02 Burb, Part 6, The "evolution" thread

[Flyin6]

Well, Part 5 is called the Duramax conversion and since that did not occur, I'll continue in this newer thread.

We have seen this truck go from a "barn-find" from Oregon from delivery through many stages of development.

At first I was just replacing normal service life components and "Doing a fluid change"

That term has significant meaning here because it applies to many a vehicle that started out as just a short resto or repair and ended up something short of a SEMA build. That concept is certainly alive and well with respect to this 02 2500 Suburban.

It got repaired, then it got lifted and got a ton of great suspension and steering. It got a gear change to 4.88's and then to 4.56. It has worn 285/70R-16 tires and it has been shod with 35" mud tires and currently wears 37" A/T's.

It once sported a 14 bolt semi-floater and stock 4.10 ratio, then for a time was fitted with a crazy Dana 80 out of a militarized up-armored Suburban. In the current configuration it as a very nicely Great Lakes Off-road (GLO-Shawn) 14 bolt full floater with Tate sourced (Yukon gear/Randy's ring and pinion) with a dura-trak and 4.56's.

The motor was freshened up with a mild overhaul at 96,000 miles and fitted with GM performance stuff, a .551" lift cam and LS-6 heads which was tuned by Skaats Performance and put down almost 500 horsepower to the ground on the 35's of that time. That would be a hundred more if it has a Camaro size tire by comparison! The motor was later on fitted with a blower cam and a LSA supercharger set to max out at 12 psi. The big HP numbers were post supercharger install.

I thought about putting a Duramax into it and then I thought I'd bolt in a Vortec 8100. I even purchased that, but after really digging into the cost of doing that right I was right back near Duramax territory, so I scrapped that idea too.

[Flyin6]

I'm now in the "I just want to use this thing mode"

So for now, no big months-long project for it to endure, just some targeted fixes.

The monster transmission converter was a joke

The Circle-D converter was nothing like what I told them to build over and over. But Brian down there apparently had his own ideas, insisting to build a 265mm high stall unit in lieu of the low stall I was asking for and paid for. His low stall unit could be brake-torqued to over 3,000RPM so it was anything but. They simply did not do what they said they would do.

I have had a good converter company cut apart the monster unit to discover it was only a stocker. They wrestled over this Circle-D unit for months and finally landed on a stock like GM LSA unit for a 6L-80 transmission. It has a lower stall than a 6.0 truck because the blower can build some power before the engine starts to make any at the lower revs.
They have built me one from a 13" converter with a billet cover and a big clutch and finally, a lower stall. John at SS Transmissions is currently installing that

The other torque converters just ruined a good truck with 7-9 mpg. I aim to change that, first with a converter then later with some other significant changes.

Follow along as I work to get this great truck dialed in as something that can cruise America, pull my light camper and hopefully provide me reliable service and better mpg's

[JR]

 

[Flyin6]

Ride report: W O W
The truck is great
That torque converter fixed everything. This burb now has all sorts of power and is really nice to drive.
I am very surprised that one change can make this much difference. Now when I put it in gear, it wants to move. When I step on the gas, it feels eager. When I press on the gas pedal a bit more, I'm into all sorts of boost and the truck is moving with authority.
There is no more revving at all. It acts almost normal except that it has a metric ton more power. I actually may not have to do anything else except solve the heated O2 sensor problem.
Its too early to tell, but it doesn't seem to be using gas like it used to. When I'd make a trip to/from the city, I'd see a slight movement off full. I've driven the truck to/from town three times and it has just started to show a decrease in fuel.
I think I am going to like this very much

[JR]

Nice, about to see how the Dmax is with the lift this weekend, going to the Ridge.

I am looking for a Tahoe as a DD. 4x4, about 100k and not black is all I want.

