Seriously: 4AT to 6MT swap

[digitalbow]

NissanClub,

Update: October 2009 - I will not resume work on this project until November and December, so this is where I stand until then.

Background: I am working through an engine replacement (my original VQ35 burned a lot of oil at rapid pace). I am also replacing the transmission because the automatic began to fail. Taking advantage of this opportunity, I am converting to a 6-speed manual with LSD. The purpose of the swap is to handle the 400+ ft-lbs of torque better than the 4AT RE4F04B - which, although offers a better gearing advantage for the turbo setup, is incapable of handling the power demands without giving in. I started the tear-down in March '09 by pulling the old VQ and transmission. Approximately 35 man-hours have been invested so far, including the removal and bolting-in of the new motor, while also rewiring and doing some other concurrent interior work projects.

My parts list, so far:

• RS6F51H 6-speed transmission w/ helical limited-slip differential (from a 5.5-gen, 2002 Maxima)
  - clutch and brake pedals
  - left and right shafts/axles
  - fluid reservoir and bracket
  - master and slave cylinders
  - hard fluid lines
  - transmission mount (you'll need one from a 5.5-gen Maxima, 5sp SE or a 6sp Altima SE-R)
  - shifter assembly, shift cables, shift knob, boot, and bezel (you'll need a Altima SE-R shifter assembly, shift cables, and a knob from either a 5.5 or 6th-gen Maxima or Altima SE-R)
• VQ35DE FWD long block (2005), Nissan-remanufactured unit
• '03 Altima SE ECU (manual trans ECU)
• '02 Altima SE information cluster panel (manual trans)
• Fidanza flywheel
• Exedy clutch kit

For those interested in cost - I will compile that once I sift through the seemingly essential items and have everything installed.
For the skeptics; it is still cheaper to 'DIY' this swap than to have a dealer do either engine or transmission replacement alone, (out-of-warranty) so why not?

Some difficulties and delays encountered thus far:

• The transmission mount, shifter assembly, and shifter cables on the Altima differ from those of the 5.5-gen Maxima. I've noted that above.
• I had a small rust line to take care of along the floor of the passenger-side, along the door.
• I really don't have the time for this project...

As far as I know, we have one 3rd gen on the forum who has gone from AT to MT (altima02dub - but with a 2.5) and a few who have experimented with converting 5MT to 6MT and adding the hLSD. I would like to make this swap as painless and cost-efficient as possible, but am realistic and expect to encounter some difficulties. I could use some wisdom and help from you all as I move along.

There are still a few concerns that I haven't resolved yet, so if anyone has some ideas, please let me know:

• Though I am going to use the MT ECU, which I had the immobilizer copied to, and L-Spec reflash performed by Technosquare. I think it is possible to get this to work with the AT ECU, however.
• There are two wire differences out of the ECM for the MT - the PNP switch and the ASCD signal. I haven't progressed to the point to figure these out yet, but I don't think it will be a big deal.
• I'm not sure if I should remove the TCU harness and box or leave it.

I'll be documenting as much as I can for you guys in this thread as I move along, so please keep extraneous comments to a minimum. (see post #10 below for first update)

Thanks in advance.
August 2009:
An update: The new VQ is in, and I'm simultaneously doing a few other odds and ends with the car that are of lesser importance, but have required a lot of time, and a near-full tear down of the interior.


At this point, here is what is left to do:

• install clutch and cover, transmission, speedometer pinion, starter
• figure wiring to fool the PnP and ASCD to cooperate with the ECU
• install clutch pedal, shifter assembly and STS
• install MT brake pedal, fluid lines for clutch
• install spark plugs, fuel rail, intake manifold, new oil pan and drain line
• install turbo down/up pipes, turbo, O2 sensors
• finish up the interior odds and ends, connect all remaining sensors

Some pictures to document the process:


RIP old VQ: Lucky to have a few buddies help me lift out the 530lb paperweight (busted VQ and transmission)




Pulling the AT crap out:



MT vs AT shifter



Maxima 6-speed parts in the box:




New VQ35DE:




Fidanza Flywheel



AT and MT ECUs



Off-topic, but I have a nearly-new 4AT for anyone needing to replace theirs. Check my FS thread for other items and PM me.

(Scroll down to post #10 for the second update)

[m_turner_02]

I can't offer any help, but I am definitely subscribing for info/progress....ever think of posting this on the org in the 6th gen forum to see if anybody over there has done the swap?

[200hpAltima]

digital: correct me if im wrong but you are a 2.5 correct? If soo why not back that with the Sentra SE-R 6 speed which will bolt directly to the 2.5? I also believe that the SE-R has HLSD also. Thats just a suggestion tho! Subscribed for info still.....and prices!

[3rdgen2.5s]

^^^ He has a 3.5

[L31_06]

Since you mentioned that you want to make it as painless as possible, why not just get a 5mt to get it over with? Do you really need the 6th gear for "mileage?"

[200hpAltima]

whoops. Sorry thought it was a boosted 2.5 hehe. Disreguard my entire post lol

[TUKO316]

i have a friend who is converting his auto 6th gen maxima to a 6 speed. ill ask for his help. i kno he bought a different ecu so you might have difficulties there.

i suggest the stage 2 jwt to keep things simple. stage 1 is good for 400-450. but i have had it for 20k and am not to crazy on how it grabs. i want a more rugged/harsh clutch.5 jwt is very streetable.

wouldnt it have been less complicated to build the aauto tranny? im glad you might be a pioneer for a swap though.

[Midnite2.5S]

Subscirbed to see how it goes

[SE-R Tuner]

This is not gonna be easy my friend. I thought about doing it in my car, switching for 5auto to 6spd w/HLSD, and lets just say you are braver then I. If i was you i would have just swapped out for a 5spd auto w/lsd and got another ecu and called it a day...

[digitalbow]

A few more pictures of some odds and ends:


A closeup of that stupid metal piece that sticks out underneath (I unbolted mine - it is listed as an 'air guide' for the A/T - shown in the mounting diagram below)



The rust I was talking about earlier? Yeah, check yours out. I fixed mine with a few minutes on the die grinder and then some primer, however other members have cautioned that it may extend further. This is a big thing to check on your Altima, as this appears to be common.




Maxima shifter cables



Multitasking...


Some future work...



Putting the new VQ in was actually the easiest part so far...


(Scroll down to post #21 for the third update)

[200hpAltima]

sick!!!

[5altima0]

i think altima02dub did it even though it was a qr but still id ask him,

[L31_06]

very nice!



-I thought altima02dub had a five speed swap instead of the 6?

[m_turner_02]

^^you're right, but same concept

[kasey07]

i think the reverse lights are tied into a coupler that attaches to the tranny. when you enter reverse it detects it and engages the lights. im not sure how the auto trannys activate the reverse lights