letsbangout
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- Dec 3, 2010
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Hi all,
I'm trying to determine whether I have issues with my motor mounts. Per this thread: http://www.tahoeyukonforum.com/forum/showthread.php?t=20800 my tranny has a rough shift from 1st to 2nd (which I've now driven on for 15k miles), and also what appears to be a hesitancy to unlock the TCC. That is, unless I'm braking in a chauffeur-like fashion, the tranny kicks hard when shifting from 2nd back to 1st when I've come to a complete stop, and sometimes waits until I take my foot off the brake to make the shift at all. Aside from SunlitComet's comments about the potential to break a mount because of the 1-to-2 problem in the thread, the shift from 2-to-1 when stopping is probably worse because it's intense all of the time and because the pressure has nowhere to go except into the mounts, whereas the 1-to-2 only happens sometimes (I suspect because of bad post-cat O2 sensors, which I'm replacing this weekend). Every time the tranny kicks at a dead stop, I say to myself.. "GAH! this has to be harming something else besides the tranny." So I took my truck to Aamco today for an inspection of the mounts, and a general inspection secondarily. The guy "tested" the mounts by putting my truck in gear, holding the brakes and bringing it up to what was probably 1300 or 1400 RPM and noting how the engine jolted up. Only by watching the engine jump up probably 2 inches on the driver's side, he concluded that this particular mount is worn and should be replaced. I said ok, but that isn't entirely convincing to me, because the engine has plenty of torque at those RPMs and some of that movement would be normal with brand new mounts, and I suggested that if the mount was weak it should show signs, like hairline cracks, of which he couldn't find any, either on top of underneath with the assistance of a flashlight.
And so I ask - aside from doing what the manufacturer suggests - raising the engine, pulling out the mount and physically inspecting it - is there any other way that I as a non-mechanic would know I have a bad motor mount?
As for the transmission problems, I think the most logical thing I can do now is replace the post-cat O2 sensors (i've gotten P0141 codes several times) and hope that fixes the 1-to-2 shifting problem. I'm still not sure about the 2-to-1 issue. I'm pretty well convinced that neither are related to the valve body because all symptoms are intermittent; a worn valve body should produce consistent and persistent trouble. If anyone has any commentary on the transmission stuff, do tell.
Thanks in advance!
I'm trying to determine whether I have issues with my motor mounts. Per this thread: http://www.tahoeyukonforum.com/forum/showthread.php?t=20800 my tranny has a rough shift from 1st to 2nd (which I've now driven on for 15k miles), and also what appears to be a hesitancy to unlock the TCC. That is, unless I'm braking in a chauffeur-like fashion, the tranny kicks hard when shifting from 2nd back to 1st when I've come to a complete stop, and sometimes waits until I take my foot off the brake to make the shift at all. Aside from SunlitComet's comments about the potential to break a mount because of the 1-to-2 problem in the thread, the shift from 2-to-1 when stopping is probably worse because it's intense all of the time and because the pressure has nowhere to go except into the mounts, whereas the 1-to-2 only happens sometimes (I suspect because of bad post-cat O2 sensors, which I'm replacing this weekend). Every time the tranny kicks at a dead stop, I say to myself.. "GAH! this has to be harming something else besides the tranny." So I took my truck to Aamco today for an inspection of the mounts, and a general inspection secondarily. The guy "tested" the mounts by putting my truck in gear, holding the brakes and bringing it up to what was probably 1300 or 1400 RPM and noting how the engine jolted up. Only by watching the engine jump up probably 2 inches on the driver's side, he concluded that this particular mount is worn and should be replaced. I said ok, but that isn't entirely convincing to me, because the engine has plenty of torque at those RPMs and some of that movement would be normal with brand new mounts, and I suggested that if the mount was weak it should show signs, like hairline cracks, of which he couldn't find any, either on top of underneath with the assistance of a flashlight.
And so I ask - aside from doing what the manufacturer suggests - raising the engine, pulling out the mount and physically inspecting it - is there any other way that I as a non-mechanic would know I have a bad motor mount?
As for the transmission problems, I think the most logical thing I can do now is replace the post-cat O2 sensors (i've gotten P0141 codes several times) and hope that fixes the 1-to-2 shifting problem. I'm still not sure about the 2-to-1 issue. I'm pretty well convinced that neither are related to the valve body because all symptoms are intermittent; a worn valve body should produce consistent and persistent trouble. If anyone has any commentary on the transmission stuff, do tell.
Thanks in advance!
