How To: RB25 trans mated to z32 Trans - LOTS of pictures

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Booztd 3
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How To: RB25 trans mated to z32 Trans - LOTS of pictures

Postby Booztd 3 » Thu Feb 08, 2007 8:29 am

Guys

First off, I would like to preface this with a warning. THIS IS NOT FOR THE AVERAGE MECHANIC. Hell I wouldnt even recommend this for the skilled mechanic. I consulted my older brother who owns a speed shop in springfield IL named FC Customs (www.fccustoms.com) to help with the work. This work is being done because I am swapping an RB26DETT into my Z32. More info can be found at my website http://www.rbz32.com

Over the last two nights we broke down the Z32 Tranny, as well as the RB25 RWD Tranny. We then mated them together following Charlie C's suggestion that the input shaft needed to be swapped to compensate for bell housing lenght.

I will also re-preface this write-up by warning you almost every picture contains the 'shocker' LOL. We were feeling goofy during the process, so why not spice up the pics a little bit?

Here we have the Z32 Trans



You will begin by pulling the outter detent ball out of the trans. On the upper side close to where my bro's index finger is pointed in the picture above. Remove the 17mm bolt on the left hand side and remove the spring and then remove the ball. Keep these in a safe place.

Now you'll remove the front cover like so



Front Cover removed



Now you'll need a few different sets of snap-ring pliars. There is one small snap-ring and washer and a large snap-ring once you get the front cover off



Snap Rings





Now We'll work on the shifter rod. Begin by pulling the 10mm bolts out and pull the cover off. You'll see this



There are two dowel pins you need to remove in order to get the shifter rod out.

Now we'll remove the bell housing by removing the casing bolts in the middle of the trans. You'll need a hammer to separate the two pieces.



A close-up of the gear-set



Our next part is a highly debated topic regarding Z32 and RB trannies. The 4th gear synchros DONT grind, its actually the insert springs. You can see in the next few pics how the teeth have been ground and dulled down





Now you'll remove the forks from the gear-set





After you've removed the shifter rod and the pieces inside the trans, you can now remove the tail section casing





Here is another component that causes the grinding



Notice the teeth are worn down



Now this is where things get hairy. You're going to need the bomb-diggity puller set in order to get everything off the right way. We accomplished this witha $2500 Set from Snap-On



Gears starting to come off



Using the pinch puller for the lower bearing





We had to craft this next setup out of threaded rod and one of the pullers. It worked at least!



After removing the other gear above with the pullers, the remaining gears should come off with some prying/tapping of a hammer. Now the directions call for pressing the shafts out of the center-section. We did this using a press. Since the shafts are still bound together by the gears, you must press the shafts out one bit at a time, and then switch to the other shaft and press it out a bit. This makes is so the shafts dont bind.



This is how we felt at the end of night 1



Moving on to day two, we have an RB25 RWD Trans



I'm not going to go through the dissasembly process, because its quite identical to the process of removing the front/rear casings.

Here we have the Z32 Input/Output Shaft on the top, and the RB25 Input/Output Shaft on the bottom



Here are some comparison pictures of the bell housings





My stuff was pretty dirty and my bro's shop just had gotten a new parts washer in. This thing RULES. I give you ......"The Cuda"



Parts going in



Here's how the bell housing turned out



Center Section





Here the RB25 trans gearset.



Since I wont be needing alot of extra parts, we opted to cut the countershaft out with a plasma cutter, and avoid a crap-ton of parts removal.









Now since the input shaft isnt bound by the counter shaft, it slides right out



The mess we made



Now we're finally on to the reassembly process. We heated the parts on that usually get pressed on. We just put them in the parts washer for a few minutes and they went on pretty easy with a hammer. We used alot of the insert springs and such from the RB25 trans since they were in alot better shape than my Z32 trans. It basically ended up taking all the good parts from both and combining them.



Everything into place, forks are back on





Snap-Rings going back on



Front Cover sealed up



My brother on the right and tony (stallone) on the left. These guys were a huge help and I couldnt have done it withouth them



The completed RB25/Z32 Trans





Now onto some notes:

When I first read what needed to be done to the RB25 and Z32 trans it made a lot of sense, having to use a different input shaft to compensate for bell housing length, but the way I understood it was that the RB25 bell housing was longer, thus making the input shaft longer as well. If you read through this how-to, you’l definitely see that the bell housing is actually shorter. So in theory if we just switched the bell housings, the input shaft would be too long on the transmission, but this really isn’t the case. We measured the input shaft length, and theres only 1/8” different between input shafts. It is more than likely this 1/8” would be negligible when installing the transmission, considering the input shaft does not even fully seat on the pilot bushing. Even if you did run into that issue, you should be able to cut off the excess 1/8” from the Z32 input shaft.

Here is also a picture of the puller kit we used



Some pics of the shop and the cars

Panoz GTS on the dyno and STS C5



My bro's mid 10-sec stock block/stock head/stock cam 05 mustang





Their Ford GT



Blower & AFR Head setup going on an escalade





Arial View



Peace!


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Postby xsublimefrekx » Thu Feb 08, 2007 3:53 pm

amazing write up and amazing shop.

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evildky
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Postby evildky » Thu Feb 08, 2007 5:38 pm

um.....why? it just seems like a lot of work for what? different gearing? am I missing something? nice job with the writeup I just can't figure out why?

