Author Topic: Rpll Bar Lower Mounting  (Read 892 times)

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Offline Footer

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Rpll Bar Lower Mounting
« on: Saturday,June 27, 2020, 10:24:52 AM »
Hi Guys,
I'm trying to remount the front anti roll bar on my 73 Twin Cam Special and have come up against a road block.  In the picture, when all the washers and bushings are mounted, their doesn't leave any room to start the threads on the lock nut,  I've tried a lot of things , going so far as to blocking under the roll bar and then lowering the corner of the car onto the bar, hoping to compress the assembly with the weight of the corner enough to start the nut,  Alas, no luck!  Perhaps there is a secret to getting this accomplished that I am not privy to. 

Lacking an alternative solution, my next step is to cut off enough of the bushing to let me get the nut started, but I really don't want to do that.

Any suggestions would be greatly appreciated.

Footer/Bob

Offline BDA

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Re: Rpll Bar Lower Mounting
« Reply #1 on: Saturday,June 27, 2020, 12:14:38 PM »
Those rubber bushings look a little thick to me but then mine have been compressed for a long time. You could try a C-clamp or something similar. You might try jacking it up and lowering it on something so it pushes the anti roll bar up and compresses the rubber. It looks like you don't need to squeeze it that much.

Offline 4129R

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Re: Rpll Bar Lower Mounting
« Reply #2 on: Saturday,June 27, 2020, 02:00:21 PM »
The front of a Europa is very light, so you can compress the A/R bar top bush enough by using a G clamp just so you can get the thread started.

I had this problem with new bushes.

Make sure the raised parts of the metal washers are seating correctly in the O of the A/R bar end.

Once you get the thread started, the rubber bushes squash quite easily.

Offline Grumblebuns

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Re: Rpll Bar Lower Mounting
« Reply #3 on: Saturday,June 27, 2020, 04:20:33 PM »
Is your ARB stock? I noticed that the end is much thicker than what my TCS was fitted with. My TCS ARB tip end is about 0.23" thick. What's odd is that the ARB fitted to my S2 look very much like yours. I believe the PO of my S2 fitted an aftermarket bar from a TCS. See the pictures.
 
Pic 1 is a stock TCS ARB (I believe going with bar diameter)
Pic 2 shows a TCS and S2 comparison
Pic 3 shows bar on my TCS
Pic 4 shows the bar of my S2 which looks very much like yours. The PO apparently used used much thinner rubber bushes to make the nuts fit.

Offline Footer

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Re: Rpll Bar Lower Mounting
« Reply #4 on: Saturday,June 27, 2020, 05:47:16 PM »
As usual, lots of good information here,.  Thanks!
BDA and 4129R, your suggestion for the c clamp is a good one. I had tried this, but couldn't get a "square" grip on the roll bar and the clamp kept slipping off.  I'll go back and try a different mount to see if this can get it done.  I think I can get about 1000 lbs of pressure from the c clamp and that is more than I was able to generate using the weight of the one corner.  Perhaps with the weight of the corner and the c clamp I can get it done.  The raised parts of the metal washers do not quite fit into the ends of the bar and that adds to the spacing issue.  I'm going to counter sink the O's further than they are to seat the washers fully.  That might do it all by itself.
Grumblebuns, thanks for all the pictures.  Your pictures  #3 and  #4 look identical to my arrangement, until I took the old bushings off.  They were severely flattened, more so than your's.  But the bar in the pictures is identical to mine.  I believe mine is stock since it was essentially one owner when I got it, but I could be wrong.  I know that the bars came in three thicknesses, 1/2, 5/8 and 3/4"(mine is 5/8 ") but I don't know if the ends were the same or different.
I've given up for the night but tomorrow may be the one.

Thanks again.




Offline kram350kram

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Re: Rpll Bar Lower Mounting
« Reply #5 on: Saturday,June 27, 2020, 06:31:38 PM »
Not all that related but I just painted my ARB off my '74 TCS and it's 11/16" in diameter, with ends like that shown in the 2nd post, top bar in the photo. I guess this must be an aftermarket bar as it's not one of the standard 1/2, 5/8 or 3/4" units? My bar does have the upset locaters for the strut link bushings. Any comments? 

