Please help. 2011 suburban rwd transmission revs for a second then instantly jerks when taking off from a stop sign.

[Tozan]

Mine did that at 205k a few times over the course of 3 months..... Then failed completely.. Left me stranded 80 miles from home...

 

[swathdiver]

...when I come to a stop and try and take off it acts like it's in neutral for a split second then BOOM catches and goes.

No still hasn't been fixed

 

[jhous09]

The transmission has less than 1500 miles on it now. Has been gone through again for my piece of mind. The shop also replaced the tecm while the transmission was apart again. So I'm thinking it isn't the transmission.

 

[TollKeeper]

Being a transmission is a hydraulic device, I would make sure the pressure is right. It could have a clog in one of the cooling lines, the cooler itself, a misaligned o-ring at the connections, or?

Its one of the reasons most dealers will require a radiator replacement when replacing a transmission.

 

[petethepug]

If it’s any consolation my first rebuild in shop took a dump after a month. I was genuinely not concerned and brought it back. Another week later better than new again. It failed because a pump was not installed correctly.

Peace of mind and no stress believe it or not.

 

[NickTransmissions]

The transmission has less than 1500 miles on it now. Has been gone through again for my piece of mind. The shop also replaced the tecm while the transmission was apart again. So I'm thinking it isn't the transmission.

Ask them if they replaced the low sprag and corresponding snap ring (both must be replaced on all overhauls on these transmissions). That was my first thought as well when you had posted but didn't want to waste time unless you were still having the symptoms. The low sprag only holds in 1st gear and since first gear is so deep in these transmissions, you're in and out of it very quickly. So fleeting neutrals in first can def be the sprag either rolling or snap ring popping out, causing the sprag to slip.

Here's my 6L80 Diag Vid that explains how to map symptoms to potential causes in case you're interested and want to know more - skip to 19:22 for sprag discussion.

 

[Geotrash]

Ask them if they replaced the low sprag and corresponding snap ring (both must be replaced on all overhauls on these transmissions). That was my first thought as well when you had posted but didn't want to waste time unless you were still having the symptoms. The low sprag only holds in 1st gear and since first gear is so deep in these transmissions, you're in and out of it very quickly. So fleeting neutrals in first can def be the sprag either rolling or snap ring popping out, causing the sprag to slip.

Here's my 6L80 Diag Vid that explains how to map symptoms to potential causes in case you're interested and want to know more - skip to 19:22 for sprag discussion.

Bless you, sir.

 

[jhous09]

Finally got ahold of the guy that rebuilt it. He said he tested it and it worked. According to him it either works or it doesn't and he doesn't do it because it's a 500 part