Poll: How has your 8-speed been for you?

TXGREEK · February 3, 2019

Flush with Amsoil “100%” synthetic transmission fluid, I’d do that first before taking it to a dealership to experiment on your vehicle. I’ve heard replacing the factory transmission fluid actually made it shift normal. My transmission has a weird soft clunk from take off but only happens 1 out of 20 times which really doesn’t bother me much but may have my transmission flushed and use only Amsoil 100% synthetic

Sent from above

diyer2 · February 3, 2019

IMO

I don't have an 8 speed trans. and I'm glad of that.

GM will approach this with the least amount of cost.

They have proven that with a fluid change, cheapest shot for a remedy.

I wouldn't count on a recall. Lots of money to do this and will be avoided if they can.

Z45 · February 3, 2019

21 minutes ago, TXGREEK said:

Flush with Amsoil “100%” synthetic transmission fluid, I’d do that first before taking it to a dealership to experiment on your vehicle. I’ve heard replacing the factory transmission fluid actually made it shift normal. My transmission has a weird soft clunk from take off but only happens 1 out of 20 times which really doesn’t bother me much but may have my transmission flushed and use only Amsoil 100% synthetic

Sent from above

That's what I did around 10,000 miles. Now at 20,000 and is actually shifting much smoother. While the say GM and Mobil 1 are full synthetic, that term is ambiguous. Full or fully synthetic is the new name for synthetic blend. Full synthetic oil is a marketing term that in no way defines the quantity of synthetic content.

When you see the words 100% Synthetic on a bottle that means that EVERY SINGLE DROP of oil in your bottle is a synthetically produced compound, mixed with fully synthetic additives.

qwank · February 3, 2019

1 hour ago, M1ck3y said:

If this was true gm would do a recall. Have they? Because if they have I'm going in to get this done, otherwise I'm not going to waste time at the dealer arguing about how a transmission is supposed to operate.

They literally just figured out the problem was the fluid within the past few weeks. I've driven a ton of these 8 speed trucks with the scan tool and pico scope on them, to record and send GM data over the past 6 months. We've replaced everything from torque converters to whole transmission assemblies, and now they are saying it's just the hydroscopic fluid. I'm going to bet there will either be a customer satisfaction recall, or some sort of extended coverage on the issue.

qwank · February 3, 2019

5 hours ago, CadillacLuke24 said:

qwank is there a new part number for the non-hydroscopic fluid? Or is the 19353429 number for the Mobil LV HP I've been finding on Google still valid?

the new part number is 19417577. The Service bulletin is 18-NA-355. It just came out January 17, 2019. This is all brand new information from GM. Everyone will be talking about this in a few weeks, You heard it here first

M1ck3y · February 3, 2019

5 minutes ago, qwank said:

They literally just figured out the problem was the fluid within the past few weeks. I've driven a ton of these 8 speed trucks with the scan tool and pico scope on them, to record and send GM data over the past 6 months. We've replaced everything from torque converters to whole transmission assemblies, and now they are saying it's just the hydroscopic fluid. I'm going to bet there will either be a customer satisfaction recall, or some sort of extended coverage on the issue.

Awesome, Thank you!

JacobC1983 · February 3, 2019

12 minutes ago, qwank said:

the new part number is 19417577. The Service bulletin is 18-NA-355. It just came out January 17, 2019. This is all brand new information from GM. Everyone will be talking about this in a few weeks, You heard it here first

Great information here. Thank you.

SS502 · February 3, 2019

2 hours ago, M1ck3y said:

If this was true gm would do a recall. Have they? Because if they have I'm going in to get this done, otherwise I'm not going to waste time at the dealer arguing about how a transmission is supposed to operate.

The trick is, take your truck in (if it’s really having problems) to establish a trend. If they can duplicate it great and if not you are on record for an issue. Then continue to (as you say bicker) report a problem. They know there is an issue and will eventually do the flush. I’ve already been advised by my service department NOT TO WAIT if I start having problems, they know not everyone is going to leave their truck overnight just for them to duplicate, especially if it’s intermittent. Far cheaper for them to do a flush/fill than for you to drive it to the point of total failure.

