03 5.3L AWD Conversion van mechanical issues. Service manual available? - Chevrolet Forum - Chevy Enthusiasts Forums

03 5.3L AWD Conversion van mechanical issues. Service manual available?


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nitroheadz28's Avatar
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February 15th, 2017, 4:07 PM   #1  
03 5.3L AWD Conversion van mechanical issues. Service manual available?



So it turns out my nice looking express, isn't so nice underneath the body. I had an inspection done today, and I have a few issues. I'd like to do as much of the work myself as I can, but have never worked on something so monstrously huge and AWD. Not to mention there isn't a ton of info out on forums about them compared to the muscle/ sports cars I'm used to.

2003 Express 5.3L AWD

Issue #1: Transfer is leaking where the 2 halves meet. Seems pretty self explanatory, just trying to find a service manual to see what needs to come out before I can drop the t-case.

Issue #2: Coolant leak, I was looking at it with my mechanic buddy and there is some dexcool sitting at the bottom of the engine. At the top it looks bone dry, once again I'd like to check the manual before I tear into it so there are no surprises.

Issue #3 (Most annoying): Van will not run properly in gear when cold. It idles perfectly fine, when you shift into gear and start driving it will cut out, buck, then surge, and usually stall after. It restarts perfectly fine, and will idle fine in gear until you get moving and it acts up under throttle or when the van is moving. It runs perfectly once the temp gets past 1/3rd of the gauge.
So far I checked/ cleaned the air box and throttle body, both generally clean. I unplugged the MAF and tried again, does the same thing. I will have to check fuel pressure, IAC, and spray carb cleaner around the intake to see if I get a response.

If anyone has any suggestions or a link to a shop manual, I'd really appreciate it.

 
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February 20th, 2017, 11:23 PM   #2  
I figured I'd update this thread, since there is barely information on these AWD vans in case someone has the same issue in the future.

So far I've been working on the transfer case, the steps are:

-Disconnect front and rear driveshafts, remove the boot clamp on the front shaft to slip it out
-Drain fluid
-Unbolt fuel filter bracket and ABS block
-Disconnect VSS speed sensor and vent hose on top
-Support the transmission crossmember, unbolt the trans mount, remove the 8 bolts holding it to the frame and drop the crossmember
-Undo the nuts holding the t-case to trans, remove transfer case
-Disassembling the case: Remove drain plugs, VSS sensor, bracket on top of the case, and pry out the front input shaft seal/ output shaft seal.
-Remove all transfer case bolts, pry the case open. Its RTVed, no gasket.
-When reassembling, you will need the input/ output seals, and a new transfer case to transmission gasket. Transfer case bolts are torqued to 37ft-lbs, crossmember bolts are about 45-48ft-lbs, trans to t-case I'll have to check. Fill the transfer case right up to the fill drain plug. GM calls for RTV on the case halves, I'm using Hondabond. You can use anything but the Permatex stuff has let me down before and HB has been great for non gasketed mating surfaces.

In my case, everything was pretty damn rusty. The fuel filter nut is seized on and I'm still fighting it, had to disconnect the filter to drop the crossmember (Thankfully I was changing it anyway).

This is everything that had to come out:



Transfer case:




I'm still waiting on the seals to get here, will update as I go along.


Last edited by nitroheadz28; February 20th, 2017 at 11:34 PM.
 
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February 22nd, 2017, 7:38 PM   #3  
Well, I'm already starting to hate this van..

-The Pioneer radio I hooked up wouldn't fit because of the way the dash is cast, it required one dremel dying and it's replacement barely able to cut through. But the radio now mounts perfectly:




-The damn transfer case seal races are rusted into the case pretty good. Will try to heat up the case next and see if it helps any:



-Spare tire was stuck as I've learned is typical for most GM trucks, the secondary latch was seized. Going to cut that sucker off:


img upload

The saga continues..


Last edited by nitroheadz28; February 22nd, 2017 at 7:42 PM.
 
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February 22nd, 2017, 8:38 PM   #4  
Great info. Keep your head up.

 
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February 25th, 2017, 10:53 AM   #5  
^Thanks! It helps having fellow mechanic buddies to talk me off the ledge a bit haha, I was supposed to head off on my cross country trip 2 weeks ago and the van is pushing things back a bit. Anyways, quick update on this unruly transfer case:

I brought it over to a friend and with ample amounts of beer, cursing, torching, and penetrating spray we were able to split the case apart and get the seals off. Man the RTV is on there GOOD. The front output shaft race was rusted into the shaft and we messed it up a bit with chiseling the race off, but even after cleaning it up a bit it was pitted anyways.

Notice: I'm using Snap On's prodemand program, which I guess is similar to alldata. You do do NOT need to remove any seals to open up the case, so if your seals don't leak I'd recommend not touching them to avoid a disaster like mine. You also don't need any special tools to remove the shafts and chain drive, so its worth it to do this job yourself. Total parts cost was under $230, shops quoted me $350-600 just to open the case and RTV the two case halves. It would probably be close to $1000 with parts and the extra labor to do all the seals if they don't come off easily like mine. Worth it despite the aggravation, and knowing you did it right= priceless (Lots of second rate shops in the area).

One recommendation, DO NOT bother ordering seals from rockauto for it. Skip the aggravation and order OEM parts straight from the dealer wholesale network, the SKF part for the front input shaft seal has the wrong inner diameter.. About 2.5mm too large. $40 in express shipping down the drain, and another $53 for 2 day air for the OEM stuff . Luckily it seems most OEM parts are still available, I ordered a new input shaft along with all the seals, the t-case to trans gasket, and a couple bolts to replace rounded ones. Stay tuned..








