HELP! ADVICE! - UPPER/LOWER INNER SHAFT BUSH

[Lex68]

Hi all,

Here to pick brains please!

Apologies for long thread, need to be clear

Ok, lower and upper controls arms removed, control arm shaft bushings were tight and assume were torqued correctly, and removed lower and upper controls arms,however, I failed to check the distance between the boss and the inside of the control arm where the 'spacer tool goes, so I don't know the original dimension to assist troubleshooting

After getting info of the forum, I produced a spacer (tool 3A5) with 20mm width and proceeded to install the bushings, I screwed them in till the gap closed on the spacer, removed the spacer and continued to torque to a point where it was continuing to close the 20mm gap. The good book says if you cant reach the specified torque (40ft Ibs - 60ft Ibs) new bushings are required.

So... are you usually able to re use the bushings or was the original torque / spacing on the control arms incorrect or do you need to replace the bushings once removed (as the thread that has been cut into the bushing when originally installed been disturbed?)

I have only attempted to install one of the 4 control arms assuming they have the same issue.

Will new bushings solve this and be able to cut a new thread or do I need oversive bushings to compensate for the wear on the control arm that creates the cut?

Thanks Renno

[Blacky]

When I did my front end up I just bought new bushes, they aren't that expensive

[Lex68]

Blacky,

Yeh got no probs getting new bush's dont want to go around in circles.

Thanks for the reply

Renno

[Lex68]

Something simple yet a pain in my backside

The theory is screw both bush's in until gap closes on spacers, remove spacers and the bushes should torque off soon after, ensuring the gap is even on both sides....yes?

I have been told that the spacer used to set the gap is 20mm wide and is used on the Upper and Lower control arm.... yes/no?

Upper Control Arm
OK........Got new bushes, for both sets of control arms. On both the upper inner bushes one side torques off after removing spacer
and the side continues to screw in till bottoming out after removing the spacer (Is control arm stuffed?)

Lower Control Arm
The gap between the lower inner boss to inner side of the control arm is ample (the dimensions across the control arm are in limits, there abouts) now
after placing the control arm on the control arm shaft and screwing the bushes on they get pretty tight and the gap has not even closed onto the 20mm spacer yet.....Is this normal. Do I continue as I feel it is way above the torque required?

Thanks in advance

[Craig Allardyce]

Lex, by the sounds of it you need an oversize bush (OD) for your control arm. The bushes should not continue to turn when you go past the set tension. I have seen this before where people have welded the bush to the arm. If your arm is stripped out I'd get another that has the threads in good nick and try again.

With what your saying about the lower arm, are you saying they are tight and the bush hasn't bottomed out on the arm??
Usually there is some slight distortion on the arms as you are trying to align threads on the arm with the bush and then the bush with the pivot pin. I'd check the fit of all bushes to pivots and arms separately before assembly. Swap around till you get a good match or find which one might be the problem. The bush should not bind when tensioning and prior to bottoming out in the arm. I would also check that the pivot pins are set right in the front end. Check the dimensions are as per spec. They can move when disassembling and removing the arm if the pivots are loose. I have found sometimes they are out and the bush bottoms out on the pivot pin internally. You can confirm this by removing the grease nipple and checking depth.

[Lex68]

Thanks for the reply,

Yeh I've got spare top arms that I am cleaning up now and I will gather my thoughts and attack it tomorrow.

And, actually, there is one control arm pin (pivot) that is shorter on one side than the other....It was way tight and I was little reluctant to go push and damage tooling, might put some heat on it?. I'll give that another go too!

Thanks again for the reply

Cheers Renno

[Craig Allardyce]

Renno, those pivots are screwed into the front end! If they are loose you need to replace them with oversize (OD) ones. They are screwed into the sub frame at a set dimension and torque. If correct this gives the correct spacing of the wishbone to the front end and all that is needed after that is the spacing tools )or vernier as I did, to mount the arm in its correct spot.
From your writing I'm thinking you are trying to move the pivots by pushing or pressing them???????

