I’m trying to diagnose something I’ve noticed the last few months in my 2008 Suburban 1500. It may be one issue or a couple.
The 4L60E shifts perfectly from 1 to 2. 2 to 3, though, is almost always soft. It’s not a slip or hesitation as much as it is what I’d describe a nosedive of momentum. 3 to 4 seems perfectly fine, FWIW. Both shift solenoids were replaced with OEM about 12,000 miles ago. If I accelerate a little more aggressively, the problem seems to subside. Some 2-3 shifts are just fine. I didn’t really notice this when I bought it a year ago, but it may have been there.
I’ve also started to notice a small clunk or thunk that seems to coincide with shifts. It seems to be downstream of the transmission - maybe driveshaft or the rear end. (It’s not quite the same, but it reminds me of issues I had with a 2001 Jeep Cherokee. They were caused by an ungreased slip yoke.) There’s also a little play in the driveline, a slight hesitation between acceleration and engagement in the differential. I call it slack. The same Jeep had this issue, albeit considerably more advanced, and it was solved by new spider gears.
The truck has 121,00 miles on it. Transmission fluid is good and at the correct level. The gear oil in the diff. is a synthetic with 12,000 miles on it.
FWIW, none of this is to the point that the average driver would notice any of this. Just being a car OCD BITOGer, it’s bugging me.
Any ideas? I'd appreciate your thoughts.
The 4L60E shifts perfectly from 1 to 2. 2 to 3, though, is almost always soft. It’s not a slip or hesitation as much as it is what I’d describe a nosedive of momentum. 3 to 4 seems perfectly fine, FWIW. Both shift solenoids were replaced with OEM about 12,000 miles ago. If I accelerate a little more aggressively, the problem seems to subside. Some 2-3 shifts are just fine. I didn’t really notice this when I bought it a year ago, but it may have been there.
I’ve also started to notice a small clunk or thunk that seems to coincide with shifts. It seems to be downstream of the transmission - maybe driveshaft or the rear end. (It’s not quite the same, but it reminds me of issues I had with a 2001 Jeep Cherokee. They were caused by an ungreased slip yoke.) There’s also a little play in the driveline, a slight hesitation between acceleration and engagement in the differential. I call it slack. The same Jeep had this issue, albeit considerably more advanced, and it was solved by new spider gears.
The truck has 121,00 miles on it. Transmission fluid is good and at the correct level. The gear oil in the diff. is a synthetic with 12,000 miles on it.
FWIW, none of this is to the point that the average driver would notice any of this. Just being a car OCD BITOGer, it’s bugging me.
Any ideas? I'd appreciate your thoughts.