Which speedo gear will I need?
Thread Starter
Drifting
Joined: Apr 2002
Posts: 1,451
Likes: 0
From: Owensboro Ky
Which speedo gear will I need?
I just purchased a Dana 36 w/ 3.54 to replace my anemic 2.59's? What speedo gear will I need to used to get an accurate reading from the new gears? Any help will be much appreciated. :cheers:
Thread Starter
Drifting
Joined: Apr 2002
Posts: 1,451
Likes: 0
From: Owensboro Ky
Re: Which speedo gear will I need? (ZAD54)
OK, so if no one knows the correct speedo gear I'll need, does anyone know the formula I can use to figure it out. Or better yet, does anyone know which retailer i can call so they can sell me the correct speedo gear. I'd really rather replace it than wire in the electronic device, but if everyone thinks thats better, I might just go that way. :confused:
Drifting
Joined: Nov 1999
Posts: 1,801
Likes: 2
From: St. Paul MN
Re: Which speedo gear will I need? (ZAD54)
Well, I only know a little about this. I'm pretty sure you are going to need the other vehicle speed sensor (vss). There are two different ones and I don't think the one you have will work for the gears you are going to. Also, if you put it together and drive it and go a certain speed on the speedo and know that actual speed you are going (like use a GPS) you can take those two numbers to a good speedometer repair place and tell them what speedo gears you have and they can tell you what speedo gears you need to change to. That's what I did. But before you put the speedo gears in write down what number teeth are on the driven gear (that's the cone shaped gear that fits onto the vss shaft). You don't make any changes to the spiral gear mounted on the output shaft of your tranny, at least I don't think you do. I'm sure others will have more info on this.
Melting Slicks
Joined: Jul 1999
Posts: 2,875
Likes: 0
From: Olive Branch (Memphis suburb) MS
Cruise-In II Veteran
Re: Which speedo gear will I need? (ZAD54)
8648680 gear, 25513050 gear, and 10456089 sensor(this was for my 92, yours may be different) if you are going from the 2.59s to 3.54s. Total shipped to my door $36.62. Give Jeff Kopp a call at Superior Chevy 1-800-728-8267 and let him know you're on the forum. :cheers:
Drifting
Joined: Nov 1999
Posts: 1,801
Likes: 2
From: St. Paul MN
Re: Which speedo gear will I need? (Ramrod92)
Wow, if that is the correct price for the things he needs I will be surprised. The VSS for my '86 was nearly $100. I wonder if they changed them somewhere in there and the '92 uses something different?
Race Director
Joined: Dec 1999
Posts: 11,813
Likes: 32
From: Work
St. Jude Donor '09
Re: Which speedo gear will I need? (Ramrod92)
I second this motion! He set me up with the same stuff last week, it was at my door the next day. He'll give you what you need.
Eric
Eric
Thread Starter
Drifting
Joined: Apr 2002
Posts: 1,451
Likes: 0
From: Owensboro Ky
Re: Which speedo gear will I need? (Ramrod92)
Thats basically what I had planned, a phone call to Jeff Kopp should take care of it. He really has a following here doesn't he. Just about like Rich at Cruzin Performance. Thanks again :cheers:
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: Which speedo gear will I need? (ZAD54)
My 1984 - 1989 Genuine Corvette Parts book, says you will need: A
8642620 15 tooth Grey Drive gear. AND a
25007339 Sensor in all cases. Plus either a
25513049 42 Tooth Green Driven Gear for P255/50ZR16 Tires OR a
25513050 43 Tooth Purple Driven Gear for P275/40ZR17 tires or P315/35ZR17 tires.
All of these numbers were current as of 1989. Any or all MAY be superceded. However, these numbers WILL get you the correct parts. None of these numbers are currently in use with your 2.59 rear gears. All three parts must be changed for YOUR particular swap. I can't help you with pricing or availability. Good luck.
8642620 15 tooth Grey Drive gear. AND a
25007339 Sensor in all cases. Plus either a
25513049 42 Tooth Green Driven Gear for P255/50ZR16 Tires OR a
25513050 43 Tooth Purple Driven Gear for P275/40ZR17 tires or P315/35ZR17 tires.
All of these numbers were current as of 1989. Any or all MAY be superceded. However, these numbers WILL get you the correct parts. None of these numbers are currently in use with your 2.59 rear gears. All three parts must be changed for YOUR particular swap. I can't help you with pricing or availability. Good luck.
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