Shifting 205 Transfer Case with Auto Trans in 70 4x4

[stringpickin]

Hey and Good day.. Thank you for your time and help. I recently did a 700r4 conversion on my 70 chevy 4spd. I am hoping someone can tell me the tricks on shifting the transfer case in and out of the different ranges.
It seems that I have to turn the motor off to get it in to low range or out, and even have the problem in to 4 hi. It is really a hassle when I need to use 4x4 on hwy conditions. Having to pull off to the side of the road to take it out of 4Hi to get it back in 2standard is not fun.
Even after I stop If I put the trans in park or in nuetrual. I just can't seem to get it to work smoothly without turning off the truck. Is this normal with auto's? I have never had an auto 4x4 so I have no idea what the standard means and tricks of shifting these things are.
I looked for GM's standard operating directions on line but have not been able to find it easily. My truck has the standard manual locking hubs and original 205 transfer case married to a 700r4 via Advance Adapters. Thank you very much for any input. Treat me like a dummy, I won't mind.. lol.. Stringpickin

[CraigS]

You're doing pretty much what I have to do with mine. I have a '72 with 454, TH350 and NP205. 4 Low is almost impossible without stopping the engine or at least putting it in park. Any little bind will keep it from shifting cleanly. 4HI is a little easier and just takes a little finessing the gas pedal to match engine speed to the coasting speed of the truck. And this is with a newly rebuilt 205. Moving from 2HI to 4LO is a problem because the transfer case moves thru neutral (no gears engaged) and that allows the mainshaft to speed up with the automatic. Then it won't go either way.

[Truckstuff]

I have a Turbo 350/205 and putting it in Neutral works on mine.

[stringpickin]

Thank you Craigs,, I sure wish there was a way to get it working like Truckstuffs.. Truckstuff is your rig fairly fresh or does it have some miles on it.. Thank you. Anymore help or suggestions, comments etc. still very welcome.

[Truckstuff]

stringpickin.... The 205 has many miles on it. I have taken the 205 shifter assembly completely apart, cleaned it up, welded up the groves on the linkage rod, put some never seize on the shifter bolt/pin and put it back together. It now has a more positive shift. At the same time I put new gear lube and Lucas heavy duty oil stabilizer in it..

[mrein3]

My truck used to have a manual transmission. I miss those days where when you jam in the clutch you can shift the 205 with no problems.

Now with the th350 it seems like I'm always "unbinding" it so I can shift it. I think you are just going to have to get used to putting it in neutral and slow the torque converter down before you can shift it.

I never "shift on the fly" with my truck. Gernerally I know I'm going to need it and put it in 4wd before I move.

I think the problem is that this is an old mechanical system. If the torque converter is spinning faster than its stall speed you are moving the transfer case input. It appears that you can't be moving the drive line input when you shift the 205.

[stringpickin]

Hey Truckstuff and mrein3. Thank you for the input. I have thought that possibly after time when the newness of everything wears off a bit that it might loosen up and become easier to shift. I wonder if yours TruckStuff works so well be cause it is basically worn in well but in good tolerance working condition..? Mrein3 is your set up pretty new? or plenty of miles on it and still a pain? That is what I was thinking basically as well, the tranny spinning even in nuetral keeps the main shaft spinning enough to not let the transfer gears line up and drop in. Does that sound right or am I not understanding it correct? If one could reach in and stop the trans shaft from spinning all would be well eh?

[mrein3]

Originally Posted by stringpickin

Hey Truckstuff and mrein3. Thank you for the input. I have thought that possibly after time when the newness of everything wears off a bit that it might loosen up and become easier to shift. I wonder if yours TruckStuff works so well be cause it is basically worn in well but in good tolerance working condition..? Mrein3 is your set up pretty new? or plenty of miles on it and still a pain? That is what I was thinking basically as well, the tranny spinning even in nuetral keeps the main shaft spinning enough to not let the transfer gears line up and drop in. Does that sound right or am I not understanding it correct? If one could reach in and stop the trans shaft from spinning all would be well eh?

The transfer case I took out had at least 160k miles on it.
The transfer case I put in was out of a used '72 Blazer. It too had a ton of miles on it.

I think you understood the point I was trying to make - that is you need to stop the output shaft of the tranny (thus slow down the torque converter) in neutral, or have the truck stopped and in park.

Even with those two things (neutral or in park) I still have troubles at times shifting the x-fer.

I think it is just the nature of the beast.

[Bill W]

So your saying you cannot shift on the fly with the front wheels straight and going at a steady speed into 4-hi? 4-lo I can undstand. In fact on my 91 suburban the instructions tell you to stop completely put tranny in park or neutral and then shift into 4-lo.

As for 4-hi, even with a stick shift tranny you do not have to push in the clutch to engage 4-hi. Just pull back on the transfer case lever and it goes right in. Steady speed (any speed) and wheels pointed straight help.

To put it back in 2-hi should be same procedure. Steady speed, wheels pointed straight and a little bump on the transfer case stick and back into 2-hi it should go. No clutching needed in almost all cases. So I think even bolted up to a automatic it wouild work the same.

Bill

[Bobalouie]

Mine is all stock, 65K miles, and I just slow down to less than 5mph and let her coast, shift the trans to neutral, and shift the transfer case into whichever range I want. The slow coast eliminates the binding, and if you dont ram the Tcase shifter, you wont get any grinding either.

[stringpickin]

Thank you thank you. Bill I am going to goof around with it on friday. I have another thread going about noises, piston slap or 700r4 noise? after I find out if everything is tight in the torque converter area I am going to try a couple of your suggestions. As you also Bobalouie I will give that a whirl too. It seems like I have tried all that has been mentioned somehow or another in just getting it to work.. I have gotten lucky a couple of times and had it come out of 4wd low easy. And I believe I have pulled it in to 4 hi one time. It does seem if I remember the main problem though is trying to get it 4X and back to 2wd without grinding tranny gears. Then I end up turning it off so I can get that done, being nuetral or park won't allow it. Will try again, there maybe a finicky little thing it likes and It is just so new to me I haven't found it. But it does seem a lot of us here have troubles with the autos. Soooooooo...

[stringpickin]

Update. For any who knew I had another thread about engine noise, the engine is out and being broken down by Smeding Performance to hopefully find the problem. Maybe after I get it running again I can play with the 4X4 shifting issues and see if any of the suggestions helped. thanks,, string

[Touch_Of_Madness]

Uh Guys?

Remember you are driving 4x's that came out before pushbutton Transfers and Shift on the fly 4x's. The need to stop the vehicle (and or shift to neutral and or back up) is the reason that shift on the fly was set up in the newer trucks. To expect and older truck to shift on the fly isnt good on the truck (it may do it but its not designed for it). If you loose control of the truck during a missed shift and end up wrecking dont blame the transfercase. There are no syncronizers in the transfercase. . .

Remember that the vehicle you are driving is over 30 years old please.

You want shift on the fly then put in the lighter duty 208. . .

Eh never mind.

Josh? Please remove my membership from this board.