Diesel Engine Conversions Diesel Engine Swaps , 4bt Diesel and All Diesel Engine Conversion Related Discussions

Gearing / speedometer question

Thread Tools
 
Search this Thread
 
  #1  
Old 08-18-2012, 01:51 PM
Rolson's Avatar
Diesel Fan
Thread Starter
Join Date: Jan 2012
Location: Hastings, MI
Posts: 49
Received 0 Likes on 0 Posts
Default Gearing / speedometer question

Ok guys,

I have the Ford N Benz on the road and running well.

The Jeep AX-15 came with an electronic speedometer output, and the Ford uses a mechanical speedometer. I talked to a guy at a speedometer shop and he told me I would need a 35 tooth long shaft gear, and the correct holder, based on a 3.47 rear gear ratio, and 215 70R 14 tires which the tire calculator says are 25.85 inches tall.

He wanted about $260 for the gear, holder, and a new cable.

I found the gear and holder on ebay for $24, and got a speedometer cable from the local junkyard for $15.

When my speedometer on the dash says 60, the gps says only 57. When it reads 70, the gps says only 66 mph. So if I am reading 3 mph too fast at 60, do I need a gear with more teeth, or less teeth to correct it? I suppose I could just go with slightly larger tires, but there are still a lot of miles left on these, so that will be a while.

Thanks for your help.

Rick
 
  #2  
Old 08-19-2012, 11:09 AM
Grey Wolf's Avatar
Diesel Fan
Join Date: Feb 2010
Location: Acton, CA
Posts: 11
Likes: 0
Received 7 Likes on 7 Posts
Default

I believe one tooth less will get you were you need to be. My memory is a little fuzzy but I do remember one tooth equaled three mph.
 
  #3  
Old 08-19-2012, 07:14 PM
Rolson's Avatar
Diesel Fan
Thread Starter
Join Date: Jan 2012
Location: Hastings, MI
Posts: 49
Received 0 Likes on 0 Posts
Default

Grey Wolf,

Thank you for your help.

Rick
 
  #4  
Old 08-20-2012, 11:38 AM
Grey Wolf's Avatar
Diesel Fan
Join Date: Feb 2010
Location: Acton, CA
Posts: 11
Likes: 0
Received 7 Likes on 7 Posts
Default

No problem just let us know the outcome. Also before you pick up the gear verify with the speedo shop whether it is in fact one tooth less not more, fuzzy memory you know !GW
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Powerstroke36
Ford Powerstroke 99-03 7.3L
2
09-21-2015 08:32 PM
97 stroker
Ford Powerstroke 08-10 6.4L
0
02-18-2015 03:25 PM
Diesel Bombers
Latest Automotive Industry News
0
02-18-2015 01:00 PM
Down South
Ford Powerstroke 03-07 6.0L
1
01-11-2015 01:33 AM
CumminsCrazed
5.9L 24V Performance
5
10-27-2014 09:02 PM



Quick Reply: Gearing / speedometer question



All times are GMT -5. The time now is 12:40 AM.