What did you do to your GMT today? [Part II]

[Mooseman]

Today tackled the brakes on the TB that were vibrating quite a bit. Found that the front left rotor was rusty and the inner pad was worn. Right side found the caliper starting to leak at a piston. Perfect since I have basically a set of almost new brakes and calipers from the Saab when I scrapped it. Also decided to flush out the old brake fluid since I have never done it and the tester said it was full of moisture. Get the caliper and brakes on and flush the fluid, no issues.

When I jacked the rear, I saw a huge puddle. After flushing the rear brakes, I checked and it's smurf blood! The transfer case is leaking at the front drive shaft seal. I'm pretty sure it's not the first time as I faintly remember replacing it early on when I first got the truck. It could have been initiated by my son using 4x4 when he went to the family land lot with his pop-up camper as it was a bit muddy there. By this time, it was too late to go looking for a seal and more smurf blood. I'll also have to check the diffs. The rear looks like it's leaking but it could be rustproofing oil.

I'm getting too old for this "fixing shit in the blazing sun in the driveway" crap. The TB is really trying my patience lately. Maybe I'm spoiled by the new Sierra.

 

[TollKeeper]

I'm getting too old for this "fixing shit in the blazing sun in the driveway" crap. The TB is really trying my patience lately. Maybe I'm spoiled by the new Sierra.

Now you know why I bought a new truck. I get a 8 year break on fixing crap..

 

[Mooseman]

Except that the TB is usually the wife's commuter vehicle and now our son's tow vehicle, at least for the summer. I've also been wanting to replace the front and rear diffs with the ones from the Saab with 3.73 gears. From 3.42, it wouldn't make much difference but it is a 8.5". I just don't have the energy to do mods on it anymore.

 

[xavierny25]

This past weekend I replaced the ac clutch. WTF? Those clips are the absolute worst to get out and in.
Just a heads up the new ac clutch shim/spacer did not work on the shaft (to small) of the compressor. I used the original but the clutch was slipping so I removed it and everything is working great now. Ac is the best it's been in a while. The bearing on the original clutch was completely toast.

 

[Mooseman]

Finished up the TB. What took the longest was the running around in the morning. The parts house I went to didn't have it and had to wait about 45 minutes for it to come in. That was fine since I had to also go to Costco to fill the gas cans with ethanol free 93 octane. Then went to Princess Auto on the way to pick up stuff that was on sale and a marker light for the trailer that I accidentally broke while parking it in Quebec City .

The transfer case seal swap was relatively painless however the old seal was all swelled up and turned to mush. I don't think I put seal conditioner in the transfer case but I didn't trust the fluid that was in there, which was still very blue, and replaced it with new AutoTrak II.



Both diffs were a little low but checking with a zip tie, the fluid didn't look that bad so I just topped them up.

Did a test drive and brakes are back to their smooth self.

 

[Sneakycyber]

Today I retorqued all the suspension nuts and bolts on the front of my Trailblazer while its waiting to be dropped off at the transmission shop on Monday. In June I put on all new Bilstein 4100 shocks, new strut mounts, new driver side lower control arm (I messed up the strut yolk mount removing the yolk), new sway bar link pins, and rear brakes. Two weeks ago, I did the front, rear, and transfer case fluids.

 

[Mike534x]

Those clips are the absolute worst to get out and in.
Just a heads up the new ac clutch shim/spacer did not work on the shaft (to small) of the compressor. I used the original but the clutch was slipping so I removed it and everything is working great now. Ac is the best it's been in a while. The bearing on the original clutch was completely toast.

Wow! You weren't kidding that thing was toast! I'm waiting on my clutch puller to arrive, I'm curious to see what mine looks like off the Trailblazers old compressor.

As far as the shim goes, was that from the Aliexpress kit? Or some other?

I took the Trailblazer for emissions testing yesterday after work, and she failed. Both the EVAP and Oxy systems came up as the reason.....silly me forgot the battery was disconnected while the shop yoinked out the compressor.

Going to try tackling replacing the liftgate latch mechanism this weekend, it's not fully grabbing resulting in a very small amount of play so the whole thing rattles going over bumps.

