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View Full Version : WARN ing - An overdrive-related silly question...



Mark J
08-08-2021, 06:00 PM
It's me, Mark (of the Daily Puddle).
Now that I'm driving my 3B much more regularly, I've noticed something I never noticed when I drove this as a 16 year old child.
Normally my "in traffic" shift pattern (with WARN overdrive) is: first, second, second-over, third, third over.
It seems second-over and third is the same gear ratio, or if it's not, it's very close. Am I wasting my time shifting from second over to third? Sometimes it's just fun to perform this shift sequence to impress the women!
:p"Wow... all those gears, and sticks!":p

5JeepsAz
08-08-2021, 10:39 PM
Not seeing a problem.

bmorgil
08-09-2021, 06:52 AM
The technique you are using is "split" shifting or "range shifting". Yes you are wasting your time, sort of. The "ratio split" can be insignificant between second over and third, depending on your overdrive. That said you are zipping around unloaded in a gas engine vehicle. Think torque curve differences between gas and diesel. Diesels have a short torque curve, they need a lot of gears close together. Gas has a broad torque and needs ratios further apart. Heavily loaded vehicles and small engines benefit from a lot of gears when they are loaded to stay in those torque curves. The little jeep unloaded needs little help moving. This is an oversimplification but hopefully it makes sense.

Now to the "sort of wasting time" part. It is a LOT of fun split shifting with an overdrive. Nothing like using all six gears! Especially with loud mufflers.

Multiply your trans ratio times your overdrive ratio in each gear to get the final drive trans ratio for that gear.

Trans ratio x overdrive ratio= final drive ratio

The T90 is 1.55 to 1 in second. Assuming you have a .75 overdrive ratio (25% overdrive) your final drive becomes 1.55 x .75= 1.16 final drive. Third gear in the T90 is 1 to 1 so a 1.16 ratio shift to a 1 to 1 ratio is minimal.

https://willysjeepforum.kaiserwillys.com/showthread.php?2283-How-fast-is-the-RPM-at-speed-or-the-speed-at-RPM

TJones
08-09-2021, 06:43 PM
I’m with bmorgil on it’s fun if you have loud pipes!!!!
We left Toledo to get the trailer to tote the Orange Crate home and all the streets were closed downtown and the Bride was driving the pickup and I was following.
I punched in the address on the pickup because she’s terrible with directions. The navigation took her to the freeway for a short 3-4 mile joy ride and it was the first time on a freeway with the Orange Crate, I was shocked with a V6,T90,Warn Overdrive and 5.38’s it kept up with the boss doing 60-62 at I’m guessing it was running around 3,000-3,200 RPM and I had plenty of peddle left but I was pushing it with short WB and narrow gauge I wouldn’t want to push it any more than that.
Mark I always leave it out of OD and use the OD for forth gear, most of the time I start in second. I’m not sure what motor you have but the V6 has enough gumption to get her rolling in second out of OD.

Mark J
08-10-2021, 10:51 AM
Mark I always leave it out of OD and use the OD for forth gear, most of the time I start in second. I’m not sure what motor you have but the V6 has enough gumption to get her rolling in second out of OD.

I've got a CJ3B with the F134. It seems to get rolling best using 1,2, over, then I do the "useless" 3 under just to get it ready for 3 over if it looks like I'll be rolling a while.
Roger that? Over! haha

bmorgil
08-10-2021, 12:01 PM
I was shocked with a V6,T90,Warn Overdrive and 5.38’s it kept up with the boss doing 60-62 at I’m guessing it was running around 3,000-3,200 RPM and I had plenty of peddle left but I was pushing it with short WB and narrow gauge I wouldn’t want to push it any more than that.

OK the first part of the quote... before anyone tries this at home, TJ is fearless. I have driven his CJ. It cruises to 60 with ease and handles it far too well, way to smooth. In a heartbeat that thing will get away. Tim has taken some time learning to drive it and I am sure anyone with a re-powered CJ would agree, get used to it first! The Saginaw steering box is phenomenal. It is a good experience to see what happens when you have two types of CJ's to drive. First you check out the "old school". Then you jump in the same vehicle with a much better steering system and over 3 times the horsepower. The distance between the front and back wheels becomes apparent if you want to make any quick moves. The wheel base is very short. At 60 mph it feels like it is 6 inches long. Like a big racing go kart. It runs smooth as silk and tempts you to do the wrong things. In a word... Perfect.