M1ck3y · February 3, 2019

1 hour ago, SS502 said:

The trick is, take your truck in (if it’s really having problems) to establish a trend. If they can duplicate it great and if not you are on record for an issue. Then continue to (as you say bicker) report a problem. They know there is an issue and will eventually do the flush. I’ve already been advised by my service department NOT TO WAIT if I start having problems, they know not everyone is going to leave their truck overnight just for them to duplicate, especially if it’s intermittent. Far cheaper for them to do a flush/fill than for you to drive it to the point of total failure.

I had a 2010 Silverado with the 6l80. I did nothing but complain over and over again about how it clunks and doesn't shift right, and it got me nowhere. That's why I haven't gone in for my 8spd issues. Unless there's a recall I'm not wasting my time. All fixes for the 8spd up until this point have been hit and miss. Not every fix works for everyone, these transmission are just crap. I haven't met anyone with an 8spd who hasn't experienced the common issues. If you don't have any problems with your 8spd right now, you will. Either that or you have horse shoe up your butt. I don't care what this poll says.

I accepted this when I decided to buy another gm. The days of quality products are gone, its the era of more for less.

Edited February 3, 2019 by M1ck3y

SS502 · February 3, 2019

9 hours ago, M1ck3y said:

I had a 2010 Silverado with the 6l80. I did nothing but complain over and over again about how it clunks and doesn't shift right, and it got me nowhere. That's why I haven't gone in for my 8spd issues. Unless there's a recall I'm not wasting my time. All fixes for the 8spd up until this point have been hit and miss. Not every fix works for everyone, these transmission are just crap. I haven't met anyone with an 8spd who hasn't experienced the common issues. If you don't have any problems with your 8spd right now, you will. Either that or you have horse shoe up your butt. I don't care what this poll says.

Well I guess I’ll be waiting for it...I just removed the small one yesterday ?

Edited February 4, 2019 by SS502

mookdoc6 · February 3, 2019

I wonder if anybody has just replaced the M5U with the newer revised 8speeds for 2019 T1's? I usually have my fluid replaced yearly on my vehicles at a Dealership I have used over the years ON/OFF.....I use them because their prices are just almost impossible to beat? Anyway, I took the truck there for fluid replacement that I provided the Mobil ATF HP 7qts told them to charge me for the remaining and the service etc?

1.50 Hrs later they told me to pick up the Truck.....NO CHARGE! GM taking care of it? They must have sent out something that allows the dealer to use this code and GM will reimburse for Fluid and labor on M5U'S

thought I would let you all know....Or I got lucky? Doubt it...... I was happy as a pig in mud!

Edited February 3, 2019 by mookdoc6

CadillacLuke24 · February 4, 2019

13 hours ago, qwank said:

the new part number is 19417577. The Service bulletin is 18-NA-355. It just came out January 17, 2019. This is all brand new information from GM. Everyone will be talking about this in a few weeks, You heard it here first

QWANK FOR THE WIN! Thank you sir!

How much is this stuff? A quick google search got it to populate on some sites, including one of my favorites (GMPartsNow). I was shocked to see the unit price as 5-6 bucks...that sound right?

Thanks again man! My 8 speed is VERY well behaved, but my next drivetrain fluid service is coming up (transfer case, differentials, and a pan drop) so I want to get the latest and greatest (and flush if possible)

SS502 · February 4, 2019

So lets say you just wanted the new stuff and the procedure done even if you're (me) not having any shudder but would like it done for preventative measures. How much do you think it would cost to have done? I almost think I'd rather pay now, save my receipt in case it actually became a recall and hopefully never have to deal with it. I am thinking that if I wait until I have the problem, if ever (remember I was accused in an earlier post of having a horseshoe up my butt) that at that point I've probably done at least some damage? Even if I get it done and it does start having issues, I could take it back in for yet another flush on their dime. Thoughts?