1939 Ford Transmission question...78 and 48 case numbers...

The LZ's do pop up still, and become more likely on altered transmissions, which generally means HOTROD.
Last time I got a set, I found a "rebuilt trans that was the spare for my '40 Ford" for sale by someone. The trans was cheap and had an "H" at the beginning of the serial...and the 26 toothers in there turned out to be entirely unmarked, suggesting that the thing had a brand new set! That was $75...

 

Plenty of good stuff in this thread on top-loaders.. Bookmarking this one.

 

sorry guys, I've been out in the shop...I'll go back out and check synchros for LZ...and I gotta count some teeth...where's my beer?

 

Is this the half moon cutout you guys are talking about?

 

This gear has 15 teeth...

 

This gear has 24 teeth...

 

oh well, I'm still happy cause this thing looks nice inside and should work fine behind a 283. Thanks for all your help. I hate being stupid about simple Ford shit.

 

Check those caged bearings out really well too, modern replacements are garbage.

 

Thank you...will do.

 

I ran a 36 trans without the syncronizer rings behind my 283 with no problems. I'm not a tire squealer or speed shifter. If you want to dump the clutch and burn some rubber, you might want to rethink your trans choice. Other than that either one will hold up. They won't take a lot of abuse but they are not made of peanut butter either.

There is a lot of room between a trans that won't take abuse and a serviceable trans behind a 283. Mine worked fine for many years.

 

Thanks Tommy...this 283 won't be a tire squealer, it's for a driver. I've driven a friends '29 hiboy with a stout flathead (180hp) that had a '39 trans, and I drove it hard at times and it held up great...I figure a stock 283 will have the same HP as that hopped up flatty.

 

I'm bettin' you won't be running monster tires on it. I've squealed tires a few times but my 700 16s don't have a big tire patch to create a lot of pressure. The weakest link in my chain is the skinny tires that break loose before the trans gets loaded a whole lot.

 

Shim it up nice and tight when you put it together, especially the cluster gear. If it can't walk when loaded, the trans will hold up better. Also, grab Van Pelt's book too, LOTS of great info and tips on building one of these to last.

 

Thanks...my birthday is coming up soon...

 

You also need it tight in middle of top shaft where input, synchro, and output shaft come together. If case is loose, you can eliminate end play at each end and have a gap in the middle leaving you with both sloppiness and poor engagement of synchro teeth.
(and as suggested save good bearings from within cluster..repros I have seen are garbage)

 

I just bought a motor and tranny package from a guy (same guy I got my 409 from)

Supposedly the motor is a 59A-B and the tranny is "a '39 Ford with Lincoln Zephyr gears" So I'm stoked about that, but at this point it is all hearsay. "The guy I got it from ran it in his '40, and thought of me when he went to an automatic"

Anyways, can some one post a pic of this "half moon" you guys were talking about on the Zephyr gears? I'm getting a little ahead of myself, I can't pick this all up until Sunday at the earliest. He is going to Hershey.

 

Yea, another good point. Also check your brass synchro rings to make sure they're within spec, my pal Charlie clued me in to this nugget: some repros are actually too large and cause the shynchros to drag all the time, wearing them prematurely.

 

All of this info is making me think I should pull the trans out of my '35 and have it serviced this winter. It's getting stuck in 3rd.

 

vanpelt mentioned in his website that the 78 case with the full length rib was rumored to be alittle stronger, any input on this from you guys who have blew through some of these?

 

The half moon...on MOST of the 25 and 26 toothers...looks like someone ran a holesaw to cut away some of the synchro teeth on the back of the input gear.
No need for it...count the teeth on the input, 44 minus that count is tooth count for cluster on all the common possibilities.
A 59 has 59 in big letters at top of bellhousing, the part of bellhousing that is cast integral with block.

 

We duplicated that ground off section on a repop L-Z drive gear recently. Had to fit one into a 48 series case and the LZ gear needs to be clearanced like Ford did them in order to fit into the case and past the big end of the cluster gear. This pic shows what is done....

http://www.vanpeltsales.com/FH_web/FH_images/FH_trans-pics/trans-mdg-notching.jpg

 

Thanks for the pic, thats nothing like I was picturing in my head. Really cleared that up.

Another stupid newbie question, what is the benefit to having the 3" fork?

 

It fits the late type synchro.

Mac VanPelt above is really moving...he is starting to manufacture parts that had become entirely unavailable or available only in non-functional defective repro...
His book is excellent.

 

Is the 3 inch fork available? where ? Thanks. Norm

 

The late double brass ring synchros need the 3" fork, the earlier units have a different synchro assembly that accepts a smaller fork. It's not really that the fork is any better, it just means you likely have the better synchro in there.

 

We did the 91A-7230 forks a year or so ago. Didn't run a ton of them but stock is ok for now. Here's the link to the web page from our TRANS PARTS PRICES:

http://www.vanpeltsales.com/FH_web/trans-partsprices-pg3.htm

 

The trans will hold up well behind a mild 283..... IF you take it easy. I have many, many thousands of miles on mine and it still shifts smooth and doesn't make any weird noises. Get yourself a drip pan though, 'cuz they tend to leak a bit.

 

The numbers stamped on the bell part of the scse was the VIN for trucks; According to the "Green Book", Ford put the truck VIN on the top of the bellhousing, visible thru the oval shaped hole, just ahead of the shifter; I have seen a few 40, and 41 trucks with a VIN stamped on the left frame rail, between firewall and radiator.
4TTRUK

 

can you case harden the gears to prevent them from chipping a tooth? curious how to strengthen the trans to take a little more abuse...

 

There is an article from Competition Engineering on this that I have reported on somewhat here, dragster trans missions circa 1960 running early Ford with hemi's, etc.
It is just like getting 9 inch Ford to live nowadays...the gears are SOFTENED and re-heat treated to specs in article.
The lose high mileage wearabiluity, gain impact plasticity.
And the end play and fit at center is ESSENTIAL because these are spiral cut gears and on rapid clutch engagement the endplay is SLAMMED down to nothing as the spirals are loaded by the engine, enough to blow end out of transmissions...
This is the same malsdy that plagued others, like those running '55-62 Chev 3 speeds at the drags, with similar cures,,,