I also started on replacing the water pump and belt drive, the fan clutch is one SOB. I should have figured with how much rust is on the rest of the car, will attempt to build a tool from scraps to get it off. While I was there I cleaned out my noisy blower motor, 4-5 acorns bouncing around inside and about 5 fistfuls of twigs/ pine needles/ dried leaves that came out! Half of the fan shroud retaining clips broke off with the bolts stuck inside from how corroded they were, fun fun fun.

My fuel fulter is totally FUBARED as well, the nut is seized onto the fuel line fitting and rounded off. Thinking of a way to cobble it together so I don't have to have it towed over to the shop, I'm hoping they can reflare the line and add a new fitting instead of replacing the whole thing $$$. Any suggestions?


Last edited by nitroheadz28; February 25th, 2017 at 11:11 AM.
 
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February 25th, 2017, 2:06 PM   #6  
I enjoyed seeing a wood chisel in this process. I've bought gasket scrapers and found them to be worthless. Being a woodworker for 30+ years I have plenty of chisels. Next time I do a water pump on a chevy I'm going to custom modify a chisel for getting into that tight spot.

Edit, I also use sand blocks for woodworking that come in handy for stuff like this. Take a straight flat block of wood, an 80 grit sanding belt for a belt sander and some spray contact adhesive. Cut a piece of the belt glue it to the piece of wood and you have something that will give a good final surface prep for gaskets and RTV. Make sure you hold it flat when sanding.


Last edited by JIMMYDRIVER1; February 25th, 2017 at 2:12 PM.
 
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February 25th, 2017, 9:30 PM   #7  
Posted By: JIMMYDRIVER1 I enjoyed seeing a wood chisel in this process. I've bought gasket scrapers and found them to be worthless.
Razor blade for me, nice and gentle!

Quick update, today was the first day that working on the van was somewhat of a pleasure

Fan is off, I rented an adjustable fan clutch tool from Autozone. Its not listed on their site, but one of my local stores had it. Using 2 bolts through the pre-drilled holes in the wrench, I was just barely able to knock the fan loose. It bent one of the bolts up pretty good, but its off!

Water pump is off, so easy to do on these vans!

I changed the TPS and IAC, the IAC looked pretty sketchy so I was curious to see if a new unit would cure my cold rough running symptoms.

Changed the front 2 plugs/ wires while I had the front end apart, the rest I'll do from inside the van. There was definitely at least one critter making the engine bay it's home for a while, lots of acorn bits and other crap all over.

I still have to figure out what I can do about the fuel filter, my buddy suggested I install a fuel filter with 2 quick disconnect ends and hose clamp it onto the line. That would get me to the shop, but I need to think of a permanent solution in case the guys at the shop insist on changing out the entire fuel line.

Another $hitty situation... I removed the conversion rear bench seat because I'd rather just lay a mattress pad out and sleep on the floor. Problem is that the bolts go through the floor and are captured by nuts underneath (Freaking stupid design). They're seized on like crazy, maybe the guys at the shop will be able to zip them off with an impact but I really don't want to resort to breaking out the hand grinder.. Especially when I can't pull the carpet away because the seat mount brackets are holding it in place.





picture hosting

 
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February 26th, 2017, 12:03 PM   #8  
Wait you're doing this on the street? That must be hard.
How come you have acorns and mice **** in the radio compartment? That's not a good sign, if the rodents chewed the wires you can expect further electrical problems.
Best way to remove the fan clutch is an air chisel. Yes you need an air compressor for this but even the smallest $50 donut compressor would work. Air chisel cost $20 at HF. The chisel hits on that huge nut in counterclockwise direction and in 30 seconds even the worst rusted one comes off. That's one of the best advices I could give you and applies to any car with a fan clutch...

The problem with rust is that you cannot win that game. I used to live in MA and spent many days fighting rust. Problems just never stop. If you can buy a car from the south, it is well worth it, even if you have to pay for shipping or spend a few days to pick it up.

 
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February 26th, 2017, 12:05 PM   #9  
Oh, and while you have the clutch removed - do install a new one, it's only $50 from Rockauto.. They usually last about 50-60k. miles and chances are it's old. Will save you from overheating in the summer time. Since it's winter, while you're waiting for the parts to arrive, you can drive without it.

 
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February 26th, 2017, 12:34 PM   #10  
Posted By: Artie1 Wait you're doing this on the street? That must be hard.
How come you have acorns and mice **** in the radio compartment? That's not a good sign, if the rodents chewed the wires you can expect further electrical problems.
Best way to remove the fan clutch is an air chisel. Yes you need an air compressor for this but even the smallest $50 donut compressor would work. Air chisel cost $20 at HF. The chisel hits on that huge nut in counterclockwise direction and in 30 seconds even the worst rusted one comes off. That's one of the best advices I could give you and applies to any car with a fan clutch...

The problem with rust is that you cannot win that game. I used to live in MA and spent many days fighting rust. Problems just never stop. If you can buy a car from the south, it is well worth it, even if you have to pay for shipping or spend a few days to pick it up.
After doing everything from transmissions and suspensions on my trans ams and other fun cars I swore I'd wait till I got a garage before I tore into another car. I guess here we go again... Haha

I'm a little pissed at myself because I was desperate with getting an express/ savana, I'd spent over 2 months looking for one in the tri-state area and all of the ones I checked out were falling apart/ beat up. This was one of the cleaner ones, but I couldn't see the extent of the rust because of the low running boards on it (And I bought on a Sunday night so getting it on a lift was out of the question).

Having said all that, most of this work is typical 100k maintenance and having it fresh for long distance touring. As long as nothing goes wrong for a while, I'll be happy.

 
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