5 spd swap??

[Robby1870]

Alright. I really really want to do the 5psd swap for my 4T60. I may have an oppourtunity to get a good 5spd parts car this summer, a 90 GP 3.1L The motor is shot, but the tranny is good. Now, since my car is a '92, it does have the whole in the firewall for the clutch pedal, right? I was also looking at Malibuolds site on his 5spd swap and saw where to mount the master cylinder, and where to drill hole for the shifter linkage. Now, I need to know some other stuff. What about the ECM? Will I need to go to the ECM from the donor car? Im assuming yes. and the VSS, how is that gonna work? Is there a spot in the 5spd to hook it up? Is there anything else I have missed? Does anyone know if there is a write up on this swap out there anywhere, or has anyone got one they have done themselves. I mean I know this is involved, but it should be "pretty much" a direct bolt in. Any info/help is greatly appreciated. Thanks

 

Robby

[stlunatics2oo3]

i think your screwed and hope you get some info looll

[Redfox340]

it does have the whole in the firewall for the clutch pedal, right? I was also looking at Malibuolds site on his 5spd swap and saw where to mount the master cylinder, and where to drill hole for the shifter linkage. Now, I need to know some other stuff. What about the ECM? Will I need to go to the ECM from the donor car? Im assuming yes. and the VSS, how is that gonna work? Is there a spot in the 5spd to hook it up? Is there anything else I have missed?

 

- The hole should be there since the Cutlass had the available 5 speed through 1992 as well.

- As for the ECM, is it a 3.1L or DOHC? Because if it's not that same as you motor, it not going to be helpful to you one bit. As for the VSS, read up on it either in the service manual, or even better, pull it from your car now and see what results you get from it... (most likely negative, but try)

- Center console for the shifter, linkage, and you'll need some patience and some insights from others who've pulled it off. Best of luck Robby!

 

- RedFox340

[Robby1870]

oh yeah the donor car is 3.1L just like mine, I know the center console and bucket seats, cuz I got the bench seats. The VSS is like one thing Im really not for sure on. Hopefullly some one will know. Thanks for the support Redfox

 

Robby

[Guest TurboSedan]

i bought an entire 3.1/282 drivetrain from a guy on the forum and it included the entire wiring harness. the new 3.1 didn't last long, so i put my original 3.1 back in, which is still working great at 204,000 miles i would strongly reccomend using the ENTIRE engine wiring harness including the ECM from the firewall all the way to the sensors like VSS from the 3.1/5-speed if you still can. that's how mine is; i'm using the entire wiring harness, ECM and calibration from a '90 GP 3.1/5-speed on my '91 CS. everything will plug right in, and even the shift light in your dash will work. also, my speedo is spot on. the only other wiring is wiring up the cruise control cutout switch so that your cruise will shut off when you depress the clutch. swapping out the front seats is a breeze, and you should install the clutch and brake pedal while the seats are out (trust me it's much easier that way). my center console and shifter are from an '89 GP, and it all bolted right in and looks great! the 5-speed swap is basically all bolt on EXCEPT modifying that hole for the clutch master cylinder (not hard but be careful) and drilling that hole for the shifter cables. any other questions don't hesitate to ask....

joshua

[Robby1870]

I dont even use the cruise control now, with my auto, so I dont even want to hook the cruise up, I havent used it in 2 years. I know I will need the ECM from the donor car, BUT, I would really like to use my existing wiring, cuz the motor on the donor car is shot. Like, could I just run the wiring for the 5spd to the new ECM and plug all my other wiring, (except the wiring for the auto, duh) into the new ECM? I want to make this as simple as possilbe. And, I really dont want to take all my wiring off my motor and swap it for the new wiring. I really havent ever looked at the 5spd that much to know where everything plugs in, but if I get this donor car, it should be pretty easy to see. If I do get this car, I'll prolly change the clutch out, cuz I dont know how many miles are on it. I know there is a manual out there that tells how to completely rebuild the auto trans, is there one out there for the manual? I think one of those would come in really handy. Most of these questions are just to see what I would be getting myself into. The main thing Im worried about it wiring. I can do the actual install of the tranny, and pedals and seats, thats easy. Im not sure about the wiring, thats why I want to use my existing wiring and just add the wiring for the manual. Thanks Joshua, I'll prolly be in contact with you alot.