[EL TATE]

Ride report: W O W
The truck is great
That torque converter fixed everything. This burb now has all sorts of power and is really nice to drive.
I am very surprised that one change can make this much difference. Now when I put it in gear, it wants to move. When I step on the gas, it feels eager. When I press on the gas pedal a bit more, I'm into all sorts of boost and the truck is moving with authority.
There is no more revving at all. It acts almost normal except that it has a metric ton more power. I actually may not have to do anything else except solve the heated O2 sensor problem.
Its too early to tell, but it doesn't seem to be using gas like it used to. When I'd make a trip to/from the city, I'd see a slight movement off full. I've driven the truck to/from town three times and it has just started to show a decrease in fuel.
I think I am going to like this very much

congrats. sounds like that darned converter was the major gremlin all along

[Flyin6]

Ride report: W O W
The truck is great
That torque converter fixed everything. This burb now has all sorts of power and is really nice to drive.
I am very surprised that one change can make this much difference. Now when I put it in gear, it wants to move. When I step on the gas, it feels eager. When I press on the gas pedal a bit more, I'm into all sorts of boost and the truck is moving with authority.
There is no more revving at all. It acts almost normal except that it has a metric ton more power. I actually may not have to do anything else except solve the heated O2 sensor problem.
Its too early to tell, but it doesn't seem to be using gas like it used to. When I'd make a trip to/from the city, I'd see a slight movement off full. I've driven the truck to/from town three times and it has just started to show a decrease in fuel.
I think I am going to like this very much

congrats. sounds like that darned converter was the major gremlin all along

Both that Monster POJ and the Circle-D Bigger POC.

[TexasRedNeck]

That makes a lot more sense.  Congrats!


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[Sammconn]

This is great to hear.

I put a high stall converter in a caprice classic yeas ago with a paltry 305.
Did a couple things with timing and fuel.
Most 5.0 mustangs didn’t know what the heck just happened.
Dad knew I did something but no idea…

I’m glad to hear this is sorted. I hope.
I didn’t suggest this as we all “thought” you were dealing with experts. At least I did.
Run it and see what ya got now chief.

[oklawall]

Great news, now try not to become actively engaged with the local law enforcement with this new found movement

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[Flyin6]

Well, the new converter is the correct unit for this truck, and has made a world of difference for sure

But the mileage remains poor, so I have the thing in my garage once again and am tearing into it.

I know I have a problem with bank 1 O2 sensors. The heater circuit is not working for either side and is throwing the applicable codes, no matter how many times I reset it. That is where I am currently looking, but I'm having a dandy of a time figuring which wire(s) run the heater element.

I have the standard GM 4-wire O2 sensor. Two wires measure the O2 molecules and deliver that information to the ECM. That leaves two wires for the heater element. I assume one is power from the ECM/PCM and one is the ground for that circuit. I have the wiring diagrams but it is not clear which wires I should be dealing with.

My plan is to bypass whatever may be going on with the PCM/ECM or where professor numbskull dug into my wiring harness years ago and switched things up. To make that a lot simplier, my plan is to use the fuel pump relay as a signal circuit to switch a relay which will switch direct battery current directly to the O2 sensor heater circuits. Simple enough once I figure out which wires to deal with.


But while underneath just now I noticed something strange. I grabbed onto the front driveshaft and it IS NOT free spinning! What gives? With the truck in 2WD and with an open diff in the front, I should be able to turn that propeller shaft, correct? Sliding under the D-Max truck parked a few feet away, that front drive shaft rotates in 2WD/stationary...So, something is different

HELP!

[TexasRedNeck]

Jack it up and spin it. See if a wheel turns.  If it does then it’s the actuator.


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[Flyin6]

Jack it up and spin it. See if a wheel turns.  If it does then it’s the actuator.


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Which actuator? the one on the front axle?

[dave945]

If you jack it up and can spin it and the front tires spin, it’s your front axles. If you’re can’t spin it I would think it’s the transfer case that has a problem.

At least I think that would be right. Then again, I’m Air Force, we would have had it taken to a shop if it wasn’t working right 


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[JR]

If not AWD the front shaft will spin free and so will each wheel (drivers turns half the diff) Axle actuater is normally open with a spring, unless the sleeve is stuck on their.

If the shaft does not spin free, you have an issue in the Tcase unless AWD.

Mileage may always suck, its big, heavy and a gasser.

[TexasRedNeck]

Jack it up and spin it. See if a wheel turns.  If it does then it’s the actuator.


