i need a higher gear!!!

[tonkadoctor]

Rich. The E4DOA has a .71 OD ratio and the ZF5 (both gas and diesel) have a .76 OD ratio so there shouldn't be a 15 - 20 MPH difference at the speedo.

The different gear ratios between the gas and diesel versions of the ZF5 is only in the first 3 gears.

I think you better calibrate your speedo and go from there.

 

[smoking89IDI]

Mine will tach out in 3rd at 50 like you describe but I just have a F250, maybe RLDSL has a point and your missing 5th but I kinda think thats not the case, what is the speed and rpm's in fourth?

 

[Full Monte]

Monte, did you install that 4WD yourself? I've never seen an 80's ford crew cab dually with 4x4. Didn't think it was an option.

Yeah, Towcat is correct. I can't say I've seen any trucks like it since. I think it's a converted F350 SRW. Rear outer wheels are about flush with the rear axle covers.

 

[94f450sd]

e4od


around 50MPH my tach is almost redline

boy was i way off!!!anyways in 5th on the highway im doing 70 at 3000RPM.im still not happy with it.too many revs to go as fast as i like on the highway.im also used to my PSD.the psd cruises 75-80 with no problem and without the motor sounding like its gonna jump through the hood or something.

 

[Agnem]

Throw a GV overdrive under there. Double overdrive is a sweat arrangement when it comes to cruising at low RPM's, but still being able to pull hard. The Lady Moose, so equipped with 4.10's and double OD never needs to see more than 2300 to go really fast.

 

[u2slow]

I would change the axle ratio on that rig. IIRC, the F-superduties with a 5spd normally came with the 4.63 axle. Of course, there's 4.88, 4.30, 4.10, 3.73, and 3.55 to choose from also.

Did you put in the S42 or S47 5-speed? Reason I ask is the S47 is a deeper first gear so it would let you go a tad taller on the axle ratio without compromising your low end.

 

[Andylad13]

you have a sweet truck there 94. youve got a real low gear with a 5 speed. you should be happy you can pull 20,000 lbs and still "be" on the interstate!!!

by comparing your truck to the psd is apples to oranges but you know that already

the psd had more power, so a taller gear is more benificial because it has tons of power in the first gears and enough to keep the truck moving on the highway

if you want what the psd has...you know what you have to do.

 

[Diesel JD]

Also the PSD he has is an F350, so a taller gear is possible with the 10.25" than the D80 which the F-superduty has. Usually came with 4.88s or 5.13s. I think Rich has the 5.13 gears.

 

[94f450sd]

thanx andy it cost me alot of time and money to get it that good looking.

my F350 has a dana70HD in it.every superduty with a 5 speed that i cut up had 5.13s in them.i have one now from a 5 speed super duty that has 5.13s.now that i dont need the sensor on the rear and for anything but the speedo i can put that axle in my truck.but id rather find a set of gears or another complete axle with a taller gear if im gonna replace it.

i think its the S47.ill have to look at it again.but it has a hell of a low 1st gear!!i can creep reeeeeeeeeeeeaaaaaaaaaaal slow in 1st if i wanted to wich is nice cuz i can sorta sneak up on people with it

 

[Cheaper Jeeper]

FWIW there are two models of the ZF-5 - the S42 and S47 with the S47 being the slightly stronger of the two.

The S42 was available with two gear sets :
1 -- 4.65 -- 5.72
2 -- 2.60 -- 2.94
3 -- 1.53 -- 1.61
4 -- 1.00 -- 1.00
5 -- .077 -- .076
R -- 4.35 -- 5.24

The S47 was available with three different sets of ratios,
1 -- 5.72 -- 5.08 -- 4.14
2 -- 2.94 -- 2.61 -- 2.37
3 -- 1.61 -- 1.53 -- 1.42
4 -- 1.00 -- 1.00 -- 1.00
5 -- 0.76 -- 0.77 -- 0.77
R -- 5.24 -- 4.66 -- 3.79

The one I have in my truck is an S47 - the one with the 5.08 1st gear - which IMO is the best of the bunch - the strongest and most middle of the road set of ratios for the best all around use and economy...

With 4.10s and 32" tires, I turn just under 2250 RPMs at 65 mph and 2750 at 80 mph. Before the conversion when it had the old T-19 in it I was turning 2900 RPMs at 65. With the ZF it still has PLENTY of low end with the 5.08 1st - in fact, better than the old T-19 which had a 4.08:1 1st gear IIRC.

Anytime I need more grunt at highway speed I can just drop down into 4th - which is 1:1 just like 4th in the old T-19. Then I'm back to turning 2900 RPMs at 65 mph - but that spools the turbo up VERY nicely...