 

Robby

[brian89gp]

well, the auto and getrag wiring is are slightly different, and all the VSS stuff is in the ECM. To make it easy, take the ecm and wiring out of the parts car and use that. It is already wired and ready to go, the ecm is programmed etc, and you know it was working before with the 5spd.

[Guest TurboSedan]

well, the auto and getrag wiring is are slightly different, and all the VSS stuff is in the ECM. To make it easy, take the ecm and wiring out of the parts car and use that. It is already wired and ready to go, the ecm is programmed etc, and you know it was working before with the 5spd.

 

i know Eclipse5302 used his TGP harness (auto of course) when he swapped in his Getrag, and it seemed like he had more problems than i did. you'd have a couple of extra plugs hanging off too (TCC switch, gear indicator switch etc.) and the ECM might think the car was in park and have an effect on your rev limiter....i'm really not sure. using the 5-speed harness is plug & play, and besides you can clean up the engine and re-loom and re-route the harness while you were at it. btw, wiring up the cruise control cutout switch was EXTREMELY EASY; all i had to do was snap in a brown wire into the cruise control module in line with the brake pedal cruise cut-out switch. works great! the worst part of the swap was mounting the brake pedal, but you could just take an air cutoff wheel and cut the pedal shorter (so it wouldn't interfere witht the clutch pedal). if you do end up using your existing auto harness, i *think* you can use the wires from the TCC switch to the instrument cluster so your shift light will work, but mine seems to have a mind of it's own....i shift when *i* want to, not when the ECM thinks i should. one other thing i should mention is that your A/C won't work, without rewiring some stuff. i still haven't done mine. the '90 3.1/manual harness is not compatible with my '91 A/C system. Eclipse5302 knows how to do that tho, as he ran into the same problem. and since you have a '92 i'm assuming you'd have the same problem. i think i might ditch my A/C altogether so i can fit in a bigger front mount intercooler, reduce weight, and less parasitic drag on the engine.

 

well i'm rambling, but bottom line - if you want to make wiring as simple as possible use the 3.1/5-speed harness! a harness is not hard to swap over at all.

joshua

[SuperBuick]

What about when I hook up my 3.8 to a 5-speed? Will it run? My car is a 1990, but what exactly is different between a 5 speed computer and an auto computer. they never made a 3.8/5-speed so its not like I have a choice.

 

-Tom

[Guest TurboSedan]

the Getrag only has two electrical connectors: the VSS and the backup light switch. so that makes things pretty easy. i don't know anything about the 3.8 engines, but i'm assuming you'd have to use your existing engine wiring harness and either burn your own PROM or get creative with the wiring for the gear indicator switch. Ben, Shawn, Jason, (Eclipse5302) and others probably know ALOT more about this than i do....

joshua

[SuperBuick]

My tranny is vacuum control if that helps. Couldn't I just ground it so the engine thinks its always in drive?

 

-T

[Robby1870]

i know Eclipse5302 used his TGP harness (auto of course) when he swapped in his Getrag, and it seemed like he had more problems than i did. you'd have a couple of extra plugs hanging off too (TCC switch, gear indicator switch etc.) and the ECM might think the car was in park and have an effect on your rev limiter....i'm really not sure. using the 5-speed harness is plug & play, and besides you can clean up the engine and re-loom and re-route the harness while you were at it. btw, wiring up the cruise control cutout switch was EXTREMELY EASY; all i had to do was snap in a brown wire into the cruise control module in line with the brake pedal cruise cut-out switch. works great! the worst part of the swap was mounting the brake pedal, but you could just take an air cutoff wheel and cut the pedal shorter (so it wouldn't interfere witht the clutch pedal). if you do end up using your existing auto harness, i *think* you can use the wires from the TCC switch to the instrument cluster so your shift light will work, but mine seems to have a mind of it's own....i shift when *i* want to, not when the ECM thinks i should. one other thing i should mention is that your A/C won't work, without rewiring some stuff. i still haven't done mine. the '90 3.1/manual harness is not compatible with my '91 A/C system. Eclipse5302 knows how to do that tho, as he ran into the same problem. and since you have a '92 i'm assuming you'd have the same problem. i think i might ditch my A/C altogether so i can fit in a bigger front mount intercooler, reduce weight, and less parasitic drag on the engine.