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Which actuator? the one on the front axle?

Yes. If you still can’t spin it. Then it’s the t case.


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[Flyin6]

I believe it is the front axle disconnect

Here's my logic: I drove it in 2H and it turned and operated normally. Crawling underneath, I could not spin the front driveshaft, however the truck behalved as though it was in 2WD.

I placed the thing into 4H and I got some additional noise from the T-case and making a turn on asphalt almost locked the truck up, it was bindf=ing so tightly. Shifting again into 2H immediately alleviated the binding condition, but the front shaft would not spin.

Now here's the kicker. If you can remember back, I had developed a problem in the front axle after I installed the 4.56 gears. John just happened to have a customer's takeout from a recent 4.56 build in his Chevy 2500 truck. The owner didn't like the steep gears and returned to stock. I purchased that axle, changed the oil, and tossed it in. So, what if someone installed an LS differential in that axle and we never knew?

Now, is there an aftermarket LS diff for the 9.25 AAM/GM front axle?

If not, then I'm fine. If they did, then 50/50 I have one. Assuming it doesn't exist, and I don't have it, the front axle controller must have failed, or the circuit is not working. It is not throwing any codes at the moment.

[Flyin6]

Next, I made a neat and tidy little project by adding in a relay that switches on the O2 heaters whenever the switch it turned to "run." Everything was fairly close, so I tapped into the electric fan circuit as a trigger signal, then ran a 14-gage wire from the battery, through the relay, down to the + O2 heater wire in the harness.

I can't compile data at the moment until I get the front axle situation remedied, but I think I am tracking on a line to get this thing completely sorted and tuned.

Next up, during, or after the front axle thing are two troublesome lights in the instrument cluster. I have a red "Brake" warning light, and an amber "Anti-Lock" caution light illuminated that will come on 5-15 minutes into every drive.

The reason is that the 14-bolt FF axle Shawn supplied does not have a rear wheel speed sensor that I know of so the Anti-lock system will no longer work. Not that I need it, I do not, however, like those lights.

I think to fix this problem, I am going to just pull the instrument cluster, and pop the two bulbs out that illuminate those symbols. Get rid of them and I should be golden.

[stlaser]

Front axle limited slip is a tate question as I stay tf away from those awful ifs fronts.

Rear axle has no abs sensor however Artec Industries makes a kit to add the sensors at the hubs. I use them on late model jeep swaps. You may want to look into that option.

[JR]

If you can't turn the front drive shaft, then either it or the axle is in 4x4 mode. I vote the actuator is stuck or the ring is. Pull it off, push on the little pad, it should slide back and in/out easy.

I really doubt you have a LS up front and it points again to the above, "axle locked". That would allow you to drive OK, but not turn the DS and bind in 4x4.

Hook the rear ABS wire the front, should be the same. I like a "brake" light, tells of low pressure when you may not know.

[Flyin6]

If you can't turn the front drive shaft, then either it or the axle is in 4x4 mode. I vote the actuator is stuck or the ring is. Pull it off, push on the little pad, it should slide back and in/out easy.

I really doubt you have a LS up front and it points again to the above, "axle locked". That would allow you to drive OK, but not turn the DS and bind in 4x4.

Hook the rear ABS wire the front, should be the same. I like a "brake" light, tells of low pressure when you may not know.

JR, clever idea there, bro. So, you're saying to lengthen that rear ABS sensor wire and extend it all the way to the front...Then what? Splice it into the front harness somewhere?
I may just go ahead with plan "A" since it is less destructive and frankly easier.
Shawn, I'll look into that kit thing, see what it entails

Thanks to both of "U's"

[TexasRedNeck]

One thing to consider. When the ABS light is on i do not believe the system is active. Which means you won’t have ABS. Not a big deal if you know how to drive (stab braking etc) but I’m not sure of the bias setting from front to rear and whether the proportioning is affected.  Might be worth doing some emergency braking in a rainy parking lot to see what you are working with.


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[Flyin6]

Post drive report:

I think I fixed something, but could it just be the placebo effect. You know, I fix something and want it to be fixed so much that in my mind I see all sorts of changes.

