adventurenali92
Full Access Member
Sorry for the lengthy post, but I've got a problem I've never seen before and I need some opinions. 2006 Yukon xl Denali here with a rebuilt 4L65E Trans, not even a year old yet. Rebuilt trans is just under 10,000 miles since the rebuild. so I noticed Sunday afternoon driving down the mountain from where I live, I went to use my transmission to downshift to slow down on the grade, about 45mph, and when I moved the shifter down from drive to 3rd, nothing would happen. And then nothing from 3rd to second either. Very frustrating to have to ride my brakes. My first thought is something screwy with my transmission. I'm pissed because it shouldn't be happening this soon. So I get down he mountain and off the freeway, come to a stop light and I'm worried I'll be stuck in one gear and not be able drive it. But to my surprise from a stop,in drive, trans shifts through all the gears completely fine. When I came to the next light, I put it all the way to first and manually shift up through the gears as I accelerate and it shifts up through the gears fine. But still won't downshift into third or second. Super weird, no CEL, no warning lights, and fluid is right where it should be on the dipstick and nice and pink. So I called in sick to work Monday and took it to the shop that rebuilt my trans at the base of the mountain. Very good shop and awesome shop manager. He checks it out and ends up telling me it's not the transmission but something related to engine braking.
I've never heard this or seen before on a non diesel motor. I have to take it back in a few days and leave it with him for full day to figure it out, but has anyone see this before? Any ideas what might be going on? Truck is driving totally fine in drive and he said it's not doing any damage to drive normally for a few days until I can get it back to him, but I thought only Diesel engines had engine brakes, not gas motors? Like I said I've never seen this happen on any other vehicle I've owned and I'm curious as to what it might be and if anyone else has seen this before.
I've never heard this or seen before on a non diesel motor. I have to take it back in a few days and leave it with him for full day to figure it out, but has anyone see this before? Any ideas what might be going on? Truck is driving totally fine in drive and he said it's not doing any damage to drive normally for a few days until I can get it back to him, but I thought only Diesel engines had engine brakes, not gas motors? Like I said I've never seen this happen on any other vehicle I've owned and I'm curious as to what it might be and if anyone else has seen this before.
