I have a 89 Honda Prelude that has an odd problem. It runs great up until it hits around 50 mph, then a knocking sound comes from the tire areas. When it hits around 55, the car begins to shake really hard and the knocking gets louder. What could be the problem? Someone told me that it was just my tires, but the tires aren’t that old, though they are now showing signs of wear along where the side wall meets the tread. I’ve also been told that I need new shocks, and then someone else said I had to replace the entire front end. Help!
You really need to get this car into a shop and have a thorough inspection.
The knocking could be a CV joint or it could be something even more serious than that; maybe a ball joint about to break, worn out tie rods or tie rod ends, etc.
You did not state if this tire wear is prevalent on all 4 tires, if it is the front 2 only, or if the wear is only on one edge of the tire or not.
If the wear is on both edges of the tire then this points to underinflation. Check the tire pressure.
If the wear is on one edge only then that could point to an alignment problem, or a faulty suspension part.
There’s not enough info given to be real specific but it sounds like you should drive this car SLOWLY to a shop and have it inspected, especially considering this could be a faulty ball joint.
I related a story recently about a ball joint problem. This guy was lucky; some people have lost their lives over this issue.
http://community.cartalk.com/posts/list/683611.page
There is no insinuation that you are stupid here because you do not know what the problem is so do not take it that way. In the case I mentioned, this guy KNEW he had a problem and was content to drive at high speed anyway.
Thank you! I didn’t take it that way at all 
There’s no shame in asking help when you don’t know how to fix a problem, in my opinion and I certainly don’t want to ignore this either.
The wear is only on the front tires and as far as I can see it is only on the outside. What are the symptoms of bad tie rods or ends or bad CV joints? The knocking does stop when the car takes a turn, as does the shaking, so I’m very confused and more than a little frustrated.
It could be many things, but tyres are certainly one. You can have a new tyre defective or a belt can slip inside a tyre and it can do all that. You may or may not be able to see any evidence by looking at the tyre. One good way of checking it is to rotate the tyres front to back and see if it changes. I may not go away, but it likely will feel different if it was the tyres.
However there are a lot of other things that can be dangerous and should also be checked.
I suggest that you find a shop you trust and have them take a look at it. You don’t need (and should not) tell them what is wrong, but rather what you have observed. They don’t need your or our guesses, they have your description and the car.
Without car in hand I can only theorize a bit.
Chances are the CV joints are not at fault here. When bad these have a tendency to click at first, followed by rattling later on, when you turn a corner.
The wear on the outer edges of the front tires means there is too much postive camber (e.g. angled out too much at the top) or the front wheels have too much toe-in (meaning the front edges of the front tires are slightly closer together than the back edges.
This could be caused by an alignment problem or worn suspension parts, which will cause the alignment problem.
Offhand, I’m kind of leaning towards seriously worn tie rods or tie rod ends but everything should be checked while it is on the rack.
A somewhat approx. check for worn tie rods/ends could be done by jacking the car up one front wheel at a time. Grasp the tire at the 3 and the 9 o’clock position and try to move the wheel assembly back and forth. If it moves a lot then those items are probably worn out.
If you take this into a shop for inspection have them point out any slop in the tie rods/ends, ball joints, etc. From the sound of things it should be pretty noticeable. And drive slowly until the cause is determined.
Your first and simplest check is to have your tires rebalanced and then road tested.
As an attempt to stop a huge vibration a Subaru dealer replaced my front axles on 200 mile old Subaru WRX under warranty. Its still vibrated but slightly less so after that. Frustrated I took my car to a tire dealer at my expense who stated the Bridgestone RE92(OEM) tire was defective. Bridgestone replaced under warranty and reimbursed me the $48 for a rotate balance. Good move on their part as later at 35k miles I purchased $600 set of new RE960 Bridgestone tires.
Thanks for all your help guys! I took my car to a very reputable shop and found out that both front tires had severe separation. I went ahead and bought four new (Just in case) and all the vibrations were completely gone (Got an alignment too) It worked out really well and I’m glad I got everything checked out as they told me that my lower ball joints were starting to wear and that within the month I’d need the replaced. Good to know Thanks again!
I know the problem is solved, but I’m curious. Does your Prelude have four wheel steering? If so, do you have any comments or observations to make?
I’m glad you got it fixed before something bad happened. I knew I had a problem with my 92 civic because the car hopped, especially between 30 and 50 mph. There was no noise and the tire pressure was ok. I did nothing until the rear driver’s side tire literally exploded at 70 mph and the belts left a pattern across the rear quarter panel. I was glad I drive with a 10-4 deathgrip. Lesson learned.