I want to replace my 110 speedo to the 145 from a Z-28 or Trans Am. Is there anything I should know before I change it? I know I have to pull the dash pad and everything, I am not too sure about the electronics involved, if there are any differences between the two.

 

Ive changed everything up to a 1989 firebird. I've had absolutely no problems with the swap. The only thing you have to worry about is if the speedo is cable driven or electric. I think they were only cable driven up to 84 so you dont have anything to worry about. You should only have to replace two connectors in the back of the instrument cluster. These quick connects will be mounted in the dash and all you will have to is pull the old cluster out and push the new one in. Its an easy swap. Loosen the two bolts that hold your steering wheel up and put the tilt as far down as it will go. This will help you to install the cluster without cracking it. Next just test your speedo by taking your car up to 145!!!!!!!!

 

Thanks. I am glad this will be simple. My car will already run about 120 give or take. Now I will know for sure. Maybe I will run the 145 out with my new engine when (if) I get it. Thanks again!!

 

Yea you bet dude, you shouldnt have any problems

 

Uh. One more thing. What about the mileage?

 

youll have to take the plastic lexan glass cover off the 145 mile speedo first. Then you will have to take the cluster out of the white plastic backing holding bezel or whatever its called. You need to do this so that you can get acces to the speedo mechanism itself. Once you have done this then you need to pull off the orange needle from the face of the cluster then take the speedo mechanism out. This procedure is extremely easy to brake something. Then once the speedo gearing is out. Pull on the plastic or metal retainer that holds the speedo numbered gears in place. Then working one at a time change the numbers to what you want. You have to put enough pressure on the retainer to spin the numbers but not enough that you will break it. Its kinda tough so practice on your old one first.

 

Ok. This is going to be tricky. 123600. That may take a while. Thanks.

 

No you dont have to go through all the sequence of numbers. When i said go one number at a time i meant to start with the first number and work your way to the next one. Say your number is 123600 on one speedo and on the other one its 246591. Start with the number two in the 100 thousands spot and lift the retainer so you can click the gears to make it read number one. Then go to the 10 thousands spot and move the 4 to read 2. Then the thousands spot and turn the 6 until it reads 3 and so on. You dont have to go through the entire sequence just change what ever digit you want by lifting the retainer. Hope this clears that up

 

Ok. Thanks. That makes it better. I was thinking role the tenths number till they are the same....

 

Ok. Thanks. That makes it better. I was thinking role the tenths number till they are the same....

 

Good news. I got a 145 today. I got it at the Super Chevy Show today at Bristol for 40 bucks.

However, I am having a little trouble with the needle coming out and the getting to the speedo mechanism. There seems to be plastic mountings on the back of the cluster that are holding it into place. Any help here?

 

I just took the odometer and trip meter from my old cluster out and put it in the new speedo I got, was two screws holding it in which were the ones that held the face on the speedo head.

 

I was gonna do that, but I can't get to the screws to get it out. Well, not without breaking something.

 

For the mileage, couldnt you have just take out your old one out and stick it in the 145mph gauge? Just a thought

 

If you take the clear plastic bezel off, then the needle, then the two screws for the face you will have access to the odometer.

 

My needle isn't copoperating in being removed and there is a piece of plastic that is in the way the carries light to the speedo needle is in the way of getting to the second screw. I am trying, but I am being careful so I don't brake anything. I'll post pictures to see if that helps.

 

Pictures would be helpful... I'm planning this swap myself shortly