 

[Mike534x]

Rain started to roll in briefly, so I managed to just get the new fan blade + clutch installed on the TB (old fan had a wobble not caused by the water pump). So the new Hayden Clutch ($50 wholesale unit from RA) is bad, and stays engaged fully after 20 minutes of driving. Of course things are never easy, while getting the water pump pulley wrench in position, the wrench slipped and I whacked the CPS.

No damaged or frayed wires thankfully, just a little bit of plastic around the harness where it attaches at the connector broke. Unfortunately she's now idling rough, so I think I may have internally damaged the CPS, so now I'm waiting on a new one since the part stores want $80 for the in-house brand

 

[TJBaker57]

stays engaged fully after 20 minutes of driving. O

Is this an electro-viscous fan clutch? Did this driving involve keeping the engine rpm greater than 2000 for no less than 2 full minutes? That is how long it can take a functioning electro-viscous fan clutch to begine to disengage.

 

[Mike534x]

Is this an electro-viscous fan clutch? Did this driving involve keeping the engine rpm greater than 2000 for no less than 2 full minutes? That is how long it can take a functioning electro-viscous fan clutch to begine to disengage.

Nope! its a thermal one. TB is an 08 so the very first year they did away with the EV clutches IIRC, the Envoy rocked an EV one until about two years ago when I sent the PCM out to have the codes turned off.

I thought the Hayden (2851) thermal ones were safe, but they may be "iffy" like the EV counter parts. Funny enough, I did buy the same Hayden unit 3 weeks ago for the Envoy, and that too has a ridiculous 3 minute full engagement at startup before it begins to quiet down.

 

[Mike534x]

New CPS sensor arrived, but it didn't fix it.

The culprit....was the new fan blade. Swapped clutches, which made 0 difference. Removed the clutch and fan, back to smooth idling. Put the old clutch + old fan blade in and its back to running smooth.

Makes 0 sense to me, there was 0 play/wobble in the fan, and everything was torqued down. My only conclusion was that the blade must be improperly balanced by a hair. I didn't feel anything different comparing the two, so who knows. I've never seen that happen before....

 

[TJBaker57]

Nope! its a thermal one.

I used a Hayden thermal on my GFs 2008 Ranger and sure enough it also needed an extended high rev run to disengage.

 

[Mike534x]

Damn. I guess all the more reason to stick to OEM, I can live with the noise, just taken aback by how long it takes for it to disengage.

 

[Mooseman]

My Hayden thermals always took a few minutes to disengage when started. Now have a used OEM, no problems.

 

[xavierny25]

As far as the shim goes, was that from the Aliexpress kit? Or some other?

It was the kit from Aliexpress. I'll post a pick later when I get home of the difference.

 

[Mike534x]

Ended up ordering an AC Delco thermal clutch for the Trailblazer, was a tad bit cheaper on Walmarts website compared to RA. Arrived in a box with the GM/ACD label, and looks exactly like the original. Seems to work great, and as you all mentioned it doesn't stay engaged long like the Hayden does.

I ordered a second one when I got to work, the one in the Envoy stayed engaged for 10 minutes so I'm planning to send that one back to RA for a refund.

 

[Mike534x]

Welp the Hayden in the Envoy took a crap tonight, it never disengaged as of leaving work and was 100% full bore on the ride home....speaking of clutches...

The replacement unit from RA showed up, and what I found in the box was a fun surprise. So I have a Hayden box, with a.....US Motor Works fan clutch that has LEAKED all of its silicon out via the valve. Bottom of the shipping box has a spot also from where the fluid seeped through.

The only bright side is the second ACD clutch I ordered from Walmart is coming tomorrow...good timing I suppose.

 

[Mooseman]

Three things of note in your misadventures. Hayden is crap since it has failed, some douchebag made off with a Hayden at the USMW price and just because it says "Made in USA" doesn't mean squat nowadays

 

[Mike534x]

Three things of note in your misadventures. Hayden is crap since it has failed, some douchebag made off with a Hayden at the USMW price and just because it says "Made in USA" doesn't mean squat nowadays

Several lessons were learned sadly. I knew Hayden's EV clutches sucked, but I didn't anticipate that they would be able to screw up something that's been in use for decades. But serves as a good reminder to do the job right the first time, and stick with OEM or some other higher quality equivalent.

Unfortunately we're all screwed at the end of the day, with the list of reliable suppliers dwindling. Dorman seems to be on the uptick for positive reviews lately.

Email was sent off to RA with all images, hopefully they'll make it right with a credit or refund.

