Will I hate life with a 4 speed

[Northidahotrailblazer]

Well for my latest project, I’ve been hunting parts. I’ve been hunting for a zf5 or another late 90s 4.2 M5R2 that’s in my 89 b2. I can’t find a zf5 for under $1500 bucks. People are just nuts these days. I could probably find an early m5R2 but lately I’ve been seeing np435s, t18 or a t19 for a few hundred bucks. My plan is for a np203/205 doubler. I already have 513 gears and this thing will be 5.0 powered. And I’m gonna run 40s. Idk my other option is run the 4R70W that is currently behind the 5.0. Which is the cheapest option probably. I can buy a controller for $600 bucks and it wouldn’t be much more than that. But I really dislike autos….. I’d like to do 60 in this thing. I read some t19s didn’t have the super low 1st gear and were setup for more OD. I don’t need the low 1st gear, with the doubler and the 513s I will never use it. I don’t in my current b2. With its doubler, 513s and 35s. It doesn’t have much hwy for over 70. Some bigger tires would help. But it’s also a M5R2 5 speed. Idk I wish I could find a zf5 but I’d probably have to buy a whole rig just to get it. But budget is what I’m after.

 

[sgtsandman]

If I'm understanding the question properly, other than getting used to having one less gear and the fuel mileage not being as good as it could be, running a 4 speed over a 5 isn't that much different. You just won't have the overdrive gear.

Having an automatic and a manual, I do prefer the manual but there are times when that slush box is real nice to have as well.

 

[Northidahotrailblazer]

Haha yeah there was some thinking out loud in that post.i wish it was in the budget to rebuild the 4R70w but it did seem to drive ok. So idk, I’ve been burned in the mountains blowing a TC seal and having a heck of a time driving the rig out. Loose oil out of the manual well it will still drive out. I’ve just had both in this rig so it’s easy to switch back since this thing started out as a manual b2.

 

[lil_Blue_Ford]

So… other than modifying the 4R70w with a Jmod… there is a manual valve body/shift kit option for those… I’ve been considering that. As much as I like a manual, there may come a day when it’s a problem considering my hip got damaged years ago.

Highway is where having an overdrive is nice. I had a couple people try to talk me into a 4-speed in my F-150 when I swapped my M5OD out. That truck sees a fair mix of things and I didn’t want to give up overdrive. ZF5 was the answer.

Dad’s 79 is set up for low end power and has a 4-speed, he said 60 is the fastest it will go and it will overheat at that speed, 55 is about the max. He said another gear would be a world of difference.

 

[19Walt93]

The 435, T18 & T19 are all creeper gear 4 speeds, it would be like driving a 3 speed with the option of a super low gear when you wanted. No overdrive with 5.13's would make the engine scream at 60 mph. How are you going to use the truck?

 

[85_Ranger4x4]

Running a V8 with 40's... buck up and try to snag a ZF if you are going to run it much on the highway.

If you don't really need to run on the highway a lot... skip the OD.

I converted mine from a 3spd slushbox to a 5 speed, it isn't a very fulilling mod as you redo a lot of your engine swap (drivelines, shifters, exhaust etc) to save a couple mpg's on the highway... I don't know how long it would actually take to pay for itself after the fact but it will take awhile.

So IMO... do it right the first time. Redoing it after a change of heart ain't much fun.

The ZF's are nasty to buy but I have wondered how much more buy a whole truck would be compared to just a trans. Then you still have axles, t-case, engine to peddle and a carcass to scrap to recoup money.

 

[bobbywalter]

with 40s i suspect the 435 will be fine. but since you are shopping regardless...its a tough call on selection.


with the 302 in a 40 inch tire, "wheelin" application....this is not so easy to call. with 513 gears and a doubler you are way out ahead for trail....and livable for hiway. cam selection will be the biggect factor once you figure out your actual cruise rpm and primary cruise conditions in regards to weight and how high your gear is piled for wind resistance........hill and dale of flatish hiway? .... 40 inch tires with a stockish 302....overdrive is something not needed really. my goal was hiway work with 35s and 1800 cruise rpm....not for fuel economy...just wear and tear. cam selection made cruise differences for sure...but there was no real good all around outside of the he unit....


there are more options these days..


in my experience, i would prefer to run the 6r80 before the 4r70. i have run the 4r70/aod with a 302 and 38-44 inch tires with 456 and 410 gears. worked for sure...but in all of the years running that combination i always wished for a better first and intermediates to overdrive. the 6r80 did not exist when i was running that combo but i was looking at the 5s before i went to the diesel. specifically for the 1st gear. wheeling i find the auto far better than a manual in areas like the rubicon, moab, and hollister... but i like the manuals better for downhills regardless. i have both, and they suit the applications....the ranger has a 4l80 and the bronco an r1. for the road the auto is much better. wheelin...the manual is funner.

my diesel is about like a 4.0 in feel...which the 4.0 easily exceeds the crown vic 5.0s in regards to usable power off road. a well built 5.0 otoh is a different level...i ran between 280-330 crank hp versions. running an engine like that back to back up against even an ho gt or a stock explorer 5.0 engine...you would want to throw a stock headed 5.0 anything in a dumpster. adequate over a v6 is about it. if you can deal with the heat. of course you have already established your 5.0 experience.

obviously the 4r70 has a shit first gear comparatively to the 6r80... since you already have it, it is far out ahead as the cheapest option of anything at this point.

figuring streetable 40's measure between 38.5-39.25 actual...and realistic cruise load and conditions....it will work fine...

and the 435/t18/19 i suspect will be fine as well but your gearing with the doubler ....all of that drag on the 302....is asking alot out of a 302. 351 or 5.3 or stroker 351....maybe a small turbo 300 six... would be more efficient in torque availability.