96 LX Impreza Coupe swap to manual from auto

[awcforever]

Hey guys, I have a few quick questions if you would be so kind. I tried NAIOC and no one would talk so maybe you guys can help.

 

So I already pulled all of my parts and I am about to rip my Suby apart but I have to order my rear differential 

Gear ratio is 3.90 and I found a GG wagon 2002 and wanted to know if the differential is direct bolt on? Gears=good, its the mounts I am unsure of and I am ordering it from New York so I have no way to see it as the only picture is of the car itself.

 

 

I pulled all of my parts from a 96 Outback sport (except rear diff)

transmission, pedals, computer, cables, drive shafts (axles) shifter/boot, and pretty much everything else, but the rear differential was so rusted out I couldn't even get a socket on the bolts.

 

I also pulled another computer under the drivers dash labeled 4WD/MT. I assume four wheel drive / manual transmission, but what is its function? I have it just in case it makes anything easier, but have no idea what its for.

 

I have been working on cars for a long time, but just now getting into Subaru and it is a welcome task compared to VW. Subaru is just so simple......smart.

 

Thanks

AJ

 

 

[Gloyale]

Rear diff will mount in directly.

 

HOwever.....the input flange on the 02 may be larger.....just unbolt it and swap the old one.

[awcforever]

Cool, thanks!

[bratman18]

Input flange should be the same. All the r160 rear diff were the same,the r180 has the bigger flange. Those only.came in STi's.

[awcforever]

So if I order this differential I will have to order a rear mount as well to fit it too my car....right?

 

And does anyone know the function of that 2nd computer I found "4WD/MT" I have it if I need to use it, but not sure what it does. I pulled the ECU from the donor car as well. Couldn't get the wiring harness though. That turned into more of a headache than I expected.

[awcforever]

Alright guys, this is killing me! I am going over eBay trying to find a differential and the sellers who list these things are posting final drive ratios that are just not matching up with the documentation I am finding all over here and the other forums.

 

I am sure some of them are listing them as 3.90 mistakenly, but holy moly. 

 

They are showing cars EVERYWHERE having 3.90 ratios from 2002-2007 imprezas, Foresters, Legacy rears. A lot of them are really highly rated sellers, but for instance the one I am looking at is a 2002 Impreza Outback and it says 3.90 ratio, but all of the forums say it only comes with 4.11's and 4.44's. 

 

Then to make matters worse.........all of the cars listed as 3.90 FDR in the documentation on the forums are listed as NOT having 3.90 on eBay. 

 

The only rear I am sure of having the right ratio is the STI, but man those things are like $600!!!!

 

This is going to be a little harder than I expected.

 

Here is one which is a 2000 Legacy. Listed as having 3.90, but that shows wrong on the forum.

http://www.ebay.com/itm/99-00-01-08-09-10-11-IMPREZA-CARRIER-ASSEMBLY-REAR-2-2L-MT-3-90-RATIO-82905-/281255840826?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3ASubaru&hash=item417c278c3a&vxp=mtr

 

 

Here is a 2006 Impreza. Forums also say this ISN"T 3.90

http://www.ebay.com/itm/REAR-CARRIER-DIFFERENTIAL-2006-SUBARU-IMPREZA-2-5-MT-AWD-3-90-RATIO-NON-LOCK-/161235424727?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3ASubaru&hash=item258a6155d7&vxp=mtr

 

 

And lastly this is the one I am really interested in because of the price but again the forums say this car didnt' come with 3.90, but seller says it is???

http://www.ebay.com/itm/02-03-04-05-06-07-IMPREZA-CARRIER-ASSEMBLY-REAR-2-5L-MT-TS-OUTBACK-3-90-RATIO-/301045598081?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3ASubaru&hash=item4617b74781&vxp=mtr

 

Thanks in advance for all the help. 

Edited March 3, 2014 by awcforever

[awcforever]

Ok, I ordered my differential, clutch kit, and flywheel.

 

Differential came from a 2000 Legacy Brighton 5spd 2.2L. The tranny PDF chart showed 3.90 and seller listed the same so I think I'm good to go. They also have an exchange warranty if its wrong, but I think I should be good.

 

So any word on that other computer?

[Gloyale]

Input flange should be the same. All the r160 rear diff were the same,the r180 has the bigger flange. Those only.came in STi's.

 

No.  in 2002 ish they started using a bigger flange on the r160.  I put a 2003 diff into a 90 legacy and we had to change the flange.

