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Thread: Complete P11 6 Speed Swap Guide

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2013-07-31 13:22:00
Complete P11 6 Speed Swap Guide
The point of no return, 6 speed swap!
This is very involved swap and is not for the faint of heart. Due to the amount of modifications you need to do, it will be hard to go back to 5 speed, not that you would really want to do that anyway .

Parts Required
  • B15 Spec V Transmission*
  • P12 Bellhousing
  • P12 Slave Cylinder
  • Flywheel (My suggestion is JWT Flywheel that lets you use 250mm 350z Clutches)
  • Bigger Clutch (will depend on flywheel)
  • Spec V Axles
  • Mazworx Axle Carrier
  • Spec V Shifter Assembly
  • Spec V Shifter Cables
  • Spec V Transmission Mount
*04-06 Spec V transmissions are preferred due to longer gears and no syncro issues like 02-03 ones had. You can also use Maxima or Altima gear stacks, but they don't all come with Helical Limited Slip Differential (HLSD).

Approx Total price $2,000

Installation Steps:
Bell Housing Swap
Flywheel & Clutch
Rear Mount and Trans Mount
Trans Installation
Axle Brackets
Shifter Cable Installation
Shifter Assembly Installation
Slave Cylinder & Clutch Line

DYI Short Shifter
Shifter Bushings

Other 6 Speed Swap threads to follow (specific to B Chassis)
The Ultimate 6 Speed Swap Thread...Parts/Instructions/Results!!
How to: RS6 6 speed swap guide
Last edited by Vadim on 2013-09-30 at 05-05-15.
2013-07-31 13:23:00
Bell Housing Swap
See this thread: http://www.sr20-forum.com/driveline-tech/45436-how-rs6-6-speed-swap-guide.html
Last edited by Vadim on 2014-06-23 at 01-14-50.
2013-07-31 13:24:00
Flywheel & Clutch
JWT flywheel is a good way to go if you want a setup that can hold a lot of power with around stock weight flywheel. JWT flywheel lets you use your OEM length bolts, has a replaceable friction plate and lets you use 240mm or 250mm 350z clutch setups. I have an 350z Exedy Stage 1 Clutch and Disc, which is rated fro 300wtq for the heavier 350z, on a lighter car it will hold a good bit more power.

Flywheel: JWT vs Stock P11

About an inch taller then DE flywheel

Clutch Disc: 350z 250mm vs DE 215mm (JWT 2 sided metal disc)

DE disc against the JWT flywheel

Whole Clutch setup: 6 Speed vs 5 Speed

P11 setup without bolts comes in at 29.8lbs

6 Speed setup without bolts comes in at 31.2 (don't mind the paint added 2, digital camera doesn't like refresh rate of the digital scale)

To get this assembly to fit and not scrape you do need to cut the bellhousing a bit, this was done for me by previous owner.

Transmission spacer
This one is important! The pressure plate is slightly too tall thus it wills crape against the bell housing. I believe these marks were done even with two spacers in place.

This is how much clearance we have on the bell housing end

This is how far the pressure plate sticks out with one spacer

With two spacers:

I'm using ARP bolts, which are much bigger then stock. This proved to be a problem when my regular 5/8" socket didn't fit into the JWT flywheel

Luckily I had a Craftsman 5/8" in my random sockets bin (it came with one of my p11's!). Fitment is perfect!

Flywheel installed

Getting new bolts is a good idea, you also need a few extra. You need 9 x M8-1.25x20mm, don't forget lock washers!

Since this flywheel can take 240mm clutch setups and 250mm, it has a lot of extra holes. This makes it rather difficult to find the holes that you need to use for your specific clutch, especially if the flywheel is already mounted. To help me with this, while the flywheel was out I put some electrical tape (since sharpie is not visible) on the one of the holes that aligned correctly. This made my life a ton easier getting the pressure plate on.

This setup is huge!

