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Annoying suspension noise , again.

Started by westcott, July 05, 2014, 12:06:33

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westcott

As some of you may have the same noise problem or maybe solved it i would like to collect solutions for the problem here again.
   
   My car was squeeking from the first day on i owned it. Some times after havy rain drives the noise was a bit reduced but not eliminated completely.
   
   I replaced/checked every detail of my rear suspension but it still speaks to us during every ride.
   
   What i did so far:
   
   - replaced worn out suspension rubber bushings by PU parts rear and front
   - replaced the lower bearing at the koni's
   - cleaned, checked, greased and replaced all rubber dust boots
   - cleaned, checked, greased all ball joints
   
   Last week i applied some low viscouse miracle lube to all moving interfaces at my rear suspension, no success.
   
   But, a vew days later, we had a real sunny Cobra meeting tour and after a 15 minutes brake (my wife was still sitting in the car) the noises were gone completely  for the rest of this and the following day !!!!!
   
   Two days later the noise was back.....and it definitely is caused by the rear suspension parts.
   
   I think during the brake the only difference to all past situations was that the suspension was a bit preloaded and the warmed lube reached places it could not reach before.
   
   Who has solved this problem in the past and how? Any help is highly appreciated.
   
   Uwe
Everything should be made as simple as possible, but not simpler!

lightblue

Hi Uwe,
   
   Has the inner joint on the lower-rear-wishbone rear link got a grease nipple?  (that is the adjustable joint that connects the wishbone link to the chassis).  Some early cars did not and that can cause a squeak.
   
   John.

westcott

Hi John,
   
   i'm going to name  the parts as explained in the cobra 427 chassis instruction book:
   
   I think you mean the trailing link to chassis bearing (in front of the rear wheel), there is no grease nipple. Edit: This is a ball joint as well, no nipple.
   
   The trailing link to lower wishbone has a ball joint, no grease point.
   
   The lower wishbone inner bearing to chassis i have to check.
   Edit: No nipple, just a bushing, is it the position you mentioned?
   
   The only grease nipples on my rear suspension are at both ends of the so called chrome pin connecting the lower wishbone to the rear upright.
   
   Could you post a pic with the position of this mentioned grease point?
   
   Thanks, Uwe
Everything should be made as simple as possible, but not simpler!

lightblue

Hi Uwe,
   
   I don't have a 427  chassis book to refer to but it sounds like the 'lower wishbone inner bearing to chassis'.  1082 had the same problem and I drilled and tapped the boss to take a nipple.  I will try to get a picture to confirm.
   
   John

dkp_cobra

Hi Uwe,
   
   are we talking about this grease nibble?
   
   
   
   I think, the pre-owner has added this after one of the bushes had to be preplaced due to lack of grease. As I mentioned one day I had never the squeak problem.
   
   Peter

lightblue

Peter,
   
   Yes, that is the one - thanks for posting the picture.
   
   A 90deg. nipple makes it easier to grease but otherwise the same.
   
   The complicated joint has rubber-ring seals but they don't work well therefore re-greasing is necessary to stop squeaks.
   
   John

westcott

Thank you John and Peter,
   
   disassembled the rear lower wishbone yesterday evening, put in the grease nipple, greased it completely and assembled it again. I will see if the noise is gone this afternoon.
   
   After complete dismanteling i saw that the rose joint in the lower wishbone to rear frame bearing had lots of rust, water and showed some wear.
   I will replace it during the winter but have not found the correct rose bearing today.
   
   Can someone bring up a source or part number for the rose bearing?
   
   One of the two O-rings was splitted and i measured the other one, it should be 30mm x 5mm.
   
   The rose bearing ring has 39.98mm outer dia and a width of 11.01mm, the ball has a 26.06mm inner dia and a 17.40mm width.
   
   BTW, i used self tapping/forming, hardened, 90 degree grease nipples, no need to tap a thread into the hole.
   
