2006 Trailblazer - Front Differential Noise

[Goose]

II had a 2006 Trailblazer come in over the weekend with a noise in the front differential.

There was lots of noise from the front intermediate housing so I replaced the bearings and seals in the intermediate housing. I also replaced the outer intermediate clutch gear due to brunelling on the bearing surface. Went for a drive and the noise level is half of what it was. I am guessing that the side bearings in the differential are also bad. When looking at the R&R procedure for the differential it says you have to remove the oil pan.

Is that necessary and why?

[Jeff @ Able Auto]

The right axle assy passes thru the oil pan on the 4.2 inline.

[Goose]

I realize that but it only the intermediate shaft that passes through. The intermediate housing bolts on the right side of the pan. I would assume that the differential bolts on the left side, but we all know what assume means.

[steven kiser]

I believe the axle mount guides keep the axle from sliding out and are to long to force it by. As a rule I only R&R and rebuild these as any G.M. front differential. You really can't 1/2 refit these. Clean the heck out of is and make sure the races sit tight. I've seen crapolla keeping the races secure and after knocking the race and crap out the new race fits loose. The heavy vibration can cause the machined race surface to be damaged. I've pounded them out and pounded them in and when the race sat in the same place as the old one it wiggled. Price out a reman from Jasper as opposed to rebuilding that one yourself.

[Goose]

Thanks Steve. So the pan does have to be removed?

[steven kiser]

Yes. I've tried to force them by the guide and did it the first time but couldn't get it back in.

[Goose]

Thank you.

[steven kiser]

You're welcome..............

[Goose]

Thought I had better post the final cure on this fine GM product. I did put in a reman differential unit that I found locally. The races for the side bearings were loose and the bearings were shot. After the initial intermediate repair and the differential replacement I still had a noise and found the right front wheel bearing to be bad also. It was a good thing that this is a regular customer that respects and trusts me. I felt discouaged that I was not able to find all three problems initially but I guess there was soo much noise that it transmitted its self throughout the who front end. The chasis ears are normally a huge help but were not much help on this one. Once the first two problems were corrected the wheel bearing was easy to hear with the ears. The lesson to be learned is to inform the customer of what you know for sure but to leave the door open. There may be more problems lurcking in the shadows.

[ricmorin]

Par for the course these days. Those noises didn't start all at once. It was obviously ignored for some time BEFORE they brought it to you. We see it every day, and it's getting worse. My 2004 is in better shape than most 2009 vehicles I see. My tech has a 1997 (so do I) that is in better shape than many 2007 vehicles I see. Very sad.

Thanks for posting the fix.

[Goose]

This guy is a do-it-your- selfer when he can. He admitted to never having serviced the differentials or transfer case. Ok by me. More good paying work for us. And yes - it had been going on for a while. I found an old estimate for a wheel bearing from a year ago. Never had diagnosed it but on a test drive it sounded like a bearing.

[steven kiser]

I'm surprised it wasn't your fault. You took it on a test drive. When i take a vehicle on a road test and no further work is done i always create a work order stating a road test was taken but further diagnostics are needed but customer refused. My only negative post on yelp was from a customer that had noise. Exhaust was pushed up against the frame, along with a wasted rear wheel bearing. He was limited to a dollar amount and asked what was more critical. I need to add this person was Russian or Western European. I only add this because of the language barrier. I replaced the wheel bearing which eliminated the rear noise and gave him a solid pedal. It was posted on Yelp that I had failed to resolve the issue. I replied that i had spent over an hour with the customer explaining that he had a wheel bearing blown so bad the wheel would move two or three inches. This also caused a fading brake pedal, another safety issue. I showed him where the exhaust was plastered against the frame. I was restricted by funding and most of the hour was spent overcoming the language barrier. I made it absolutely plain that the more i proved my point with him over the phone the less he understood what i was saying. This is a point that drives me nuts. When someone feels they have the upper hand they understand fine but when they start to loose the discussion they seem to understand what you're saying less and less or get agitated and forceful, but this is another point. Because i had everything documented and signed i was able to offer that as proof of it was understood what he was getting and was just a grumpy old man that thought he could squeeze me a bit more. Funny he couldn't understand what i meant by the rotor pushing against the caliper creating a brake issue because of a bad bearing and the exhaust just being a noise, in his Yelp statement, but when i accused him of being a parasite attacking people using the language barrier as an excuse also known as pulling the victim card he knew exactly what i was saying. Funny how they can loose grasp of the English language when it suits them but are a laureate when they are firm in their belief of total correctness.