I don't want to "darkside" my truck - transmission swap
 

1st off, I have an almost bone stock '48 F. The only thing mechanical I have changed is to swap the rear end from the Dana 41(4.27 gears) to a Ford 9" (3.00 gears).
I still have the 41 and can go back no problem (keeping it so I can put it back to stock at any time.

226 rouge 6
4 speed spur gear crash box. (T8/T9 right?)

I love driving it, I hate the road rage I get in Denver. With the low low rear end (too low for 1st really), I am using granny to get off the line (unless I am on a downward slope). Not an issue for me, I double clutch like a pro no grinding, but I can street race the garbage truck or the concrete trucks and we sound identical 0-9mph winding the engine up to a full roar, lots of shifting (slow pause in those shifts), and people riding my butt with middle fingers extended.

Yes I've done a ton of reading on the T5 and a few other transmissions.

Tyler's thread on manual tranny prompted me to start my own thread so here it is.

I don't want to put a hole in my transmission hump 7" rearward of the existing (by my measurement the bench seat then gets locked into the farthest back position - fine with me, but nobody under 5'8" could ever drive it).

I haven't been able to find dimensions and measurements on the T8/T9 - only thing I found posted is this:
input shaft is 1 3/8 ten spline

What else can you guys tell me about dimensions to aid in the search for alternates (also - to aid future stock guys who read this feel free to post specs on the other floor shifter stock transmissions that are a direct bolt on).
I feel like the picture is no "bolt on" options are known.... but I am trying to figure out in all the 70 years of vehicles if there really is nothing else that will mate up on the front, come up through the floor in the same spot (give or take a couple to three inches), and mate up to the back.

I'm looking to keep modifications to the tranny, or any modifications made to the truck be "easily" reversible.

I feel I made a minor mistake in the rear end choice - probably should have gone to 3.50 instead of 3.00 and am willing to correct that as part of the process, no worries if your suggestion includes swapping ring & pinion.

Biggest problem with a tranny swap in the F1 is the half-round crossmember. it gets in the way of every transmission other than a stock LD3sp., HD3sp., or 4SP. (like yours). I would look into a 3rd member swap for the 9" rear, as this would be the least invasive and still net some better results. Any way you look at it, the drive ratio for a tranny wo/ overdrive is still 1:1

When I had my first f1 in 1980 I would skip 1st and start in second all the time... Once in a blue moon would I start in first just to make sure it was still ok... Never had a problem.

Understood re trans x-member. I already figured I would have to drill out the rivets and set my x-member aside with the 41 rear end and fab up a new x-member. Have welder, etc - what I don't have, I can get a buddy to fab (lathe, mill, etc)

Moe, I got the opposite problem - with the low low rear end, I almost just barely can't use 1st (worried about clutch abuse) so I start in Granny... one extra gear and that much more extended middle fingers pointed my way. (I can use 1st for a rolling stop or any down slope, just can't use it for a dead stop on level or incline at all.)

The value of synchromesh gears can't be overstated when you are in traffic. Especially when you can't keep moving enough to stay in 2nd and lug it out coming up to a stoplight. Denver drivers must be ruder than ABQ drivers, I don't get any "feedback" if I'm lagging (but of course I have the throbbing Vee Eight engine so any lagging is minimal!)

Could you measure your existing trans, or more specifically the distance from the crossmember to some landmark forward of that? I don't see how the F-1 crossmember could accomodate the 4-sp spur unless it was further back than on a 3-sp F-1. I'm thinking maybe they used the F-2 crossmember mounting holes. If that were the case, then a SROD or SMOD Ford trans (4-sp with 4th OD) would almost certainly fit. Dick/4TL8Ford measured one once and as I recall it was about an inch too long in the case to clear an F-1 crossmember.

You for sure need to get a 3.50 or 3.25 center section for your rear axle; is it 28-spline?

I'll happily measure, and now I can do it at 72degrees on a concrete floor instead of 28 degrees in a dirt floor barn! Will try to do that tonight. Spline count... would have to check tonight as well (it is out of a '72 F100 unmolested - new fluid and new front seal is all).