You will need a new Throwout Bearing, unfortunately 350z one that came with your clutch wont work, but QR25DE, SE-R/Spec V one, or GTiR one will work just fine. Spec one ran me up $55 at local dealer. Spec one on top, P11 on bottom

Install it on the TOB arm and make sure it moves easily. Be very careful with the little metal clips, if you break it, Nissan doesn't sell them separately, you have to buy the whole TOB!

Last edited by Vadim on 2014-09-28 at 21-16-05.
2013-07-31 13:26:00
Rear Mount and Trans Mount
Rear Motor Mount Bracket

Mazworx rear motor mount kit wont work with P11's or B15 due to different crossmember/rear motor mount designs. Luckily P11 and B15 rear motor mount brackets can be fairly easily modified to work.

Slightly off

Widen the mounting hole slightly

I widened the lower mounting hole too.

Sadly the 6 speed trans can only be bolted up at two points. One of the trans bolt holes is covered by the actual mount, not a huge deal but would be nice to be able to bolt it up too.

Transmission Mount
As I posted earlier, you need to get the stock bracket off. Use either spot weld drill or grind it off like I did.

Start test fitting the Spec V trans mount, this needs to be done with the transmission in place for best fitment

Stuff in the way as always, battery tray mount this time.

Needs to be trimmed to fit the trans mount

Removed the rest of the stock mount

Check fitment, as you can see still doesn't quite align.

The trans mount has raised points for what ever reason. I flattened them out with an angle grinder

The back of the trans mount needs to be cut otherwise it hits the wheel well

Battery tray is still in the way, needs more cutting.

Finally fits!

Test insert the trans mount bolt and mark where you need to weld in the threaded nuts.

Have fun drilling. Transmission gets in the way of drilling the second hole on the side of the frame, that's one main downside of having the trans in place while mocking the mount.

Now we need to hold the motor mount in place somehow. I was hoping to use a T nut, but I'm afraid they are grade 8.8 not 10.9, thus the threads could strip while tightening or under force.

To be able to get the 10.9 nuts in, I had to get creative, shaved it down and made it round with and angle grinder.

This allowed me to just insert it into the newly drilled holes

Make sure the holes align before you weld them in!

Now weld them in, I decided to weld the areas I cut too much with the angle grinder too.

Made sure I could torque the mount to 60ft-lbs as per fsm specs

Fitment test again

Painted the raw surfaces

And we are done, almost...

Once I tried to install the battery tray I found that it wouldn't clear the trans bolt, got a new bolt Grade 10.9, M10x100mm

Barely enough thread, my local hardware store didn't have anything longer then 100mm, thus this will do.

Now we are all done with the mounts
Last edited by Vadim on 2014-09-28 at 21-18-44.
2013-07-31 13:27:00
Trans Installation
This post will show you what you need to do to actually get the transmission in. There is a good amount of modifications required, I was going in blindly thus couldn't do and document changes until I saw the need for them. You should make these changes before the transmission is in, all the pictures are in chronological order. Please keep in mind picture per post count requires me to split the install pictures into multiple sections.

Required bolts for Transmission mounting

Stock Transmission Mount Removal
Spot weld remover will make your life easier here, I don't have one and figured grinding the mount off would help the frame keep it's rigidity.

Rest of the transmission mount modifications will be posted in a separate post, reason I'm posting them here is because it will make your life a lot easier removing the stock mount with no transmission in place.

Subframe Modifications/Cutting
Another thing you want to do before the transmission is in place. You can see how much more difficult it was to do this once the trans is in place.

Driverside Rear Subframe

There is also a bolt that will sit right above the subframe. You need to notch the subframe or replace this bolt with a low profile bolt. Since I can't get to this one with trans in, when the engine moves back under full throttle this bolt hits the subframe. You can hear and feel when that happens, this also overtime will destroy the bolt.

Driverside Front Subframe
There is a lip on the front of the subframe. This will prevent you from inserting the axle into the transmission. If you do some how manage to insert the axle, it will be destroyed as soon as the axle spins.

Shave, test fit, shave test fit. NOTE: To test fit the axle and to make sure it goes all the way in, remove the axle's C clip. Once your sure of you are done, reinstall the axle's C clip.

