TwinTurbo.NET: Nissan 300ZX forum - FAQ: Transmission Teardown & Rebuild
People Seeking Info
 
   


     
Subject FAQ: Transmission Teardown & Rebuild
     
Posted by BOOZTD 3 on February 10, 2007 at 5:09 PM
  This message has been viewed 8849 times.
     
     
Message 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 procedure is a bit of a 'hybrid' setup, because Im going to run the Rb26 motor, but this procedure will apply to both trannies, so there isnt much deviation between the transmissions and the way they're put together.

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

These are the insert springs, these may be broken, or worn down, but are typically are the reason our trannies start to grind. There are 3 of these in the 4th gear assembly

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!












     
Follow Ups  
     
Post a
Followup

You cannot reply to this message because you are not logged in.