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Astro Select Trac AWD/4x4, NP 242c build and install

FROM AWD'S TO 2-SPEED MANUAL SHIFT, IF IT LINKS THE REAR AXLE TO THE FRONT AXLE, POST IT HERE.

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Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by T.Low » Sat Nov 19, 2011 4:37 am

Image :drinkers:


Great thread. Yet another reason ASV will live forever.

The only problem I have with this thread is your sig line pic, Photo Van. I can never scroll on by it, always have to stop and look at the whole pic. The van catches my eye, then i quickly check out the camping gear. Then follow the mountain terrain up to the horizon line and then across the ridge and down to the sunset. Wow. Then I look for any sign of a two tracker that you may have driven in on.

The your next post stops me again with the same routine.

Carry on...Image
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Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by photo_van » Sat Nov 19, 2011 4:32 pm

So now we’ve put our tc back together and looks like this: the NP242C, 19“ long and weighs (not sure yet)
_MG_7974.jpg
So now it’s all ready to install! Wrong. While the rest of the world was using a standard NP 6 bolt TC to trans pattern, the engineers at GM decided to make our vans special and use a 5 bolt pattern like this.
Screen shot 2011-11#12C597B.jpg
But we knew that, right? Apparently they used this in “light duty” applications, the 231c I have is of the same pattern. No big problem, because we know that GM also makes a 6 bolt patterned trans/TC adapter because they are for sale ($50) on ebay. I think this is used in the ‘99 and up Astro with the NV136? It looks like this
Screen shot 2011-11#12C5954.jpg
So I’m all ready to press the “Pay Now Button” (no returns accepted) and something doesn’t look right…. “GM’s 6 bolt pattern is different then the standard NP 6 bolt pattern....”!?! “You’ve got to be !@#$%^ kidding me!!”

So no, it’s not ready to install. The bolt spacing may or may not be the same, don’t know, but the “clocking” is ~90* different. Now, we can get really creative here, or suck it up and pay the big bucks, many options.

If the 6 bolt spacing is the same, buy a clocking ring like the one below. $50 Ebay
Screen shot 2011-11#12C59E2.jpg
This set up will push the TC back 7/8” as the 6 bolt GM adapter is (go figure) 1/2” longer then the 5 bolt. The clocking ring is 3/8” thick. In my case, with the shorter TC input shaft I was worried about loosing 7/8" of spline contact.

If you have access to a lathe you could pretty easily make your own clocking ring that matted the 6 bolt TC to the 5 bolt adapter. Out of 1/2 aluminum or 3/8 steel, I think this could be a very viable option. But my brother with the lathe is a busy guy and 300 miles away. Even so, I bet you could pay to have one made for much less than $300, especially if you did the drilling yourself.

Or you can spend the $300 for one of the “castings” from the fore mentioned adapter kits.

In the end I opted for the 3” adapter from Novak.
_MG_7975.jpg
By moving the TC 1” forward (the Novak is 1” shorter than the stock 5 bolt), I can now use the stock front driveshaft. I can also use an existing rear driveshaft from a Trailblazer ($25) (more on this later)

No driveshaft work means no 4=600 $ to the drive shaft shop. Still ahead and if things don’t work out, I have all the parts to put the BW4477 back in. The Novak will require a bit of fabrication re. the mounting to the cross member (yet another leap of faith).

***UPDATE*** So, last night, as the 70 mph winds were literally ripping the shingles off our roof (again), I had an epiphany :rolleyes: . A bit late for me, but if someone else is actually stupid enough to do this.

If you used an NP 241c as your donor, I bet you could use the entire front half of the 241. Input, planetary, front output and front case with the GM 6 bolt pattern! It looks identical to the 242 from photos.

The 241c would also have (I think) the VSS and reluctor. With some modification, you might even be able to swap the output bell housing from the 241. It is cast and machined for the VSS.

You would have to some how extend the casting around the shift rod as the 242’s is quite a bit longer.
I live ~200 miles to the nearest salvage yard so I can’t check it out. This would be a super clean way to do it!


