My son owns a 2005 Monte Carlo 3.4 L. He has been telling me now for about a month now that when he gives it the gas making a left turn the wheel seems to jump or hop. Going slow he is fine and well as making a right turn. When he had his brakes and rotors replaced by a repair shop the mechanic there said he notices two problems with the car that should be looked after. One was a motor mount that he thinks is or going bad and the other is a tie rod end since the wheel moves a little at 6 and 12 o’clock. I told him we will have to get that fixed. Just yesterday he came home and said that it seems to be worse. He said it seems to slip and then catch and when it does the left wheel jumps or hops like there is power going to it a bit until he either leaves off the gas or starts going straight. I went for a ride with him and it is weird. When he does press the gas making a left it seems like there is power on the inner wheel that makes it hop a few times and then settles down. Almost like a straight axle on a turn not a slip differential. I did hear a slight thump noise which could have been the motor mount, but I am not sure at the moment. I didn’t check this out yet in the daylight to see if the engine lifts a bit when he would apply gas. That is for tomorrow. My question is would it be possible for the half shaft to disconnect enough either at the hub or the trans if the engine would lift to cause it to disengage? The left CV joint makes no clinking noises when he goes slowly on a sharp left turn so I do not think the CV joint is bad. Not sure what this could be. Any suggestions would be helpful.

 

I'm wondering if it's the CV joint being over extended (and if so, you have other problems), a seizing wheel bearing, or seizing brake caliper.

If you are mechanically inclined, have tools and a jack, start by inspecting things. Get the front end in the air, put the car in neutral and by hand, spin the wheels, see if you notice one having resistance that the other doesn't. That will tell you to look at things that interact with wheel rotation.

Have some one press the brake, validate the wheels no longer spin, then release the brake, see if you notice issue with how they spin.

Try wiggling the wheel from top and bottom, then left and right (I also like to go diagonals). If it has "play" in all directions, you have a bad wheel hub (replace with Timken hubs). If you have play in one direction, it may not be a hub, look behind and check tie rods and lower ball joints (left and right play could be tie rod, top/bottom could be lower ball joint).

Next, take the wheel off. If the axle nut is not tight anymore, this could cause some dis-locating of the steering knuckle while driving.

Check brake pad wear for signs of a brake/caliper problem.

Outside of that, keep inspecting all the parts of the car that have control on the front wheels. And yes, do this inspection on both, to validate both sides are OK or not.

 

Thanks for the reply. Here is an update.
Well he had some work done on the car. The transmission mount and right front motor mount was bad. Also the right front inner tie rod end was bad. He also got brand new tires and a wheel alignement to boot. Well I went and paid for it so he good pick it up later in the day. The shop owner said everything looks good and it is ready to roll. Later on when my son got it to drive home he said it worked fine now. However a few hours later he called me and said he drove it again and was at a stop with his left wheel turned all the way left. When he appied gas the same thing happened again, but he said not as bad but there still was a hop feeling. I am going to go to his house on Monday to check this out. I really thought the mounts were the problen, but apparently only part of it. Could a half shaft that is bad or going bad disengage momentairy and then re-engage? Like I said befiore there is no clicking from the CV joints.

 

To my knowledge, for the CV to "disengage" something has to allow it to over extend. You wheel turns based on push/pull from the steering rack and tie rods. If the rack is not properly attached to the subframe, you can have some crazy situations happen. The steering rack may be a thing to look at. Get eyes on the rack and have someone turn the wheel left and right. If the rack itself moves, you have a problem.

 

Thanks for the reply. Yes when he got the car and I told him not to at an auction the subframe was bent a little, but enough not to pass PA inspection. Since that was not disclosed he was able to get a new one installed for free. I saw the subframe and it looks new for sure, but now I am wondering when they put it back together maybe something wasn't right. Another thing is I am surprised if the rack wasn't right woundn't this have been noticed by someone inspecting the car or at least when taken for a road test? Well in a day or so we are going to check this out and see if anything looks obvious. Will keep you posted.

 

Without experiencing this issue first hand, I can't say if it should have been caught by others or not.

