8 speed transmission OK?

[chuckcrj]

I am going to buy a 17 or 18 truck soon and am wondering about the bad things I hear about the 8 speed. I will be looking at 50k plus mile to get the price in my range so won't have warranty.

 

Is it something I should avoid? Or if everything else is exactly what I want is it fine? What is the consensus here?

[2018GMC]

Yes there are complaints about the 8 speed on the internet. GM made millions of trucks and SUVs. Hundreds of thousands have the 8 speed and they are working fine.

One downside is no dipstick so you can’t easily check fluid level or color.

Get the service history from a dealer. Has it had a complete fluid exchange with the new fluid?

Take it on a long test drive. Accelerate in traffic then let off and see how it shifts. Occasionally mine has a light clunk but nothing like the loud harsh bang some have experienced.

Get it on the highway. Set the cruise and see if the rpm jumps or holds constant at a constant speed. You want it to hold constant.

I’m happy with mine but I only have 11k on my 2018.

Good luck and happy hunting!

[chuckcrj]

Thanks for the reply! Waiting for the exact right thing I want and don't want something I will hate. For work I drive a 15 with 6 spd trans and it shifts fine, just the fear of the unknown LOL

8 minutes ago, 2018GMC said:

Yes there are complaints about the 8 speed on the internet. GM made millions of trucks and SUVs. Hundreds of thousands have the 8 speed and they are working fine.

One downside is no dipstick so you can’t easily check fluid level or color.

Get the service history from a dealer. Has it had a complete fluid exchange with the new fluid?

Take it on a long test drive. Accelerate in traffic then let off and see how it shifts. Occasionally mine has a light clunk but nothing like the loud harsh bang some have experienced.

Get it on the highway. Set the cruise and see if the rpm jumps or holds constant at a constant speed. You want it to hold constant.

I’m happy with mine but I only have 11k on my 2018.

Good luck and happy hunting!

 

[chuckcrj]

Still haven't found the perfect truck. Getting close especially with prices coming down some right now.

 

Does anyone know for sure, is the truck equipped with adaptive cruise control only if you see the little gap length button on the left side of the steering wheel?

[JimCost2014]

28 minutes ago, chuckcrj said:

adaptive cruise control

K2's do not have this feature.

 

The buttons are for forward collision alert, you set the distance you want the warning to happen (red lights on the windshield).

[chuckcrj]

Finally got a truck, 2018 Denali in Dark Slate color. 5.3 with 8 spd. I really like this trans so far. 

[WilliamBos]

Beautiful truck.  Congrats.

[flyingfool]

the 8 speed got scraped for a reason, you dont see it in anything anymore yet the ol 6 speed is still out there in new models

[WilliamBos]

2 hours ago, flyingfool said:

the 8 speed got scraped for a reason, you dont see it in anything anymore yet the ol 6 speed is still out there in new models

The 8 speed never got scrapped, they are pairing the 6L80 with the 4.3/5.3 AFM, everything else gets the 8 or 10 speed.

Edited May 3, 2020 by WilliamBos

[flyingfool]

wish GM techs would post up a list of all the issues on the 8 speed here.. be nice to know what is in need of upgrading  on them..

[Danyoda]

I bought my 2018 Sierra SLT used(certified pre owned) back in October 2019. It had 21k miles at the time. Since then I’ve put around 6k. Not once have I had an issue with the 8 speed. It shifts smoother than my wife’s CVT.