TC V8 conversion people-I need some help (speedometer)

Topic: TC V8 conversion people-I need some help (speedometer) (Read 1322 times) previous topic - next topic

TC V8 conversion people-I need some help (speedometer)

April 01, 2009, 01:29:25 AM

88TC 5.0 T5 3.55 gears. What speedo gear are you running? I could never get my speedo close to being accurate. I've done this many times before in some of my mustangs and never had a problem finding the right speedo gear after a gear swap.Is it just as simple as using a speedo gear for 3.55 gears?

TC V8 conversion people-I need some help (speedometer)

Reply #1 – April 01, 2009, 02:30:07 AM

I would really think so, but I'm far from being knowledgeable as some are.
Common sense would seem to agree that 225/60 tires, with 3.55 gear, and a T5 would use the same speedo gear that a Stang with the same combo would take though..

TC V8 conversion people-I need some help (speedometer)

Reply #2 – April 01, 2009, 09:09:35 AM

You should be using a 20 tooth gear (Black Gear).

http://www.latemodelrestoration.com/iwwida.pvx?;item?item_no=LRS-17271B-K%20%20%201&comp=LRS

TC V8 conversion people-I need some help (speedometer)

Reply #3 – April 01, 2009, 12:31:49 PM

Thanks for the info-now another question. I reused the stock T5 (turbo coupe) speedo gear do you know what color that is-I mean is it black?

TC V8 conversion people-I need some help (speedometer)

Reply #4 – April 01, 2009, 01:49:44 PM

With 3.55's, stock height wheels/tires, and a T-5 it should be black and have 20 teeth. That is the Ford part/color in the link I included.

TC V8 conversion people-I need some help (speedometer)

Reply #5 – April 01, 2009, 02:43:22 PM

The stock speedo gear I removed from my '87 TC parts car with the T5 and 3.55 gears was white. The gear you need depends on the T5 you used, because different T5's use different speedo drive gears. The stock TC 4-cyl T5 has a 6-tooth drive gear. Most V8 T5's use a 7-tooth drive gear. So do most 4-cyl Mustang T5's. Some V8 T5's use an 8 tooth. You need to know which drive gear you have before you can determine the proper driven gear.

Eric's got a nice chart explaining it:
http://www.coolcats.net/tech/advanced/t5_data.html

...and once you've figured out your output (drive) gear you can find the proper speedo (driven) gear here:

http://www.fordracingparts.com/download/charts/129.pdf

TC V8 conversion people-I need some help (speedometer)

Reply #6 – April 01, 2009, 03:32:11 PM

I was going by a chart I had for Mustangs. Sorry bout that.

TC V8 conversion people-I need some help (speedometer)

Reply #7 – April 01, 2009, 06:02:46 PM

Thanks for all your help-I'll post back and let you guys know how it worked out.

TC V8 conversion people-I need some help (speedometer)

Reply #8 – April 03, 2009, 10:49:59 AM

Quote from: Thunder Chicken;265291

The stock speedo gear I removed from my '87 TC parts car with the T5 and 3.55 gears was white. The gear you need depends on the T5 you used, because different T5's use different speedo drive gears. The stock TC 4-cyl T5 has a 6-tooth drive gear. Most V8 T5's use a 7-tooth drive gear. So do most 4-cyl Mustang T5's. Some V8 T5's use an 8 tooth. You need to know which drive gear you have before you can determine the proper driven gear.

Eric's got a nice chart explaining it:
http://www.coolcats.net/tech/advanced/t5_data.html

...and once you've figured out your output (drive) gear you can find the proper speedo (driven) gear here:

http://www.fordracingparts.com/download/charts/129.pdf

If my memory serves me correctly that would be a 23 tooth gear. Must have different size wheel and tires than the Mustang I guess. I assumed (This is never a good idea) they had the same size wheels and tires.