rear end ratio
Thread Starter
|
5th Wheeling
Joined: Oct 2010
Posts: 27
Likes: 0
rear end ratio
i have a 1978 F 7000 5 yd dump with cat 3208 and 5 speed clark transmission. the truck has 2 speed rear axle, but geared way too low for my use. is there a simple way to figure out what ratio rear end i have? thanks.
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 790
From: Simi Valley, CA
Post the AXLE code found on the Warranty Plate, located on the left door face below the latch.
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,562
Likes: 424
From: Long Island USA
Bill's advise is good, as long as it was never changed for some reason.
Simple way would be to jack both wheels off the ground, put the tranny in neutral (chocking the front wheels VERY well). Using a piece of chalk, mark the driveshaft at the lowest spot near where it connects to the rear. Mark one (or both) of the wheels with chalk too. Turn the driveshaft by hand, counting how many times you have to turn it to make the wheels turn one complete rotation.
If it's a two-speed, do it with the rear in each gear. Report back
Simple way would be to jack both wheels off the ground, put the tranny in neutral (chocking the front wheels VERY well). Using a piece of chalk, mark the driveshaft at the lowest spot near where it connects to the rear. Mark one (or both) of the wheels with chalk too. Turn the driveshaft by hand, counting how many times you have to turn it to make the wheels turn one complete rotation.
If it's a two-speed, do it with the rear in each gear. Report back
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 790
From: Simi Valley, CA
K70 = F700 (diesel).
B = Caterpillar 636 cid V8 diesel / Model V190-3208.
V = Kentucky Truck Assembly Plant.
AJ5152 = 1978.
AXLE code EHH:
EH = Eaton model 17221 2 speed rear axle / 5.56/7.60-1 / 18,500 lb. rear axle capacity.
E = Ford front axle / 7,500 lb. front axle capacity.
B = Caterpillar 636 cid V8 diesel / Model V190-3208.
V = Kentucky Truck Assembly Plant.
AJ5152 = 1978.
AXLE code EHH:
EH = Eaton model 17221 2 speed rear axle / 5.56/7.60-1 / 18,500 lb. rear axle capacity.
E = Ford front axle / 7,500 lb. front axle capacity.
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 790
From: Simi Valley, CA
FYI: The 1973/79 Ford HEAVY Truck Parts Catalog is available on a CD from hipoparts.com. I'm using this catalog on Ford microfiche slides.
Trending Topics
Thread Starter
|
5th Wheeling
Joined: Oct 2010
Posts: 27
Likes: 0
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / Worst Features Of The 2025+ Ford Expedition
Brett Foote
10 Ways Ford is LOSING to the Competition
Joe Kucinski
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
Super Moderator
Joined: Apr 2004
Posts: 34,536
Likes: 2,837
Even with 42" tires, you are pushing 3000 rpm at 65 it looks like.
Probably the easiest change would be an OD Clark or other OD trans in place of your direct trans.
Maybe some help here:
Clark Transmission Rebuilding | Exchange Clark Transmissions
Probably the easiest change would be an OD Clark or other OD trans in place of your direct trans.
Maybe some help here:
Clark Transmission Rebuilding | Exchange Clark Transmissions
Thread Starter
|
5th Wheeling
Joined: Oct 2010
Posts: 27
Likes: 0
EHH axle code / 1978 F 7000
Bill
i'm playing with the new CD you suggested. trying to understand how it works. earlier you called out with axle code EHH a 18,500# rear axle, with 7,500 front axle. when i look i see H code for front axle calls out 12,000 # ford front axle. am i doing something wrong? thanks. mike
i'm playing with the new CD you suggested. trying to understand how it works. earlier you called out with axle code EHH a 18,500# rear axle, with 7,500 front axle. when i look i see H code for front axle calls out 12,000 # ford front axle. am i doing something wrong? thanks. mike
Cross-Country
Joined: Dec 2008
Posts: 79
Likes: 8
1978 was the last year Ford had sold the B-7000 and the F-7000 with the "V636" branded 3208. The two models would not return until 1983 (production start: August 1982), when Ford also revived the F-8000 and the FT-8000 (the latter was originally T-8000).
All of these, as before, had the 175-hp Cat 3208 as standard equipment (through 1986, when Ford started cataloging the 6.6L and 7.8L turbo six-bangers). The turbocharged 3208T (225 hp @ 2600 rpm) would join the fray in February 1983.
The standard V636 engine for your F-7000 is rated 175 hp, but it could also be specified with the 210 hp version. California trucks used the 200 hp V636 engine.
For those wanting to know the gear ratios to the 282V, go here:
Transmission ratios
(and then scroll down to 282V)
Engine: Ford-Caterpillar V636 (3208), 175 hp @ 2800 rpm
Rear axle: Eaton 17221
Ratios: 5.58/6.77
Engine speed at 45 MPH with tire size 10.00x20: 2111/2561
Max. speed MPH at engine speed: 59.7/49.2
For mjsnodgrass: How big are your tires, if not 10.00x20 or 11R22.5?
Thank you,
Ben
All of these, as before, had the 175-hp Cat 3208 as standard equipment (through 1986, when Ford started cataloging the 6.6L and 7.8L turbo six-bangers). The turbocharged 3208T (225 hp @ 2600 rpm) would join the fray in February 1983.
The standard V636 engine for your F-7000 is rated 175 hp, but it could also be specified with the 210 hp version. California trucks used the 200 hp V636 engine.
For those wanting to know the gear ratios to the 282V, go here:
Transmission ratios
(and then scroll down to 282V)
Engine: Ford-Caterpillar V636 (3208), 175 hp @ 2800 rpm
Rear axle: Eaton 17221
Ratios: 5.58/6.77
Engine speed at 45 MPH with tire size 10.00x20: 2111/2561
Max. speed MPH at engine speed: 59.7/49.2
For mjsnodgrass: How big are your tires, if not 10.00x20 or 11R22.5?
Thank you,
Ben
Thread
Thread Starter
Forum
Replies
Last Post
millerliteliker
1948 - 1956 F1, F100 & Larger F-Series Trucks
27
Jul 15, 2016 06:34 PM
jamusfam
1973 - 1979 F-100 & Larger F-Series Trucks
2
Apr 24, 2014 06:20 PM
civicmindeddogooder
1961 - 1966 F-100 & Larger F-Series Trucks
29
Jan 16, 2013 09:41 PM
Herrerag92
1973 - 1979 F-100 & Larger F-Series Trucks
9
May 24, 2012 11:13 PM
