Vibration Under Acceleration + Trans Mount Issue
I have a 2005 Elantra, automatic, with around 140,000 miles.
This car would start to noticeably vibrate under acceleration at highway speeds. When you let off the throttle, the vibration goes away. It only vibrates under medium to heavy acceleration and is felt throughout the whole front end.
This is not due to the rotors or tires. The tires are in balance and the rotors are not warped. I do not hear any wheel bearing noises.
I have read that this could either be the rear engine mount or the axles. There are not many posts on this subject that I could find, and most of them did not post the solution to the issue. The axle posts that I have read were on other vehicles, but I assume that could be a possibly.
Over the weekend I replaced 3 of the engine mounts. The rear engine mount was faulty, however replacing these three mounts did not solve my problem. I found a thread that had this exact same issue and the OP said a new rear engine mount fixed the problem. It did not fix the problem for me.
I did get a transmission mount, however the new one did not fit in properly. The metal cylinder that was wielded to the mount (to the transmission side) would hit the bracket that the mount was supposed to fit inside. Am I supposed to jack up the transmission to get this mount to install properly? Has anyone else experienced this issue, or did I just get a poorly made mount? The old one went in and out with no clearance issues. It also did not look damaged. I did have the transmission supported while i took the mount in and out, and I did need to jack up the transmission a small bit to unload the pressure on the main through bolt. I am uncertain if there is anything special that needs to be done other than slapping the new mount in. The old one went back in just fine.
My main question is if anyone has had this vibration under acceleration issue before, and what did you do to get it fixed?
I ordered new CV axle shafts and hope to get those installed over the weekend. I will update this thread and let everyone know what solves the problem.
Any supportive input and experience is appreciated!