 

well i'm rambling, but bottom line - if you want to make wiring as simple as possible use the 3.1/5-speed harness! a harness is not hard to swap over at all.

joshua

 

I have never done a harness swap or had any reason to have any of my wiring out. So, what Im wondering, (Ima try and make this is a clear as possilbe, but I dont know if it will convey what I want it to), and I may sound dumb for this, but like, for instance, the MAP sensor wire. Does the wire from the connnector on the MAP run DIRECTLY to the ECM, or does it run into a connector that gathers more wires, that then goes to the ECM? Im assuming that the latter is not the case. I have been looking at my Haynes manual, and of course it doesnt have diagrams for the 5 spd, only the auto. And, I think all the wiring connectors can be reached without taking anything major off the motor. (lemme know if Im wrong). I didnt know the AC wouldnt work. But, I'll get with Eclipse5302 on that, cuz I would like to have AC (I dont really care for it, but passengers do). And that shift light, yeah I have driven cars with those, and I hate them. I shift when I feel like shifting! I guess with both motors out of the cars, the wiring wont be that bad.

 

Robby

[patgizz]

the harness is way easy with the motor out of the car, as the harness should come out with it anyway to make life easier. so you'll have 2 motors/trannies sitting there with their wiring. swap harness over to your motor along with the trans and you're in business. easiest way to get the motor out is drop the whole cradle and lift the car above it.

[Guest TurboSedan]

 

I have never done a harness swap or had any reason to have any of my wiring out. So, what Im wondering, (Ima try and make this is a clear as possilbe, but I dont know if it will convey what I want it to), and I may sound dumb for this, but like, for instance, the MAP sensor wire. Does the wire from the connnector on the MAP run DIRECTLY to the ECM, or does it run into a connector that gathers more wires, that then goes to the ECM? Im assuming that the latter is not the case. I have been looking at my Haynes manual, and of course it doesnt have diagrams for the 5 spd, only the auto. And, I think all the wiring connectors can be reached without taking anything major off the motor. (lemme know if Im wrong). I didnt know the AC wouldnt work. But, I'll get with Eclipse5302 on that, cuz I would like to have AC (I dont really care for it, but passengers do). And that shift light, yeah I have driven cars with those, and I hate them. I shift when I feel like shifting! I guess with both motors out of the cars, the wiring wont be that bad.

 

Robby

 

the wiring harness for the engine itself is exactly the same between 3.1/auto vs. 3.1 manual. the MAP sensor wires go into more wires that go to EGR, throttle body etc. the 5-speed harness differs in that for the transmission there are only connectors for the VSS and backup switch - none of the extra stuff like the auto harness would have had. the bulkhead connector plugged right into the firewall connector with no modification and the fuse/relay panel snapped right into the body like the old one did. i think you'll have to pull the plenum off to disconnect the fuel injectors, but i would just pull the engine out with the wiring harness still connected to the engine and everything else and then swap the wiring over while the engine is out of the car. reconnect and reroute the new harness before lowering the engine/trans back down into the car.

 

oh yeah, one more thing: the manual equipt cars had an A.I.R pump so there are actually one or two wires on my harness that are just hanging there (i removed the A.I.R pump). it doesn't set any trouble codes tho. the A.I.R pump connects to the rear exhaust manifold, so you'll need to use a rear exhaust manifold from a 3.1/auto car or you'd obvious have a BIG exhaust leak. depending on where you live (emission laws) you may have to keep your A.I.R pump.

 

btw, for good wiring diagrams go to the public library and look at the Mitchell manuals. i copied each page on my car and my GTS and it shows differences between the manual and auto wiring.

joshua

[Guest TurboSedan]

the harness is way easy with the motor out of the car, as the harness should come out with it anyway to make life easier. so you'll have 2 motors/trannies sitting there with their wiring. swap harness over to your motor along with the trans and you're in business. easiest way to get the motor out is drop the whole cradle and lift the car above it.

 

i pulled the hood off, axles out, and just raised it out of the engine bay with a hydraulic cherry picker with no promlems. the auto came really close to the brake master cylinder tho so you gotta really be carefull and not break anything. fortunately the Getrag 282 is alot smaller (and lighter!) and lowering that engine combo back down was much eaiser. i strongly recommed a new clutch kit while you do this job, along with a resurfaced flywheel. and new motor and tranny mounts...

joshua

[brian89gp]

fortunately the Getrag 282 is alot smaller (and lighter!) and lowering that engine combo back down was much eaiser.

