Hello to all!

Hi everyone, my name is Jake!
I'm from Colorado Springs, CO, and currently attending college in SC.

I have a 1983 Ford F-150 inline six. My interaction with other members online has helped me diagnose both the simplest and trickiest problems on this truck.

A few weeks ago I took a 1600 mile trip to Colorado, and in a few more weeks I'll be going back to SC. My truck always impresses me with how far it'll go when everything's in working order.

It'll be good to be a part of this community! I've used the diagrams and part numbers posted in the tech sections a lot already.

Jake - Welcome to the Bullnose Forum!  

Nice looking truck.  Tell us more about it.  Is it a manual or an auto?  Maybe you even have the upshift indicator we talked about recently?  In any event, to be able to reliably take it on those extended trips says you've worked the bugs out quite well.  

What are you studying?  Or, what is your major?

Nice photo, Jake! Welcome!

Thanks for the welcoming words!

The truck has the NP435 manual transmission, NP208 transfer case, and what I believe to be older aftermarket wheels on 31x10.50x15 tires.

The engine is pretty stock besides what I've replaced on and around it for maintenance. But there is no cat in the exhaust, so the air pump is not hooked up either (plus 0.7 horsepower!!).

As for the upshift indicator, I have heard of that feature before! Mine has a blank space in the cluster where it would be, on the far left. I think they only put that option in on F-100 models with super tall gearing.

I like to think I've made a big improvement in this truck's drivability. It's come a long, long way since I bought it, but it seems you're never quite done working. Still have some minor running issues and of course the paint needs attention, for whenever I get the time and space to go through that.

I am studying Mechanical Engineering! It was either going to be that or Electrical Engineering, but mechanical parts are generally more intuitive to me. I am a very visual person.

You are going to fit right in.  I spent 2 years in EE at K-State, but finished up at a school in OK and the closest I could get was a degree in math and physics.  But, I've been accused many times of being an engineer.  Dad would have said "If that's a complement then I thank you."  But, I'm not sure.  

Did some graduate-level work and one course was on parallel systems, meaning how you can model a mechanical system with an electrical system.  It is interesting how a capacitor works like a shock absorber.

As for the truck, what kind of MPG are you getting?  David's six is getting close to 20 if I remember correctly, but he keeps the speed down and you might not want to do so on such a long trip.

Anyway, glad you found us!

Engineering certainly can be difficult. I am usually good enough at Math and Physics, but most of my knowledge is more practical, common-sense stuff than book learnin'!
Looking at conceptual Physics tends to confuse me pretty well until I understand how it works, but then it seems really easy. I guess I just have to keep studying the best I can.

I usually get around 17 MPG around town, but on my road trip my average was 19. Best single tank was about 19.8 miles to the gallon! I drove between 55 and 70 miles an hour the whole way. The latter was on downhill sections

can0fspam wrote

I usually get around 17 MPG around town, but on my road trip my average was 19. Best single tank was about 19.8 miles to the gallon! I drove between 55 and 70 miles an hour the whole way. The latter was on downhill sections

4 wheel drive w/o O.D. and over sized tires... that is quite good gas mileage. Have you corrected the speedometer for the non-stock sized tires? You may be getting better than you think!

The transmission I have is a granny gear, not O/D transmission. But I am still surprised by what I'm getting!

Assuming the factory tire was 29 inches, I calculate my gas mileage by multiplying odometer reading by 31/29.

You sound a lot like me.  I did the math and physics because I transferred schools and the new one didn't have engineering.  But to me math and physics are just the theoretical part of what I love - hands on real things.

As for the MPG, you are really doing well with your truck.  Those are excellent numbers for real-world driving.  

These trucks are worse than the proverbial "barn door" since they have all sorts of recesses that trap the air.  And even those that have an air dam, like David's, have such a small one that it is not nearly as effective as the recent ones.  All of that adds up to speeds north of 65 MPH causing huge drags that kill the MPG.

Yeah. My general goal for the future is to get thru college and get a decent Engineering job, so that I can make enough money to support my gasoline addiction, and enjoy my job in the process!

I was surprised to see the MPG from that speed of highway driving.
You can feel how un-aerodynamic it is when you get going fast. If you let off the gas, you start slowing down very quickly, even when going downhill.
It's even worse at high altitude; sometimes I can barely keep it at 60 with the headwinds out here.

