2008 Trailblazer SS

Update your progress on your various car projects.

Moderators: MostMint, wxo, Fred32v, Basement Paul, ttamrettus

User avatar
wxo
Posts: 1754
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Re: 2008 Trailblazer SS

Post by wxo »

I experienced two more instances of "service Stabilitrak" today. I'll order a GM Steering Wheel Position Sensor today and tear into the dash again when it arrives.
User avatar
wxo
Posts: 1754
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Re: 2008 Trailblazer SS

Post by wxo »

Today, I installed the new Steering Wheel Position Sensor from GM. This time I got the right one and it slipped right in. Short test drive showed everything normal. Now I just have to wait to see if the "Service Stabilitrak" message pops up again.

One more delivery from Amazon tomorrow and I will be ready to perform the cooling system flush on Wednesday. I'm looking forward to seeing what kind of temperature decrease I see with the 160 thermostat.

Next on the agenda after that will be to service the transmission.
User avatar
wxo
Posts: 1754
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Re: 2008 Trailblazer SS

Post by wxo »

I completed the cooling system flush & refill today. What a struggle! My truck has a heater hose assembly of hoses and metal tubing to get the water from the engine to the heater core. It attaches to the heater core with quick disconnect fittings. It looks like this:
IMG_0513.JPG
IMG_0514.JPG
This assembly is not available any more. My plan was to reproduce it with fittings and heater hose, but that plan fell apart when the Dorman connectors I bought would not fit. After many hours of work, I decided to punt and use the original assembly. I'll have to watch it for deterioration of the rubber hose parts and come up with another plan at a later date. I spent all day today on this project. I had to Jerry-Rig the Prestone back flushing kit to flush out all the old coolant. The good part of all this is that the radiator and all the parts that I could see are in excellent condition. It looked so good that I decided that there was no point in using a quick flush agent on it. I think I still have some air in the system because the temperature reading is not as low and as constant as I would expect with the 160 degree thermostat. I will let it cool and keep checking and adding coolant as needed over the next few days.
User avatar
wxo
Posts: 1754
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Re: 2008 Trailblazer SS

Post by wxo »

Still no Stabilitrak messages, but I"m not ready to say it's fixed. It has gone many weeks between messages before.
The cooling system is doing well in this summer heat. I'm liking the cooler temp readings I'm seeing on the Ultra Gauge
( http://www.ultra-gauge.com/ultragauge/v ... ercial.wmv ).
User avatar
wxo
Posts: 1754
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Re: 2008 Trailblazer SS

Post by wxo »

Now on to servicing the 4L70 transmission. I should have all the necessary parts and fluid coming today from Amazon. Among the parts is a pan with a drain plug. No more slithering around on the floor in tranny fluid for this cowboy! I decided to use this writeup on a DIY transmission flushing procedure for Chevy trucks:
http://www.gmfullsize.com/threads/how-t ... st-3630639

Still no Stabilitrak messages. :mrgreen:
User avatar
wxo
Posts: 1754
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Re: 2008 Trailblazer SS

Post by wxo »

It feels like I'm getting a little project creep. After posting a question on the TBSS forum about pulling the transmission pan, I got this unsolicited advice from a member:
----------------------------------------------------------------------------------------------------------------------------------------------------------------
Something you might want to consider while the pan is off. Sonnax makes a pinless 1-2 accumulator piston. I got mine locally for $16. Others have it also.
https://www.summitracing.com/parts/s...FUiRfgodYIIF6w
The stock one is plastic and rides on a steel center pin and the center hole wears and allows fluid to leak past it. The Sonnax one has no pin and uses two seals on it instead of one.

Easy install, take 3 6mm bolts off and remove the old piston and pin, press a ball bearing into the pin hole to plug it, and then just put it all back together. About 15 minutes max.

It made a noticeable difference in my 1-2 shift.

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Then came another recommendation to firm up the 1-2 shifts. Sonnax makes performance spring to go along with the new accumulator piston.
I have both coming. :D
User avatar
wxo
Posts: 1754
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Re: 2008 Trailblazer SS

Post by wxo »

Another success. I've been thinking about installing a transmission temperature sensor and gauge, but I guess I just forgot about it over time. With this transmission work just around the corner, it came to mind again. I did some research and ultimately figured out how to display it using the HpTuners Scanner program on my laptop. I will monitor it for a while to understand the trends and then decide it I want a permanent gauge or not.
User avatar
wxo
Posts: 1754
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Re: 2008 Trailblazer SS

Post by wxo »

Yesterday, I took another step in my truck's 100K revitalization program. She got new rear shocks. A month or so ago, after I had lowered the rear air suspension adjustment to make the truck sit level (it was somewhat tail high from the factory), I noticed that the rear end got bouncy. When I started looking for shocks, I was amazed that the selection was limited to only one, the GM replacement shocks! GM had advertised that the TBSS came equipped with Bilstein shocks so I guess the GM choice wouldn't have been bad. Regardless, I kept looking until I found an alternative on the TBSS owner's website. They offered a set of Belltech shocks configured specially for the TBSS, so I got them. They arrived yesterday and I got them installed immediately. They eliminated the problem entirely. She rides a bit taught now, but I think that will ease as the shocks get some miles on them.
User avatar
wxo
Posts: 1754
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Re: 2008 Trailblazer SS