 

Mounting will all be the same except maybe the length of the studs in the rear plate.........some are short, some are long depending on the model/year it came from.

[bratman18]

Weird. I have swapped drive shafts and rear diff from impreza to legacy to forester, anywhere from 96 to 04 and they've always been the same.

[idosubaru]

you already got one, but check out this site:

 

www.car-parts.com

 

next time also post in the parts wanted forum here, people have rear diffs laying all over the place. 

[awcforever]

you already got one, but check out this site:

 

www.car-parts.com

 

next time also post in the parts wanted forum here, people have rear diffs laying all over the place. 

I'll have to remember that. I've used www.car-parts.com before, but out my way the salvage lots want more money than a new/rebuilt unit would cost.

 

So it looks like I'm good to go as far as parts, 

 

Got transmission, flywheel, clutch, both bearings, drive shafts just in case, starter, clutch and brake pedals/cable, shifter with cables, and a bunch of miscellaneous things.

 

Thanks again for all the help, it is much appreciated. Few more questions though if you can help.

 

So a lot of folks say "you don't need the ECU" for the swap but my question is since I have it will it be plug and play or ????

 

Also, that other computer I grabbed under the drivers dash labeled "4WD/MT" what is its function. I haven't pulled my car apart yet, but I assume I will have one that will say "4WD/AT" right?

[WoodsWagon]

Probably cruise control? You will have to mod one wire on the ECU connector to tell it its now a manual and bypass the neutral/park interlock. Plus wiring in the reverse light switch and neutral switch on the trans.

[awcforever]

Probably cruise control? You will have to mod one wire on the ECU connector to tell it its now a manual and bypass the neutral/park interlock. Plus wiring in the reverse light switch and neutral switch on the trans.

Ok, so should I scrap the manual ECU i took?

On the reverse lights are they currently working from my shifter or the auto trans?

The neutral switch.........are you just talking about the safety so you can't start the car with it in gear?

 

Thanks for the help

[awcforever]

Ok, here's what I have:

Auto trans, shifter, cables, TC, driveshafts and computer all pulled.

 

I was about to install the flywheel but Adv Auto sent the wrong freekin flywheel bolts so I put an order in at the dealer today for my throw out bearing clips, flywheel bolts, the dust boot for the shift fork, and the 6 bolts for the pressure plate.

 

When that stuff comes in on Thurday I will be ready to install transmission. I have the rear differential pulled out and the replacement 3:90 diff ready to go in, but I really want to clean and paint it.

 

I found the electrical schematic ALL DATA and the reverse lights wire is brown and yellow so I am going to splice the reverse wire into the reverse plug harness on the manual trans which should take care of that. I think I'm going to skip the clutch safety switch for now, and I need to get the mechanical (trans, diff, shifter) stuff done before I start tinkering with the electrical. The cylinder lock for the auto shifter is still engaged because I had the car in neutral when I pulled the drivetrain, so I will figure that out.

 

So far so good. I think everything should be square when I'm done.

One thing I did do that I haven't found any documentation on is I went ahead and plugged the manual ECU into the place of the auto ECU. I found out that the donor car was the same year and even better same color so I think it will work, plugged right in with no issues, but by all means let me know if you have any other information.

Thanks

AJ

Edited March 10, 2014 by awcforever

[Numbchux]

ECUs are the same. It's the harness that tells it to perform as an AT or MT. So that was just extra work. You will still have to modify the harness to work correctly (bypass the neutral safety switch, at the very least, which can be done in the engine bay).

 

Not sure what other electrical box you grabbed, but chuck it.

 

You shouldn't need to swap the front axles.

 

 

Swapping the pedal box is possible with the steering column in, but I recommend taking it out...

[awcforever]

ECUs are the same. It's the harness that tells it to perform as an AT or MT. So that was just extra work. You will still have to modify the harness to work correctly (bypass the neutral safety switch, at the very least, which can be done in the engine bay).

 

Not sure what other electrical box you grabbed, but chuck it.

 

You shouldn't need to swap the front axles.

 

 

Swapping the pedal box is possible with the steering column in, but I recommend taking it out...

Pedal box was actually really easy, I already have the cable routed through the firewall and the trans bolted up I had a long swivel that made it REALLY smooth, but the rear differential I ordered was from a 2001 Legacy and my axles dont fit so I am having issues even finding replacement axles. If you search advance auto they only have fronts...?

