Transmission/transfer case issue

[Kuehjo]

Aloha all!

So. I've had my VX for about 6 months now. I don't think I've put 1000 miles on it yet - though I WANT to.
Here's my current issue:

The truck starts and runs fine. In fact, I have NO complaints when its cold. But after it starts to warm up I start to get a problem. It first manifests as a rattle/buzzing feel/sound that comes up through the floorboards and pedals and feels a bit like a heat shield. It happens at two particular times - if I'm letting OFF the gas pedal to coast or perhaps decelerate (although if I brake, it almost immediately seems to go away) and when I go from coasting to accelerating, before i really have power transferring through the drivetrain - you know - that "back side of the power curve" spot.

Well, it gets more interesting. Occasionally I'll be cruising along in overdrive, and all of a sudden it will pop out of fear. Not the shift lever - that never moves. But the transmission will jump from overdrive to neutral. The only way I can get power back is to come to a complete stop, and then start out again. Sometimes it will shift back into overdrive again (until it pops out again, that is) - sometimes it won't, leaving me in second. If I manually shift down into third, it isn't actually third that I get, but second - but at least I have power again (up to about 40 miles an hour, at which point second gear is pretty well topping out.)

I've checked fluid - its full in both the transfer case and the transmission itself. My brother had a problem very similar to this on a 2003 Duramax, and it ended up being his transfer case that the shift forks had basically worn out. I'm not yet convinced that I have EXACTLY the same problem, but I seem to remember on of our members runs a transmission shop - I'm really hoping he (she?) will weigh in for me...

Looking for any and all suggestions - I will be casting no aspersions, and no idea is too dumb to be considered!!

Mahalo!

Jonathan

[Mile High VX]

That would be Melanie from Little Rock, AR that has the shop.

I'd hit her up over on the VX facebook page for some help.

[Kuehjo]

That would be Melanie from Little Rock, AR that has the shop.

I'd hit her up over on the VX facebook page for some help.

I appreciate that - thank you. I knew there was SOMEONE on here...

[Kuehjo]

Hmmmm - new update...

So I've been reading a bunch about the 4L30E. Sound like the 2-3 solenoid is going out. And a solenoid kit is about $150 and a couple hours on your back. I can do that.

Update though - I have NOT been driving the truck (not repaired, and I didn't want to make things worse) until yesterday. Drove GREAT yesterday with no shift issues - just still that vibration/buzzing when just off the throttle. Had to drive the truck to work today (that's about a 40 mile commute). Doing its usual thing (except no transmission shift issues - thank you Lord!) until about mile 30 when I noticed that the vibration/buzzing had basically disappeared - but right about the same time as my TOD check light began blinking.

Hmmmm. So probably that buzzing is a TOD/transfer case issue. Probably not a bad half-shaft or universal joint. Certainly not a loose heat shield.

I'm not sure whether to be grateful, or super worried... Yet...

[MsConduct]

On the topic of transfer cases... my VX recently started making a knocking noise when coasting. Sounded like maybe U joint, maybe CV, but those have all been checked out and appear fine. Mechanic thinks it is something in the TC, but doesn't get into those, so recommended a transmission shop.

This is way more of a project than I am able to take on.

I'm in So Cal, with extended AAA towing, but don't know where to take it. I want to find someone with access to parts, some knowledge of the nuances of these beasts, and all that. I can't find "Mike" who used to be in Monrovia at Sierra. As I recall, there were some other experienced mechanics out there but I can't recall how to contact them.

Any ideas? Or maybe the problem is something else entirely?