# Some vibration in the rear-end...



## Xyclonik (Feb 9, 2009)

So...

I have a 1986 300ZX N/A. Yesterday I replaced the rear brake pads and as I was leaving I noticed some vibration in the rear-end and a sound similar to something dragging on the asphault. Though only when I lightly pressed the brake pedal. Also, the E-brake is barely holding. The car has new shocks/struts, new CV Axles and new wheel bearing on the passenger side. The bearings on the driver-side are fine.

Today, I got up under the car and tightened the E-brake adjustment all the way and it was firm and holding until I took a drive and used it to slow the car and it again slackened. I cannot adjust it anymore. We had used some needle-nose pliers to turn the calipers back when we put the new pads in... Is it possible that the calipers are not re-adjusting/racheting back into the proper place and tightening up for the E-brake?

I also noticed while the rear-end was jacked up from the differential that with the car started and the rear tires spinning in gear that when I would compress and release the clutch the rear-end shuttered/vibrated.
Possible rear-differential inner bearing going bad?

Any input would be appreciated.


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## Xyclonik (Feb 9, 2009)

Figured out the grinding sound and rear-end vibration shortly after the first post, just updating in case anyone else has this issue in the future.

It was the caliper sliding pins, they were worn-out and the holes they go in a little wallowed out. Replaced the caliper mounting bracket, greased the sliding pin holes and used new sliding pins, bolts, and rubber boot.

I just recently found out that my car has many more miles on it than I originally thought, almost twice as many in fact... It just turned 425,000 miles on the original power-train. 
No wonder the sliding pins were so worn. O_O

The only things it's needed replaced besides normal maintenance were the alternator, AC compressor, sliding pins, and passenger-side wheel bearings.


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## Nissankid (Jan 15, 2010)

I am having a bad grinding noise in the rear end of my car. I have a 1986 Nissan 300zx non turbo. When i start out it does not make the noise until i get going about 15-20 mph and then it starts to sound like gears grinding. could this be a bad U joint or is it more likely my gear box were the drive shaft goes in?


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## Xyclonik (Feb 9, 2009)

Did you bother to read my post? Check to make sure the calipers aren't vibrating. Jack the rear-end up from the differential with a floor jack, use some jack-stands so the car doesn't fall on you, put the car in neutral and let off the parking brake so that the rear tires free spin. 

Now, climb under the car and look at the inside of the wheel and caliper while rotating the tire both directions, do this to both tires. Do you notice the calipers vibrating, stuttering, or making any noise in either direction? If they are, your sliding pins for the caliper probably need lubing or replacement. I think Oreilly's Auto Parts carry the new sliding pins with bolt and rubber boots for under $10. 

If the calipers aren't doing anything, then you have other problems. You could always grab things under your car like the driveshaft, differential, sway bar, etc... and try to shake them hard. If they move, something is loose. 

Try taking the rear tires off or crawling under the car and looking for yourself first, before posting.


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## Nissankid (Jan 15, 2010)

I did get under and look my brakes are fine they are brand new. but my cv shaft can be pulled back and forth should there be that much play in them?


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## Xyclonik (Feb 9, 2009)

Yes, the CV shafts are supposed to move back and forth. Who did the brakes, you, and how long ago? Did the noise start shortly after the new brakes were put in?


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## Nissankid (Jan 15, 2010)

Me and my brother. but today i put it up on jack stands and started the car and put it in gear and started to go and at first the left side spun but then it stopped but the right kept going fine. its like the cv shaft is not grabbing or the teeth are grinned off. also when i put the e brake on the right side does not spin but the left works then. I am lost and would love some help thanks.


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## skittle (Apr 27, 2010)

Sounds like you might have put the parking brake on backwards on the left side and it is binding on the caliper. 

check out http://carfiche.com/manuals023/cars/

and download the FSM for free for your 86 that will help greatly.


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## Nissankid (Jan 15, 2010)

OK so my brother came over and looked at it we figured out that the e brake cable was seased up on the driver side but now it still makes the noise on the passenger side so we think it might be the caliper is hanging up some how. so i am going to replace the hole thing with one off my other car. Well first the mounting bracket then if it still does it the hole thing. Does this sound like a good idea? (sorry not to car smart since i have just finally got the car running and on the road)


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## skittle (Apr 27, 2010)

Pull the wheel off and check for movement laterally, did you use the anti-squeal stuff when putting on the new pads?


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## Xyclonik (Feb 9, 2009)

Caliper Sliding Pins... How many times to I have to say it? When you replace the rear brakes pads and/or rotors, you need to make sure that you lube the sliding pins, or replace them if they are worn out, and if rubber boot that keeps the grease in is dry-rotted or cracked, replace it too.


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## skittle (Apr 27, 2010)

Check that as well. Last thing you need is to be driving and the brakes seize on you.


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## Nissankid (Jan 15, 2010)

Xyclonik i realize that. I was just saying would it be easier to replace the whole caliper. Lol i am going to go and see how much the slider pins are today at Advanced Auto. Also no i did not use the anti-squeal stuff. But the one thing my brother said is that the caliper felt tight and did not have any play other then you can slide it in and out on the pins so i am assuming that Xyclonik was right they are worn out thanks sorry for being a pain do not know to much about it.


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## Nissankid (Jan 15, 2010)

Hi one more question i bought the new pins and it is still making the noise so i am going to replace the caliper bracket but i can not find them anywhere for my year could anyone help me out with a place they might know of?


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## skittle (Apr 27, 2010)

You can try rockauto.com they might have it, if not check out the for sale section on zcar.com


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## Xyclonik (Feb 9, 2009)

Did you lube the sliding pins with proper grease and replace the rubber boots as well so that the grease doesn't just squeeze out? If yes, then your e-brake setup may need adjusting or repair/replacement.


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