 

I have the wires for the trans harness ready to go for the neutral switch. I just used a scotch splice and clipped them from the harness. Ohmed out the wires on the auto to find that. 

 

SO....all I have to do now is re-install my shifter, I removed it because my fidanza short throw showed up. As far as the rear issue goes. I may just leave the rear shaft out for a while until I can find axles because as it sits I'm having no luck, but I have to pull a 4.7 from a Ram pickup before Friday and need the room so I'm going to at least get it driveable for now.

 

Any luck on finding the ECU pinout? I have found numerous pin outs for the ECUs, but none from my year as far as the wire I'm supposed to be grounding out.

[Numbchux]

Pedal box was actually really easy, I already have the cable routed through the firewall and the trans bolted up I had a long swivel that made it REALLY smooth, but the rear differential I ordered was from a 2001 Legacy and my axles dont fit so I am having issues even finding replacement axles. If you search advance auto they only have fronts...?

 

I have the wires for the trans harness ready to go for the neutral switch. I just used a scotch splice and clipped them from the harness. Ohmed out the wires on the auto to find that. 

 

SO....all I have to do now is re-install my shifter, I removed it because my fidanza short throw showed up. As far as the rear issue goes. I may just leave the rear shaft out for a while until I can find axles because as it sits I'm having no luck, but I have to pull a 4.7 from a Ram pickup before Friday and need the room so I'm going to at least get it driveable for now.

 

Any luck on finding the ECU pinout? I have found numerous pin outs for the ECUs, but none from my year as far as the wire I'm supposed to be grounding out.

 

I just looked up rear CVs for an 01 Legacy at work (AutoZone). We offer new and reman. Both special order from my store, but both available.

 

I hope I misunderstood what you're saying, but your car is not driveable without the rear end hooked up. You will fry your center diff very quickly.

 

 

ECU pinouts are very common. All '96-'99s use the same. It's marked AT/MT identification. I don't remember when they stopped putting that wire in the harness....so you may not have that pin. I sacrificed an old harness once to add that pin though.

[awcforever]

Everything is finished! Mechanical wise. I've been driving the car back and forth to work for a bit now, but I havent' figured out the "B135" ground pin yet. I can't seem to find a good clear schematic to give me the ease of mind to mess with it. I got my axles and hooked up the rear diff, but what I mean was that I would leave the rear diff out and cap the tail shaft with something to protect it. I don't think it would hurt.....my father in-law bought an outback and for years thought it was all wheel drive, but there was no rear drive shaft....lol! We thru one in and away he went.

 

The ECU is the issue though. I have both AT/MT ECUs. Currently I'm running the MT with no issues, but the check engine light is on.

[WoodsWagon]

A/t doesnt mind not having the rear driveline hooked up but you will cook the center diff in a 5spd if you try that.

[idosubaru]

good job cranking it all out.

 

 

what I mean was that I would leave the rear diff out and cap the tail shaft with something to protect it. I don't think it would hurt.....my father in-law bought an outback and for years thought it was all wheel drive, but there was no rear drive shaft....lol! We thru one in and away he went.

 

you can only do that in an automatic with the FWD fuse in.  or alternately if the Duty C or clutch plates are sticking - then you can do it without the FWD fuse.

 

it would be disastrous to do that to manuals which have a viscous center diff. it's not "if" there would be issues, but when.

[awcforever]

good job cranking it all out.

 

 

 

you can only do that in an automatic with the FWD fuse in.  or alternately if the Duty C or clutch plates are sticking - then you can do it without the FWD fuse.

 

it would be disastrous to do that to manuals which have a viscous center diff. it's not "if" there would be issues, but when.

Ok, I'm tracking now. It was definitely automatic. I'll have to remember that for the manuals. That could definitely be catastrophic.

 

SO the car is running and driving fine aside from the check engine light. I have a schematic of the ECU layout from one of the sites on here, but its all laid out "flat" and even being an HVAC technician I can't de-code the method of finding this pin. I would "assume" you would read it left to right, but its greek to me in the manner they outlined it. I have both ECUs still for AT and MT. Currently the MT is hooked in my car and being used. I am ok with making the pin and doing all of the grounding, but its un-nerving until I find some documentation or pictures with a better description of what I am supposed to be grounding. I'll keep the search going though.

 

Also, my drain plug is shot on the M/T front end. I just went outside and its puking gear oil in the parking lot. Probably a quart sitting there..........that explains the 3rd gear grind I got all of a sudden.....low fluid.