Astro 4x4 Adventure VAN

PJorgen

Desert Dweller
Wish I had your brains and/or talent. I had an '03 AWD Safari (GM version of the Astro) but sold it because it wasn't a capable off-roader with the stock transfer case.

Good luck, I will watch this thread to see what you do next.
 

Herbie

Rendezvous Conspirator
Awesome work Sharkfox. I'm sure you've seen Dean's similar project (the fruits of which are now on my van), but just in case you haven't, I'd hate to see you reinvent a wheel. Here's how he did the cable-shift NP233.

For me, the cable-shift is really the best because you only have to make one small floor penetration (and one hole in the driver's seat mount). I too prefer the simplicity/robustness of a mechanical actuator vs. the electronic shift.
 

Sharkfox

Observer
Awesome work Sharkfox. I'm sure you've seen Dean's similar project (the fruits of which are now on my van), but just in case you haven't, I'd hate to see you reinvent a wheel. Here's how he did the cable-shift NP233.

For me, the cable-shift is really the best because you only have to make one small floor penetration (and one hole in the driver's seat mount). I too prefer the simplicity/robustness of a mechanical actuator vs. the electronic shift.

Thanks Herbie. My shifter and t-case have been installed and functioning for over a year now. I'm still trying to play catch up to where my build is now on this thread. I did consider using a push-pull cable at first but decided to use the materials I had on hand to fabricate one.
 

Herbie

Rendezvous Conspirator
Thanks Herbie. My shifter and t-case have been installed and functioning for over a year now. I'm still trying to play catch up to where my build is now on this thread. I did consider using a push-pull cable at first but decided to use the materials I had on hand to fabricate one.
LOL, I hear you on catch-up posts. Well, can't wait to see how you finished it off. The more the merrier!
 

Sharkfox

Observer
Designing the shifter and linkage was a mathematical exercise.
First I determined the force required to shift the t-case. The simplest way I could come up with on the fly was with a fishing scale. Hook it to the wrench and pull slowly while watching the scale until it shifts.
Once I knew that, it was a matter of converting it to the torque required and calculating appropriate linkage lengths.

The plan was to cut a hole in the floor close to the base of the driver's seat and keep the handle close to the floor and out of the way. I decided that I would cut a small hole in the floor and bolt the shifter in place. I made two mounting plates. One above the floor and one below the floor. The plate above the floor has the shifter pivot attached to it.

Here are the pieces that make up the pivot and mounting plates.







Everything on the top side is tacked up ready for test fitting.



 

Wiley

Adventurer
For me, the cable-shift is really the best because you only have to make one small floor penetration (and one hole in the driver's seat mount). I too prefer the simplicity/robustness of a mechanical actuator vs. the electronic shift.
Plus it looks bad *** having the shifter in the floor.

Great van Sharkfox, hurry up with those pics
 

Sharkfox

Observer
The shifter was semi-designed so it was time to do the t-case swap before I could finish it up. The transfer case got a new set of seals and a fresh supply of fluid before the installation.
The actual physical swap was surprisingly straight forward. I dropped the axles and pulled the stock transfer case out.



The bolt pattern on both transfer cases are the same. I swapped the studs out of the original and bolted the 4x4 case in.
Everything lined up like it was supposed to. I reattached the axles and that was about it. Pretty simple conversion.
Thanks to the Astro Forefathers I was able to figure out the electrical side of this project. I followed THIS BULID (thanks Herbie) to get the transmission to shift when put in low range.

The VSS connections were different so I had to replace the old plug with this one.



Soldered and heat shrinked to keep everything tight and clean.




Now that the transfer case was in, I could start aligning the shift linkage and finish assembling it.



More to come.....
 

dar395

Adventurer
Herb Do you access that roof box very often? I have several but can never get serious about using them because they're so high off the ground![/QUOTE said:
Man some days ya just got'a back up. missed that box first time though. I been trying hard to find an Astro van factory roof rack for my Sanvana. You can put a 7.5' Awning rail on them. But not to get off this post, I luv the utility vans and this one is great looking!
 

Sharkfox

Observer
Here are a few pictures of the shifter installation. I'll try to get some updated shots of the completed linkage below the floor too.
The hole in the floor mat is kind of sloppy but I was planning to cover it up with a generic shifter boot once it was all done.

There is a micro switch mounted to the shifter that gets depressed when the shifter is put in 4-lo. The reason for this is to ground a terminal at the ECU that allows the transmission to shift normally when in low range.
The bolt is installed to fine tune the point of contact. Everything is tacked in place here for a quick test fit.


Once I was sure everything was in the right place, I finished welding, shot it with a couple coats of paint, and bolted it all together.
I didn't want the shifter to be too intrusive or in the way of any type of future center console so it is tucked pretty close to the base of the driver's seat. Since most of the driving is done in 2WD mode, the shifter is low down and out of the way in 2WD.



Here it is in 4-Hi...



Here it is in 4-Lo. Notice the micro switch is depressed here.



Here it is with the seat back in place.
It's tight, but the shifter clears the seat reclining lever and seat belt.



 

BigC

Observer
Looks sharp! I like how you kept it so low to the floor in 2wd mode, keeps it out of the way tucked in there next to the seat as it is.
 
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