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Rotating Knocking Sound??

Posted: Mon Aug 11, 2014 7:43 pm
by 90GTZHO
Okay so heres the scoop. When i bought my 95 it needed lots and lots of help. Ive addressed lots of issues but one. When im driving on a bumpy dirt road, i get a knocking sound from up front that i cant tell where its coming from.

At first i thought strut mounts, cause they were shot. Then i swapped out both subframes and control arms and other things. Heres whats been changed:

New strut mounts
93 subframes and control arms with good bushings
New ball joints
New front brakes
New front hubs
Added an upper strut bar
New engine mounts
New endlinks

Im confused at this. Everything is tight and nothing appears to be moving around. Now heres the funny part. When i changed the upper motor mount, the knocking didnt seem as bad, but now i get the same noise at highway speeds from 55mph to ~60mph. The knock sounds like a rotating knocking type sound that comes from the middle/passenger side. Like an axle thats got a bad joint, but they seem tight.

Could it be a bad axle? They do not click or knock when making slow speed turns. Whats going on here?

Re: Rotating Knocking Sound??

Posted: Tue Aug 12, 2014 3:42 am
by 1988GTU
could be trans (internal-diff) , axle, inner tierod bushings, or if you have a strut bar the alt. could be smacking it.

Re: Rotating Knocking Sound??

Posted: Tue Aug 12, 2014 7:43 am
by heavywoody
What condition is the trans mount in? If that's bad, it could allow the drivetrain to move around more than it should, allowing the alternator to hit the strut tower as mentioned above.

Re: Rotating Knocking Sound??

Posted: Tue Aug 12, 2014 9:51 am
by 90GTZHO
Trans mount is original (152k miles). It sagging. When i changed the engine mount, the motor actually leans to the drivers side now. So if that mount is that bad, it can cause this knocking sound? Right now the alt is no where near the blower. The sound actually seems to come from the floor board area. If that trans mount is less than decent, and the tires are slightly out of ballance, could that be my problem? If i change the mount and i still have the knocking, what next? Other mounts are new.

Re: Rotating Knocking Sound??

Posted: Tue Aug 12, 2014 9:52 am
by 90GTZHO
Correction, alt is no where near the srut bar, not blower lol For the record, this sound was present when i bought the car, which did not have a strut bar on it. I havent been able to full investigate the rack and inner tie rod bushings. Everytime i look at the car its always hot :-/

Re: Rotating Knocking Sound??

Posted: Thu Aug 14, 2014 11:53 pm
by 90GTZHO
Okay, so...changing the trans mount didnt make the knock go away. And with the car on flat level ground, and cold, i can rock the motor anx produce the sound. Exhaust isnt hitting anything and i cant tell any other problems. Only thing left is the axles. I can grab the center of the axle and move them in and out and make the same sound, is axles my final problem?

Re: Rotating Knocking Sound??

Posted: Fri Aug 15, 2014 3:26 am
by 1988GTU
that or diff/internal trans issue.

Re: Rotating Knocking Sound??

Posted: Fri Aug 15, 2014 10:47 am
by 90GTZHO
At lower speeds when you hear the knocking, if you unload the left suspension, some of it goes away. At higher speeds it doesnt matter. And like stated earlier, everything but struts and axles is new.

Re: Rotating Knocking Sound??

Posted: Fri Aug 15, 2014 11:33 am
by 1988GTU
Even the strut mount are new?

Re: Rotating Knocking Sound??

Posted: Sat Aug 16, 2014 1:27 am
by 90GTZHO
Yes they are new too.

I found the problem. Inner tie rod bushings. At highway speeds and low speeds, there would be enough vibration to cause a "rotating knocking" sound. Had a friend help me today after work and found the right inner tie rod end bushing is, like, gone. There is atleast a 1/4" of travel for the end on the mount. Explains why i have a slight pull in the front end too.

Gonna order the problem solver kit and call it a day :-)

Re: Rotating Knocking Sound??

Posted: Sat Aug 16, 2014 6:23 am
by 1988GTU
1988GTU wrote:could be inner tierod bushings
:beer:

Re: Rotating Knocking Sound??

Posted: Sun Aug 17, 2014 12:37 pm
by 90GTZHO
I missed where you said inner tie rod bushings :-/ need to get my eyes checked :-( Thanks man!