 

No joke, putting the 282 on the engine is as simple as picking it up and putting it on the engine . I'm not even going to think about trying that with a 4t60.

 

My tranny is vacuum control if that helps. Couldn't I just ground it so the engine thinks its always in drive?

-T

Yes. You cannot use a 3.1/5spd ecm and/or chip on the 3.8, you must retain the original 3.8 ecm and wiring. After that you need to do some tuning because with an auto, there is always some load on the engine cause of the torque converter, on a 5spd the second you push the clutch there is basically no load. There are slight differences in the tuning cause of that, but being that its a 3.8 I don't know any more.

[Robby1870]

I Dont have any emissions laws in KY, my home, or IN where I go to school. Hell, my car wouldnt pass emissions now (no converter), so that A.I.R. things is no big deal, I'll just keep my stock manifold. I guess a harness aint that bad, just plug and play, like you said. But, you mentioned the under hood fuse box, I would need the one from the donor car Im assuming. If I do this, I would have the ECM from a 90 and Tranny from a 90, so my speedo should be correct right? I hope I Have enough money/time this summer after the W-body gathering, or I may not go to it, and use the money I would have used to go to it, to buy this donor car. I can get an engine hoist, and have access to a small 3 sided carport and driveway that is not used by anyone. So, I should have enough room and tools for this. Malibuolds, you didnt drop your subframe did you? Did that make it more difficult? I wont have constant access to a lift to do this, so I'll prolly be doing it with jackstands and the engine hoist, like you did.

 

Robby

[Guest TurboSedan]

I Dont have any emissions laws in KY, my home, or IN where I go to school. Hell, my car wouldnt pass emissions now (no converter), so that A.I.R. things is no big deal, I'll just keep my stock manifold. I guess a harness aint that bad, just plug and play, like you said. But, you mentioned the under hood fuse box, I would need the one from the donor car Im assuming. If I do this, I would have the ECM from a 90 and Tranny from a 90, so my speedo should be correct right? I hope I Have enough money/time this summer after the W-body gathering, or I may not go to it, and use the money I would have used to go to it, to buy this donor car. I can get an engine hoist, and have access to a small 3 sided carport and driveway that is not used by anyone. So, I should have enough room and tools for this. Malibuolds, you didnt drop your subframe did you? Did that make it more difficult? I wont have constant access to a lift to do this, so I'll prolly be doing it with jackstands and the engine hoist, like you did.

 

Robby

 

the underhood fuse/relay box is just part of the whole harness, so you don't need to mess with it - just snap it back up into the body while you're installing the 3.1/manual harness into your car. they can be rewired (i've actually done one), but that's not something you'll need to worry about. the only reason i had to rewire mine was because it got cracked up in shipping and would no longer snap into the body.

 

or are you still wanting to use your original 3.1/auto harness?

 

i did NOT drop the subframe or move it or anything. it came out with a hydraulic cherry picker that i rented and i did it all by myself. just raise it slowly and keep checking for clearance, stuff you may have forgotten to disconnect, and ecspecially the clearance with the master cylinder. i didn't even remove the radiator and everything was easy. reinstalling is even easier, but installing the Getrag onto the engine is a TOTAL bitch if you do it yourself like i did since you have to get the splines aligned while making sure the throwout bearing (release bearing) stays in place and get the dowl pins in and the bolts in. i did it by holding the engine above the ground slightly (with cherry picker), while sitting down and lifting the trans on. if the splines weren't aligned i'd have to put the trans back down on the floor and turn the engine slightly and try again. so make sure you have a friend around to turn the engine for you when you do that!

joshua

[Robby1870]

I think I have decided to use the 3.1/manual harness, given how easy it now seems. Good to know about not dropping the frame or radiator. I didnt want to mess with that stuff. Yeah, I knew that gettin the tranny onto the motor would be hard cuz it all has to be lined up. Me and my dad, and prolly a couple of my friends, would be doing this, so I'll have plenty of help, hopefully.

 

Robby

[patgizz]

maybe its cause i have ABS - with that stupid pump in the way it didnt look like a good idea to pull the thing out the top.