To reinforce it and prevent water from getting in, you should weld it.

Except that will hit the axle again, thus get the grinder out again and grind it down, try not to grind too much, otherwise you will have to reweld any holes.

Check clearance

Another thing I did is flatten the axle zip tie head

Fairly close to the subframe, so far (over 500miles) it doesn't seem like there is any contact

Transmission Installation
Now we can actually try to get the transmission in. Since the transmission is much bigger, clearance is a big issue. At one point after about 2 hours of trying to get it aligned right I was kicking the transmission which magically got it in!

I could lift the old transmissions by bolting the chain to the motor mount points, this wont fly with the bigger 6 speed trans. I had to find new lifting points

You will probably have to unbolt the lower control arm subframe mounting bolts to get it out of the way.

Slow and tedious process, and least you have a window to see how far the input shaft is from the clutch disc.

Since I didn't shave rear of the subframe ahead of time, this was a very painful process. I should have dropped the transmission and grinded this off, but somehow I force it in.

Now the input shaft finally was able to align with the disk

With some kicking I was able to force it in

Once it's bolted up you can remove the hoist and get to working (I'll post bolt sizes later)

Bolt up the starter too. I was able to get away with using one OEM starter bolt.

Steering rack clearance is tight too.

Now that you have the transmission in place, you can work on installing the motor mounts and axles. Rest of these steps assume you have the motor/trans mounts and axles installed already.

Hook up the speed sensor

Here is the harness for the reverse and neutral switches

Shorter one goes to the reverse switch (blue sensor)

Longer line goes to the neutral switch (black sensor)

Find a good spot for the frame ground, can be seen to the right of the wire harness

Battery tray will need to be cut a little

The Axle dust cover will rub and needs to be cut down

You can see where it rubbed for me, cut that whole section off.

Should be good after that

Filling transmission with oil
Loosen the fill plug with 10mm hex Allen socket

I used GM Syncromesh, you need about 2.4qts, used a pump to get it in, hard to get to that fill plug otherwise.

Keep filling until some comes back out, then stick your finger in the fill plug and feel for the oil, if you don't have any on the tip of your finger fill more.

Install the boot for the TOB fork

Install the P12 or Maxima (needs to be modified) slave cylinder

That's it for transmission modding/installing. Put everything together and go for a test ride!
Last edited by Vadim on 2015-03-27 at 03-42-56.
2013-07-31 13:29:00
ABS Ring

One of the issues with Spec V axles is, the ABS ring is much smaller.

OD of the Spec V ABS ring is 78.2, OD of P11 is more like 85mm

ID of P11 ABS ring is 76.7mm

Two rings side by side, the idea is to shave the Spec V one to fit inside the P11 one.

I used very high tech tools to get this done.... Angle grinder has been a miracle tool in this 6 speed swap adventure


Do note how the stock p11 ABS ring looks, on stock axles it's solid towards the inside. Now this could interfere with the ABS sensor, if you have aftermarket axles, they most likely will not be solid (my P11 EMPI ABS ring looks the same as the EMPI Spec V one).

To be SUPER safe I welded some spots, this is an overkill, friction alone would hold them in place (as long as you didn't overshave the Spec V ring!). Welding it just caused more head aches then it's worth imo.

Shaved it down:

Fit's on the Spec V axle perfectly. NOTE: This is how the ABS ring is oriented on the stock P11 axles, but with Spec V axles this wont work because the solid bar will be right where the ABS sensor is.

Flipped it:

Here is why, I had a spare knuckle to test clearances with

Here is what EMPI P11 Axle's ABS ring looks like in reference to ABS sensor

This is why I flipped the ABS ring to have the solid ring towards the outside. As you can barely see the ABS ring sits more forward on Spec V axle then on P11 axle.

Axle Comparison

Spec V ontop, P11 on bottom

End of axle comparison, and modified ABS ring comparison. Once again you can see that ABS ring sits more forward on the spec v.

Axle Seals

Axle seals look to be the same diameter for both sides, but they are slightly different.

