Spanky1113

Hi. I'm new to the site, but I've been looking around all morning and can't quite find out what I need, so I figured I'd ask

I've got a 1986 Firebird with the V6 2.8L engine in it. I got the car from a friend of the family's in 2004. In March of 2005, on it's first long distance drive (45 minutes...), the oil pump blew, the engine locked up, and I blew a piston...

So it sat in the shop for sometime until my dad (a mechanic of ~20 years) was able to find a replacement engine. He found another 1986 Firebird with the same engine, so he swapped it out. But instead of just taking out the engine, he swapped out the transmission too.

Since doing that, my speedometer hasn't worked. It just sits at 0. My dad believes that it's because of the different transmission and the speedometer won't hook up properly to it.

I've looked around, but I can't seem to find information for the base model Firebird (unless it's called the Sport Coupe Berlinetta).

As of right now, we're looking into an aftermarket speedometer to use until we can get the actual one fixed.

If someone could help me figure out what transmissions are able to go in my car, or a simple and cheap way to fix my speedometer, that would be great.


Thanks!!

//<86TA>\\

iTrader: (14)

have you checked under the car to see if the wires for the speedo are connected? if the replacement trans came from a bird it should work no problems, provided the two cars had the same gear ration in the axle

Spanky1113

I haven't personally checked, but my dad did the swap, so if he says they aren't connected, I'm gonna believe him.

He said they wouldn't connect, so I dunno.

John in RI

iTrader: (167)

He needs to pull the speedo sending unit from the tail shaft of the original tranny and swap it into the replacement tranny. It's very possible that the speedo sensor in the replacement tranny is not the same style as the one that was originally in your car.

Be sure to have him look / make notes as to the speedo "drive" gear on the tranny shaft ( INSIDE the tail housing ) and the "driven" speedo gear at the end of the sensor from your ORIGINAL set-up. He will need to use gears of the same color and tooth count in the replacement tranny in order for the speedometer to display the correct readings.

1986 Firebird V6 2.8 means you probably have 3.42 gears in your car. You should use a 15 tooth grey gear IN the tanny and a 42 tooth green gear ON the sensor with 15 inch wheels. (or 41 tooth yellow gear ON the sensor with 16 inch wheels)

Spanky1113

Thanks for the help! I'll help him do that this week.

If we ever locate the original tranny (someone stole it outta the loaner car), I'll make sure to check all that stuff >.>

Spanky1113

Well, I talked to my dad about it this morning and he swears on his life (he didn't say it, but it seems like it at least) that the ONLY way to fix it is to swap out the whole transmission.

He's got the shop, tools, and knowledge to do this, so it would be really awesome if I could get him to help me (not to mention a cool father/son project ).

He's buying some aftermarket speedometer where you put magnets around the driveshaft or something...not sure.

Anyways, if someone could help me come up with a convincing argument, it would be greatly appreciated.

P.S. Feel free to use lots of technical jargon...he'll understand it even if I don't lol.

sofakingdom

iTrader: (1)

He's wrong.

There is NO DIFFERENCE between the transmissions themselves in this area.

You need to locate the speedo gears and VSS from your old trans, and put them into the one in your car now.

Without that, you can swap transmissions out every single day, and twice on Sundays just for good measure; and maybe still NEVER get a working speedo.

Spanky1113

Do you know of any sites where I can price/purchase the gears? I've looked around on ebay and googled a couple, but didn't come up with anything.

sofakingdom

iTrader: (1)

Try here.

You may need a VSS as well, if you don't have one in your trans, and/or your old one is gone.

Spanky1113

Thanks man! That's cheaper than what I thought it was going to be.

So, the VSS just has to fit and it'll work?

vbMike

iTrader: (2)

I agree. All you need to do is swap the sending unit and the drive and driven gears and it will work. Here is another site where you can buy the gears. I think they also have a calculator to figure out which gears you need to buy.

http://www.bowtieoverdrives.com/cata...BCAT&CATID=DA2

Spanky1113

Thank ya! You guys freakin' rule! lol.

Would purchasing just the gear kit first and installing it without the new VSS be a good idea? Ya know, just to save money if I don't need the VSS.

sofakingdom

iTrader: (1)

The VSS holds the driven gear. You can't put that in without a VSS.

So you need to have a VSS on hand when you put in the gears, one way or another. Either your old one, or you need to buy one.

Spanky1113

Ooooh, ok. I gotcha.

And since I wasn't able to connect the speedometer cable to this transmission, that means that this VSS is wrong.

sofakingdom

iTrader: (1)

Does your car have a speedo cable (mechanical) or a speedo connector (electronic)?

