So I just bought a 2006 V6 Pony package after my pristine 40th anniversary was destroyed by a tree.
When I first bought the car I noticed that the shocks needed to be replaced, about a month later the motor mounts went and I replaced them. Now it’s starting to get cold outside and every time I drive the shifts are late from 1-3. First thing after starting and letting it warm up it drives a bit sluggish. It shifts perfectly after, but once I get on the highway and have to hit 70 or 80 the rpms stay at about 2,250 to 2,500. I was thinking about changing fluid and filter and maybe replacing the solenoid block.

 

Yep, i would start with maintenance as you've already defined it. Fluid filter and solenoid pack. The 5r55s is notoriously picky over used fluid and being under filled. Be certain to use only Mercon V fluid. Stay away from the universal fluids. DO NOT USE MERCON LV! Wrong fluid and it will ruin the transmission.

 

Should I go ahead and change the gear oil in the back axle?

 

That would not be a bad idea. That is supposed to be done every 50-75K but since you bought the vehicle used, it won't hurt. Be sure you get the gear oil AND friction modifier if the fluid does not come with any already added. I think the Motorcraft brand gear oil is the only one that comes with the modifier added. Read the label to check or just buy the gear oil from one our site sponsors. They will tell you if if the gear oil you are buying requires any other additives/friction modifiers.

 

When I bought the car it had 142k and it just recently started shaking pretty bad before I replaced the motor mounts. I was already planning on changing the tranny fluid but got sidetracked. Now since yesterday and this morning it has a slight rattle while idling in drive. And it’s whining while changing gears from 1st to 2nd. I was going to replace the tranny mount while I was doing the motor mounts but I couldn’t get the cross member off the exhaust stabilizers.