[Robby1870]

maybe its cause i have ABS - with that stupid pump in the way it didnt look like a good idea to pull the thing out the top.

 

yeah, luckily, I dont have ABS. Plus it would be harder to hook the axles for the manual up with the ABS.

 

Robby

[Guest TurboSedan]

yep no ABS here either. besides it would probably interfere with my turbo i'm planning on. another downside about the manual is that you can't use the newer ('96+?) brake booster due to clearance with the clutch master cylinder. i already have '94+ rear discs, and i have almost all the stuff needed for '95+ front brakes (just need pads and swap my lowering springs in). with some good pads and SS braided hoses, i think my brakes will be more that suffecient even without ABS or the bigger booster.

joshua

[Robby1870]

Malibuolds, just want to ask how much faster, you think, your CS is with 5spd? I know, that more power is gettin to the ground, and you have a closer ratio tranny with the 5spd, cuz the 4T60 1st-2nd ratio difference is huge (2.9-1.6). I can already take some cars off the line, but after 1st gear, the car falls on its face, cuz of the 1.6:1 ratio in 2nd gear. Just curious. I see your planning a turbo. EVENTUALLY, like in 2 or 3 years, I wanna do the turbo swap over too. My plan is to get as much N/A HP out of that I can, then turbo it and rebuild it at the samet time to get maximum power from it. Im thinking 300+ (with a chip) is pretty attainable. What kind of clutch did you use when you put your 5spd in? Cuz, I would obviously put a new one in with the tranny out. Did you use the GM Synchromesh fluid for it? I have heard good things about that stuff. Just curious

 

Robby

[Guest TurboSedan]

HOLY SHIT is all i can say hahaha the car was a total turd and if i floored it would downshift REALLY hard...so i pretty much could never floor the car. and yeah the drop in RPM (w/auto) from 1st to 2nd was terrible for acceleration. the power i gained (thru gearing) was WAY WAY beyond my expectations. also, you do the shifting yourself so you if you are REALLY getting on it, you can let 1st go up to about 30mph (like 5000 RPM) and then do a snap shift into 2nd and the engine is in it's sweet spot - gaining acceleration quickly until about 45mph and i shift into 3rd gear. 3rd gear isn't much to brag about, and i usually stick it in 4th around 60-65mph when racing, but on the street it seems races only get up to around 60mph because you don't want to run over some kid crossing the street or get a ticket n'stuff.... one thing tho... you have to really practice shifting the car and ecspecially LAUNCHING it with a manual. the way you launch and shift will win or lose a race. i've had my Getrag in the CS for almost a year now and am just now getting the launch thing down. i can shift it pretty quickly, but to launch good i gotta get the RPM's up to almost 3000 and 'feel' the clutch out; trying not to spin the tires, avoid wheel hop, and not let the clutch slip too much. it really takes alot of practice. i'm using GM synchromesh (like $10/quart ). and the clutch is just a standard replacement but has held up fine and has never slipped (as if i'm putting that much power out anyway). i think the clutch was a DynaPak or something, made by Borg/Beck. i'm not sure i already thru the box away. when the turbo goes in the clutch will be replaced with something better. i'm still not sure what clutch i'll use tho.

 

btw, if you want to get more power out of the n/a 3.1 whatever you do DON'T raise the compression ratio if you are planning on a turbo later. when i rebuild mine i'd like to get pistons that drop the compression down to 8.2:1 or so so i can get more boost and avoid detonation.

joshua

[Robby1870]

yeah, Im not gonna raise compression at all. 8.9:1 is somewhat low, I'll just have to stick to like 12-16 lbs of boost. With that 8.2:1 you mentioned, you could run some serious boost, prolly well over 20 lbs. I was looking gear ratios for the 282, and 3.77 in first coupled with the 3.61 final drive would give some pretty good first gear acceleration. 2.19 for 2nd aint that bad. Since I wont be putting much power to the ground, I'll just go with a stock replacement clutch for now. I'll get the GM Synchromesh fluid too. Now, I just gotta come up with $300 for the parts car. Which means I'll have to do some extra work this summer, but I wont mind when 5spd is hooked up. I should start this project the first of July, that gives me two complete months to finish it before college starts up again in Sept. Maybe I can get it done somewhat fast, so I can practice my launches! 8)

 

Robby