Now, for the install. But it’s late November, I live at 7,000’ and wrench in the dirt/snow, stay tuned….
Last edited by photo_van on Sun Nov 20, 2011 12:43 am, edited 1 time in total.
1998 AWD/4WD
4" lift, 31x10.50's, NP 242j/c hybrid, 4.10 gears, S10 front disconnect, rack & pinion steering, trans cooler, rock sliders, ARB fridge, house battery and 100w solar, swing out rear rack with foldout camp table, bed and passenger swivel chair
dirt bag camping rig
1981 Toyota 4x4 pu
1974 John Deere 710
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Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by 1Gary » Sat Nov 19, 2011 10:21 pm

Great thread. =D> =D> Keep it coming bud :prayer:
1979 Malibu drag race only car
1999 Sonoma 4.3 5 speed-Rufus
1989 Astro-Ole Yellar cancelled-still selling off parts
1985 Astro-shop van R.I.P. my friend
1994 Astro LT RWD W4.3 rod knock RIP
1982 Winnebago single rear wheel-Chevy 350 Scraped 1/28/13-broken dreams......


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Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by doyoulikeithere » Thu Nov 24, 2011 5:55 am

Extremely Interesting.
Nice work, keep it up !

:prayer: :supz:
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Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by timelessbeing » Thu Nov 24, 2011 12:13 pm

I love this topic but I'm kinda lost already :rolleyes:
I hope there will be a summary review before the final test.

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Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by photo_van » Fri Nov 25, 2011 5:31 pm

re. the difference between the 242 and the 241 speedometer bellhousing. Machined VSS port on the 241, longer shift rod housing (lower left) on the 242
Screen shot 2011-11-24 at 6.28.07 AM.png
Screen shot 2011-11-25 at 9.20.24 AM.png
1998 AWD/4WD
4" lift, 31x10.50's, NP 242j/c hybrid, 4.10 gears, S10 front disconnect, rack & pinion steering, trans cooler, rock sliders, ARB fridge, house battery and 100w solar, swing out rear rack with foldout camp table, bed and passenger swivel chair
dirt bag camping rig
1981 Toyota 4x4 pu
1974 John Deere 710
Image

photo_van
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How many wheels are on an Astro van? (4): 4
Location: 7000' in the Mountains of California

Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by photo_van » Thu Dec 29, 2011 5:26 pm

alright. Christmas ment Santa and all those other Christmas things. It also ment taking the van to a warmer, drier, dirt free environment where I could finally complete the install. A BIG thanks to my brother for letting us hang at his house, use his shop, spill atf on his driveway and for his willingness to spend Christmas Day (and a couple of days on either side) looking like this:
_MG_8061.jpg
I also just noticed the little check box allowing the drop of the signature and photo, sorry about all that repetition!

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Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by photo_van » Thu Dec 29, 2011 11:30 pm

I thought that the tc build was going to be the hard part, wrong again, the install had a few surprises and details I wasn't expecting.

So first we had to remove the existing tc. Lifted or someone had the hint of losening the rubber trans mount and jacking up the trans to get to the bottom tc bolt; GOOD TIP!

Once the case was out I got my first good look at the trans output shaft. Since the new Novak trans/tc adapter is an inch shorter than OEM I knew I needed to cut ~1" off the output splines. No problem there, plenty of splines and a cut off wheel on an angle grinder made pretty quick work of that.
_MG_8051.jpg
Next, since the Novak adapter is designed for a Jeep aplication.I needed to figure out how the new adapter was going to mount to the OEM rubber frame mount. Not too difficult: cut most of the top off the metal OEM mount and cut the radius off and bevel the adapter.
_MG_8054.jpg
The mounting holes look close to the edge, but that's just the bevel; there is actually a lot of "meat" there.

