speed sender?

Ok so I've gotten my 2nd ticket for this lovely problem. The problem is that while 0 to ~55(mph) works all well and good(off by little to none) 60+ becomes extremely inaccurate. My speedometer will hover around 60mph and I will actually be doing much faster (cop this time says 80mph .. was 88mph last time). If I quickly accelerate it will go past 60 but will drop back down w/out really droping in mph at all, if any.

Well after the 1st time I took it to the dealer after 3.35hrs of them trying things, test driving, trying
another, ect. they say it's the "speed sender" in the tranny. They tried a new "speed gear", "cluster" and checked the "speed sensor" as well.

I was just wondering if any of you out there know if this is accurate and have any idea of how much it would cost to go about replacing this
"speed sender"?

Anyhoo if you would like more info I'll try and provide it. Oh and thanks in advance to anyone trying to help. Sorry I'm not really to car knowledgeable. Oh and the car in question is a '97 VW Jetta GL (automatic)

Did they put in a new sensor or are you wanting to do it yourself?

On the invoice it says speed sender located in the transmission is what the problem is. They checked the speed sensor and I guess it was ok.

Well I called over to the dealership to get a quote on replacing this part, and they said tranny would have to be replaced (rebuilt?) and it would roughly cost $2000 for tranny and $600 for labor. Is there any other possible causes that might be cheaper and fix the problem?

Have They Or You Replaced The Speedometer Drive Gear In The Transmission? It Is Located On The Speed Sensor. What Can Happen Is The Gear Gets A Crack In It And At Faster Speeds The Gear Starts To Seperate And Does Not Make Good Contact With The Gear On The Ring Gear. I Have Also Seen The Same Thing On The Plastic Gear That Drives The Speedometer Gear That Is Attached To The Ring Gear. If You Remove The Speedometer
Sensor, Which Is Very Easy To Do, You Can Look Down There And May Be Able To See Something. If The Problem Is With The Plastic Gear On The Ring Gear The Transmission Will Need To Be Torn Down For Reapir.