Laurence

The yoke is in great shape. No rust; nice and shiny. The splines had a thin film of oil in them. I had the dealer look at it, thinking they would know what to do, All they could come up with is to use the GM special lubricant #12345879. It is a PTFE filled high temp grease. What will that do to the transfer case oil?

Well guess what? This problem is still not solved! I replaced the drivers side temp blend door actuator (underneath on the pass side) a couple of times but no change. I had it diagnosed at the GM dealer and they said the pass side actuator needed to be replaced (?). So I did thinking perhaps the controller was getting confused. I thought it was OK after but eventually the problem came back. The actuator motors I used were not Delco but Dorman. When I reset the system all works good for a while but then the driver's side blows hot in the summer and cold in the winter. The blend door moves freely. So the only things I have changed are the blend door actuators. Nothing else. I have moved the actuators around but it is always the driver side that is bad. Do you think replacing either the cabin or duct temperature sensors could help? I don't use the truck much and that is why this issue is dragging on so long.

I have been doing some reading on this issue. Lubricating the splines is a GM recommended procedure for 4x2s only. GM does not permit this for 4x4s. ( Bulletin # 09-04-21-003B). The grease will migrate into the transfer case and contaminate the oil. Transmission fluid is supposed to lube the splines in this case. I'll have to pull the yoke out and see if it is dry. What has been the experience of you 4x4 guys? Thanks for pointing me in the right direction.

I have a 2006 GMC 2500. The problem I have now is dimming of the DIC and mirror display. I can be driving on a bright sunny day, and at any time the DIC will dim. The mirror temp and compass display will also dim and will be unreadable it is so faint. The two displays will dim at different times. I have auto-on lights and daytime running lights.Is this related to the cold solder issue I see in other topics? Thanks again!

I have a 2006 2500 Duramax 4x4. It has 100k miles on it. Occasionally when I come to a stop, it feels like someone is bumping in to me in the rear. This could be happening at the final downshift but I can't tell. The Allison is so smooth. I have no signs of any trans problems at all. Fluids are up. Temps are normal. Any idea what this could be?

Oh; there are two? I did not know that. Anyways, I replaced the one that is reached from the passenger side. Where is the other one? The motor I removed did not seem to have any defects. Laurence

Hello again. I replaced the blend actuator and I reset the system (recalibrate). It was wonderful to have AC again! But; the the same problem started again. Full heat from the driver's side. The pass side is cool. The actuator I replaced is mounted under the duct work; accessible from underneath the dash. Any opinions on what this could be? Help!

Hello there. I hope that someone can answer this one. I see there have been some postings about heating and AC problems. I have a 2006 GMC 2500HD with Duramax. It only has 138000 KM on it so far. In the winter, the heater will start blowing ice cold air from both sides. I do the recalibrate sequence and it behaves for a while. I have driven many miles in -30 deg C weather with no heat. In the summer, the driver's side will pump out the heat. The pass side is cold. The recalibrate only solves the problem for one restart. This heat issue has been around a lot longer than the cold issue. Are these two problems related? What do I need to replace to fix this? Thanks for your help! Laurence