T5 and Ford Toploader 3 speed OD driving opinions

I am wondering what the opinions are on how a T5 drives that has the 4 cyl 4.03 gearset. It seems that this is a pretty wide ratio transmission and I want to hear about how it does in the real world. Is it kind of similar to big jump in ratios like a typical 3 spd would be or only a little bit better because it has 4 forward gears instead of 3? Usually the 3 spd has a large jump between 2nd and 3rd gear. The T5 appears to have a large jump between 1st and 2nd. With the deep 4.03 first gear, it seems that 1st gear will wind out too quick and you have to shift very quickly to second and then the jumps seem to be a little better spaced for 2nd to 3rd and then 3rd to 4th.

Secondly, what are the opinions on the Ford Toploader 3 spd OD from the late 70's up to about 1985 in Granadas as cast iron, and later all aluminum SROD, the last were all aluminum with a top mounted shifter?


I am looking for opinions for it behind a N/A Flathead V8 and behind a blown Flathead V8.

Has anyone ever torn up a 4 cyl. T5 behind a flathead, N/A or blown, under normal driving conditions or even spirited driving?

Thanks,
Roger

 

Opinions? You'll get plenty. Let's start with facts:

S10 T5 with the 4.03 gearset has the following ratios:

1st - 4.03 2nd - 2.37 3rd - 1.49 4th - 1.00 5th - 0.86

S10 T5 with the 3.76 gearset has the following ratios:

1st - 3.76 2nd - 2.18 3rd - 1.41 4th - 1.00 5th - 0.72

Let's assume a 4500 rpm shift point for "lively" street driving (reasonable with flathead). I don't know what rear gear you have, but we'll assume, for the sake of argument, that you have the 3.78 and 7.00x16 rear tires with a 30.4" diameter. With the 4.03 gearset, it looks like this:

1st @ 4500 rpm = 27mph
2nd @ 27 mph = 2670RPM (1830 rpm drop)
2nd @ 4500 rpm = 45mph
3rd @ 45 mph = 2800rpm (1700 rpm drop)
3rd @ 4500 rpm = 72mph
4th @ 72mph = 3000rpm (1500 rpm drop)
4th @ 4500 rpm = 108mph
5th @ 108 mph = 3880rpm (620 rpm drop)
5th @ 4500 rpm = 125mph

Let's do the same exercise with the 3.76 gearset

1st @ 4500 rpm = 28 mph
2nd @ 28 mph = 2535 rpm (2000 rpm drop)
2nd @ 4500 rpm = 49 mph
3rd @ 49 mph = 2890 rpm (1610 rpm drop)
3rd @ 4500 rpm = 76 mph
4th @ 76 mph = 3175 rpm (1325 rpm drop)
4th @ 4500 rpm = (still) 107 mph
5th @ 107 mph = 3220 rpm (1280 rpm drop)
5th @ 4500 rpm = 150 mph!

Now, let's look at a stock Ford 3-spd. I'll use a 16T gearset (best Ford offering) - ratios are:

1st - 2.82 2nd - 1.60 3rd - 1.00

1st @ 4500 rpm = 38 mph
2nd @ 38 mph = 2540 rpm (1960 rpm drop)
2nd @ 4500 rpm = 67 mph
3rd @ 67 mph = 2800 rpm (1700 rpm drop)
3rd @ 4500 rpm = (still) 107 mph

So, comparing the rpm drops between shifts, and the speed build between gears, either 5-speed is far superior to the 3-spd. Surprisingly, the drop on the 4.03 gearset is not as significant as it is on the more desirable 3.76 gearset, but you're right, you shift a bit sooner...a whole 1 mph.

Last "fact" - there are no "4-cyl" T5 if we're talking S10. You need to identify a T5 by whether or not it is WC or NWC and the gearset. The S10 offered both the 4.03 & 3.76 gearset behind just about any engine combo (4x4 were all 4.03 to my knowledge).

OK - opinion - the T5 is so far superior to the Ford SROD or any other 3+OD it's not even funny. Yes, you shift more frequently, but that means you keep your engine in it's power band more and have a perfect gear for every situation. Most like the 3.76 gearset for the better OD, but 1st is a little short. Ideally, the 3.76 gearset with a 3.54 rear gear would be almost perfect...

 

Great info!

 

......and, just an opinion here. The wife's stock 8BA flatty powered fenderless roadster has a 3.76 gearset S-10 T-5 with a 3.00 gearset in an 8" Ford diff and 28" rear tires. The stock 8BA loves this setup, it moves easily off the mark, cruises like a late-model on the freeway at 65 mph and the acceleration is plenty good. When we switched from the old three speed where she was getting 16 mpg...it went up to 19-20 mpg with no other changes. It's a much happier car and alot more fun to drive.

 

Thanks Flat Ernie for the data and Retrorod for the real world experience.

I have a NWC T5 with the 4.03 gear set and I have a spare NWC 4x4 version with 4.03 gear set. So, Flat Ernie's data on 4x4 agrees with this one also.

To give a little background, I am working on a Model A and will be using a Flathead V8 warmed over with a 144 Weiand Blower setup running about 5 lbs of boost and 9" Ford rearend. So it is not real special or wild and in a fairly light car. I was figuring on using a 3.50 ratio or a 3.25 ratio in the rearend. I had thought that the 3.25 would probably be the better choice with the 4.03 gear set and it seems that Flat Ernie's suggestion above that the 3.76 gear set working really well with a 3.54 ratio seems to comfirm my thinking that the 3.25 might be a good choice.

Also wondering about how the same NWC T5's have held up in much heavier cars like later 30's, 40's, and 50's whether running a flathead or a more modern motors like Olds, Hemi's, SBC's, or SBF's.

Roger

 

I had an aluminum SROD behind my Y block. The ratios really suck, plus is leaked right through the side of the case. I stepped up to a 3550 which is wonderful. I also had a 4 cyl T5 behind a hot flatty in a light roadster. You are right about first gear being a little short, but all the better to hear the pipes. When I dragged it, I started out about 2500 and pulled away in second. Once you have a fve speed, you will never look back. There is a ratio for every speed the motor likes to run.

 

First, SROD is crap! The iron Orion is a good transmission if you have the torque to work with the gears.That said, a T5 is a nice transmission to drive, slick shifting and good ratios. A flathead will be happier with a T5, I think.

 

I've run a NWC T5 in front of a stroked 351W (377" & ~350HP) and it lived for years, but I didn't abuse it. Eventually, the synchros gave up and I ended up double-clutching darn near every shift. I finally replaced it with a WC T5 and haven't had an issue since (and I do push it hard).

All else being equal, a lower first gear (higher numerically) will be weaker than a higher first gear (lower numericall). This is due simply to the mechanical leverage and the aluminum case design of the T5. The torque ratings on the T5s are somewhat misleading and really only serve as a relative rating, IMO (ie - to compare one T5 to another).

You will be fine running a NWC T5 in front of a flathead...even a mild blown flathead. If building your T5 from scratch, one of the most important specs is the end play - I like to build them up to the tight end of the spec. Otherwise, run a good shifter with mechanical shift stops and synthetic ATF and you'll be fine.