Driving down the street in my 2009 Hybrid Tahoe 2WD @ 35 MPH and the engine light comes on, nothing seemed amiss at first, stopped at a light and it had a really hard time getting any speed, felt like a fuel problem. Got up to 40 MPH and BANG then nothing except neutral, coasted to a stop and had to have it towed to the dealer.
8 Transmission codes and the pan was filled with used to be the internals of the transmission, it was a mess, looked like a pile of scrap metal & clutch pieces. Dealer said it was far beyond repair. To make matters worse, the dealer just did a $1500 transmission repair 5 months ago, in retrospect the transmission was probably in self destruct mode 5 months ago.
I purchased this vehicle new in 2009 and to say I am meticulous and gentle with my vehicles would be an understatement. I have dealt with all of the other typical quirks of this vehicle(locks, mirrors, dashboard, etc) in stride but for the transmission to fail at 155K miles is unacceptable...especially considering my intense maintenance schedule and gentle driving habits.
Sadly this will likely be my last GM vehicle after 30 years for me and my company.
I would SERIOUSLY warn anyone considering buying one with some miles or keeping one past 150K miles to reconsider. GM seems to have taken BMW's lead and built in a self destruct mode.
There are many great things about these vehicles(the brakes come to mind), unfortunately the engine, transmission, Traction Battery, and a bunch of other things that will bankrupt you, self destruct at 150K+ miles(maybe sooner with lax maintenance)
Oh and FYI, the transmission was $6K at the dealer, $4K for the transmission and $2K for labor.

The dealer gave me a brand new 2017 Suburban to drive for two weeks while they were repairing my car, thankfully I didn't care for it (I think they were hoping I would buy it)

I loved the Hybrid Tahoe....until it started to fall apart. May be time to look for a replacement daily driver.

At least it still looks good.

 

Is there a sort of warranty? It must be their fault if they cannot overhaul a transmission?

 

What did the dealer do to it before for $1500?


The base transmission on these has a much better long life record than your experience demonstrates here.


Many are over 200,000 including towing.

 

The dealer previously replaced the valve body and control module. However, I think this was an exercise in futility as the Transmission was already on its way out.

I routinely drive 90-99 MPH for long periods of time(there are lots of wide open roads in Arizona) & in extreme heat(120+ ambient) and in retrospect I believe this is what led to the premature failure. Sadly I just don't think this transmission was cut out for high speeds under extreme heat.

Although I have never towed anything with it, I have also at times traversed extreme grades(20%+) to which I can attest this vehicle does NOT like. I do carefully monitor the trans temperature and it has never even come close to overheating.

High speeds, extreme heat and steep grades seem to be the trifecta of death for this transmission.

 

Since you're an old owner I'm surprised that the tranny imploded like you said. Did you drain and fill the tranny at 100k miles? I also did 90-98 mph like you said and travelled a lot in high speed as well as prolonged heat and idling with no problems. Even towed several of my vehicles and it proved to be strong. A misdiagnosis doesn't mean it was failing.

 

I had the dealer drain/refill/replace transmission filters at 70K, 120K and 150K. The 70K was replaced when an internal electronic module melted and necessitated fluid replacement , the 120K was routine maintenance, the 150K was when the valve body and controller were replaced. They didn't mention anything was out of sorts when they worked on it and it didn't behave unusually (beyond what others have already discussed on this forum) until it quit.

With this vehicle I do very little idling , no towing, probably 75% highway, avoid traffic at all costs. It had 10 miles on it when I bought it and no one except me has ever driven it.

My maintenance schedule for all of my vehicles is beyond rigorous.

I suppose there is a slim chance the dealer/technician just didn't know how to repair it and figured full replacement would be the path of least resistance but I am a long time customer and have no reason not to trust them.

The one bright spot is GM provided a 3 year / 100K warranty on the re-manufactured transmission...so I'm good to go for a long time. I have tried to replace the Tahoe with another daily driver several times but I find myself choosing to drive it over my other choices...I don't know why.

 

A new transmission should have been the first thing to come to mind. Regional expertise is hard to guarantee especially for hybrid transmission. This is not your regular tranny repair.

 

Sorry to hear the news. But for me it is strangely good news. I have a 2008 w/ 197k miles, and I have done very little except oil changes. My tranny has started giving me more difficulty with starts and clunking a bit. If I can replace for $6k and it saves me car payments for another couple of years and 100k miles or so, ill be happy to do so.

 

This was my thoughts exactly, my Tahoe is in otherwise flawless condition and I certainly wasn't going to scrap it over a 6K transmission. Now I'm good to go for another 100K miles. My only minor concern is I hope the traction battery lasts at least the expected 10 years (2019), at least I can test and replace the cells if necessary.

 

Could this be the problem with my '08 Tahoe? I've read every thread on this subject, and it seems like NO ONE can properly diagnose the issue I'm having with the hesitation moving from Mode 1 to Mode 2. Just dropped another $225 on a full battery cleaning. After the work, my MPG was still only 18.5 going 70 MPH in 80° weather across flat land.


What was your gas mileage before and after the new tranny? Mine's only got 140,000 miles on it, and I'm afraid to do a transmission fluid change. But I'm also concerned about the valve and Transmission Control Module.