Chevy & GMC Vans

Hey Snowgeek, nice to see you around again - hope you and the family are doing well!

Racerx7, if it helps I can copy the wiring diagram images from the GM eSI manual on my computer and send them to you since I'm probably going to go the same route here soon. Might save some time, or not.

Racerx7, if it helps I can copy the wiring diagram images from the GM eSI manual on my computer and send them to you since I'm probably going to go the same route here soon. Might save some time, or not.

Hey Strover. Sure, send me what you got and I'll see what I can do with it

Striver good to be back.... i am excited for some new projects!!

I am on the hunt for the parts needed for this t-case. I have a few c-list leads already and then the pick n pull lots as soon as I have time. I need this project staring me in the face.... My van has been begging for low range but have never been willing to give up awd.... Driving super windy roads with no guardrails and more 20 mph corners than you can count each day I go skiing is not a place for a darty 4wd van.

Ryan

Ryan, I should mention that all of these early NP cases are subject to the infamous "pump rub" or "pump knock", in which the internal pump locator clip breaks off and let's the lugs on the pump wear a hole through the rear magnesium case. It's not a hard fix, BUT, if the case was allowed to run low or out of fluid, chances are the internals are worn. Look for excessive wetness on the top half of the case at the tail shaft, a sure sign a hole is present. Before you even go to pull one, pull the drain plug and see how much fluid is in it, and what condition the fluid is in. The "pump rub" fix is not an expensive one, just extra time involved. I used it as a bargaining chip when I picked one up.

Snowgeek wrote: My van has been begging for low range but have never been willing to give up awd.... Driving super windy roads with no guardrails and more 20 mph corners than you can count each day I go skiing is not a place for a darty 4wd van. Ryan

Yep, I know those roads, same reason I was slow to swap. It's my backcountry trailhead rig! Note the chains the LandCruiser had to put on to follow. Heh, heh

Hello,
For which years Astro will a NP 236 just bolt in without any driveshaft, gearing, etc. modifications? Would 1998-2005 work? Also, do you have guidance for wiring up the 4x4 transfer case? Thank you.

Jesse

Hello Jesse. Yes, the 236 will fit those years of astro vans. The 236 is just a 2 speed version of the 136 that's in the later model Astro vans. It's a direct swap out as far as the mechanicals go. No cutting of anything. The TCCM, switch and wiring is the tricky part. But it all works out as if the factory did it. And I can guide you, or anyone with the wiring.
Good luck

Thanks for the quick reply and offer to guide the wiring job. Are you considering writing up a walkthrough like you did with the mechanical side of the swap?

trip_south wrote:Hello,
For which years Astro will a NP 236 just bolt in without any driveshaft, gearing, etc. modifications? Would 1998-2005 work? Also, do you have guidance for wiring up the 4x4 transfer case? Thank you.

Jesse

If you are asking what year Astro a 236 will bolt into, it will only work in Astros that came with the 136, which is escaping my old brain.... I can tell you for sure that it will not work in a '98. Anyone out there remember what year they made the switch?

That would be 1999 thu 2005 with the np136. As far as wiring goes I believe racrx7 is the first to get it all done. Hopefully he can find the time to explain what he did and how.

Damn, found a blazer being parted out with everything I needed.... When I told the guy what I wanted he blew me off and now says he isn't parting that one out. Guessing he doesn't want to pull the harness... The search continues.

Ryan

racrx7 wrote:

Racerx7, if it helps I can copy the wiring diagram images from the GM eSI manual on my computer and send them to you since I'm probably going to go the same route here soon. Might save some time, or not.

Hey Strover. Sure, send me what you got and I'll see what I can do with it

Let me know what year/model for the 236 and if jpeg image files work, I usually just use a photo editor like GIMP to add text or whatever.

Let me know what year/model for the 236 and if jpeg image files work, I usually just use a photo editor like GIMP to add text or whatever.

A '99-00 should do just fine.
Thank you!

So I assume I should replace the output and input shaft seals of the 236 from the Blazer prior to installing in the Astro. I found this kit:
http://www.americanpowertrainwarehouse. ... s-o-rings/

Will I need any special tools or materials for replacing the seals? Any tips? Does anyone have the procedure for this?

Thank you.

Jesse

Hi,

I have a NP233 electric 2 speed t case from 98 s10 that I was going to put in my 2003 AWD Astro. But maybe I should get a 236 instead?

Did some mild wheeling today in some sandy areas. Astro AWD does work well. A lie range would be nice for hills.

AP