It's subtle, but like that.

So, I think it idles smoother, more quickly. Before there was the constant smell of gas fumes, not that doesn't seem to be there, but I may not be smelling in, I'm not sure. But driving, it feels crisper. I step on the gas and do not experience a half-second lag, just a nice clean "Push." Although the thing doesn't accelerate hard like you'd expect a supercharged vehicle would, it moves about briskly with what seems like almost no throttle. That is, essentially, the demonstration of "Torque." Well, there is more of that for sure.

My theory is that without properly heating the O2 sensors for the past few thousand miles, it has been running around in some level of the fuel enrichment mode. We all know the factory tunes vehicles pretty fat to prevent the onset of detonation. We all know that normally a tuner will start to lean the mixture, paying close attention to the Wide-Band O2 to get to some better ratios. There is a lot of extra power in the proper leaning of an overly rich tune just as there is the power to gain by advancing the timing to a point.

I want to say that finally, my truck is fueling at closer to the optimum ratio which is translating into this overall increased responsiveness and "crisp" feeling.

So, on to sorting out the front axle to see if I can free that up and get it working properly.

[Flyin6]

One thing to consider. When the ABS light is on i do not believe the system is active. Which means you won’t have ABS. Not a big deal if you know how to drive (stab braking etc) but I’m not sure of the bias setting from front to rear and whether the proportioning is affected.  Might be worth doing some emergency braking in a rainy parking lot to see what you are working with.


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Ahead of you friend.

When this first started I did a few panic stops. I wanted to make sure it was not a Dodge or early Ram truck. Those would swap ends so easily. All of mine did it to me, and one time my brother borrowed the truck, had to stop abruptly and the truck spun around on him.

So being a graduate student on correcting sliding trucks, I tested mine and this Burb has no such tendencies. It will lock up all four, and rather easily (The big brake kit??) but remains pointed in the direction of travel

That's why I feel I can go sans this anti (knowin' how to drive) system.

[TexasRedNeck]

Good to know. You are usually ahead of me but it was worth putting out there

Have you pulled the plugs to “read” them for richness?  One would think the over enriched condition would show on the plugs


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[Flyin6]

Good to know. You are usually ahead of me but it was worth putting out there

Have you pulled the plugs to “read” them for richness?  One would think the over enriched condition would show on the plugs


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Yes
Very rich earlier on

Haven't checked yet

Have another fuel system problem, a weird one. Plan to give it a full eval after I resolve

Another weird problem: At some point along the way the fuel gage stopped reading full. Only reads something short of 3/4 when topped off. When it is below 1/2 about 3/8 of a tank I will refill. I can only get like 22-23 gal in there.

The dual tank chevies are hybrid and odd animals. The aft tank will fill but will give no indication it has. An owner will notice the fuel gage takes quite a while going from full to 3/4. Then it races to empty much faster than you'd expect.

The reason for this is that the aft 6-gal tank has a fuel pump that will switch on and off to continue to top off the main 31-gal tank until empty. That explains how the needle seems to have two speeds.

I just learned that the computer" or controller or whatever it is splits the single fuel gage into two units! The aft tank fuel level sensor controls the top "half" of the gauge, while the forward/main tank level controls the bottom half of the gage.

So, this makes sense to me now. I believe the aft fuel level sensor has failed and therefore the forward/main fuel tank sensor can only drive the gauge to near 3/4 full.

I think I'll need to replace the aft fuel level sensor and test to see if the aft fuel pump is working.

This may be a good time to change out that aft 6-gal tank for something larger.

[oklawall]

For the front axle, would it be easier to remove the drive shaft from the axle you would be able to spin the drive shaft and the yoke and see which is locked up and which isn't.

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[Flyin6]

For the front axle, would it be easier to remove the drive shaft from the axle you would be able to spin the drive shaft and the yoke and see which is locked up and which isn't.

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Great idea! Man, sometimes you overthink things so much you forget the basics. Thanks for reminding me!

[EL TATE]

I believe it is the front axle disconnect

Here's my logic: I drove it in 2H and it turned and operated normally. Crawling underneath, I could not spin the front driveshaft, however the truck behalved as though it was in 2WD.