Spanky1113

I've heard speedo cable alot so I'm going to assume that.

sofakingdom

iTrader: (1)

Bad bad bad bad word to use concerning what parts you have....

Break the word down into its component parts: 3 letters, then 1 letter, then 2 letters.

"Make an {donkey} out of u and me".

That's what doing that does.

Go look at the parts, and see what you've got, if you don't know. NEVER EVER do that {donkey} u me thing.

vbMike

iTrader: (2)

Some cars have electric speedometers, other are driven by a cable. I believe your car is supposed to be an electric speedometer but I think I read somewhere that base model firebirds got a cable driven speedometer. I don't know for sure, I'm a Camaro guy.

You need to find out before you buy anything.

Spanky1113

Ok, scratch everything.

My dad just told me that the new transmission he put in there is a different model and everything, so just changing the VSS and drive and driven gears wouldn't fix it.

..../sigh

Maybe I'll call up the shop tomorrow and while it's up getting new tires I'll have them find out what kinda transmission it is...

sofakingdom

iTrader: (1)

Changing the model of trans is HIGHLY unlikely. Not impossible, mind you; just, HIGHLY unlikely.

Not that it would matter: as you no doubt noticed, alot of the various transmissions use the same VSSs and gears. Not ALL, but ALOT.

Don't bother with the tire shop. Most likely, all you'll get is blank stares.

Instead, go here and print out the page, and get up under there while it's on the lift and look at it yourself and figure out which one it is.

Not to be cruel to your dad, but at this point, he's not being very helpful. I'd suggest not bothering with asking him any more stuff either, since it doesn't seem to be getting much info for you; and instead, do your own research.

Spanky1113

lol, true. but it's at the shop where he works and I'm not paying for the new tires, so I don't mind.

But yeah, I'll do that. Maybe I'll fax it to 'em, hope for the best lol. I've gotta work 9-5 tomorrow and that's when they're putting it up.

Spanky1113

Woohoo!!!

While my car was up they found out it was the 4L40 tranny so that solves that. Now all I gotta do is come up with the cash and time to put in the parts.

How long, roughly, would it take to do this job? (swap out the VSS and drive and driven gears)

sofakingdom

iTrader: (1)

Never heard of that one? I'd love to see the pan, so I can add it to my database. Please take a pic and post it.

Sure it's not a 4L60?

If it has a removeable extension housing, you'd have to take it off (a few bolts and maybe the mount), and it'd all be right there. If it's a 4L60, which is another name for the 700, that'd be 4 bolts, plus the mount.

Spanky1113

Lol, yeah. it's the 4L60. I guess all the "4"s got to me >_>

Oh, and something I was thinking about today. Here's how my car is shifting.

1st - 2nd: 10mph

2nd - 3rd: ~25mph

3rd - 4th: ~40-45mph

And most of the time, when I first start up my car, the first time it tries shifting into 4th, it won't. The rpm's keep going up, but there's no shifting. But, if I manually put it back into 3rd from having the car in Drive, the car will jerk like it's being downshifted, but the rpm's don't change, then I push it back into Drive, and nothing happens.

Also, when I full throttle it, nothing happens. Like, the rpm's shoot up, but it doesn't downshift and there's really no acceleration.

Will switching out the VSS and drive and driven gears change any of that or is there something else I need to do to fix that.

Spanky1113

Hmmm, i guess editing doesn't move it to the top of the list lol.

Anyways, can anyone help me with my questions in my previous post? Thanks

sofakingdom

iTrader: (1)

Those shift speeds sound about right for a 700.

The whole description of how it shifts, just means, it's messed up. You need another one. That one is defective.

Shifting is ENTIRELY hydraulically controlled in that transmission; the only electrical thing is the torque converter clutch. The VSS can affect that one thing, because the VSS is how the computer knows how fast the car is going, and therefore whether it would be reasonable to consider operating the TCC. But as far as shifting gears, no, the VSS has nothing whatsoever to do with that. So no it won't affect it. That's completely internal to the transmission.

You might try setting the TV cable properly. If it's wrong, the trans won't ever shift right. It doesn't sound like that's causing your problem, but it MUST be right for the trans to work right, so it's worth a try. For a description of how that system works and how to set it, go here.

Spanky1113

Thanks for the info, I'll read the link when I get home from work.

This morning, which was warmer than it has been, I let my car sit for like 5 minutes before going instead of pulling right away like normal. Today, it shifted fine into 4th gear.