99 Maxima Shakes under acceleration over 2000 rpm

[mhomma]

Hi all, new to the forum and have an issue with my 99 Maxima with automatic transmission. The car has been shaking under acceleration past 2000 rpm around 50-60 mph. When I take my foot off the gas and let it coast, it goes away. Haven't taken it in yet, but was wondering what it might be. Thanks in advance for any help.

[maxhopper]

Welcome to NICO.

I guess it could be a problem with the trans, not really sure. Do you have any warning lights on/over drive light flashing? Is the shaking in any gear above 2000rpm or only in over drive?

[mhomma]

It does have a check engine light, but checked the code and it is the knock sensor. Cleared it and it only comes on when the car is shaking so I don't think that there is a problem with the engine. I changed out the transmission mount because it was trashed. The rubber was cracked and pieces of it were missing. I thought that this would fix the problem, but it is still doing the same thing as before I changed out the broken mount. I checked the transmission fluid and it is above where it should be. I guess the people that I took it into over filled the transmission. It also hard shifts when I pull out of the driveway. It only seems to do it in reverse and first gear. I think that it does only behave this way in the highest gear of the automatic transmission. Because at lower speeds, I am at the same RPM's and it doesn't shake. The car is still driveable, but it is a pain not being to go for long drives on the freeway.

[NutriaforBreakfast]

Are cv axles ok?

[mhomma]

I don't know. How can you tell if they are alright. I do know that if they are going out that you usually get that cracking and poping sound when you turn the wheel. Just starting to get that, but it isn't as bad as I have seen on other vehicles when I had to change them out. I don't recall having the car shake on a Sentra SER that I had when I had to change out the CV Joints.

[NutriaforBreakfast]

See if the rubber boots are torn on the inner and outerCV joints. A mess of grease also might be indicative of aproblem. Shaking has been a problem with mine when theywere going out as well as noises. Mine was making the noiseswhen the boots were torn and they were dry-metal to metal.

[mhomma]

One of them is torn and the other is not, but from the sound that they are making, I know that at least one of them is shot. I know that you usually have to replace both of them when they go bad. How hard is it to replace the CV joints?

[NutriaforBreakfast]

Chiltons has good instructions as well as the FSM. It is best to havetwo people help if possible. Is a DIY job but recommend reading directionsfirst. Some people say you can replace just the rubber boot but unlessyou are experienced with this I would just change out the entire shafts.DONT FORGET to change out the seals where the shafts meet the transmission as they might be damaged by the removal of the shafts.You will want to have a seal puller on hand-maybe you can use a screwdriver. You want to have the torque wrench available to reassemble.This is also a good time to check your brakes as well.

[mhomma]

I will give it a try. Thanks for everyones help. I will let everyone know how it goes.

[Jdmstyles]

Bent wheels or unbalanced tires?

[mhomma]

Thought about that, but ruled it out because it only does it under acceleration. If I take my foot off the gas the shake goes away even at 70mph. I only have the shake at higher speeds under acceleration.