I placed the thing into 4H and I got some additional noise from the T-case and making a turn on asphalt almost locked the truck up, it was bindf=ing so tightly. Shifting again into 2H immediately alleviated the binding condition, but the front shaft would not spin.

Now here's the kicker. If you can remember back, I had developed a problem in the front axle after I installed the 4.56 gears. John just happened to have a customer's takeout from a recent 4.56 build in his Chevy 2500 truck. The owner didn't like the steep gears and returned to stock. I purchased that axle, changed the oil, and tossed it in. So, what if someone installed an LS differential in that axle and we never knew?

Now, is there an aftermarket LS diff for the 9.25 AAM/GM front axle?

If not, then I'm fine. If they did, then 50/50 I have one. Assuming it doesn't exist, and I don't have it, the front axle controller must have failed, or the circuit is not working. It is not throwing any codes at the moment.

a 9.5 semi float GM rear diff can be made to fit in the front IFS 9.25 as they are the same ring gear center diameter bolt pattern and spline count... if the tires spin in the same direction when you jack up you have an LSD. but i'm more concerned about gear ratio accuracy at this point. do you have a 4 post you can get it up on and run in 4wd in the air and check tire rotations?

[JR]

Yes, when the ABS light is on that system is disabled. It will however brake as normal vehicle without bias being affected at all.

Its called threshhold braking or was when I was taught how to do it (lots of spins involved)

[Flyin6]

I believe it is the front axle disconnect

Here's my logic: I drove it in 2H and it turned and operated normally. Crawling underneath, I could not spin the front driveshaft, however the truck behalved as though it was in 2WD.

I placed the thing into 4H and I got some additional noise from the T-case and making a turn on asphalt almost locked the truck up, it was bindf=ing so tightly. Shifting again into 2H immediately alleviated the binding condition, but the front shaft would not spin.

Now here's the kicker. If you can remember back, I had developed a problem in the front axle after I installed the 4.56 gears. John just happened to have a customer's takeout from a recent 4.56 build in his Chevy 2500 truck. The owner didn't like the steep gears and returned to stock. I purchased that axle, changed the oil, and tossed it in. So, what if someone installed an LS differential in that axle and we never knew?

Now, is there an aftermarket LS diff for the 9.25 AAM/GM front axle?

If not, then I'm fine. If they did, then 50/50 I have one. Assuming it doesn't exist, and I don't have it, the front axle controller must have failed, or the circuit is not working. It is not throwing any codes at the moment.

a 9.5 semi float GM rear diff can be made to fit in the front IFS 9.25 as they are the same ring gear center diameter bolt pattern and spline count... if the tires spin in the same direction when you jack up you have an LSD. but i'm more concerned about gear ratio accuracy at this point. do you have a 4 post you can get it up on and run in 4wd in the air and check tire rotations?

I believe it is the front axle disconnect

Here's my logic: I drove it in 2H and it turned and operated normally. Crawling underneath, I could not spin the front driveshaft, however the truck behalved as though it was in 2WD.

I placed the thing into 4H and I got some additional noise from the T-case and making a turn on asphalt almost locked the truck up, it was bindf=ing so tightly. Shifting again into 2H immediately alleviated the binding condition, but the front shaft would not spin.

Now here's the kicker. If you can remember back, I had developed a problem in the front axle after I installed the 4.56 gears. John just happened to have a customer's takeout from a recent 4.56 build in his Chevy 2500 truck. The owner didn't like the steep gears and returned to stock. I purchased that axle, changed the oil, and tossed it in. So, what if someone installed an LS differential in that axle and we never knew?

Now, is there an aftermarket LS diff for the 9.25 AAM/GM front axle?

If not, then I'm fine. If they did, then 50/50 I have one. Assuming it doesn't exist, and I don't have it, the front axle controller must have failed, or the circuit is not working. It is not throwing any codes at the moment.

a 9.5 semi float GM rear diff can be made to fit in the front IFS 9.25 as they are the same ring gear center diameter bolt pattern and spline count... if the tires spin in the same direction when you jack up you have an LSD. but i'm more concerned about gear ratio accuracy at this point. do you have a 4 post you can get it up on and run in 4wd in the air and check tire rotations?

