Squealing Noise - 96 Ext. Cab, 2.7L

Hi all,
I have been experiencing a strange noise that I've been unable to diagnose, and I would appreciate some suggestions for what I should test next.
The problem is this: there is a loud squealing noise that builds up from 40 mph and stops increasing in volume at around 60 mph. I have tested a few things, including the speedometer cable, carrier bearing (has been an issue in the past), and vacuum leaks (using break cleaner, I couldn't find any, doesn't mean there aren't any though). As best as I can tell, the problem is correlated to speed, as it doesn't occur when I rev up the engine from a standstill, but only at around 40 mph.

Any ideas of what could be causing this are appreciated.

 

Try putting the trans in neutral when it makes noise to see if it is engine or chassis related.

 

My last annoying squeak ended up being the hood latch. Made no sense and my ear test failed.

 

I have a 96 Tacoma 2.4L that part really is not specific to my issue, I am trying to find out if I have a bad speedometer cable or a bad speedometer it self?? from 30-50 mph only when the weather is cold. I get that horrible sequel and sometimes the needle will jump. It is I really think the cable. I have looked and my truck has the cable, not a sensor. But it looks like a major thing to replace the cable. Is there anyone here that has replaced the speedometer cable?? I am looking for a short cut,, and easy way to replace it. I can't have it done, by a shop. Way to costly . Any ideas ???

 

I think you can grease the cable, some how

 

I am hoping to spray it from the bottom? because I have to pull out the dash instrument panel. I don't want to pull that out unless I am going to get a new cable and replace it. Any ideas on to what I can spray up into it, I an thinking WD-40 or silicone to help break down the gummed up lube thats in it. Because it is fine in the warmer weather, like 40 deg and above. I just bought the truck in May of this yr, she told me it has a horrible noise when it's cold, and after you drive it for a few miles it's better, but only bad when it's cold. Well,, all summer I never had any thoughts about it, I had been going through the things as replacing a broken spring, tuning it up, replacing minor stuff. And the first freeze happened and wow it was soo noisy . I was shocked .. but that's still a minor thing for as cheap as I got the truck...

 

I had that noise in my 95 M/T V6. I solved the problem by parking it in my heated garage. Seriously though, I think you can pull the cable out of the housing from the bottom, clean it and grease it as you put it back in. Might be worth a try.