Passenger axle seal on left, driver seal on right. Passenger one is shorter and has a smaller rubber ring that sticks out

Passenger axle seal out

Note of advice, do this while transmission is out, took me a good hour just to get the new seal in! I hate new Nissan seals that have metal shells, which are much more painful to get in then older styled ones seen above.

I will cover Axle Brackets in another post, rest of these steps assume you have the axle bracket installed and mounted already.

Axle inserted:

Fits well, ABS should be happy.

One issue with Spec V axle is, I think it's a little too short for P11's, you can see how much the boots are stretched. This is with Mazworx Axle bracket.

Driver side fits fine

Axle nut comparison, Spec V one is still 32mm but has washer built into it, it seems. My axles only had one 32mm nut, so I ended up using stock 35mm ones.

Note after driving about 200 miles, I checked the axles, and the boot might have shifted out of it's place. I will continue monitoring it.
Last edited by Vadim on 2014-09-28 at 21-26-53.
2013-07-31 13:30:00
Axle Brackets
Axle Bracket

Axle Brackets: P12, P11 Base, P11 LSD

Axle Brackets: P12, Mazworx DE/VE, P11 LSD

Stock P11 bracket wont work, LSD or not. It sits too close to the block.

Not to mention it wont align to any mounting holes

Stock P12 one has the right angle, but wont work with longer Spec V axles without major mods too.

And it's too short

If you bolt it directly to the axle, you wont find anything to bolt it up to

This is why you should just get a Mazworx Bracket, which is a fine milled Aluminum piece!

One issue with it is, it's just bolted together, Coheed had it rattle loose over few hundred miles. Red loctite is used in these by default, but I decided to graze it.

Fit's so well and has an additional (4th) mounting point!

Aligns well with the trans

Axle Bracket positions the axle well into the transmission too

I used Alumaloy sticks to "weld" it in place.

Since I had to heat up the metal pretty hot, that burned off the red loctite of one of the bolts (it's a through hole unlike the other two)


Last edited by Vadim on 2014-09-28 at 21-30-19.
2013-07-31 13:30:00
Shifter Cable Installation
Get a hold of a Spec V shifter assembly and cables. Now you can use 5 speed Altima/Sentra shifters too, but there is no rear lockout thus while shifting into 6th you can accidentally grind against the reverse gear.

Spec V cables are a little too short for P11, from what I'm hearing Altima and Maxima cables should be much longer thus will be more forgiving on routing.

Now my select cable was broken, simply had to innovate.

Start by pulling out the stock shifter, linkages and related parts (this includes the 5 speed trans ).

Shifter Cable Installation

You will have to pull back the carpets too. I decided to completely pull them out and put down some sound deadening material while I was at it.

This is where the ECU mounts, this is also the only spot I could find that would work decently enough for the shifter cables. Anything closer to the shifter because the shifter cables can't bend too much. Anything further and we are in the ECU mounting area and wiring harness area. Though you could route the cables above the ECU if you have an Automatic and have the whole in the firewall already. I didn't want to go through the pain of drilling a hole in the firewall though.

Marked the spot, drilled one hole, verified location, started cutting away.

Cutting this was a royal pain, no space for an angle grinder, and dremel took a very long time and wasn't all that much more comfortable. Keep in mind in this spot, there are at least two layers of sheet metal stamped together.

Another issue is the shape channel, the mounting bracket doesn't quite sit flush against the body.

Test fit after cutting the hole, the hole will need to be around a 1.5" x 1.5"

Started cutting the bracket to fit also using the hammer to shape it.

After you are done test fitting remember to pain the raw metal.

Positions it right before the ECU, this is about as close as it's going to get.

One of the bracket's mounting points is right under the ECU mounting nut, it get's a little harder to fit.

All bolted up and painted with some high heat exhaust paint just in case.

Shifter mounting bracket on the transmission, this picture is mainly for orientation reference.

