5.3 4x4 Driveline Swap, it begins!!!

[chaosR]

So its been two weeks tomorow sine i started the project. I did not spent the whole 14 days on it. But 10 for sure. That's 8-10 hours a day. This includes a couple of days of running around to get supplies ect. Im posting this just to let folks know how long to expect to spend on such a swap. I had the van running for a few seconds yesturday just to check my wiring up to this point. So that was nice to hear it come to life. Since my last update i have done quite a bit and i will post it all up when i can as i go.

here is some more pics with updates.

[chaosR]

IT WORKS!!!

Well after aprox 3 weeks of hard work the van runs and i was able to take it for its maiden voyage. It was only for a few blocks as my allingment is compleatly out from changing all the a arm bushings ect. When this gets done in a few days i will report more on the drivability and the change from AWD to 4x4. But it really rips, it feels faster than my vortec 5.7 van, even with the 31" tires

Yesterday a budy came by with his fancy scanner tool and we checked all my conections. The engine, transmission and DBW and cruise were all happy. But the T case module had some codes so we cleared them and the 4x4 selector buttons and t-case begun to function.

Looks like i first timed 'er on my wiring. I dont think i can say that has ever happened before.lol.
Anyway the only aditional wiring i may need to do is figure out a way to trick the T-case module into thinking i have a locking front diff. Either that or get the actual diff motor from the truck and plug it in to the wiring. But i bet the motor is bulky. And i may be able to acomplish the same thing with a simple relay instead. The reason this is a issue is the new trucks have led's on the selector butons which blink when you select a specific mode. It keeps blinking untill the module is happy that all the cyteria for the mode you select have been met. Im my case it thinks the front diff is not locking in, so the button led indicator keeps blinking. Im sure this will drive me nuts, especialy driving at night.

All my stock guages work, apart from the temp sensor. I need a 3 wire coolant sensor vs the 2 wire stock on the truck, i ordered it today so i will report on that later. I used the V6 oil pressure sensor with a adaprter i made. I can't seem to find one that has a 16x1.5mm male to 1/4"x18 NTP female. 1/4" NTP is what the stock sender is and 16mm is the truck block. There is one avalable that goes from 16mm to 1/8 NTP, but then you would need another adapter from to go from the 1/8" to 1/4". By then the whole shabang would be like 4 or 5 inches long.
I was able to get rid of the stock speedo buffer box the 95 had and plug the PCM VSS output wire directly to the speedo imput at that plug. So that's sweet! The only other wire required for the guages was the check engine from the PCM.


For now here is some more pics of the mods, i will post more info and pics later as i have time

[chaosR]

UPDATE!

Well after 4000km on the van since the swap i can report that it is very good. My first trip out after the swap revieled a couple of issues. One was the cruise did not work. I later found the brake wire for the Drive By Wire Module was hooked up to the wrong wire on the van.

Apperantly the PCM must see the brake wire and the converter lockup wire working in conjunction for the cruise to enguage. So with the brake off, there must be power to converter lockup and no power to cruise brake wire. When brake is on , no power to converter and power on to cruise. If they dont jive, cruise will not enguage. Smart little box!

Anyway the DBW and cruise all works good now with the stock van cruise buttons, so have no fear going with newer driveline DBW stuff.

The other issue was a loose ground, luckly i have a second battery on board for my camping heater, i used it to start the van in the bush as the main batt was dead due to the loose ground. Phew!

I had a local AC shop make me new lines and the AC is now back in business too.

The van with the 5.3 is very revy. Much more so than my other 350 van. I seems to be just as fast but has less bottom end, it builds power up top and then really goes. It's nice for passing on the highway over 60mph. The faster you go the more power it makes so thats actually nice for something lifted pushing all that wind and with big tires on it.

The 4x4 functions work great. And 4 low is amazing! My first weekend out i couldint belive the things i climed and the places i went with it. We shall see how the Auto 4x4 works in the winter, hopefuly good as it is very similar in function to the newer AWD systems. And i loved the stock AWD for winter traveling.

Anyway i hope this post is helpfull to anyone thinking about doing this, it's a project alright but very doable and worth the effort.

I got some exporing and camping to do!

Cheers everyone!!

[icebrrg3rd]

Those are some awesome shots! I would have loved to see your van climbing that, and the faces of anyone else who had thought "A minivan 4-wheelin?" Glad you got everything running well, motivates me to do my "simple" 350 swap!

-Andrew

[wheels55]

Fantastic outcome. Pictures make it look like a great deal of fun.

