New Flathead Owner Questions

[PutPut6]

Hi guys, I've been on the forum for a while since I have a 67 mustang, but I just bought a 49 F-1 with a 226 flathead and a floorshift 4spd or 3spd, I don't even know which it is. I know very little about these old trucks and have a lot to learn. First off, can any of you point me to a good place to get info on doing a 12v conversion? Also, I was shifting the tranny through the gears in my garage and got it stuck somehow, don't know if it's stuck in a gear or wont shift into any gears. Any ideas on what the deal is? Thanks for the help.

 

[Anonymous]

Run, don't walk, to www.ford-trucks.com. There is a 1948-1960 forum there. Do a search on 12V conversion and you'll find tons of information.

 

[Fred]

There were three transmission choices for '48 half tons: light duty three speed, a Ford tranny (resonably tought if not abused); heavy duty three speed, a Borg Warner trans (I don't remember which); and a four speed "crash box" granny gear, a Warner T9. The light duty three has a shifter that tapers down as it approaches the shift nob. The heavy three and four speeds have a thick shifter that doesn't taper.

The easiest way to do a 12V conversion is to change generators. The '56 and later 12V Ford generator will bolt onto your motor if you swap the pulley, front cover, and rear plate from your 6V generator (or in your case I think you can just bolt it on with the strap. It looks better to swap things though). The stock wiring, if it is usable shape, will handle 12V just fine, as will the switches (but not reostats, like heater). You have to add resistors on the feed wire to the gauges. Change bulbs and you're done. But why? If it starts hard, fix the engine or starter. If the lights are dim, fix the wiring. I have driven 6V cars daily, withing the last five years, and had no problems. Now if you start talking about adding air conditioning... go 12V.

I forgot to add: you need the regulator to go with the 12V generator (obvious) and you will be switching from positive to negative ground so you have to reverse the wires on your amp gauge.

 

[PutPut6]

The wiring is pretty much non existant, so I'm starting mostly from scratch and figured I might as well go 12v. Does what you said about the transmissions also apply to 49s? I think the shifter does taper, although not much.

 

[PutPut6]

Can anyone identify what transmission I have from these pictures? I've been trying to compare it to diagrams I have found online and I think it's a synchronized 4speed.

 

[addo]

Wow, that's an old style box. As it looks somewhat like a later T-series, I'd suggest T-9.

The forks and rails are integrated in the top cover. Lift it off if curious. Gates wear on many such boxes but this was all blacksmith or "engineering" shop fixes in the day. If you have an oxy it can probably be made like new.

Cheers, Adam.

 

[Fred]

Yes, '48 & '49 used the same transmissions. That is a non-syncro box. It is correct for your truck. They are very tough if you don't run them dry or tear up the gears grinding them. You can install the light duty three speed in your truck by changing the tranny, the drive shaft (the light three uses a slip joint at the transmission tail shaft, your four speed uses a slip joint after the u-joint), and possibly the clutch & flywheel, depending on how big your clutch is. The light three is sycronized on the top two gears; for first & reverse you should be stopped before putting the trans in gear. If you want to go highway speeds (70 m.p.h.) you can install a '49 to early '51 Mercury overdrive tranny which requires: a column shift setup out of a late '50 to '52 pickup, a shortened driveshaft, & a reworked rear motor mount (possibly modifying the cross member, I havn't done this on a truck yet).

You can buy reproduction wiring harnesses for your truck. They arn't that expensive and are much better than the universal "hot rod" wiring kits you can get, assuming you are leaving the truck basically stock (which you should).

 

[Anonymous]

i did what fred said with the Gen. and it worked out nice. don't have it running but it is all bolted up. as for a trans you can get a adapter and run a toploader four speed!

 

[Lazy JW]

Sweet 8) Leave it stock. Only Real Men can shift a crashbox properly. That tranny is from a forgotten era, when Men were Men. Nowadays folks whine if they have to drive a manual tranny, and REALLY snivel if granny gear isn't synchronized :roll: Learn to shift that gearbox and you will understand the difference between DRIVING and merely operating a vehicle.
Joe

 

[PutPut6]

How exactly do you go about shifting a non-synchronized transmission the correct way? I've never driven one.

 

[addo]

To upshift, I believe:

(1.) Clutch pressed in, shift out of gear to neutral. Clutch out.
(2.) Clutch pressed in, shift into new higher gear. Clutch out.

Not sure if the procedure for shifts down is any different, especially in regard to motor braking.

 

[StrangeRanger]

Downshifting:
1) Clutch in, shift to neutral
2) Clutch out rev engine
3) Clutch in, shift to lower gear before the revs fall
4) When in gear clutch out

 

[PutPut6]

Thanks guys. That's how I thought it went, just wanted to double check.

 

[PutPut6]

Hey guys, you were right Fred, I popped the cover off the tranny and it is indeed a non-synchro 4spd. The oil in it looked quite old and there was water in it :roll: but everything moves freely and there appears to only be a little surface rust inside. Here's how it looked after I drained the tranny. I cant wait to get this thing on the road. There's nothing like the sound of straight-cut gears

 

[Asa]

were you able to check wear?
see how much play there was between one gear turning and the next turning?

 

[PutPut6]

I didn't do any measuring, but I did shift through all the gears and turned it by hand. There seemed to be little play.

 

[addo]

The wear is usually most in the top cover, which holds the shift forks, lockouts and detent balls.

Wonder if that trans would run ATF with modern full oil seals? Awesome gear whine then, and a race-car notchy feel to the shift!

 

[StrangeRanger]

Bad Addo, no cookie.

That box needs real gear lube not ATF. I'm only guessing here, but my all-purpose answer is Redline 75W90 synthetic or possibly 80W140 synthetic if the tranny is going to see real "truck" use.

Modern trannies use ATF not because of the gears but because of the needle bearings which won't lubricate well with high viscosity gear lubes. I don't think they'd invented needle bearings yet when that gearbox was designed.

 

[addo]

Wouldn't it nee d alow-sulfur or whatever gear oil - or isn't it that ancient?

Bad Addo, no cookie.

I just ate two donuts. Mmm, grease...

 

[Lazy JW]

If it has bronze or brass bushings, etc. I would certainly try to find low-sulfer gear lube for it.

Please pass the doughnuts
Joe