The car has a bad vibration under acceleration on the RF. I have pulled the wheel and checked everything. The problem is what I think is an upper ball joint. There is a large about of slack at the top part where I see two small bolts and what looks like an upper control arm. Since I'm not familiar with this suspension set-up I'm asking for clarification of this.

 

The two small bolts are at the top of the steering knuckle (#2) and if I am correct, the ball joint (#4) goes in there. It looks like a bolt on ball joint or is it press in?

 

Yeah, based on that picture and the work I've done on 5th and 6th generation Accord suspensions, it should be the same...yes, that is the "upper ball joint". Is there anything other than the slack that makes you think that it's the UBJ? Have you had an alignment? Is the tire and wheel combo balanced? Does the boot on the UBJ look damaged? Have you compared the other side of the car to see if it has the same movement? The ball joint will have some slack normally, that's what allows the knuckle to go up and down while keeping the wheel/tire relatively vertical.

If it IS the UBJ, then you would remove the cotter pin and castle nut on the bottom of the bolt part of the UBJ, release the ball joint (it is wedged into the upper A-arm). This can be done by either just tapping the arm, using a pickle fork type ball joint remover, or a combination of the two...or the preferred method is using a leverage screw type ball joint removal tool ($20 at local autoparts store) that won't damage the boot and you don't have to beat on stuff hoping it comes loose.

Then remove the A-arm or the extension that appears in that diagram, and then change the ball joint. Couple options here depending on your handiness. You can beat out the old one and tap in a new one or the easier method is to use a ball joint press to press out the old one and press in a new one ($15-20).

Luckily the UBJ isn't nearly as much of a pain to break loose as the LBJ on Accords.

Hope that helps.

 

I checked all the other components and the UBJ was the only place there was movement.

Yes, about 15k ago.

Yes, the day I pulled the wheel to check everything.

Didn't really notice, will take a closer look.

No, but I will. The vibration is on the right so I only checked the right.

Understood, but this is A LOT of sloppy slack.

It appears to me that the (#4) ball joint will bolt to the (#3) control arm?

 

Okay, hold up. I just looked up 1990 Accord DX Four door and I get this:


Which looks basically like mine, with the UBJ pressed into the upper A-arm. Is this what yours looks like, or does it look like the picture you posted? (I'm guessing one of the websites has it wrong).

If it's like the pic I posted, then you'll press the UBJ out of the arm and press a new UBJ into the arm (with or without removing the arm). If you are gonna improvise with a hammer or vise or whatever, you'll likely need to remove the arm. If you use a ball joint press (I got mine for about $30 from harbor freight tools) then you can do it on the car.

If it looks like your picture then either
1. The UBJ is pressed into that little extension bar (#4) and you replace it as described above, or
2. The UBJ is part of the bar like you said might be the case (I'd be suprised if this is the case).

 

Your picture is correct, so it is press in. I'll either buy the tool, pull the arm and take it to a press, or just get a shop to do the work. I do appreciate all your help and I'm going to check everything again. Many thanks!

 

NP, good luck with it. If you take the arm off to have someone press out the old and in the new, you can probably do it with regular hand tools. Just use some leverage and hit the arm nearest the UBJ with a hammer and it should come loose. Then you can take off the arm and take it where you want.

 

Before you bother taking the balljoint out of the upper arm, make sure you can buy one. I think for *most* years(?), you have to buy the entire upper control arm.

 

I changed (you're right, once again, Jim) the entire control arm since an upper ball joint can not be had.

The crazy insane harsh vibration has now just changed to a vibration and before the steering wheel would shake in my hands but now it does not. There is something else wrong, perhaps the lower ball joint that has been over-looked but will soon will be looked at more closely.

The tire might even be bad, I'm gonna put the spare on and see what happens. Could a bad rotor do this? I checked the tie rod end and wheel bearing and there was no play but the lower ball joint needs to be looked over again.

What is funny is that if I feather foot the gas there is no vibration and if I apply the brakes softly and gradually, no vibration. However, if I accelerate hard the vibration is very bad and the same with harsh braking, a bad vibration.

The upper ball joint fixed the (shake) problem at least 50% but now I have to figure out what else is going on under that RF fender.

 

Here's a couple more ideas for you to check out. Maybe it's just a combination of stuff?

1 - Inner driver, or inner CV joint on axle. The tripod bearing wears a low spot in the track where it rides, so now the axle can wobble a little off-center. Usually causes more vibration on the throttle vs. coasting. (But this doesn't explain the vibration while braking.) Get under, grab the axle, try to shake it (make sure the car is properly supported...) The inner joint shouldn't be loose.

2 - Other ball joints, like you said you're gonna check the lowers. Also check the little balljoints on the steering tie rods. Check BOTH SIDES. It feels like one side, but that can be deceiving.

3 - Brake rotor. Uneven imprinting of pad material onto rotor; get them resurfaced. But usually this vibrates at moderate braking as well as hard braking?

4 - Swapping tires around is a good idea. Definitely check that out.