[dvil]

WOW! What a great project. Best reading i've had since ehhh kindergarten. Really impressive to make it all work together. Thanks!

[chevymaher]

I just re-read everything. Nice job. Glad your getting to enjoy it now.

[MadMaxiVan]

i agree,ive gotten my 5.3,411computer,wiring harness-complete to bulkhead connector, etc and have been reading this thread.
you did it in two weeks,which really is good and renews hope that i could actually do this myself as well.
great job,btw.

the hardest part so far is actually figuring out that wiring..

theres a couple of other details too,like,
what torque convertor do we use if we are keeping the original transmission?
98 2wd/ astro.

my game plan is to get another junk astro and build everything on that subframe and then do the swap.

o,and those exhaust head bolts are a PITA,who designed such crappy bolts and so small??

edit,btw,what kind of gas mileage are you getting with the 5.3 ??
what size gears are you running?
thanks

[grandamle91]

Just wondering how you tried into your wiring for the gauges and ob2 port etc.?

[chaosR]

Sorry i have not been on here for a while, but life just takes over, i moved this summer ect.
Van is working great i got over 10,000 k on it now since the swap. And i have been able to build some other stuff for it which i will post later in a different thread.
>MadMaxiVan, As far as the fuel milage i did not do a official check as of yet. Its better or same as the V6 was. But I always drive 120-130km /hr thats 75-80mph on our hiways out here and now there is a lot of idling going on because of winter. I will do a test from gas station to gas station doing a even 60 mph one day soon.

>grandamle91. The obd 2 i very easy, ther is only a couple of wires you need. If your doing the 4x4 like me there is one extra data wire from the t- case module. Check out this site, there is a ton of info there as well as all you need to know about the OBD 2

http://lt1swap.com/wiringharness.htm

As far as the guages on my 95 I wrote about most of it in this thread.
It was easy for the speedo, there is a PCM wire, i sent my PCM to the guy on lts1 above. He took off all the theft crap and the emissins stuff as well as changed the PCM speedo VSS output to work with my guage signal. From there its one wire to the connector of the calibration box under the dash. Its the white box you change on the older astros if your changing the gearing in your diffs ect.

I took this box right out on mine as mentioned in previous posts, i hated the ABS on the van so thats the only thing that stops working if the box is removed. I pluged the wire from the PCM to the speedo input wire and thats it. If you want to keep the box and ABS just plug the wire in there and it should still work.If your swaping the transmission and t case like me then that's the only time you need to worry about it. If your just doing the engine the speedo should work as before.

Next i sugest you remove the oil pressure sender from the V6. also mentioned earlier, and go get a adapter i talk about and put it on the 5.3 or 6l. Then your pressure guage will work like before.

And lastly get the 3 wire chevy water temp sensor i mentioned before, here is the PN and some more info on that. Keep in mind im in Canada so hopefully the PN are the same where you are. ( for the connector i cut and used the TPS connector off the V6, it's the same)


Coolant sensor 3 wire
GM Part nbr: 12551708 NAPA P/N- TS5721 ($25.49)


GM Connector part nbr: 12551708 NAPA P/N- EC89 ($19.29) for the connector.

A = Black............Coolant temp input to ecm, low reference
B = Yellow...........Coolant temp input to ecm, sensor signal
C = Green............Coolant temp input for cluster mounted temp gauge

Cut the stock coolant temp connector off the LS engine and replace it with the 3 wire. The black and yellow are a loop to the PCM tie those to the wires that are there on the LS harness after you cut off the conector. The Green wire is on your van, so find it and tie into that. It goes to your guage.

Thats what i did and all my guages work properly
Cheers!

[grandamle91]

So you used the 5.3 engine harness? I'm planning on getting a harness and 6.0 engine from a 02+ Chevy Express. I'm going to be using my tranny and s10 t case

[DRZ]

So you used the 5.3 engine harness? I'm planning on getting a harness and 6.0 engine from a 02+ Chevy Express. I'm going to be using my tranny and s10 t case

'99 and newer the temp gauge gets its signal from the computer, '98 and earlier it comes direct from the engine so plan to install another temp gauge sensor on the engine before you put it in. Also the ABS electronics changed between '98-'99 so that isn't going to work. I "think" just installing a '99 & newer ABS pump on the frame will cure that but I didn't try it so can't say for sure. If you use the '99 or newer battery box, the Gen IIIs computer will slip right in. That is another reason to use a truck motor or at least the wiring harness as that has the puter in the Astro position unlike the Z28/Trans-Am that has it on the right.The last problem I think you're going to have is the fuel gauge. That system changes at the '98-'99 model year as well and I never did figure that out. Good luck with your project and it's well worth it when done imo. I used the engine AND transmission from the '99 Trans-Am into my '98 Astro so other than changing the shifter shaft between the two while the trans pan was off to install a new filter and oil, I had no problems matching up there.