It's the same ratio Tate. I can switch it into and out of 4WD driving down the road with nothing mere that a slight rumble from the front shaft. I've been in vehicles with mismatched gear ratios. They tend to want to bind over time and can be a bear to make a tight turn-in. My truck has no such symptoms.

[EL TATE]

10-4. keep me updated. pretty sure i sold you that t case. the clutches can be extremely tight. i'll ask tech about the front driveshaft not spinning in 2wd though

[JR]

Is this manual or all actuators? One on the axle is electric for sure. But maybe one of the 2 in the Tcase is massed up?

[EL TATE]

Is this manual or all actuators? One on the axle is electric for sure. But maybe one of the 2 in the Tcase is massed up?

electric shift 246g

[Flyin6]

10-4. keep me updated. pretty sure i sold you that t case. the clutches can be extremely tight. i'll ask tech about the front driveshaft not spinning in 2wd though

OK

[Flyin6]

Is this manual or all actuators? One on the axle is electric for sure. But maybe one of the 2 in the Tcase is massed up?

electric shift 246g

Yes

[KensAuto]

Don, your chebby doesn't have abs sensors in the rear. It just has a sensor on the back of the transfer case.
Not sure why it's still considered a 4 wheel abs system.

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[TexasRedNeck]

Then the brake light being on could be the ABS motor itsself (common) or parking brake switch?


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[Flyin6]

Don, your chebby doesn't have abs sensors in the rear. It just has a sensor on the back of the transfer case.
Not sure why it's still considered a 4 wheel abs system.

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Really???
This is one of the problems with stretching a project over years...You can't remember everything you did or encountered

[Flyin6]

Then the brake light being on could be the ABS motor itsself (common) or parking brake switch?


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I am fairly certain that the Anti-lock brake light automatically triggers the brake light illumination as well.
So, with what Ken just said, it sounds like I have a failing or failed Anti-lock brake module.

So, Ken here's a question. Could the anti-lock brake motor assembly just have air in it? All this happened subsequent to me installing Shawn's 14-bolt axle. I disconnected the brake lines (Obviously) and later bled the system.

1. Could air have traveled up into the anti-skid module and
2. Is Shawn the cause of all this?

[Sammconn]

I’ve been without funtioning anti stop brakes for probably 10 years.
Go to the anti stop module.
Under the drivers seat essentially.
There will be a power connection.
If it has power the module has failed.
Then you just ignore the lights. Lol.

I probably will steal the one from my spare truck.
I may dissect the broken one as well.
There is a relay and transistor inside and one of them generally is the culprit.

[dave945]

Is that what that ABS light is on the dash of the van?  I thought it was telling me the kids were all ready to go: All Buckles Secure.   Huh, learn something new every day.


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[Flyin6]

Is that what that ABS light is on the dash of the van?  I thought it was telling me the kids were all ready to go: All Buckles Secure.   Huh, learn something new every day.


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Doesn't sound like you've learned much at all on the day the teacher discussed anti-lock brakes!

;-)

[KensAuto]

I wouldn't jump to conclusions until you get the codes.



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[JR]

I think you have a Tcase issue.

[KensAuto]

I think you have a Tcase issue.

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[Sammconn]

I wouldn't jump to conclusions until you get the codes.



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Agreed.
I had codes saying anti stop brake module.

[Flyin6]

I wouldn't jump to conclusions until you get the codes.



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I'm not reading any codes Ken. My not-so-advanced code reader is not all that advanced, not like those things you real mechanics have that can tell you how much the occupant weighs in the driver's seat, last thursday!

[JR]

Don't think a code reader will tell you about wrong spline on the VSS module or an in op shift motor.

Those would all tie to possibly something mech in the tcase.

[EL TATE]

The unit i sent you had a shift motor on it. could very well be the issue. but i would still like an up in the air w/ all 4 wheels off the ground test. 2wd/4wd check driveline free spin, and verify front wheels spin in opposite direction not same.