Drill a couple of holes in the mount and call it good!
_MG_8052.jpg
Attempting a mock install to see how everything lined up we found that the tc wouldn't "suck up" tight to the trans adapter. After scratchin' the head a bit I figured out that the TC input splines were running up against the FRONT end of the trans output splines. Nothing a die grinder couldn't fix.
_MG_8059.jpg
1998 AWD/4WD
4" lift, 31x10.50's, NP 242j/c hybrid, 4.10 gears, S10 front disconnect, rack & pinion steering, trans cooler, rock sliders, ARB fridge, house battery and 100w solar, swing out rear rack with foldout camp table, bed and passenger swivel chair
dirt bag camping rig
1981 Toyota 4x4 pu
1974 John Deere 710
Image

photo_van
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Posts: 594
Joined: Wed May 18, 2011 11:38 pm
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How many wheels are on an Astro van? (4): 4
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Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by photo_van » Sun Jan 01, 2012 2:44 am

Here's what the BW TC looks like next to the NP 242
_MG_8048.jpg
So now time to bolt it up. Because of the narrow space between flanges on the Novak adapter I had to go get studs for the TC
_MG_8060.jpg
So now it should slide right in and look something like this
_MG_8081.jpg
note; I clocked the TC clockwise max.

Now put in the shiny "new" ebay, aluminum, Trailblazer driveshaft and it's drivable.
_MG_8046.jpg
But wait, that u-joint I "measured" up on the new driveshaft to be the same as an Astro? It doesn't actually "mic up" the same. Fortunately I'm in the "city" now and can drive down to the neighborhood driveshaft shop and get a conversion u-joint (2=11530) purchased and installed for $40.

Next, the linkage......
Last edited by photo_van on Sun Jan 01, 2012 6:12 am, edited 1 time in total.
1998 AWD/4WD
4" lift, 31x10.50's, NP 242j/c hybrid, 4.10 gears, S10 front disconnect, rack & pinion steering, trans cooler, rock sliders, ARB fridge, house battery and 100w solar, swing out rear rack with foldout camp table, bed and passenger swivel chair
dirt bag camping rig
1981 Toyota 4x4 pu
1974 John Deere 710
Image

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Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by TroySmith80 » Sun Jan 01, 2012 3:27 am

Great project, thanks for documenting!

photo_van
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Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by photo_van » Sun Jan 01, 2012 3:41 am

The shifter and linkage ended up a bit more of a chore then I anticipated.

I started with a shift lever and pivot bucket from a Jeep Wrangler
Screen shot 2011-12-31 at 7.08.27 PM.png
The Wrangler shifter is designed to mount on the transmission tunnel so the lever is short and the bucket is angled. I wanted the shift handle at seat hight so I needed to extend it.
_MG_8043 1.jpg
_MG_8045 1.jpg
I didn't want to pull up the carpet and rear heat duct to cut a big hole in the floor to mount the shifter pivot. Instead, I cut a 3" long 5/8" slot through the carpet, ducting and floor for the shift lever only, and mounted the pivot bucket under the floor.
_MG_8069.jpg
Since the TC is a 5 speed the pivot arm on the TC has quite a long throw (aprox 10:00 to 1:00) In the 10:00 position the arm requires a slight upward push from the shifter linkage. This was achieved by extending the shifter linkage arm by ~10" as seen in the previous photo. Also note that we extended the shifter pivot shaft by three inches to get the shifter closer to the drivers seat.

The last part of the linkage was the fabrication of this 5/16" rod to connect the shifter to the TC
_MG_8069.jpg
Attachments
_MG_8062.jpg
1998 AWD/4WD
4" lift, 31x10.50's, NP 242j/c hybrid, 4.10 gears, S10 front disconnect, rack & pinion steering, trans cooler, rock sliders, ARB fridge, house battery and 100w solar, swing out rear rack with foldout camp table, bed and passenger swivel chair
dirt bag camping rig
1981 Toyota 4x4 pu
1974 John Deere 710
Image

photo_van
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Posts: 594
Joined: Wed May 18, 2011 11:38 pm
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How many wheels are on an Astro van? (4): 4
Location: 7000' in the Mountains of California

Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by photo_van » Sun Jan 01, 2012 4:17 am

As previously posted, the 4L60e transmission (in an Astro) will not shift when the TC is in low range. Also as previously posted, there is a fairly simple fix; ground terminal 23 of plug BLACK on the ECU when in LO range.

