Tranny died, need advice

[sargentrs]

Lost 2nd gear in Ol' Betsy a couple days ago. She just won't go in anymore. She's been jumpin' out of 1st for a while, started jumpin' out of third a couple months ago. 2nd's been the only reliable gear for a while but now she just won't go in. Like hittin' a brick wall tryin to shift into 2nd. Started grinding shifting into second right before she refused to take it anymore. Here's the question:

1970 LWB Sport Custom. 302 ci. with 3.03 manual tranny (2nd one), and aftermarket floor shift when the column shift got too finicky.

What to go to?

1. Put another 3.03 in her? Looking at a parts truck (1979 LWB, wrecked) with same drivetrain. Bonus is power front disc brakes and working 3 on the tree. Can put her back to original column shift.
2. Swap it out for 4 spd out of a 5.0 Mustang (what am in for?)
3. Go automatic? If so, what have I gotta swap out in addition to tranny?

What about the driveshaft if I go 4 spd or auto? Any clean swaps or do I have to have one made?

What do you think guys? Anybody got experience with the above choices? (Duh, stupid question!) You guys have done it all! I'm not worthy!

[fordman]

the easiest route would be the 79 dentside. as far as wheather or not to go witha 4spd or a auto for a better chooooice would depend on how you use your truck. the three spd driveshaft would probably be too long for a 4 spd or auto.

[sargentrs]

Thanks, that's what I was thinking. I like "easy". what about the steering column? Will it swap clean so I can get my 3 on the tree back? My Mr. Gasket floor shifter was starting to tick me off.

[fordman]

i know the 79 auto columns are different. i dont know if the 3 on the tree columns are different though. the length of the 79 will be shorter than your mamual column is though. but you can probably mix and match parts from both columns and make one good one. the center shaft will be shorter not the whole column. both columns use different bearings also. but the shift shafts and shift arms should be the same.

[MadMaxetc]

Why not put a T-5 from a 95 mustang with an S-10 rear+shifter?

Or a M5R2 (is that right?) the one behind 300s in the 80's & 90's?

[Leadfoot]

well with drum brakes a std. trans is likely the better rout, just because it really help when you can down shift.

personally Im not a big fan of any 3 speed trans though, floor or on the tree.

if it where my truck I would go with a c4 or c6 auto trans, and disk brakes. with the auto or 4speed you would need to likely cut the front section of the drive shaft though.

its really going to be your pick. but also before righting off the old trans check you cab mounts because if they are soft linkage bind will cause the said problems that you are having.

[fmartin_gila1]

There are a few of us that have the T5 in their pickups(Ihave in mine). As long as you only use it for transportation with an occasional light load, it's OK, but the T5 is only a light duty tranny. Consider what you will be doing with the unit.
Fred

[AlleyCat]

The 79 parts truck sounds like the way to go but take a look under it before you decide to buy.The reason I'm saying this is I'm parting a 78 LWB, 300, 3 on the tree.The 3.03 in this one has a longer tailshaft than a 3.03 from a bump.It also has a slip yoke and a 1 piece driveshaft.The 1 piece shaft would have to be shortened due to the differences in wheel base from bump (131") to dent (133").I don't know if all the later dentsides used the longer trans but this 1 isn't the first I've seen.

[sargentrs]

Linkage could be an issue but even with the linkage disconnected and shifting ON the transmission, she won't go into second. The levers/rods that came with the Mr. Gasket shifter are sloppy and the levers aren't offset at all so the rods aren't a straight shot and cross over each other. Anybody got some spare levers? I tossed mine when I swapped to floor shift, bad idea.

So, I'll probably need a new, original length, shift tube if I use the '79 column? If that's the case, I might as well just rebuild the old one. I've read the tech paper and I think I can handle it.

Is there any auto tranny/driveshaft combo that'll swap out without cuttinng down or stretching? Like, from a car or newer truck? I've got the 2 pc. shaft now. What's the pros and cons of using a 1 pc?

I just use the truck for a daily driver but have loaded 1500# of wet sand in her before and drove it 40 miles (3 trips). She took it like a champ!

[sargentrs]

P.S. thanks for the tip about the 3.03 tailshaft and difference in wheelbases! I never would have thought to look and the wheelbase difference wouldn't have been obvious.

[fordman]

well i think we all need to figure out which driveshafts fit which trannies. and get soem measurements and post them someplace. because i dont know whihc driveshafts will interchnage with what for sure. i don't think a 3 spd driveshaft will fit a auto. the autos shafts are so much shorter than the three spd shafts. i do think the np435 shafts are about the same as a three spd but i'm not 100% sure on that.

[sargentrs]

While we're talking about NP435's, they appear to be pretty popular here. From the sound of things, maybe a little easier to find than another 3.03. What's it take to swap to that?

[MadMaxetc]

...Anybody got some spare levers? I tossed mine when I swapped to floor shift, bad idea.

PM me. I have a set and a 3 speed column from a 73.

[fordman]

i also have a 3.03 sitting here that works. i could send you the whole hing or just aprt from it if you want to do that.

[sargentrs]

sent you a pm, fordman.