At first I tried to send the shifter cables under the sub frame, which as you can see failed

The only way is under the subframe, which is kind of tricky because the shifter cables are much thicker then the gap. On the driver side of the subframe there are fuel lines, thus I suggest forcing them through the passenger side. I used a long screw driver to push/dent the sheet metal above the subframe. This gave me just enough clearance for the cables. When sending these, make sure you send Select Cable (one closer to driver side) first then the shift cable. This will avoid the pain of them crossing and having to fight to uncross it while it's between the subframe.

Now it reached perfectly

Used washers from a local hardware store

Mounting cables to the shifter assembly

You can see what the shifter cables look like after they are mounted, that's about as much as you want the cables to bend.

Now P11's have a unique problem, they have air passageways to the rear passengers, the shifter cables wont let you bolt them up

I had to cut one of the mounting tabs and just force it in

I noticed my select cable fix wasn't working all that well, it was binding a good bit and it kept on coming out.

Took a piece of a hose that fit on the select shifter and over the O hanger

Used a big washer and a C-clip, and it's probably more reliable then stock now!

Once all is put together, the shifter cables are plenty far from the exhaust so should be safe without any shields.
Last edited by Vadim on 2014-09-28 at 21-32-36.
2013-07-31 13:31:00
Shifter Assembly Installation
Shifter Assembly Installation

By now you should have pulled the old shifter and related components. This will give you an empty hole in the shifter area, put it the dust boot for the shifter.

Shifter assembly plops right in

I didn't have the spec v nuts, so used a washer and stock nuts. Stock nuts have cuts in the threads and might strip easily so be careful not to overtighten.

Rear of the shifter can be tigthened with the stock screws

You can reinstall the heat shield now too

Get the shifter assembly in, getting the cables in can get pretty tricky if your not wanting to remove the second part of the center console.

Center Console
USDM Center console needs to be trimmed to fit.

JDM Center console is no exception

I had to trim the main center console (the one usdm/jdm cup holder ones bolt up to) a bit too. Test by shifting and seeing what hits, then trim it.

Shifter Surround
As for shifter surrounds, JDM one is no go, ashrtray and cig lighter is in the way of the shifter cables

USDM one has the cup holder in the way, you loose the useless cup holder with this conversion. This is why I went with JDM center console.

When you go to install the shifter surround you wont be able to even push it in without hitting the shifter cables

Take a dremel and go to town

Shift into all gears and make sure it moves freely

Once you get it to plop in, the cig lighter is awfully close to the shifter cables

Make sure the wiring sticks to the right of the shifter assembly

The leather boot does fit, but since I had to cut so many tabs off it doesn't like to stay in one spot.

Also the shifter boot sits too high on the spec shifter rod, so getting any kind of shifter on will be a bit tricky. I had to cut the stopped a bit to be able to force it down to fit any shifter on it.

Stock Spec shifter definitely a "short" shifter (read not short throw).

I used the old hammer I had around simply because it just bolted up. I wouldn't mind getting an original Altima or a Spec V shifters but they are $80 brand new, so not happening until I find one at the yard.

All done!
Last edited by Vadim on 2014-09-28 at 21-33-27.
2013-07-31 13:31:00
Slave Cylinder & Clutch Line
Slave Cylinder

The Spec V one wont work...

If you flip it upside down it would almost work if you shaved enough but the bleeding it would be impossible.

Here is a P12 slave cylinder (left) next to an aftermarket maxima one modified to fit (right). As you can see the P12 one has a smaller angle thus fits better.

If you didn't loosen the stock slave cylinder's line while it was on the 5 speed trans, this will be hard to do. I was able to hold it in place with a screw driver in the motor mount bracket, that allowed me to loosen it.

P12 slave cylinder installed

Clutch Line

As for the line, my line would not even come close to reaching the new slave cylinder spot, I do have the damper bypassed though. Safest bet was just to make an new hard line, $5 at your local auto parts store, plus another $5 for a brake line bender.

You will need a 3/16" thick line 20" long, Metric thread with standard flare.

You will need to put 3 90* bends into the new line.

Now the SS line reaches perfectly, no extra slack!

Have fun bleeding the line, which is a rain dance of it's own! See the how to here.
Last edited by Vadim on 2015-05-08 at 02-58-40.
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