
I had to modify it by separating the press deck by using pipe nipple and longer bolts to hold the deck together. You have to do this because the gearset is too large to fit.

http://www.harborfreight.com/bearing-se ... 93980.html

http://www.harborfreight.com/14-piece-g ... 30305.html
A few couplings from mcmaster to piece both of the bearing puller sets together to make a long enough puller to remove the speedo gear/reverse bushing. (this is also one of the hardest parts to install I heated it up in the oven no real good way to press it on unless you fab up a tool to use 3rd gear on the press deck)

You need the jaws to pull off the 5th counter gear and the small silver bearing puller to remove the speedo gear/reverse bushing

To pull off the speedo gear/ reverse bushing I used an electric impact to pull it off. I do not suggest you use that I'm just letting you know how much of a PITA it is.

Pliers for flat retaining rings
http://www.amazon.com/Lisle-44900-Lock- ... 59&sr=8-15

Pliers for normal eared rings
http://www.amazon.com/Astro-Pneumatic-9 ... 359&sr=8-2

A dead blow hammer
http://www.harborfreight.com/4-lb-neon- ... 41800.html

Small gear puller for reverse idler gear bearing
http://www.autozone.com/autozone/access ... =70134_0_0_

I bought this for cheap press tools. I'm not sure if I needed it for the rebuild but I might have....
http://www.harborfreight.com/20-piece-m ... -5494.html

You'll also need a small sledge and punch set to remove the pins for the shifter forks.

If I remember any other tools I "collected" I'll edit this post.

FYI

http://beergarage.com/PathTransmission2Prep.aspx

The 300zx, pathfinder, rb25/26, D21 V6 all have very similar transmissions.

[RRRRB]

Does anyone know where i can get the snap rings and any other small parts for the shifter assembly. Or what will work from a USDM vehicle.. When i got my motor/trans swap it had a cheap POS super short shifter in it and now i dont have any of the snap rings etc needed to put a ISIS shifter back in..

[240z4u]

You can use the snap rings out of a KA shifter (at least I THINK that's what I used)

[RRRRB]

Is there anything else that sits in there I have everything from the shifter down...

[BoredEE]

Compare what you have to these diagrams

http://www.courtesyparts.com/pathfinder ... _4786.html

For that circlip I found one that works at sears for ~$2