I had thought I could simply run a wire from T-23 thru the TC position switch to ground. But upon examination of the TC switch I found that the contacts were the same in 4hi PT as in 4 LO; silly huh? So THAT wasn't going to work.

One could mount a dash switch but I wanted something more seamless.

We opted for a moment switch mounted to the shifter bucket and triggered by a cam on the shifter pivot. This pic shows the bucket and switch before modification, but you get the gist.
_MG_8055.jpg
The unusually cool thing about the BLACK plug on the ECU is that it can be almost entirely disassembled. This is the plug from the "back"
_MG_8066.jpg
This is the other side
_MG_8065.jpg
So now you need a little tiny tube (female pin receptor) to solder on to the wire. I ended up using a 22-26 gauge, phone wire butt connector. This was slightly big so I filled it with solder and drilled it out with a very small drill.
_MG_8064.jpg
I pushed this into the plug from the back and secured it with a dab of silicon then pushed the plug back into the ECU
1998 AWD/4WD
4" lift, 31x10.50's, NP 242j/c hybrid, 4.10 gears, S10 front disconnect, rack & pinion steering, trans cooler, rock sliders, ARB fridge, house battery and 100w solar, swing out rear rack with foldout camp table, bed and passenger swivel chair
dirt bag camping rig
1981 Toyota 4x4 pu
1974 John Deere 710
Image

photo_van
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Posts: 594
Joined: Wed May 18, 2011 11:38 pm
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How many wheels are on an Astro van? (4): 4
Location: 7000' in the Mountains of California

Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by photo_van » Sun Jan 01, 2012 4:26 am

So that's pretty much it, bolted up the stock front driveshaft
_MG_8072.jpg
Looks to have about the same clearance at the crossmember
_MG_8073.jpg
Lots of room
_MG_8070.jpg
_MG_8071.jpg
1998 AWD/4WD
4" lift, 31x10.50's, NP 242j/c hybrid, 4.10 gears, S10 front disconnect, rack & pinion steering, trans cooler, rock sliders, ARB fridge, house battery and 100w solar, swing out rear rack with foldout camp table, bed and passenger swivel chair
dirt bag camping rig
1981 Toyota 4x4 pu
1974 John Deere 710
Image

photo_van
I sleep in my van
Posts: 594
Joined: Wed May 18, 2011 11:38 pm
antispam: No
How many wheels are on an Astro van? (4): 4
Location: 7000' in the Mountains of California

Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by photo_van » Sun Jan 01, 2012 4:46 am

And the finished project inside
_MG_8077.jpg
I didn't think I would need an index plate but I was wrong, I made this one out of plate aluminum
_MG_8078.jpg
The shift pattern on the handle Isn't correct for the 242, maybe next time :muhaha:

I wanted the shifter tight to the seat so the center "console" would still fit
_MG_8080.jpg
And here are a couple of linkage shots I forgot to add
_MG_8067.jpg
_MG_8068.jpg
So that's it. :bounce: Questions, comments, flames welcome. A new Van for the new year

HAPPY NEW YEAR :cheers:
Last edited by photo_van on Sun Jan 01, 2012 5:50 pm, edited 1 time in total.
1998 AWD/4WD
4" lift, 31x10.50's, NP 242j/c hybrid, 4.10 gears, S10 front disconnect, rack & pinion steering, trans cooler, rock sliders, ARB fridge, house battery and 100w solar, swing out rear rack with foldout camp table, bed and passenger swivel chair
dirt bag camping rig
1981 Toyota 4x4 pu
1974 John Deere 710
Image

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Re: Astro Select Trac AWD/4x4, NP 242c build and install

Post by timelessbeing » Sun Jan 01, 2012 10:55 am

Congrats!
4-Low is high on the list of wants for my Astro. I'm still trying to figure out how to implement AWD+4Low with minimal fabrication.
Unfortunately, your conversion sounds complicated. :( What was the total cost?

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