Re-reading your earlier posts, perhaps checking the bushings on the lower control arms are in order. If I understand, from a dead stop if you have the wheels turns (like to the left) and go to accelerate, the car "hops" as it makes the turn? And it's the front end "hopping"? If that is correct, don't focus on the rack as much, look at these parts (I think they might be more important):
- Lower control arms (signs of being bent or bad bushings/bushings popped out of place)
- Front sway bar
- Front sway bar bushings (there are two and they should be in brackets bolted to the subframe)
- Front sway bar end links and bushings (these are the assemblies connecting the sway bar to the lower control arms)
- Front coil springs on the struts

Any noises associated with this "hopping"?
When was the last time a shop checked the alignment?
The fact you said the subframe was damaged when the car was first bought, how was it damaged? Were there signs of an impact of some sort?

If any of that is out of order, this may explain some of what's going on.

 

Thanks for the reply. Well the first thing his car got a 4 wheel alignment just done this past Friday (11/22) since the inner tie rod end was replaced plus he got 4 new tires. He was given a sheet with the before and after specs of the alignment which shows that everthing now is in spec. There was also a trans mount and right front motor mount replaced. He used to have a bang noise when he would give it the gas to go and then off of it. That is now gone. So far I only drove in his car once so he could show me what he was talking about.
I will try to make myself clear here. He drove the car not me, but I will have to in order to get a better feel for it.
Anyway, from a stop going to turn left when he pressed on the gas to go it felt like nothing happened, but then it felt as though the power was all going to the wheel with the least amount of travel (inner) making a hop or jump feeling. When I say hop the car isn’t going up and down like a rabbit it is more like if you have a straight axle making a turn and the inner wheel has less travel and will try to spin on the asphalt. That is actually how it feels like it is slipping on the road making the turn. However, when he goes slowly around a turn it does not do it. I mean like up to 10 to 15 mph from a dead stop. Now a right turn it does not do it at all no matter how fast or slow he goes. As for noises I did not here any at all. As for the subframe I believe it was bent in the front part of it on the right side, but ever so slightly. When he took it for inspection after getting it from the auction they caught it and said try to get your money back or get a new one installed. They did say it wasn’t that bad and nothing was damaged, but it would be better to get a new one. That is where he was able to have the auction foot the bill for a new one to be installed since it was not disclosed in the sale. The items you listed to check I am going to make time Monday hopefully if it isn’t snowing and see what I can do. I will keep you posted as to my findings and thanks again.

 

Yeah, this seems to be a tough one to figure out.

Reason I asked about the subframe damage is it "might" tell a story of another spot to check (as I'm sure "good" parts from the subframe were re-used when a new one was put on).

I assume the problem can be re-produced regularly (that it's not very intermittent)?

If the suspension looks good, this is a bit "off the wall", but I'll throw it out there.... Under the hood, the engine is held to the front radiator core support with 2 dog bones (they have a bushing on one end and are forked on the other end that bolts through a bush on the mounted held on to the radiator support). Check those bushings, see that they are not damaged. The theory I'm working on it that perhaps the motor and trans are leaning one way or the other due to improper support (I doubt this will fruit anything, but out of desperation, checking it takes a couple of minutes).

If all this shows no evidence to the issue, I'd consider consulting a reputable transmission shop at this point. See if it's an internal trans problem.

 

I know you got the wheel alignment done. But I can'thelp but to think how much this reminds me of.a bad ball joint. My 88 IRoc 350 did the same thing after having the front left frame rail replaced. It was a bad ball joint. I would also have all the welds on the sub frame checked. It could be that one or more of the welds cracked.
Over all, it's gotta be something that is supposed to hold the tire securely on the ground. Best bet, get the front end of the ground and watch the tire and associated parts as the wheels are turned across the full radius. I don't think there is any other way to find the problem part!

 

Thanks for the reply. I plan on checking this out either Monday or Tuesday. Hopefully it isn't the transmission. That would be a bit pricey. Since I really only worked on engines a bit I have no idea what in the transimmsion would cause this to happen. I am not even sure if there are electronics that control how the transmission functions. I am going to do some reading on this.
All I know is I want to get to the bottom of this for sure.