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Re: (evildky)

Postby Booztd 3 » Thu Feb 08, 2007 6:45 pm

evildky wrote:um.....why? it just seems like a lot of work for what? different gearing? am I missing something? nice job with the writeup I just can't figure out why?
Maybe you should have read the first few opening paragraphs.....
Booztd 3 wrote:This work is being done because I am swapping an RB26DETT into my Z32. More info can be found at my website http://www.rbz32.com

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evildky
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Postby evildky » Fri Feb 09, 2007 8:09 am

ok I still don't get it, if you're putting an rb in why not just use the RB25 trans like everyone else? what about the Z32 internals made you want to run them over the Rb25 gearset? was the purpose to allow you to use the Z32's shorter tailhousings and linked shifter? I perspnally would love to hase a trans taht the shifter fitted directly into, did you do it to be able to use the stock trans mount? seems fabbing up new mounts would have been easier, again maybe I'm missing siomething, I just don't see why?

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Re: (evildky)

Postby Booztd 3 » Fri Feb 09, 2007 9:10 am

evildky wrote:ok I still don't get it, if you're putting an rb in why not just use the RB25 trans like everyone else? what about the Z32 internals made you want to run them over the Rb25 gearset? was the purpose to allow you to use the Z32's shorter tailhousings and linked shifter? I perspnally would love to hase a trans taht the shifter fitted directly into, did you do it to be able to use the stock trans mount? seems fabbing up new mounts would have been easier, again maybe I'm missing siomething, I just don't see why?
Everyone else? There are only a handful of RB Z32's in existance, and I know they arent using the complete RB25 trans. The z32 internals are identical to the rb internals. My z32 had a 4th gear grind so I used the teardown as an opportunity to take all teh good parts from both trannies and make one solid tranny.

What I did allows me to use the stock trans mount, stock driveshaft, stock shifter, stock wiring harness, etc.....Two short evenings worth of work and I can do all of that AND have a rebuild tranny thatll shift like butter, is worth alot more than just throwing in an RB25 trans of which I have no history on, fabbing up a custom cross member, fabbing up the shifter area, and having a custom driveshaft made.......you dont agree?

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evildky
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Postby evildky » Fri Feb 09, 2007 5:54 pm

when I say everyone else I guell I mean all the S13, S14, Z31, S30 and S130's running RB's of which there are a lot! the Z32 swap is rare I suppose as it's a latteral move

as for the tradeoff of work, I am gonna guell the output shaft is splined the same so the slip yoke and shaft fromt he z32 can be retained just needs to be shortened, shorten and ballance at a professional shop is only aobur $100 with a 1 day turn around, and the shifter looks like it should come up in the right location and would allow for removal of all the extra linkage and brackets that burden the z32 trans, and I'd be suprised if it didn't fit the stock z32 crossmsmber but even if ti didn't it should eb a simple job to cut, pivot, slide or whatever is needed and weld it back together, and the beauty of the stock rb trans is if you should granade it you just swap another in it's place instead of repeating the mod process, not trying to bust your balls just trying to figure out where you're coming from, you obviously have some skills and lots of great tools and high dollar toys to play with (I have a thing for the Panoz Esperante which si of course the road going sibling of the GTS)

I did a similar swap in my 240Z, using a 240SX 5 speed, it only required changing the front case, mainshaft bearing and boring the countershaft holes, and then I had to have a driveshaft made as well as customizing the trans crossmsmber (and series 1 crossmsmbers are getting impossible to find) I did it all so I could have a 5th gear in a trans that could take a beating (I later swapped in a T-5 which worked with the same modified crossmsmber but required a completely custom drive shaft)

nice job

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Re: (evildky)

Postby Booztd 3 » Sat Feb 10, 2007 7:14 am

evildky wrote: the beauty of the stock rb trans is if you should granade it you just swap another in it's place instead of repeating the mod process,
My argument to this....do you know what RB25 trannies are selling for right now? I'd rather spend 250 on a Z32 trannie and a night or two in the garage swapping the bunk parts than trying to track down an RB tranny and paying 800-900 for it

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Re: (Booztd 3)

Postby jEzTeR » Sat Feb 10, 2007 4:16 pm

Wow that is a great shop!

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Re: How To: RB25 trans mated to z32 Trans - LOTS of pictures (Booztd 3)

Postby maxnix » Sat Feb 10, 2007 6:59 pm

Thanks for rthe write up and documentation.

As for the title of this forum, I seem to recall the 1600/2000 roadster was named the Fairlady in Japan.

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evildky
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Postby evildky » Sun Feb 11, 2007 7:48 pm

the raodsters were called fairlady's in usa as well, the Z was never a fairlady in america, excepting the fairlady edition in 96, of 300 cars

the z was to be a replacement for the 4 cylinder convertable and to carry on the fairlady name but MR K. changed the badges as he felt the name was too feminine for the us market and the 240z was born

and the fairlady was origionally given it's name due to the japanese CEO's fondness for the american movie "My Fairlady"

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Re: How To: RB25 trans mated to z32 Trans - LOTS of pictures

Postby walperstyle » Fri Jul 09, 2021 9:07 am

ADMIN: Please do whatever you can to get these pictures back and hosted on the site server. This information is going to be a goldmine once the automatic R34's are selling in the US. Proper site maintenance requires admin to delete nonsense posts and questions with no answers so they don't show up, and indexing pictures of valuable information so it's not lost, as seen above.

Please PLEASE get in contact with this guy and see about finding the pictures.


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