[Canz]

Hello, I have a 04 trailblazer with 130,000 miles on it. Last week I replaced my radiator and water pump and added a transmission cooler, because it has been running hot (over 210) it’s been doing this for the past 3 summers and I have previously replaced the thermostat and fan clutch and it’s still running hot. Think I will be trying one of those fan clutch bypasses in the near future and hope that helps.

But on to my bigger problem after I got done replacing my radiator and water pump I notice a vibration starting at about 3000rpm and ending at 4500rpm. and not sure what could be causing that. I don’t think the fan clutch is misthread or anything like that because it went on very easy. I also noticed I am now leaking front differential fluid from the driver’s side seal and possibly the rear seal. The front differential fluid was changed about a month ago in South Carolina while on a PA to Fl road trip at my father in-laws who is a Nissan mechanic. When he changed the fluid it was very Gray. He said the might be some wear in it, but I wasn’t going to push the free labor further because he was already doing about $1000 of free work at his dealership.

What can I be expecting with this differential and could this be the cause of my vibration, and not an unbalanced pulley like I was thinking?

 

[racer383s]

At what road speeds are the you experiencing the vibration?

 

[Canz]

It kinda does it at any speed as long is its in that rpm range.

 

[ylab]

What about the transfer case fluid, was it changed and if so did you use Autotrac (or RP Synchromax) fluid? - The Transfer case can create a vibration or shake when the wrong fluid is installed, badly needs replacing or the level is low. Many mechanics try to use DEX3/6, which doesn't have the friction modifiers that the Autotrac spec calls for. W/o those friction modifiers, the clutch plates partially engage causing a vibration or shake.

I only mention it as you mentioned that you did change the axle fluids, figuring you may have also done the transfer case as well.

 

[Canz]

The Transfer case fluid was changed as well with one that has the friction modifiers in it.

 

[drkhead]

Motor mounts?