It is a '90 F250hd with 7.5L and C6 3-spd

I like the truck but don't like the tranny, it doesn't have enough gears. Since I am not interested in OD units like Gear Vendors, could someone explain what I should expect from a newer, say 90-95' F250HD also with 7.5L but with 5 speed?

Do 5 speeds last longer than C6?

I know at identical speeds, they will turn lower rpms.

 

The c6 is a fairly stout tranny, and reasonable to service and rebuild. I understand your concern about gearing, especially with the current slew of gas prices.

There are four options:

1. Install a gear vendor unit (you ruled it out, but I'm meantioning it anyway so others can see it)

2. Swap out the C6 for an AOD, a non-electronic over drive automatic. While they have a bad reputation all of the "issues" in reliability can easily be built out. There are rebuilders that have successfully fed the AOD 600-1200 HP on the drag strip and they hold together just fine. So putting one into a heavy truck with a 460, is not an issue.

3. If you like wiring, and lots of it, you can convert your EFI wiring/EEC to a newer F-series configuration which will give you the capability to use the E4OD, which is an electronic overdrive automatic, also a decent, stout piece if rebuilt correctly. These too also got a bad rap in the industry when they first came out, but most of those issues were really caused by horrible coding in the EEC's. Since it's electronic, it's just following instructions, and the early EEC's that controlled them, often shifted very slowly thus causing bog, mis-shifts, sititng in the wrong gear to long, and of course any time you shift an automatic tranny slowly you're wearing the surface of the bands and clutches.

4. The ZF S5-42 or S5-47 are two manual transmissions, available in 2wd or 4wd that are excellent choices for your truck. The one in my crewcab lasted 370K-ish before it started getting anoying with the whining. About 1/3 of that mileage was under heavy loads (towing cars, gravel, trailers, appliances, plywood, sometimes a combination). The gear rations for the ZF's with the 460 BBF bell housing are great for trucks - nice low granny for getting a heavy load to move forward which is always useful, though unloaded you'll probably start off in 2nd gear and shift upward. 5th is an overdrive, I think it's 0.75 or 0.76, and with stock tires and 3.55 gearing that means you're purring about 2200 RPM to do 65mph.

Manual transmissions generally last forever assuming you're not towing past the capacity of the truck, and popping the clutch often. Parts are only so abusable. They all break eventually.

 

So ZF S5-42 is as heavy duty as C6?

And what do you mean popping the clutch?

 

I agree with everything frederic said.
If you already have the truck I'd run it as is and add a GV, especially since it's a C6, if you are shopping I wouldn't settle for anything but a 5spd.
Most all of my trucks have been manual, I prefer to "row my own".
This last truck I bought is an auto and I am already regretting it.
I guess it comes down to how much you hate to shift.
If it's all about mileage, the money it costs to convert will take a long time to payback. The differences in mileage will be very little.
I had a 5spd F250 Extra cab 4x4 460 it got 10mpg.
I now have an F350 Auto reg cab 460 it is getting around 8.5-It would be better but the Lockup TC isn't working correctly.
Same driving style for both.

"popping the clutch"= dumping the clutch, not a nice easy release, basically just letting your foot off of the clutch without following the pedal up.

KO

 

The ZF is a stout piece. Like I said, mine lasted 370K with 1/3 of that being towing, hauling, sometimes way up towards the limit of the truck (15klbs).

Popping the clutch just means putting the tranny in gear, and letting the pedal up very quickly going from "not engaged" to "engaged" rudely and abruptly. This wears the clutch surface quickly and also stresses the teeth on the hardened gears inside the transmission, as well as the various shafts everything is pressed onto. More than likely the transmission will survive this anyway, as stuff "further back" will break first, particularly u-joints and rusty driveshafts.

Like Kiohio I prefer a stick for a variety of reasons.... mostly because I control the shifts therefore I can shift earlier for better mileage when unloaded (often I'm in 5th gear 35mph, when unloaded) and for towing, depending on the weight, I can shift later for more torque to get the load moving then shift my way up through the gears into overdrive (5th).

I don't mind automatics in cars, because cars rarely weigh more than stock loaded because there's not enough space to put anything really heavy in. Though one time many years ago, I hauled home a chrysler hemi from a junkyard in the truck of my FWD Lincoln Continental. Not because I wanted to, I was there to pick up a door panel for something else, but I spied the hemi sitting on the side and this particular yard sells all engines, no matter what it is, for $200 a pop. A rebuildable hemi for $200 is not something you leave sitting at the junkyard. So, in the trunk it went.