   Thanks for your support,
   
   Uwe
Everything should be made as simple as possible, but not simpler!

westcott

The internals of the lower wishbone inner bearing to chassis looks like this after a quick clean up, what you see is the bearing outer ring sitting in the wishbone, kept in place by ring and groove.
   
   The ball is rotated out in this picture.
   
   
Everything should be made as simple as possible, but not simpler!

westcott

The bearing ring outer side has no grease hole or groove. If you drill the hole in the middle of the lower wischbone it will be directed to the bearing and grease flow is blocked. Therefore i ground a small distribution groove going from the drilled grease hole to both sides of the bearing ring. So grease will be distributed to both sides of the bearing easily and kept by the O-rings. Don't apply too much grease with your press, the grease will push out one or two o-rings and your sealing is gone again.
   
   
Everything should be made as simple as possible, but not simpler!

westcott

The ball itself is guided by this adjustable assembly. The nuts can position the ball (in the installation the ball is sitting in the bearing cage/ring) to front or rear direction to adjust wheel alignment if necessary. On my car the wishbone was adjusted to the most rearward position possible. The adjustable, bored out threaded pin is sitting between the metal flanges, kept in place by a screw as you can see in Peter's picture.
   
   
   
Everything should be made as simple as possible, but not simpler!

westcott

After the bit of metal work i cleaned all parts, preloaded the assembly with grease and installed the parts back to the car.
   
   The left hand side was done Thursday last week, the opposite side on Saturday last weekend.
   
   The result ????
   
   The squeek is gone completely !!!!!
   
   Thanks John for the info and Peter for the picture.
   
   After the disassembly i saw that the ball and bearing ring showed some wear but will do its job for the rest of this year.
   
   To one of the bearing rings was the following part number electric scribed:
   
   RB7 210 ML
   It is the same kind of bearing as used for the lower Koni mount but with different dimensions.
   
   I could not find a reference in the www, does someone has a source for this part?
Everything should be made as simple as possible, but not simpler!

westcott

O.K. maybe not correct written to the bearing so the 7 could be a J without lower bow and the part number could be:
   
   RBJ 210ML, makes more sence, doesn't it?
Everything should be made as simple as possible, but not simpler!

westcott

Update:
   Found the part RBJ 210ML in the UK, can order them online, payment by Paypal is possible, delivery worldwide, delievery will take 2-4 days.
   
   What a perfect day !!
   
   RBJ-210ML - ROD END BEARINGS
   Also known as RBJ210ML, dimensions:
   26mm x 40mm x 17.5mm x 11mm.
   
   They match the measurements i have taken from the old parts with a simple caliper:
   26.06mm x 39.98mm x 17.49mm x 11.01mm
Everything should be made as simple as possible, but not simpler!

Flyinghorse

I (MKiv crs) found that the 2 nuts with o ring carrier groves needs threadlock/locktite to stop them coming apart and making the rear suspension very "sloppy". (i failed my MOT a few years back on this. It also leads to some rear steering.)
   
   Also the long bolt that goes through this tube and the nut on the end(not much space and angled chassis supports to insert) can work loose as the bolt threads need to be in the "nyloc" so some spare nylocs should be carried(dont reuse or add locktirte)
   I did wonder if some people have "shorter nuts" or aircraft locking low profile nuts there.
   
   I have been told from an authoritative source that some of these rear bearings come in various  sizes (varies by car) so measure up before ordering (40mm on later cars  with some imperial 1.5" on earlier cars)
   
   Here is the tube on my car with the rose joint off(CRS)
   Graham

westcott

Hi Graham,
   the tube and nuts are the same, just the nuts on my assembly where not symetrically adjusted, the position i showed in the pic is the one the assembly showed in the car from the beginning.
   
   The dimensions of the bearing are defined by the part number, so have a close look at this number.
   
   RBJ-210ML has metric dimensions.
   
   Uwe
Everything should be made as simple as possible, but not simpler!