Jump to content
Ultimate Subaru Message Board

4wd AT to 4wd MT Swap: Activation?


Recommended Posts

Got to thinking ahead about this swap I'm looking at. The new chassis has a 4wd AT in it right now, along with a leaky engine ('94 Loyale Wagon, btw). If I pull the engine, 4wd manual tranny, & driveshaft out of my '92, and pop it into the '94 chassis, will the 4wd pushbutton system all hook up relatively the same? Or will I need to rewire & reroute?

 

Also... from what I've heard, the front half of the driveline is a different size in the AT than the MT, due to the differing size of the trannies. If I understand that correctly, then the mounts for the carrier bearing ought to be in the same location, right?

Link to comment
Share on other sites

The mounts for the carrier are the same. I did the exact same swap last june.

You will need to bypass the neutral safety switch. either by using a jumper wire or just cutting the two wires off the plug and splicing them together.

Its pretty much a straight bolt in type of thing. the only real wiring issues are the neutral safety switch, reverse lights cruise control(if you have it) and 4wd light

Only one I have bothered with is the neutral safety switch.. Been too lazy to deal with the rest.. I have since pulled the PushButton 5 speed and replaced it with a FT4WD 5 speed.

Link to comment
Share on other sites

Been thinking about the neutral safety switch. It's purpose (in an AT) is to make sure the car won't start unless it's in neutral or park, right?

 

Ain't that the same idea with the clutch safety switch? Make sure the engine won't start 'less you've got the clutch pushed in.

 

If the NSS just sends a on/off signal to the ECU (Off = in gear, On = neutral or park, or vice versa), wouldn't it be possible to wire the ECU up to the CSS instead?

Link to comment
Share on other sites

Loyale's don't have a CSS. You can just reach in the window, turn the key, and start it. As for the NSS... in the wiring harness going into the shifter, you'll need to connect the two center wires- the black/white and the black/yellow. This will make the car think it's in park.

Link to comment
Share on other sites

Hmmm... I had a '90 for a few weeks and it didn't have it. My 92 didn't have a brake switch for the auto trans. Could just reach in and turn the key. Every manual Subaru I've ever had, I could actually start it while in gear with the clutch let out.

Link to comment
Share on other sites

So if there's only two leads coming off the NSS, here's how I'd have set it up, if I was a Subaru engineer.

 

Run some juice through the hot lead. If the tranny's set in neutral or park, close the switch & the circuit, and the ECU knows the tranny selection due to the hot circuit. Or vice versa... hot if the tranny's set in drive.

 

Same thought for the CSS. Assuming Subaru didn't complicate things by saying "Safe to start when hot" for the NSS, and "safe to start when cold" for the CSS, all I'd have to do is take the leads off the NSS and run them out to the CSS.

 

I think...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...