But for a truck, while newer trucks handle shifting much better and more intelligently, nothing beats your own brain if you know how to drive a stick. And I don't mean knowing which way to move the shift lever and how to push the clutch to the floor several times.... I mean truly knowing how to drive a stick - shifting unloaded is very different then when you have 15,000lbs attached out back, and it's more of a "feel" thing than anything else.

You mentioned the gear vendors unit initially, and I have one with the housing and bracketry specifically for my vintage (93) ZF-shifted 2wd crewcab, but I haven't installed it yet. It's 1:1 / overdrive unit, so this basically can serve two purposes - if I leave it engaged in overdrive all the time for unloaded truck use, it changes all my gear ratios so 4th gear would be about the same as 5th gear is now without that unit installed, so 5th would be an additional overdrive. Also, I'd be able to use the granny gear as a take-off gear which I normally do in 2nd, again unloaded.

When loaded, I can use the gear vendors unit as a gear splitter, making the ratios closer and overlapping more, which is fantastic for hauling heavy, heavy loads. The gear vendors unit I have doesn't quite split perfectly in the middle of each gear, but it's close enough it won't be unpleasant, and the usefullness is very high. I can keep the engine right at peak HP/Torque and gear my way up to highway speed.

Even though I bought it used, I spoke to the folks at gear vendors on the phone and they assured me it will survive behind the new 500cid twin turbo stroker I'm building. I'm very skeptical just because it's my nature, but I'm going to try it anyway. 10 gears for towing is a good thing, at least for me. What I may do is change out the 3.55 gears in the rear end to 4.11's, which will give me tremendous gearing for towing, and the gear vendors unit will put the gearing back "right" when I don't need that function, kinda like a 2-speed rear concept.

Anyway, sorry to sidetrack, hope I answered your questions.

If you swap in the ZF 5-sp, you'll also need to install the hydraulics of the clutch pedal assembly. You can use an aftermarket pedal system like wilwood, tilton and a bunch of others, or you can scoure junkyards for the entire F-series assembly, and fangle it in that way.

The only caveat of the ZF is there is one fluid that is recommended by Ford (I forget what it is, maybe someone can chime in here) and I highly, highly recommend you buy that fluid from Ford. Because of the mileage I keep racking up on my crewcab, I visit my dealer annually, they smile, and hand me the bottles of what I want so I'm not to sure what it is anymore. ALmost a brainless function at this point. But obviously it wasn't for naught, as my tranny lasted 370K before I chose to rebuild it. I probably didn't need to at that point, but it was rattling a bit and being annouying in that sense, and I didn't need the truck for a while so it was convienent to take it out, rebuild it, and put it back in.

 

I am not interested in swapping anything, GV or a 5 speed, but rather getting a newer vehicle, maybe 5 years newer, with the 5spd.

I hear C6 is heavy duty and lasts a long time. Is there a heavy duty 5 speed like it, is my question, and what years was it available in.

GV, an expensive after market unit - which for one thing, will *never* pay for itself (I sat down a few years ago and figured out it would take about 100K miles to break even, but that's a moot point) ----- doesn't solve the fundamental problem of overheating. Autos with overdrives are less reliable than C6. I don't trust any of them really, even with frequent flushing, and after market coolers.

I drive a 5 speed on a daily basis and get incredible mileage. Of course I shift for economy.


I think I can do better than 6 towing 9 mpg empty in this truck, if I had a 5 spd and kept the rpms below 3000 at 55-60 mph.

 

I hear C6 is heavy duty and lasts a long time. Is there a heavy duty 5 speed like it, is my question, and what years was it available in.

All of them that are in 3/4 and 1tons of all years that you are talking about will be the Heavy Duty 5 speeds.

Standard trannies are the Workhorse of transmissions.
Especially the 3/4 and 1ton standard trannies

KO

 

Be careful. There are some light duty F-250's with 302's and the much weaker Mazda 5 speed.

 

I'd love to have a C6/GV setup.

It basically turns the C6 into a 6 spd tranny and those C6's are the best shifting, more reliable, and probably the best trannies Ford ever made.

My dad had one in his 88 F-250 with 130k on it and it shifted like new before it got rid of it.

The ZF is a strong and nice unit as well, I swapped one in my F-150.