T5 to 700R4 Swap? - Third Generation F-Body Message Boards

Smoke_Jaguar · 06-03-2009, 03:24 PM

Been browsing the forums looking for information on swapping to an automatic transmission and everything seems to be on going to a manual. I assume it's a pretty straight forward swap (pedal assembly, transmission, torque converter, flywheel [I think] kickdown cable and a bit of wiring for the lockup), the main detail that seems like it will give me the most trouble is the lockup. I've put in automatics before, but they always had the 4 pin connector already on. Where exactly does that run off of and will it require any extra sensors, a TCM, ect?

Looking at transmissions at the local scrapyard (also have one from an old V8 S10 I built a while back) and want to get a comprehensive list of what all I will need to avoid putting the thing out of comission for too long.

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Maverick H1L · 06-03-2009, 03:53 PM

First question is why? You do realize that having an automatic transmission is more of a convenience thing that anything else, right? Automatics are slightly less efficient than manual transmissions (40+% for automatics, even with lockup converters vs 35% for most manuals, AFTER the engine warms up enough for the TCC to engage), for one, and they weigh more (sprung weight, which everyone knows is a good thing to get rid of) for 2. And, to top it off, autos are more prone to failure, with all of those seals, gaskets, pistons, springs, and other rotating mass that is subject to pressure when running.

Second, you have most of your list right, but you're still missing a couple of things, such as a plate to mount the shifter you're missing from the list, and the PROPER (externally balanced) 2.8 automatic flexplate (NOT flywheel, those are for manuals). What do you plan to do with the clutch hydraulics when you ditch the rest of the clutch system? If you do decide to ditch the hydraulics, what are you going to do with the hole in the firewall? You also forgot you'll need to replace your torque arm mount (not available from GM anymore, IIRC) and your catalytic converter hanger (something I am 100% positive you can't get from GM anymore as I don't have one, have been looking for one, and REALLY need one) because the tailshaft housing bolt hole spacing on the lower end is different. And, if you don't have the automatic crossmember already, you need to get that and a trans mount as well, along with possibly a replacement ECM (or just the chips), and the connector for the transmission case. You might want to invest in a trans rebuild as well, so you are 100% sure you aren't putting a POS into your car that, if you get everything done, will fail 5 miles down the road.

Smoke_Jaguar · 06-03-2009, 07:00 PM

As for the reason why, I simply prefer the automatics over the manual. I realize the issues with efficiency and the complexity it adds. I see no real advantage in the manual for me and automatics have always worked well for my driving style.

As for the components, the mounting blate is a breeze (being friends with a machine shop owner has some perks), flex plate isn't too terribly hard to get (my bad on calling it a flywheel), catalytic converter is aftermarket and the hangars were redone anyways and I can can get a mount as well. Most of the underbody parts I will probably salvage as well. As for the rebuild, that was already planned as well as using a new torque converter. Main concerns was with the lockup and ECM end of things.

Maverick H1L · 06-03-2009, 09:02 PM

Forgot a couple of things:

If you don't have one already from another trans, a torque converter dust cover is a nice thing to have.

Also, not knowing for sure as I have only seen a carbed V6 at the junkyard with the 5-speed (with my own eyes, anyways), you might need a throttle/kickdown/cruise control cable bracket that holds the cables in place on your intake.

You may not want to, but you could (not saying you have to, but it is a safety thing) pick up a park lock cable, that runs between the shifter and the ignition switch to lock the key in the cylinder until the trans is in Park and won't let you move the shifter until the key is turned "on" .

You might want to look under your console and see if you have the connections for the Neutral safety switch down there. If not, you need it, and you'll have more wiring to do.

Smoke_Jaguar · 06-03-2009, 09:44 PM

Thanks, forgot all about the park lock cable, that could be interesting. Also, it's fuel injected V6, though I have yet to see another at the scrapyard with anything but an automatic (of the same year at least). All said and done though, this is going to be one hell of a job to do.

Maverick H1L · 06-03-2009, 10:02 PM

Also, just remembered the speedo parts. You will, depending on whether you have a cable or electric speedo and whether you have factory 3.42 gears or not, need to do something about a VSS for your car. Getting speedo gears is not as easy as you might think, but the Gear Box might possibly be of some use. From personal experience, the guys at the dealers couldn't find a decent speedo gear in the catalog any more than they could find their noses in a dark room (I fought with them for 3 months about a driven speedo gear for my T5 swap and STILL ended up with an extra drive gear I can't use).

:edit: I looked at Gear Box and it seems they only have cable driven speedo gears for T5's... Maybe eBay?

Smoke_Jaguar · 06-03-2009, 10:08 PM

I am probably going to raid salvage for them, everything on my car is factory (only has 60k miles on it), only thing aftermarket was the stereo system and that gutted before the oil was changed even (thanks to the lovely wiring job and me not wanting an electrical fire).

Edit: Speedo is mechanical

Maverick H1L · 06-04-2009, 12:26 PM

Quote:

Originally Posted by Smoke_Jaguar

I am probably going to raid salvage for them, everything on my car is factory (only has 60k miles on it), only thing aftermarket was the stereo system and that gutted before the oil was changed even (thanks to the lovely wiring job and me not wanting an electrical fire).

Edit: Speedo is mechanical

Finding the cable drive shouldn't be too hard. Look at Camaros up to 89, trucks, pre-87 Birds (or a bird with the idiot light cluster... yes they do exist, there's one in my fave junkyard), etc. As for the gears, IIRC (as I haven't counted the gear teeth on my 2 gears in a while) the drive gear is kind of a tan or puke green color and has 15 teeth, and the driven gear is orange and has 48.

However, you need to get your axle code off of the front of the pass side axle tube on the rearend, which is probably covered in rust and you'll need a wire wheel to read the code (and possibly a piece of chalk). Your 86 should have either the 8JC or 8KA axle codes if it has a 3.42 rear gear in it, otherwise you'll need a different set of gears to match your gear ratio. If the rearend code doesn't help you, count the teeth on your existing speedo gears (should be a purple 7-tooth drive gear on the trans output shaft inside the housing and a 19T white gear on the speedo cable drive unit) and get the drive and driven gears that match the ratio the closest.

BTW, you CAN get the 700R4 dust cover from the Gear Box. Also, it's too bad you don't live a little closer to me as my whole trans swap package is sitting in my garage, minus the park lock cable that I had to cut to remove, and my flexplate wouldn't help you any as it is for my 3.1 externally balanced engine.

chevyracingrox · 06-04-2009, 11:29 PM

700R4 also weighs about 100lbs more than a BW T5. you can easily sell the old manual transmission parts.

jensen73110 · 06-04-2009, 11:46 PM

You could easily sell them to me.

I'm gonna go to a 5 speed someday.

Lack of shipping costs would be nice too.

drwhyer · 06-06-2009, 02:33 AM

Hey Smoke_Jaguar I am doing the opposite three days ago I pulled my 3.1 v6 mpi and transmission to put in a carb sbc 350 v8. A doner car might be your best bet, Or find someone like me who just pulled their engine/transmission for a swap. I had some issues with my v6 engine but the transmission never missed a beat. Good luck with your swap.

drwhyer · 06-07-2009, 02:20 AM

Also make sure your radiator has provisions for a automatic transmission cooler. If your radiator doesnt have them then you will need one that does.

Smoke_Jaguar · 06-08-2009, 03:29 PM

The list just keeps stacking up, I am honestly considering just finding a good body with a working automatic transmission and just starting from there. Automatics have a nice convienance factor, just as long as they're already installed..