 

[Mike534x]

I was pleasantly surprised with how quick RA was to respond back, shot the email off at midnight and got a response around 10 this morning. They're offering a full refund, and told me to keep the bad clutches. I could toss them in the trash...or maybe repurpose them? I'm thinking paper weights, or a door stopper. Can't really imagine what else they would be good for.

 

[TJBaker57]

Some time ago I started the TrailBlazer and as the A/C blower spun up there was an odd sort of thud sound and nearly all air movement ceased. Seemed like some dust came out the vents as the thud sounded. I have the CJ2 with rear console controls and blower and vents and those kept working so I at least had some cooling.

The fan made a hell of a hum when turned up full and I could get a faint wisp of airflow out the panel vents but that was it for the front portion of the system.

Sort of put it aside for a while since I have the Yukon. But this coming week I will be making a trip to the front range where the good U-Pull yard is so I thought I should dig in and see if I needed a part.

Pulled the blower out for a look. Someone had been busy in the outside air intake it seems!!




Since it is a 2002 I have the provision for a cabin air filter. Pulled off the door for that and found another load in there!

Examination of the material shows no signs automotive materials so that's good. I need to investigate and see where the access was.

 

[Mike534x]

Managed to get the struts changed out on the Trailblazer last weekend. Rented a 3 piece pitman arm puller kit from Advanced, but they didn't fit over the yoke too well. It did pop free, took my foot as leverage against the fork and a few blows with the BFH on the stud. Finished up in about 4 hours. It wasn't terrible, but not a fun job either.

UCA (mainly the bushings), and UBJs are shot as well as the LBJs. I've got new LCAs with the BJs already, just waiting on tie rods to get here. Rides much better though, but still not great over bumps. I think the stock 18" low profile wheels are contributing to the rougher ride.

 

[Sneakycyber]

I got my Trailblazer back from the Transmission shop. New "The Beast" Sun gear, upgraded and replaced clutches, new fluid, new filter, RR on the transmission. Total out the door was $3749.41

 

[xavierny25]

It was the kit from Aliexpress. I'll post a pick later when I get home of the difference.

Pic's of the oem and Aliexpress ac clutch shims. Original at the bottom and 2 from Aliexpress on top.
Looking at the old clutch again and everyone can see where the carnage all happened.

 

[TollKeeper]

Drove it for the first time in a month. Started up just fine, and a bit of a stumble, and quickly smoothed out.

Then used it for XUV things. When and got a bunch of fence boards, a door, screws, caulking, etc.

My roommate was not expecting it all to fit, or any of it... I keep having to remind him that my XUV transforms!

 

[Mike534x]

Still waiting on the new plate sticker for the Trailblazer to arrive. Otherwise I gotta once again replace the front links on the Envoy, after 2 years the Moogs are shot. Partly my fault, I opted for the quicker route to work which is a 3 mile ride of bumps, dips and poorly patched pot holes (the road needs a resurfacing badly). Needless to say, I'm taking the longer way from now.

Are other brands that seem to hold up relatively well? I wasn't impressed with the Delco Pro's prematurely failing after a year in the rear nor the Suspension Maxx links.

 

[TJBaker57]

Just had my mind blown. I was doing some experiments/tests of the underhood ground points. I have no troubles was just playing around as I am known to do. I was investigating what symptoms would occur with this or that ground bad.

Discovered some unexpected things like the headlights and fog lights worked normally with the right side ground (G103) disconnected. According to wiring diagrams from multiple sources this should not work!

Anyway I moved onward and investigated symptoms with G102 and G105 also disconnected. I found that with those grounds disconnected most everything still seemed to work normally at least without starting the engine.

I did some resistance tests between the disconnected grounds and frame and/or battery ground. With G103 and G102 I read 1 ohm in one polarity and 3 ohms in the other polarity. Strongly suggests these grounds are interconnected through some circuitry somewhere even though schematics show them isolated.


Now it got really weird.

With no key in the ignition I pulled the multifunction switch to the flash-to-pass position. The high beams came on as they should but also the check engine lamp came on, the throttle body reset, and the fuel pump primed !!!

I have the answer but does anyone have a guess (without going to any great lengths researching)??

 

[azswiss]

Floating ground with just enough potential to momentarily trigger the relay powering the key-on-engine-off position.