I noticed a mileage difference depending on the speeds I drove. My best tank was out East on the slower roads, where I was doing 55-60 the whole time. With my gearing I'm doing around 2,000 revs at that speed.
Usually got high 18's around Kansas territory as the speed went up and the air density went down.

Not only does the wind resistance hurt the MPG, but the lack an overdrive hurts as well.  Big Blue has that 460 spinning at 2500 RPM @ 65 MPH, which works out very nicely when towing but seriously unnecessary when cruising.  And that is with 33" tires and 3.55 gears!  So I have a ZF5 that'll go in to replace the T19 this winter, and that will drop the RPM to 1800, which is much more reasonable.

Oh, yeah. That's another good point!
I've thought about the idea of an overdrive conversion before, but I don't think I will do that anytime soon.

I would realistically have the option of a ZF5, Mazda five speed, or an earlier SROD/TOD/RUG/etc transmission.

My problem with the ZF and the Mazda is that they're very modern units. Both have integrated bellhousings (except some ZF's) and they also have internal hydraulic release bearings. I don't like the idea of running either of those on an old truck, where things in my opinion should be simple and serviceable. I've driven several Rangers with the Mazda five speed and they all feel sloppy and vague, in a non-feedback rubbery way, not in a classic "dump truck" way. I've never used a ZF before, but they seem to be a little tougher and better in general.

I could run a SROD or similar four speed overdrive, but the gear spread is not really any better than what I have now. I'd also lose a usable low gear, unlike the five speed units or my current granny gear. On top of that, the SROD and toploader overdrives aren't known for being very tough, and shifter parts are getting rare.

I like my NP435 for the most part. It could use a rebuild eventually due to normal wear, but I feel confident in trusting it to work whenever I call on it. With my axle gearing, it is the same or better than an overdrive transmission with 3.55 or 3.73 gears, except for the gear spread.
If I made a change, I would consider taller gears and a T19. I could use the synchronized, reasonable first gear to take off, and then I'd have enough high gears to be comfortable at 70 and above.

I have read about some super old-school Clark overdrive units and similar, which are basically ancient ZF transmissions (compound low, 2 underdrive, one direct, one overdrive). They are extremely heavy and sometimes not fully synchronized, but it would be interesting to try and run one of those!

Of course, for most sane people, a ZF5 is a perfectly fine option. I'm sure it would be a treat to have those close ratios and usable low and high gears.
I hope your swap goes well. Especially w/ the mass of a 460, those low revs will help.

There are more modern overdrive units, like a Gear Vendors or Doug Nash.  Jonathan has one of each of those and is trying to figure out which he wants to use with what transmission.

As for the ZF5, they are rugged and are a true truck transmission.  The syncros are a weak point, so you don't want to hurry them in shifting, which is why that recently rebuilt ZF5 isn't going in Dad's truck and, therefore, is available for Big Blue.  And the low 1st gear and tall 5th gear do work out very nicely.  I ran that tranny in Dad's truck, prior to the rebuild, for several thousand miles and loved it.

Oh yes, thinking of it one way there are three versions of the ZF5: the small block bolt pattern one that does have an internal clutch slave cylinder; the big block bolt pattern unit with an external clutch slave; and a diesel unit with an external slave.  But the gas versions have a wide ratio gear set and the diesel has a close ration set of gears, so that's another way to differentiate.  And then there's the ZF5-42 vs the -47, which have 420 and 470 ft-lb ratings respectively.

As for the T-19, there are a few versions of those.  Jonathan and I had a discussion about them in this thread recently.  You might find it interesting given your engineering background.  

I forgot about those bolt-on overdrives. Those are a good option too!

Maybe when I have little more time and money and a little less mechanical things to get in order, I'll figure out my best solution for an overdrive!

Sounds like a big block or diesel ZF wouldn't be too bad, apart from the sheer size and price to obtain one. I'm sure it would help drivability.
IIRC those ZF's just run on ATF. My NP435 takes a GL-4 gear oil, so when I get around to changing the fluid I'm gonna have to find a place that stocks that.

With my NP435 and tall gears, I often have to use first gear if there's any amount of uphill to the road. My clutch is very old (maybe original) and has some chatter to it, so I can't slip it for very long.

Also I'm sure you know with your wide-ratio T19 that the gap from 3-4 in these trannies is astronomical. I can go around corners as low as 15 miles an hour and stay in third, and then shift to fourth at 30-35 and that's all I've got.