Automatic Transmission 2-Speed thru 10-Speed GM Autos | Converters | Shift Kits
Sponsored by:
Sponsored by:

Making the speedo work in a TH350.

Thread Tools
 
Search this Thread
 
Old Jul 13, 2005 | 05:17 PM
  #1  
Dragaholic's Avatar
Thread Starter
9 Second Club NA
iTrader: (180)
 
Joined: Mar 2003
Posts: 5,943
Likes: 1
From: Houston, TX
Default Making the speedo work in a TH350.

Correct me if I'm wrong, but what parts are needed is a reluctor wheel and speed sensor. If you are converting from a 6 speed, you'll need the 6 speed reluctor wheel and if youre converting from an A4, you'll need the 4L60E reluctor wheel because they have different number of tooths and you cant interchange because the reading will be off. Also, if youre converting from an A4, the reluctor wheel will press right on, but if youre converting from a 6 speed it will not fit because the T-56 and TH350 have a different size output shaft and the T-56 reluctor wheel will have to be machined to fit. Is this all correct? Is this a hard task to tackle? I'd like to keep my speedo in case I do ever take it on the street even though its a track car. Now of course, mounting the actual sensor is something youre going to have to rig/fab up yourself correct and it has to be positioned precisely so that it gets accurate readings. Anyhow, fill me in or correct me if Im wrong because I need to decide what I'm going to do before tomorrow morning, my tranny is in the process of being built locally and I'm either going to take him the parts or just do without a speedo. Thanks.
Reply
Old Jul 13, 2005 | 08:17 PM
  #2  
SUX2BU's Avatar
11 Second Club
iTrader: (14)
 
Joined: Apr 2002
Posts: 3,267
Likes: 1
From: DFW, TX
Default

i just plugged mine intomy front wheel sesor. it was free and it doesn't get thrown off when you put different size tires out back.
Reply
Old Jul 14, 2005 | 10:07 AM
  #3  
Dragaholic's Avatar
Thread Starter
9 Second Club NA
iTrader: (180)
 
Joined: Mar 2003
Posts: 5,943
Likes: 1
From: Houston, TX
Default

Plugged it into your front wheel sensor? If that does work accurately, how did you manage to plug it in way up in the front? How about did you route the wire without it being in the way of anything or possibly being damaged? Lastly, are the harness connectors the same?
Reply
Old Jul 14, 2005 | 11:42 AM
  #4  
SUX2BU's Avatar
11 Second Club
iTrader: (14)
 
Joined: Apr 2002
Posts: 3,267
Likes: 1
From: DFW, TX
Default

Yes it works flawlesly. you do have to splice the wheel sensor plug and your wheel sensor. Basically just leave your wheel sensor pluged in (it is already safely routed to the computer) and follow the wires to the computer find the pin outs for the speed sensor and splice.
you do lose your ABS but i took that out a long time ago.
Reply
Old Jul 14, 2005 | 11:44 AM
  #5  
SUX2BU's Avatar
11 Second Club
iTrader: (14)
 
Joined: Apr 2002
Posts: 3,267
Likes: 1
From: DFW, TX
Default

Oh and you put in your front wheel heigth for wheel heigth. and put 2.76 for your gear ratio.
Reply
Old Jul 14, 2005 | 11:56 AM
  #6  
Dragaholic's Avatar
Thread Starter
9 Second Club NA
iTrader: (180)
 
Joined: Mar 2003
Posts: 5,943
Likes: 1
From: Houston, TX
Default

Sounds easy enough. Do I have to do any modifications to the computer? Losing ABS isnt a problem because I took it off long ago. Is there anything else you lose or affect by splicing the speed sensor into the wheel sensor? I didn't understand your 2nd post.
Reply
Old Jul 14, 2005 | 02:50 PM
  #7  
SUX2BU's Avatar
11 Second Club
iTrader: (14)
 
Joined: Apr 2002
Posts: 3,267
Likes: 1
From: DFW, TX
Default

What i meant was that if youy just splice the wires the speedo is going to be off. Use edit or HP tuners to change your gear ratio to 2.76 and tire heigth to what ever your front tire is. i have 195 r 15's. Don't take everyones word for the heigth. i measured the actual circumference of my front tire and divided it by pi and got like 24.84" or something, not 26" like everyone says.
Reply
Old Jul 14, 2005 | 03:19 PM
  #8  
Dragaholic's Avatar
Thread Starter
9 Second Club NA
iTrader: (180)
 
Joined: Mar 2003
Posts: 5,943
Likes: 1
From: Houston, TX
Default

So changing the gear ratio to 2.76 and entering in your tire height as your front tire is required to get accurate readings? Why is this?
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

 Brett Foote
story-1

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-2

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-3

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-4

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-5

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-6

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-7

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-8

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-9

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
Old Jul 14, 2005 | 04:00 PM
  #9  
12secSS's Avatar
TECH Junkie
iTrader: (30)
 
Joined: Nov 2001
Posts: 3,690
Likes: 1
Default

The gear ratio change is due to the pulse variance from the trans output shaft speed and the wheel sensor output signals. The front tire size is due to the fact that you are no longer using the rear tire to calculate the speed of the vehicle, but rather the front tire.
Reply
Old Jul 17, 2005 | 09:36 AM
  #10  
NosboySS's Avatar
On The Tree
iTrader: (1)
 
Joined: Dec 2001
Posts: 128
Likes: 0
Default

Im glad i saw this post ive been dealing with this for a while and waisted hundreds of dollars on false information. IM going to go ahead and do it the ABS way. I herd about it when it was a brand new ieda and nobody had figured out the gear ratio tire size deal yet, but now that the math and thinking has been figured out for me im going to take advantage of that! Thanks!


Spdfreakls1

Last edited by NosboySS; Jul 17, 2005 at 09:38 AM. Reason: Nossboy didnt log out! lol
Reply
Old Jul 17, 2005 | 11:19 AM
  #11  
SUX2BU's Avatar
11 Second Club
iTrader: (14)
 
Joined: Apr 2002
Posts: 3,267
Likes: 1
From: DFW, TX
Default

No problem man. it just took a little figuring and i got it to where it works perfect.
Reply
Old Sep 16, 2005 | 11:34 PM
  #12  
kevredz's Avatar
On The Tree
iTrader: (2)
 
Joined: Oct 2003
Posts: 148
Likes: 0
From: Abilene, Texas
Default

Originally Posted by SUX2BU
No problem man. it just took a little figuring and i got it to where it works perfect.
I just wanted to confirm that calibrating the speedo for 2.76 gears for this is DEAD on.

Thanks alot, SUX2BU. Saved me alot of time and guess work.
Reply
Old Sep 17, 2005 | 12:16 AM
  #13  
SUX2BU's Avatar
11 Second Club
iTrader: (14)
 
Joined: Apr 2002
Posts: 3,267
Likes: 1
From: DFW, TX
Default

no problm man just happy to add some info to tha site.
Reply




All times are GMT -5. The time now is 02:41 PM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-04 18:13:20


VIEW MORE
story-1
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-2
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-3
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-4
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-5
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-6
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-7
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-8
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-9
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE