Transmission Swap Suggestions

I have the manual clutch linkage SROD 4 speed. I am going to be putting in a clutch soon.

I was thinking....what manual swap could I do that would have better gearing? 1 to 2 is okay, but 3 is like spaced way out from 2. 4th seems like an OD gear. Sloppy long throw shifter. Just not a huge fan of this 4 speed so far.

Does anything direct swap without having to change driveshafts or cross members?

I will drive it like it is for now, but I want to keep an eye out for something better.

I have a c6...but....poo....its auto. Blah!

Thank you for any guidance.

I don't know about the SROD, but I know that a ZF5 can swap in to replace a C6 w/o changing the driveshaft.  At least on a something with a 460 pattern.

Let's see what the others say.  But don't do the C6.

I think the NP435 is about the same length as the SROD, but I've never put my hands on an SROD on the ground.  I guess you could research Gary's parts catalogs to see if there's a different d'shaft for each trans.

Ray,

This may not be in your list of potential swaps, but since you're looking for suggestions, you should consider a 5spd from a 1988-1996 pickup. My personal thought is that if you're going to go through the trouble, might as well go 5spd.

With that you'll have two options. The 3/4 ton ZF5 trans, or the half ton M5OD trans. I'm running the M5OD in my 1984, and Reamer is running the ZF5 in his 1986 Flareside 4x4. I believe had had to have his driveshafts adjusted slightly, but he had an NP435 to start with. The heavier ZF5 is a more desirable transmission, but finding one for a 4x4 with a SBF bolt pattern is not quite as easy as finding an M5OD. For what I'm doing with my old truck, I'm more than happy with the M5OD.

The 5spd swap is a little easier on the 1984-up (gas) and 1983-up (diesel) as they came with hydraulic clutches. However, swapping in a hydraulic clutch is not a big job either imho.

Anyway, just food for thought. Some folks are not interested in a 5spd. Some love them.

Hey! '83 was the year for 460's too....
Are they not gas?  

Yeah Ray's options are all complicated if he wants to keep overdrive.
By finding a hydraulic pedal assembly, master cylinder and reinforcing the firewall if he wants to keep it from tearing. (I put the little patch on mine before it tore...)

Nothing wrong with the M5OD. They shift a little more 'car like' and don't seem to have the rollover rattle and endplay problems of the Zf5.

All good advice.

You can see the ratio differences, and play around what-ifs in the calculator, here: Driveline/Calculators.  And you can see that the SROD's ratios are a big compromise as it is a 3-speed with an OD tacked on.  Compare the SROD to the M5OD, which is a nice, evenly-spaced 5-speed, and it is obvious.

Then compare the M5OD to the ZF5.  The ZF's creeper gear means it is really a 4-speed for most situation.  And for a light truck and daily driving those situations don't happen often.

So I'd recommend the M5 for your truck, Ray.

I like the M5OD in my Ranger, but as previously mentioned, it really does shift more like a car.

My only gripe with the M5OD is the internal slave cylinder. Great idea......when you can find a slave cylinder that doesn't leak after a few thousand miles.

Everyone, thank you for clearing this up. Looks like if I did a swap I would be in for some good down time. I think for the time being I will live with what I have.

I might LS swap it later and do a 6 speed....

I really want to try to turbo charge the 300. I may start there. If the SROD grenades, I will do the M5OD or ZF5

Ray - I remember you trying to speed-shift the ZF5 in Dad’s truck. It ain’t gonna happen. The ZF5 is a truck transmission which shifts slowly, and one of its weaknesses is the synchros.

So if you want a quick-shifting tranny I’d recommend the M5OD. I haven’t had one, but from what others are saying it shifts faster/better than the ZF5.

Gary Lewis wrote

Ray - I remember you trying to speed-shift the ZF5 in Dad’s truck. It ain’t gonna happen. The ZF5 is a truck transmission which shifts slowly, and one of its weaknesses is the synchros.

So if you want a quick-shifting tranny I’d recommend the M5OD. I haven’t had one, but from what others are saying it shifts faster/better than the ZF5.

HAHAHA that was a long time ago already. Yeah I think I ground a gear or two didnt I !???

Just FYI:

Ford documentation refers to the Mazda & the ZFs as "M5OD", and both were available in the F150.  The Mazdog is the M5OD-R2 (the -R1 was in Rangers & B2s); the ZF S5-42-7 (420 lb-ft; close- & wide-ratio) is the "M5OD-LD"; and the ZF S5-47 (470 lb-ft) is the "M5OD-HD".









My '95F150 2WD has the Mazdog (a reman after the original broke), and it shifts easily.  I've never driven a ZF long enough to get a feel for it.  But the ZF has a known weakness of the front case NOT being strong enough to withstand the force that the concentric slave applies to the clutch diaphragm, so it collapses inward.  I don't remember if it was revised to alleviate that problem or not, but I assume so, since the ZF is still a popular swap.

Steve83 wrote

Just FYI:

Ford documentation refers to the Mazda & the ZFs as "M5OD", and both were available in the F150.

Actually, they were both available in the F250 as well. My M5OD-R2 came out of a 1991 F250 2wd (Light duty).

Gary Lewis wrote

So if you want a quick-shifting tranny I’d recommend the M5OD. I haven’t had one, but from what others are saying it shifts faster/better than the ZF5.

The M5OD still shifts like a truck transmission, but is a lot smoother thanks to the synchros. I have a Hurst short-throw shifter installed on mine and that helps the shifts feel more crisp.

salans7 wrote

The M5OD still shifts like a truck transmission, but is a lot smoother thanks to the synchros.

Are you talking about one in particular, or all 4 M5ODs?  They're all fully-synchronized, and they're all for trucks.

I'm think about going M5od as one of my neighbor has one they don't want (Auto fan as Wife as issues shifting), but looking at the Gear ratio's of the Srod and my 3 speed, yea it is ruff 2-3 shift. M5od looks to smooth it all out.

I put a Tremec TKO-500 in mine.  It was direct replacement for SROD, after I had Silver Sport Transmissions relocate the shifter location to match my truck.  Direct replacement besides that because I didn't need a new drive shaft, bell house, or clutch.  I voluntarily put new clutch kit, bearings, and rear-main seal in while I had transmission out of course.  But it wasn't cheap, cost about $3,000.  But truck was given to me in excellent California condition, and I drove it 8 years with no repair cost... so I decided to to spend the extra couple grand to get brand new modern-day 5 speed.  In-line six should last forever, so I think it was a good investment, considering condition of truck and my plans to keep it forever.  I did swap myself with no experience; took me all weekend.

TKO-500 is nice.  Fixed the large gap between 2nd and 3rd.  I want to change rear end to 3 or 3.25 now (currently 2.75) because I like to drive 70 mph and that happens to be too high for 4th and too low for 5th.  It's always something, right... but rear end is due for a rebuild anyways so I don't mind.  

I hated SROD since I was a child.  My grandpa took me fishing in mountains a few time a month... and couldn't get it in 3rd gear going there, so we drove 35 mph the whole way with big line of cars stuck behind us, and pulled over at every opportunity to let them pass.  I thought he was just a lame driver until I was old enough to drive it and couldn't get to 3rd gear going up hill, and I had to drive 35 just like he did.  I wish he could ride with me now going up the mountains at any speed I desire.

I couldn't find any other direct replacements for SROD.  I only found a rebuilt SROD from auto-zone for about $1500 and the TKO for about $3,000.

Tremec TKO in 1981 F-150 Flareside with 300 inline six, stock bell house, stock clutch, stock drive shaft.

Took this photo today and remembered I still need to put the clutch boot on it, I forgot to when I had the chance.  Also need to hook up back up light.  The cross member is original, I put it in backwards to line up with transmission mounts, but it was designed to go in either way to fit multiple transmissions.  

My buddy has a TKO-600-RR behind a 347 in his Cobra replica.

Lakewood bell with a pull slave.

The tighter ratios in the road race version give it a tall first but it sure is nice to shift!

I think $3k is way off the table for Ray, but it's always nice to dream.

ArdWrknTrk wrote

I think $3k is way off the table for Ray, but it's always nice to dream.

Not sure why you think that. However, I could buy an entire parts truck with a 300 and 5 speed for that kind of money.

Anyway, Thanks for the info. My truck is also a Cali truck. Mine is 4x4. Can the TKO500 be ordered for a 4x4?

That sounds nice that I can keep the original bell housing and clutch. That means I can keep the mechanical clutch linkage, and dont have to swap in the hydraulic setup.

I know they can be had with 3 shifter positions and many ratios.

What they call Ford spline is the input, but I've never personally seen one with a transfer case bolted to it.

I imagine divorced is easy enough to do.

If you want to LS swap this truck why would you dump 3k into a Ford gearbox ?

ETA: I can't imagine why you would need (or, want) a 5-600 ftlb gearbox for a 300, no matter how built it is.