Edit: 4A thru the 3 Ohm alternate current path gets you 12V.

 

[TJBaker57]

So the answer to my post yesterday.....

With G103 disconnected (or bad) the high beam 12 volt power seeks an alternate ground through anything sharing the same ground splice.

Among the devices grounded to G103 is the solid state driver module for the cooling fan. That driver is designed to be powered by the Ignition 1 output from the ignition switch.

Turns out enough power will flow backwards through this device to activate systems that are connected to ignition 1.

This includes PCM 1 fuse #28.

So a floating ground at G103 can activate the PCM if the high beams are activated without turning the key!!

I confirmed this by measuring voltage at fuse #28 whilst pulling the multifunction switch to flash-to-pass position with no key in ignition. Also removed the solid state driver and the condition was not observed.

 

[TJBaker57]

The previous answers the issue about energizing ignition 1. But that still leaves the question about how my lights grounded at G103 still worked and where that resistance to frame ground is from. Wiring diagrams show the various grounds as being isolated from each other but my tests between G103 and G102 suggest otherwise.

 

[Mooseman]

I've been driving the TB to work every day since my wife is always complaining about it and she doesn't drive to work every day or as far. Need to put more mileage on it and less on the Sierra even though the Sierra is much cheaper on fuel. And I park on the street so it's easier to park.

It only has 187k Km, which is low for a 17 year old truck even though it has had its share of issues, some of which due to low usage. I still like it but I need to get a better radio with Android Auto.

 

[Mike534x]

Had the weirdest issue with the Envoy the last few days. The front wipers stopped working, stayed parked no matter what speed the control was set to and it wasn't activating the washer fluid pump either. Did some digging around, and came across a post on the OS of someone having the same problem as me...

The fix? Replacing the ignition switch. Sitting here in the parking lot at work going no way, that couldn't be it. Swapped the old switch with the new Dorman I bought as a spare, and the wipers are working again. Swapped the old switch in, and back to not working. New one goes in and it's working.

Will report back how the Dorman turns out. I've got a WVE (NTK/NGK) switch as well that's my other spare, so we'll see how long it lasts.

 

[TJBaker57]

Had the weirdest issue with the Envoy the last few days. The front wipers stopped working, stayed parked no matter what speed the control was set to and it wasn't activating the washer fluid pump either. Did some digging around, and came across a post on the OS of someone having the same problem as me...

The fix? Replacing the ignition switch. Sitting here in the parking lot at work going no way, that couldn't be it. Swapped the old switch with the new Dorman I bought as a spare, and the wipers are working again. Swapped the old switch in, and back to not working. New one goes in and it's working.

Will report back how the Dorman turns out. I've got a WVE (NTK/NGK) switch as well that's my other spare, so we'll see how long it lasts.

Yep! Powered from terminal A (brown wire) of ignition switch. Contacts probably getting pitted.

 

[Mike534x]

Yep! Powered from terminal A (brown wire) of ignition switch. Contacts probably getting pitted.

View attachment 114245

Oh wow! I didn't realize how much the switch was actually tied into everything! What an odd decision, I guess it makes sense that its usually the first suspect in anything electrical gremlin related going on.

 

[Ilikemy3s]

Finally replaced my standard power mirrors (with a copy adjustment motor in each) with a set of power heated turn signal mirrors. The adjustment movement is very smooth. Can't wait for the first cold damp morning to see the heating function work.

 

[Mike534x]

Got the new links installed on the front, lasted about 3 years according to my Amazon history. No surprise both sides had excess play in the upper and lower sockets of the links. I'll probably kick myself later on, but I picked up a set of Mevotech Supreme links to try out. Side by side, they're a bit bulkier/hefty compared to the Moogs. We'll see how long these last.

 

[flyboy2610]

Finally replaced my standard power mirrors (with a copy adjustment motor in each) with a set of power heated turn signal mirrors. The adjustment movement is very smooth. Can't wait for the first cold damp morning to see the heating function work.

I did this to the wife's '06 TB and my '04. One of the best upgrades you can do, IMHO.

 

[azswiss]

Replaced the hood springs. Only the driver's side broke but replaced both as they are original. The slotted core alignment stub split after wearing down over many (21) years of use.

 

[xavierny25]

Rear differential swap completed.

 

[Mooseman]

Nice! I guess you had to shorten the driveshaft?