Post by wxo »

I finished my DIY transmission fluid flushing procedure today. Prior to that I pulled the pan and changed the filter and replaced the pan with one with a drain plug. It should be much easier next time.
User avatar
wxo
Posts: 1754
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Re: 2008 Trailblazer SS

Post by wxo »

I forgot to mention that I also changed the 1-2 accumulator piston to a new type of pinless piston. I also changed the spring to a more heavy duty one. One of the guys on the TBSS forum said that the OEM piston is plastic and sometimes cracks develop over time. While I had the pan off it was relatively easy to install the piston and spring. The 1-2 shifts are noticeably more firm but not harsh. It feels good.
User avatar
wxo
Posts: 1754
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Re: 2008 Trailblazer SS

Post by wxo »

I was out and about this morning, the truck was running well, and I suddenly remembered that I haven't seen the "service stabilatrak" message in a long time. I think it's time to declare it fixed by replacing the steering wheel position sensor.
User avatar
GMJohnny
Posts: 1228
Joined: Wed Feb 04, 2009 10:56 am
Location: Auburn Twp, Oh

Re: 2008 Trailblazer SS

Post by GMJohnny »

It's a wonderful feeling when none of the "bad thing" indicator lights are on!

GM
User avatar
wxo
Posts: 1754
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Re: 2008 Trailblazer SS

Post by wxo »

I had been seeing that Service Stabilatrak message since I bought the truck in 2011. I quickly learned that shutting off the truck and restarting reset it and I was good to go for quite a while. At first, I did some searching on the web and found nothing conclusive so I just lived with it. Over time the message began appearing more often. A couple of months ago on a day when the roads were damp, I got the message and decided to ignore it. After all I was within about 9 miles of home and I didn't want to stop to reset it. I was traveling up a long hill, not too steep, and I was in the left lane. There was a guy on a cell phone in front of me going slow and I was getting more aggravated by the minute. Eventually traffic cleared in the right lane and I decided to pass on the right. As I pulled out and gave it some gas, it downshifted and the rear broke loose on the damp pavement. I was sideways in one direction and when I corrected I was sideways in the other direction. :shock: I caught it and got it going straight and was ever so thankful that there was nobody near me. I wonder what it looked like from the outside because it was plenty busy inside. I believe this is the reason GM provides stabilatrak in the first place. Had mine been active, I think this incident could have been avoided. After that I went back to the web and this time there was a consensus, 6 years later, on what fixes the problem...replace the steering wheel position sensor.
User avatar
wxo
Posts: 1754
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Re: 2008 Trailblazer SS

Post by wxo »

We were close to home on our trip back from Jasper Georgia on Monday. A large dump truck ended up in front of me for the last 10 miles. Since debris was falling off the truck, I stayed a safe distance back as we traveled the 55 MPH two-lane. Near the point where I was getting ready to turn off, we heard a loud bang as something hit the truck. I didn't see it coming. Sitting on the cowling in front of me was a large rock. I scanned the windshield and saw no cracks and a quick look at the hood from the driver's seat revealed nothing. I assumed it had hit the roof, so we stopped to take a look. Amazingly there was no damage to the roof, hood or windshield, but there sat the rock in the cowling near the windshield wipers. Upon closer examination, I saw marks that indicated that the strike was directly on the RH wiper pivot. I also saw that the "rock" was actually a large piece of semi-solid mud. It even molded itself to the wiper arm. I tested the wipers and on the first pass, the RH blade fell off. I reattached it and they seem to be working normally. State Farm just narrowly missed another claim.
IMG_0617.JPG
IMG_0621.JPG
IMG_0622.JPG
User avatar
wxo
Posts: 1754
Joined: Mon Jul 18, 2005 9:09 pm
Location: Raleigh, NC

Got my Transmission Fluid Temperature display working

Post by wxo »

Since I've been towing lately, it rekindled my interest in monitoring my transmission fluid temperature. Originally, I thought about installing a sensor and gauge, but lost interest when it got complicated. Then I learned that there is an upgraded model of my UltraGauge which theoretically could display Trans Temp and several other pieces of manufacturer unique data. So I ordered a new UltraGauge MX 1.3 and set out to see my Trans Temp. They have some parameters pre-programmed for this data, but since it is manufacturer and vehicle dependent, it didn't work in my case. I browsed the web for days without success and gave up. I opened a support ticket with UltraGauge and they provided minimal help so I finally told them that that I wanted to return the unit. The next day I got a response with some useful tips. With this I was able to get the thing working. Hooray!
UGauge showing trans temp.JPG
Post Reply