home made twin stick (t-18) wont fo into low 2wd ?

[buzzinhalfdoz]

i made a home made twin stick for my 1970 CJ5 t-18 4-cyl.
i have 2 seperate levers one for 4wd to 2wd and the other for low-high.
it will only shift into low if it is in 4wd.
is their some internal changes to make so it will work ?
thanks

 

[Hedgehog]

Without additional surgery you should have:

2 wheel high, the left lever back and the right in neutral

2 wheel low, the left lever forward and the right lever in neutral

4 wheel high with the left lever back and the right back lever in 4 wheel high

4 wheel low with the left lever forward and the right lever forward back in 4 wheel low

Basically if the right lever is back the left lever can ONLY be back, it WON'T go forward, except for neutral.

If the left lever is forward the left lever can ONLY be forward, it WON'T go back, except for neutral.

Further surgery on the T-case will allow options like front wheel only in high or low. With other disastrous options available. This has been covered several times and I'm too tired right now to rewrite about those.

 

[BusaDave9]

There are detent pins that prevent 2WD low. You will want to remove the rods that go between the 2 shift rails.

Once those rods are removed you can shift each shift lever any position you want.
But be careful. If you are in 4WD high and you want to go to 4WD low it would be possible to get the front in high and the rear in low. The jeep won't move and the TCase will be bound up. It would be hard to shift the levers back into neutral or anywhere else.

 

[Hedgehog]

And BusaDave9 covered the option of removing the "pills" nicely.....

 

[Hedgehog]

A brave man knows when to admit a mistake. I gave instrucions for my Dana 20 transfer case. I'm not at all sure the same shift pattern is true for the D-18 transfer case.

 

[Sasquach]

Isn't the 18 a twin stick already? Im only familiar with whats in my 3b and early CJ5's but thought all were twin stick.

 

[TroyaCantrell]

My 18 the left lever forward disengages the front drive shaft when forward and is labeled in - out, forward being out. Right one is low range when forward, neutral in the middle, high when back.

Also, when in neutral on the right stick there is no drive at all to either axle.

Troy Cantrell
Sent from my iPhone using Tapatalk
Build thread - '66 CJ 6:
http://www.jeep-cj.com/forums/showthread.php?t=15075

 

[Hedgehog]

As said before, there is confusion here.

- a T-18 is a 4 speed truck transmission

- a D-18 is the older transfer case with an emergency brake on it. Many came with factory twin sticks, but not all.

- a Dana 20 is a newer transfer (~'72-'80) case that is a bit more efficient in transferring power at highway speeds. These transfer cases never had twin sticks and are converted to twin sticks with after market or home made conversions.

 

[buzzinhalfdoz]

sorry for the duplicate post(too many beers)
it is a stock 1970 transfer case(one with emergency brake on back)
must be d-18(it is a 3-speed)
what is the procedure to remove the rods between shift rails?
is this necessary to use 2wd low?
thanks
ps so the right lever stays in nutral for 2wd?

 

[BusaDave9]

If you don't need to rebuild the transfer case it is a real pain to remove those detent rods. You have to remove both shift rails. To do that you need to loosen the shift forks. To do that you need to remove the TCase and take it apart. You can gain access by removing the bottom access plate.

There still seems to be some confusion on the drive train. You have a 3 speed transmission and a Transfer case. Since say you have a 3 speed so I guess it is a T90. Check out this link: http://www.jeep-cj.com/forums/f105/manual-cj-transmissions-12112/#post97083

You have a Transfer case that I would assume is a Dana 18 based on the year. Jeep never did have a 3 speed transfer case but there are a couple after market transfer cases that have 3 speeds.
Here's info on the Dana 20 Transfer Case: http://www.jeep-cj.com/forums/f105/transfer-cases-12108/#post97069

 

[Sasquach]

sorry for the duplicate post(too many beers)
it is a stock 1970 transfer case(one with emergency brake on back)
must be d-18(it is a 3-speed)
what is the procedure to remove the rods between shift rails?
is this necessary to use 2wd low?
thanks
ps so the right lever stays in nutral for 2wd?

For the dana also known as spicer 18;
The left lever can be though of as 4wd or 2wd, in(4wd) and out(2wd)
The right lever hi range, nuetral, low range
so no the right lever needs to be in high range for 2wd.
your original post makes sense now that we know the T case involved. The factory makes it so no 2wd low range available because increased stress of the gear reduction only being applied to half of the designed drivetrain.

 

[Posi]

The D-18 came with a single stick behind a V6

You can also keep the pills and shave the rails a bit to get independent front and rear, best of both worlds.

 

[Sasquach]

Why do you go to that work over removing the pills? What am I missing?
Thanks

 

[Posi]

Why do you go to that work over removing the pills? What am I missing?
Thanks

Removing the pills will allow you to shift the axles independently, rear only low or high, front only low or high. The downside of removing the pills is if the driver accidentally shifts the front in low and rear in high it will bind the gears in the case. If your lucky the gears will only bind, if you shift then apply the skinny pedal your case and gears will be toast. The factory installs the pills so this doesn't happen.

By grinding down a section of the rail I was able to retain the safety of the factory pills and still gain all the benefits of removing them. Best of both worlds.

Hope this helps