Sorry I called it 1st but your right it was granny.... I would change the gears first and then see if you need to do a different trans... If you can keep it all in one then it's even better

Hey Bryan,

I don't know....first a 9" rear end...then a new 4-speed tranny. I think a 460 will be next. You're well on the way to the dark side!!!!

If I do a darkside, it would be my granddad's '47 tonner - he already swapped the motor to a Buick back in the mid 60's. I just don't have the heart to tear up something that is so close to original as my '48. I had to do somethings to make it useful and safe, but it's so close to stock I want to keep it that way. (The '47 needs a ton of work, it was dismantled down to the frame in the 80's - not sure I want to do all that work... it's a labor of love, but I'm just not in the right setup to take it on.)

Bryan. I may be confused about the T5. But I thought I read somewhere there was two different positions for the shifter, one bing forward of the standard position.. Maybe different models of the same tranny. I thought I would mention this and someone else can correct or have knowledge about the tranny. chuck

My understanding is there are dozens of options (as with the three decade long run of em in every domestic producer)... Haven't figured out the Astro van - but the S10 keeps coming up in my search as the most desired (albiet 7" out of place).

Yeah...but think of the benefits...someone gives you the finger...you light up the tires until there's so much smoke that you can't see the finger anymore...problem solved!!

I'm with you on the stock truck. I spend a lot of time in Colorado, and I do have to say...there are a lot of really bad drivers out there. I say ignore them and let them pass you with their finger in the air (they are probably trying to tell you their IQ!!).

A couple of years ago my brother and I drove from Denver to Glenwood Springs...it had snowed, melted, re-froze, and then snowed some more. I slowed down, but we counted 48 solo spin-out accidents during the drive. My brother and I laughed when I said...you know...passing the first 45 or so spin-outs at a high rate of speed is understandable, but by the time you see #46 you might start to think that the road is slippery!!!

Dan

Optional shifter position for the T-5 Tranny
Any T-5 Tranny used in the F-series Trucks will have the shifter located to the rear of the original position - How far depends on the yr/model.
Pre-T-5 Mustangs had a Tranny that the original shifter was further back than the T-5 - When the Mustang owners wanted to upgrade to the WC-T-5 the shifter location was to far FORWARD to comfortably drive (You had to lean forward to shift)
A company in the link at the end of this missive developed a remote shifter to move the shifter handle to the rear in the Mustangs to make them drivable.
HERE COMES THE SOLUTION: Purchase the item shown or make your own version and mount it in reverse of the Mustang setup to move the T-5 shifter FORWARD in the F-Series
Taa-Daa
Mustangs Plus
Disclaimer: I have no association with the above indicated company nor do I supply batteries used for construction of continued use of said contraptions.

You wouldn't think so, Ross, but it does. The light duty 3-speeds and the 4-speed crash box are the same length and will bolt in place of each other. The synchromesh 4-speed used in the bigger trucks (T-98 I think?) is a different story. It does require the use of an F-2 and larger crossmember.

As far as the OP's situation goes, I agree with the others. The 3.00:1 gear in the rear has to go and is probably most of the problem here. A 3.25 or 3.50 would net a big improvement. The nice thing about it is that the 9-inch is already there. A little salvage yard shopping should turn up a third member with a more desireable ratio. You could swap it in in a couple hours. I'd try that before worrying about the transmission. If a better gear gets you to where you can take off easily in 2nd, then I'd be looking at swapping in an original light duty 3-speed. At least then you'd have a synchronized 2nd and 3rd shift and wouldn't have to do the crash box clutch shuffle in traffic - and you can still call it stock. In my opinion, the T5 swap is a nice upgrade, but the crossmember mods required are pretty intense and would be best done with the cab off.

I happen to have both a 3.25 and a 3.50 center section, both are 28-spline open diff's.... also a complete '71 axle I'm not going to use. As usual, I can't find anyone who needs one now. I also have a 80's Bronco 9" with nodular iron center section, 31-spline, 3.50 gears, 5@ 5.5 bolt pattern, that is about 2" wider than stock for our trucks (fat rear fender guys???)