Offline jbcollier

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Re: Rpll Bar Lower Mounting
« Reply #6 on: Saturday,June 27, 2020, 07:34:53 PM »
Footer/Bob, trim the rubber bushings by half.

Offline Footer

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Re: Rpll Bar Lower Mounting
« Reply #7 on: Sunday,June 28, 2020, 05:55:18 AM »
Trimming the bushings was going t be my next effort.

Thanks.

Offline Footer

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Re: Rpll Bar Lower Mounting
« Reply #8 on: Monday,June 29, 2020, 01:53:49 PM »
FINI!  The roll bar is in, finally.  I did three of the things mentioned in the string to get it in.  First I counter sunk the stud holes more to allow the raised washer to seat better, then I mounted everything except the last washer and compressed the bushes with the nut.  Then I used a c clamp and alternated between the nut and c clamp until I had enough compression, being held with the clamp, to add the bottom washer and nut.
I don't like the looks of the final assembly, the washers are not parallel to each other and the two middle ones don't rest square to the flats of the bar.  Seems as though the angles are interfering with each other.  Other than bending the bar I'm not sure how to clean it up and I don't want to start bending the bar. 
The passenger side shows signs of a pot hole collision that did some damage to the bar, vertical link and mounting stud.  Perhaps this tweaked the bar some.
I don't have any safety concerns with it this way but could be wrong.  Let me know if I'm uninformed here.

Offline BDA

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Re: Rpll Bar Lower Mounting
« Reply #9 on: Monday,June 29, 2020, 02:37:13 PM »
It looks fine to me. It looks like you could tighten it a bit more to some bulge in the upper bush and a bit more in the lower bush but I wouldn't worry about things not being square. The bushes help with that. I would be a bit concerned if there is significantly more pre-load on one side than the other.

Offline Fotog

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Re: Rpll Bar Lower Mounting
« Reply #10 on: Tuesday,June 30, 2020, 05:56:39 PM »
Not all that related but I just painted my ARB off my '74 TCS and it's 11/16" in diameter, with ends like that shown in the 2nd post, top bar in the photo. I guess this must be an aftermarket bar as it's not one of the standard 1/2, 5/8 or 3/4" units? My bar does have the upset locaters for the strut link bushings. Any comments?

My TC built Aug '72 has a 11/16 bar.  I've wondered, but it is likely stock.

Offline Footer

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Re: Rpll Bar Lower Mounting
« Reply #11 on: Wednesday,July 01, 2020, 09:12:10 AM »
Thanks for the comment BDA, but I'm ignorant as to the meaning of pre-load in this instance.  Could you explain that further for me?

Offline BDA

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Re: Rpll Bar Lower Mounting
« Reply #12 on: Wednesday,July 01, 2020, 10:44:29 AM »
If your bar is not even on both ends (i.e. one side bolts on and you have to twist the bar to get the other end bolted on), you will get a different effect between left and right turns.

In a turn, the outside suspension will push the bar upward which pushes upward on the inside suspension and thus reducing the roll of the car. If you had to twist the bar upward on the right side, you are setting a pre-load down on the right side and a pre-load up on the left. When you make a left turn, the right side will move up but the force the bar imparts on the left will be less by the amount of the pre-load thus reducing the effectiveness of the bar. For right turns, the effect is to force the right suspension down and essentially increasing the roll of the car..


Offline Footer

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Re: Rpll Bar Lower Mounting
« Reply #13 on: Friday,July 03, 2020, 05:20:15 AM »
Thanks BDA!  Lots of things going on in a turn that I was not aware of.  The geometry and physics are mind boggling.  I always thought it was amazing, for the relatively small contact patch of the tires being able to create as much grip as they do.

Have had some delays on the motor, mostly because of the virus, but the parts I'm doing are coming along nicely.  Real good learning experience.