[Lex68]

G Day Craig and thanks for reply,

Yes, the control arm shafts (pivots) are indeed screwed in to such a point where a specific measurement with a tolerance of 1/64 " is allowed for both top and bottom control arm shaft. Both shafts are fine (tight not loose), however one of them is short on one side than the other (this is how the front end came before I stripped, cleaned painted and now attempting to re assemble. (and in order to adjust to the correct length I will need tool 3A4

My main problem is the bloody bushes / spacer and torqueing!

Upper Control Arm

1. I place the control arm onto the the control arm shaft (pivot)
2. place spacer as per picture (Is the spacer distance for upper and lower 20mm?)
3. Place bushe in control arm screw into arm and onto pivot until any space is given up and contact made with the spacer.
4. Remove spacer
5. Attempt to torque, but my bushes keep on going on, which in turn narrows the gap between the control arm when I try to attempt it again.

Lower Control Arm

Same as above, however

I go to set one side of the control arm and I notice the other side has come off the pivot all together with a good 10mm gap from the end of the pivot to where the control arm hole should be placed to begin installing the bush. This is why I ask is the spacer the same size for the bottom bush installation.

I am thinking if my bushes do not torque off after removing the spacer I will weld. Sick of buying replacements!

Here are some pics

Cheers

[Craig Allardyce]

Ok Lex, the pictures help a lot.
Your upper control arms are stuffed if the bushes keep turning (Threaded eyes are stripped out by the sounds of it).
If your lower control arm bushes keep turning and don't get to the correct tension then they are too.

From memory I think the two spacer dimensions are different. I'm not sure, I don't have my books at hand as I'm packing to move. Do you have a workshop manual (original GM) as it would detail two different tool part numbers in the special tools list at the end of the suspension section.

Either way you don't need the spacers. I did mine using a vernier. I set the arm on the pivots equal distance then started the bush on the pivot till it just started to touch the arm. Do the same with the other bush. Once both are started then thread them all the way once they index into the arm (A little on each side at a time whilst checking as you go). Don't tension when bottomed yet, check your distances on both sides and depth to the pivot through the grease nipple hole in the bush. If all looks good tension (hopefully though tighten ok). You may have to set the bushes a couple of times to get the hole lot central. I would not weld to the control arm!
Hope this helps.

[feute]

G'day Lex

The lower spacer is 3A6 and is 38mm wide not 20mm

Hope this helps

Cheers
Gary

[Lex68]

Cheers and thankyou for the replies

I have a specific Holden FB manual which I have recently acquired (gold) I have the gregory's No. 67 FX-HR and the Max Ellerys 48-63 manual to cross reference.

Finally.......thankyou to FEUTE with the spacer dimensions for the lower control spacer
Tool 3A5 / 3A6, must be different, one would think? ......Different part numbers!...
I was told they are both the same! on this forum (wont go there) until I tried

chees guys..........

[TimR]

Hi everyone,
I've just taken apart the front end and found that pretty much all inner shafts have stripped threads on the support arms.
Just adding on to the above post.
I haven't found any oversized bushes to rethread for. Has anyone else solved this problem with a helicoil or will this take too much material out?
Best bet to find replacement support arms?
Thanks in advance

[Craig Allardyce]

Tim don't panick on this just yet. I'm not sure but where they loose when you removed them? They never look like they have a lot of thread on them from the start. Screw the bush back in to the arm and if it tensions up you're ok. I'd do this when you're at reassembly stage.
Don't do a dry run before that. Each time they are tensioned you loose a little meat till they eventually do strip out.

[TimR]

Brilliant, thanks for the help!
They were on fairly tight to begin with, soaked them for a while prior to try to avoid stripping anything.
A couple seem worn more than the others, I've picked up another front end with better threads and will see how it all goes back together.
Thanks

[Blacky]

There's nothing worse than when your shaft doesn't fit snugly in the bush