Tires
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Joined: Jan 2001
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From: Virginia
Originally Posted by 86F150302
Yea I knew that.
What would be a good tire brand to look into? I would like a cheaper brand street tire. Any brand I should look into so i can check out their site?
What would be a good tire brand to look into? I would like a cheaper brand street tire. Any brand I should look into so i can check out their site?
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Postmaster
Joined: Dec 2007
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From: Jacksonville FL
I really like the BFG radial T/A but I dont like the price 
Might have to keep mine untill they need replacing then buy new ones. I was planning on selling these to a friend then buying new ones because mine are almost brand new.
http://www.walmart.com/catalog/produ...ex=&tire_size=
Might have to keep mine untill they need replacing then buy new ones. I was planning on selling these to a friend then buying new ones because mine are almost brand new.http://www.walmart.com/catalog/produ...ex=&tire_size=
Posting Guru
Joined: Jun 2002
Posts: 2,091
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From: Suffolk, VA USA
Sorry it took a bit to get back to you...
Assuming everything in your truck is original you have an AOD transmission with a 3.55 rear axle.
Given this your truck came stock with a 19 tooth speedometer drive gear. To get the speedometer correct with the 235/75 15s you'll need to get an 18 tooth gear...this makes sense as the general rule of thumb is a 5% change in speedometer readings per gear tooth. If you go with the 255/60 15s mentioned earlier the math puts you between two gear sizes, but a 20 tooth gear will give you the closest to accurate speedometer reading.
Assuming everything in your truck is original you have an AOD transmission with a 3.55 rear axle.
Given this your truck came stock with a 19 tooth speedometer drive gear. To get the speedometer correct with the 235/75 15s you'll need to get an 18 tooth gear...this makes sense as the general rule of thumb is a 5% change in speedometer readings per gear tooth. If you go with the 255/60 15s mentioned earlier the math puts you between two gear sizes, but a 20 tooth gear will give you the closest to accurate speedometer reading.
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Postmaster
Joined: Dec 2007
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From: Jacksonville FL
Originally Posted by ri_truck_guy
Sorry it took a bit to get back to you...
Assuming everything in your truck is original you have an AOD transmission with a 3.55 rear axle.
Given this your truck came stock with a 19 tooth speedometer drive gear. To get the speedometer correct with the 235/75 15s you'll need to get an 18 tooth gear...this makes sense as the general rule of thumb is a 5% change in speedometer readings per gear tooth. If you go with the 255/60 15s mentioned earlier the math puts you between two gear sizes, but a 20 tooth gear will give you the closest to accurate speedometer reading.
Assuming everything in your truck is original you have an AOD transmission with a 3.55 rear axle.
Given this your truck came stock with a 19 tooth speedometer drive gear. To get the speedometer correct with the 235/75 15s you'll need to get an 18 tooth gear...this makes sense as the general rule of thumb is a 5% change in speedometer readings per gear tooth. If you go with the 255/60 15s mentioned earlier the math puts you between two gear sizes, but a 20 tooth gear will give you the closest to accurate speedometer reading.
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Joined: Jun 2002
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From: Suffolk, VA USA
AOD is an Automatic Overdrive transmission...from the documentation I can find Ford only used the C4 in trucks for a realtively short period, mostly in the 70's...if I remember right they stopped in the late 70s/very early 80s...like maybe 81 at the latest...I had a 77 F100 with one. The AOD was a follow on tranny to the C4 with an overdrive gear added for better fuel economy. It takes a beating on here opinion wise, but the couple that I've had, including my current truck have held up pretty well. Best way to confirm your tranny is too look at the tranny fluid pan and count the bolts. If you have 14 bolts its an AOD, 17 bolts its a C6, and 11 bolts could be either a C4 or C5. The AOD is what your truck what was built with...unless you know the whole history of it who knows what someone might have put in...one of the joys of owning an older truck...I'm doing body work on mine right now and although the truck looked pretty good it's amazing the crap I've found under the old paint this week....
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Postmaster
Joined: Dec 2007
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From: Jacksonville FL
Originally Posted by ri_truck_guy
AOD is an Automatic Overdrive transmission...from the documentation I can find Ford only used the C4 in trucks for a realtively short period, mostly in the 70's...if I remember right they stopped in the late 70s/very early 80s...like maybe 81 at the latest...I had a 77 F100 with one. The AOD was a follow on tranny to the C4 with an overdrive gear added for better fuel economy. It takes a beating on here opinion wise, but the couple that I've had, including my current truck have held up pretty well. Best way to confirm your tranny is too look at the tranny fluid pan and count the bolts. If you have 14 bolts its an AOD, 17 bolts its a C6, and 11 bolts could be either a C4 or C5. The AOD is what your truck what was built with...unless you know the whole history of it who knows what someone might have put in...one of the joys of owning an older truck...I'm doing body work on mine right now and although the truck looked pretty good it's amazing the crap I've found under the old paint this week....
thought the BOLD D was OD and the D was drive
What speed is the AOD? 4 speed?
Senior User
Joined: Sep 2004
Posts: 200
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From: Cathedral City
Here's a web site that will do all the math for you. Just plug in the original tire size, 215/75X15.
Then you can play around with different sizes and keep close to the original diameter.
That way it doesn't effect your speedometer to much.
I used it when I went from 15" wheels to 18" wheels. Went from 70 series tires to 50's.
I found a tire size that was within 1% of original. So my speedometer reads 60 when I'm doing 59.8.
http://www.miata.net/garage/tirecalc.html
Then you can play around with different sizes and keep close to the original diameter.
That way it doesn't effect your speedometer to much.
I used it when I went from 15" wheels to 18" wheels. Went from 70 series tires to 50's.
I found a tire size that was within 1% of original. So my speedometer reads 60 when I'm doing 59.8.
http://www.miata.net/garage/tirecalc.html
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From: Suffolk, VA USA
It's a three speed automatic with an extra overdrive. If your set your shift lever to D it will drive like a three speed automatic. If you set it to bold D the fourth overdrive gear will kick in when you hit a steady speed over 45 mph. If you drive the truck in bold D you'll notice it kick in and out of overdrive depending on the engine load.
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Postmaster
Joined: Dec 2007
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From: Jacksonville FL
Originally Posted by ri_truck_guy
It's a three speed automatic with an extra overdrive. If your set your shift lever to D it will drive like a three speed automatic. If you set it to bold D the fourth overdrive gear will kick in when you hit a steady speed over 45 mph. If you drive the truck in bold D you'll notice it kick in and out of overdrive depending on the engine load.
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From: Denver Metro Area, CO
I have a 1981 Shop Manual, it's the only place I have to look up these codes. I'll bet you could take your information to the Parts dept. of your local Ford dealer, they'd be authoritative....
-ct
-ct
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