TJones
08-10-2021, 01:08 PM
Oh Stop it Bmorgil...........

gmwillys
08-10-2021, 04:06 PM
I agree! The Orange Crate is one mean ride for sure! I loved the response that the 252 Buick offered just in the yard drive I took. It did handle like a go cart. A great piece of craftsmanship if I do say so!

TJones
08-10-2021, 05:06 PM
Thank You much guys!!!
I could of never done it without y’all’s help!!!
Mark J these 2 guys are truly a wealth of knowledge not to mention LarrBeard and the late Pelago.
I was full off dumb questions when I started my project a few years back and after a couple dozen dumb ones they all convinced me that there is no such thing as a dumb question, so that’s why I have what I have today. It didn’t take me long to be ALL Ears from that point on!!!

5JeepsAz
08-10-2021, 05:51 PM
True, shifting is very glorious. Go on, just shift and smile!! Why all this counting gears? And TJ obviously built it so well it can do things no old jeep is supposed to do. And he know its capabilities like nobody else. So, I'm guessing every ride along ends with "can we do that again?"

51 CJ3
08-11-2021, 07:24 AM
Many years ago, when the national speed limit was 55, I owned a ‘66 CJ5 with the 225 and an overdrive. Ran it on the interstate around Tucson all the time with no trouble keeping up with traffic on 32” tires. I couldn’t keep a speedometer cable in it so no clue as to my speed but people weren’t very inclined to drive 55 on the highway anymore then than they are today. I used to scare my buddy by fishtailing it when making u-turns on pavement. It was fun to split shift but not practical. I would do it more on open parts of a trail when locked in low range than on the road. The glass packs mounted to the headers ended below the doors. That Jeep was a mess but I wish I had kept it. It was in much better shape than the 3A I own now.

bmorgil
08-11-2021, 07:40 AM
A '66 with a 225 was a nice package. Good power, those would go anywhere with tall tires.

gmwillys
08-11-2021, 09:25 AM
In my opinion, split shifting is way more fun when you have a 5-4 Brownie box backing an 8V71 or a 6V71. I never had the opportunity run a 12V in any configuration. The gear combinations were outstanding, and you could pull a mountain, while making the Detroit scream.

A 225 is a torquey engine. Lots of go anywhere ambition.

TJones
08-11-2021, 10:32 AM
I agree with gm on the Detroits, you had to run them like you were mad at em:):)
Years ago my Grandfather bought a 11 cy self-loading scraper (it was a Wabco made by Westinghouse) and it had a 4-71 Detroit in it.The self loading paddles on the bowl were driven by 2 electric motors and the steering was an electric motor as well and the 4-71 drove the generator that supplied electric to steer it and drove the paddles. The only way you could steer it was a toggle switch on the dash, so you held onto a sissy bar and worked the switch left or right to steer it and the ONLY way it would steer is to keep the RPM's up.
That being said as a teenager, indispensable, young and dumb, and full of trying to destroy everything with a engine they put me in it:):)
I am telling you that you had to keep it pedal to the metal constantly, that's probably why at only 60 something I have a bad back and hearing aids because it bounced you around like a carnival ride at the fair and with a straight pipe on a 2 stroke 4 cylinder diesel and it was loud!!!!

bmorgil
08-11-2021, 04:39 PM
See what you started Mark!

Mark J
08-11-2021, 05:00 PM
See what you started Mark!

I've learned a lot on my jeep issues and ... on completely different things as well!
Just spend the last 15 minutes Google-searching/reading on Brownie boxes and 8V71 Diesel engines - made from 1938 to 1995?! That's an insanely long run.

gmwillys
08-12-2021, 05:29 AM
We try to not stray too far off the reservation when it comes to the topics of discussion, but sometimes life's experiences put things in a different perspective. Splitting gears with a Brownie box with both hands, arm through the steering wheel, running the go pedal, and watching for some hun yuk to pull out in front of you is definitely a juggle. There is rarely a day that goes by on here that we don't all learn something new from one another.

LarrBeard
08-12-2021, 07:00 AM
When you get BMorgil, TJones and GMWillys telling equipment stories, there isn't much they haven't driven or broken at one time or another.....