Rear wheel bearing - "Knocking from suspension over bumps"

PostPost by: JonB » Fri Jan 05, 2018 1:14 pm

So, an approach evolves. Spacer, spinner, torque, heat cycle a few times, hope Mars is in the constellation of Sagittarius, etc.
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PostPost by: KevJ+2 » Fri Jan 05, 2018 1:14 pm

I made up a packer with an old caliper piston welded to some box section + lots of heat and cursing :D

sam_1279-640x480.jpg and


sam_1280-640x480.jpg and
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PostPost by: JonB » Fri Jan 05, 2018 3:34 pm

And so..

743dd922-6996-4d8b-815f-a231a128b39d.jpeg and
Gotcha!


What a pig!
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PostPost by: alan.barker » Fri Jan 05, 2018 3:47 pm

What a pig!!!
You can say that again, my handle on the TVR forum is "plasticpig72"
Guess where i got that from :mrgreen: :mrgreen:
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PostPost by: JonB » Fri Jan 05, 2018 4:27 pm

Not entirely sure about the thread, mind.

9ffd6882-da73-4c7b-bb39-c95f25d9646a.jpeg and
Shagged..?


The nut had no thread at all. I was able to wind a new nut onto the axle, so maybe it?ll be ok.
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PostPost by: alan.barker » Fri Jan 05, 2018 4:40 pm

Well done you got the hub off.
What you need is a "Thread File" and a careful clean up.
A "Thread File" has different thread pitches on the 8 different sides so be carefull to use the correct pitch.
Don't be tempted to try and use a Swiss triangular File to clean up the burrs. You will mess it up.
A "Thread File" is the best tool in your workshop to have.
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PostPost by: rgh0 » Fri Jan 05, 2018 11:06 pm

Wait until you have it fully apart before deciding to reuse it. If the bearings are as bad as you say the bearing surfaces may also be damaged.

if i were cleaning up a thread like that I would wire brush it to clear out any rubbish and then carefully run a nut up and down it a few times to help straighten out any bent threads. If the nut could not be run up it I would use a die to clean up the damaged section of thread.

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PostPost by: UAB807F » Sat Jan 06, 2018 8:00 am

well done that man !

Y'see, all you needed was a bigger hammer...... :D

The thread doesn't look too bad, as Rohan says a wire brush to clear out the debris from the previous nut and then a quick go with a die & it'll be good as new.
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PostPost by: JonB » Sat Jan 06, 2018 12:56 pm

We will soon see about the state of the axle... meanwhile I got the outer doughnut bolts off (what a faff, one of them had rusted to the doughnut sleeve) but the manual is rather badly written. Says "remove the the outboard drive shaft by releasing the three bolts securing it to the Rotoflex coupling". That should be SIX bolts to the Rotoflex couplings (plural), otherwise the shaft cannot be removed. Silly me. I took the shaft to doughnut bolts out then realised I still couldn't move the drive shaft because it has those "fail safe" pegs. I put the bolts back in "grrrr..." and now have to remove the doughnut to output shaft bolts (grrr...).

I am beginning to think that I should replace the doughnuts (got some serviceable used spares here), or cough up for the CV joints. But of course, if I take the halfshafts fully out, then I may as well pull the diff to replace its seals and mounting bushes. But if I take the diff out... and so on!
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PostPost by: JonB » Sat Jan 06, 2018 1:57 pm

How do you get the shaft out? It?s got these pegs sticking out into the middle of the doughnuts that mean I can?t get them free!

Don?t tell me I have to take the wishbone out!
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PostPost by: JonB » Sat Jan 06, 2018 3:35 pm

Fortunately, the outer wishbone bolts were easy to remove. Pull the hub out a little and the half shaft fell out. Hooray!

I had to turn the whole hub assembly round (removing the handbrake rod clevis pin first) to get at the inner bearing circlip, but I got it out with a little bit of effort. The axle was a little trickier, it required some moderate heat around the carrier and whacking out with a suitable drift (a piece of tube that goes over the threaded end and sits on the shoulder - should've used that when I pulled the hub). So here's some pictures.

img_4443.jpg and
Some sort of locking fluid?


Inner carrier looks like it's been assembled with a locking or seating compound (the red stuff).

img_4442.jpg and
Game over I think.


That groove is where the bearing was. It measures 28.84mm and the shoulder around it is 29.97mm. Nearly all the axle play is accounted for by it. Do I need a new axle, or can it be repaired and if so, how?
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PostPost by: UAB807F » Sat Jan 06, 2018 4:46 pm

You can use a process called "metal spraying" to rebuild shafts and bearing surfaces, if you do a search for "Metal Sprayers" you'll probably find someone local. Quite a common process to rebuild pump shafts, etc. I bet there are videos on Youtube showing the process.

Having said that my personal preference would be for a new shaft if at all possible. I'd only repair that one if I had serious budget concerns or new ones were NLA.
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PostPost by: alan.barker » Sat Jan 06, 2018 5:15 pm

I had that problem on a 1970 +2S in the past and i got it "metal sprayed" no problem.
If you get it "metal sprayed" then get the 3 lugs that are in contact with the Brake Disk machined at the same time that the metal spraying" is final machined. That makes sure that the axe of the drive shaft and Brake Disk are running true. If you don't you risk that the Brake Disk will wobble :shock:
With all the knocking about that it has had :roll:
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PostPost by: JonB » Sat Jan 06, 2018 6:27 pm

Approximately how much would it cost to metal spray and machine?

I'll wager the thick end of a replacement shaft. And of course, the weakness imparted by the groove is still present, I'd guess. Correct me if I am wrong, but doesn't metal spraying just build up the shaft so that the bearing can fit properly? Or will it restore the shaft's strength?

What specifications would they need? I suppose they can measure the remaining (undamaged) shoulder but I am not sure about the legs. Are there any known specialists who have done this to an Elan shaft before (with good results of course)?
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PostPost by: alan.barker » Sat Jan 06, 2018 6:49 pm

Hi Jon,
as i said above i have had a drive shaft metal sprayed and there were no problems after.
When the spraying has been done it has to be put in a Lathe between centers and turned to correct dia for the new bearing. While it is still in the Lathe it's just a 5 minute job to face the lugs to be 100% sure the Brake Disk will run true.
I was lucky because a friend worked in a machine shop so it was done free gratis :)
There is also the posibility of hard chroming or ceramic repair. So 3 choices.
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