[chaosR]

So you used the 5.3 engine harness? I'm planning on getting a harness and 6.0 engine from a 02+ Chevy Express. I'm going to be using my tranny and s10 t case

Yes i did use the truck engine harness as i used the engine/trans and 246 auto t-case from the truck. You may want to re think using the s-10 t case if you plan to drive a lot during the winter. I did a lot of resarch before i did this swap. And many people say the astros are very skechy on winter roads and especialy higways if you need to use the hi 4x4. Much more so than the s-10 trucks aperantly. One of the reasons i did the 246 electronic button operated t-case is becouse it has the Auto 4x4 function which is basicly AWD. So your getting the best of both worlds, you have a v8, full 4x4 functions and AWD for great everyday winter driving. And honestly it's nicer when everything comes from one donor vechicle. Not only for instalation but repair down the road. This way you only need to tie into existing systems on the van and eveything is made and programed to run with the new comonents..for example a 6l usualy comes witha 4l80 trans. hevier duty shaft wise ect than the 4l60... if your 4x4ring well and want to have no issues...well you know what im saying here, its woth it to do it the first time. But hey its just my opinion and i dont know what your goals are for your rig.
Im and super happy with my swap above. Cant stop using the van and go out exploering and camping every chance i get. But i think the next one i do i will do the 6.0L like what you are planing. The 5.3 is very good, but a lifted van with winches buch racks ect, is heavy. I did weight mine recently at a truck scale its 4600lbs. yikes! No rear seats eather. So thats full size 4x4 territory kind of weight. A 6.0L will definatly have a easier time pushing a tall large brick through the air.

Fuel milage wise, i just came back from a 725km / 450mi round camping 4x4 trip today. It consisted of a few days of camping so there was some idling, as well as slow 4x4 trails. About half 300km/ 190mi was hiway (@ 110km/hr or 65mi / hr) there and back. I burned 94.5l or 24.96 gal of fuel ove the trip.
So that works out to be 13l/100km or 19.5mi /gal. Not bad conidering the mixed conditions, and mountain terrain i was in. I will do a streight hiway run one day on a calm day and a semi flat higway to see what that shows. But i bet it would be just as good if not better with a 6.0L. As we know from experiance with small engines like the 4.3 and small v8's smaller dosent always mean better fuel milage.

all the best with your build.

[trapper20]

I had the s10 case in my van, great in the mud but jerked around in the snow and ice. It was safer in 2wd in the winter.

[Ragenme]

Awsome job.

[TheOtherByron]

Very nice build!

Please pardon my n00b questions, but I'm trying to wrap my head around something. You used the stock front differential and axle things with the donor transfer case? The Astro's front systems are strong enough to handle the extra power your V8 makes?

[WoodButcher]

[chaosR]

Thanks guys:)

No such thing as knob questions on here TheOtherByron, thats what this is for to help each other out. Yes i used the stock diffs in this build as well as my 2wd 350 van years ago. From what ive heard form driveline shops the stock rear end is good for 350-400 hp. The weakest link in it is the stock posi g80 set up with HP put to it. I know quite a few guys who have blown theirs up. Including me in my 2wd with a vortec 350-280hp or so. If they get to many miles on them (mine had 280km) and you got power thats usually what fails, the little pins in there break and well... its a mess after that. The rest of the parts can easly handle it if there was regular maintenance. Dont forget in the 90's this rear end was in the half ton trucks too.

I rebuit the 2wd with a aftermarket possi. And plan to do the same on this 5.3 4x4 van. What ive done before is get a whole diff from a local junk yeard ( $125 around here) Then rebuild it as i have time and the cash. Then do a swap when done which is a days work. That way i keep the van on the road in the meanwhile.

As far as the front end goes it basicly uses the same size gears ect as the rear, but does not have the g80 posi and has a aluminum body which may be the weak point. But the front diff sees a lot less use then the rear so it lasts. Ive seen guys with 350 hp vette engines in the awd vans and it held up fine. And If your 4x' ing the bigest thing that kills drivelines is wheel hop.