'68 lower control arm won't fit in subframe

[DAVEN1256]

Looking for a suggestion on how to solve this problem. I cannot get this lower control arm to fit into the subframe. The overall dimension between the outer edges of the bushing's (measured at the inner metal collars) is an eighth of an inch too wide. The bushings are pressed in as far as they will go. I have tested two other old control arms (that are too ratty to use) and they fit fine into the subframe so I'll rule out the problem being with the subframe. I really need to use the control arm in the photo as it has already been blasted, primed, painted, and has the bushings and ball joint already installed.

Any suggestions would be appreciated.

Thanks.....Dave

[L78 steve]

I may be wrong but I remember the bushings installed in the same direction, not opposed. Will check tonight.

[Gramps69Z]

Large end of bushing should be to the outside. The fit will be tight so I little lube and persuasion might be needed.

[169INDY]

I had to use a Jack & a Block of Wood to get my driver side to "SLIDE" it into the subframe gap. It was a bear to align and used a bar to remove it and try again. I used PST replacement bushings and attributed the tight fit to the new bushings and lack of give of the urethane bushing material. I used the silicone grease supplied with the suspension kit as an aid to lube the install also. 1/8" (0.125") is tight but if I remember correctly the subframe is flanged and rounded (radius) and should have some Flex to it. It may be possible to Dremel grind down the inner sleeve a few thou' to give you some clearance. I have never had these just "FALL" out or into place.

Jim

[DAVEN1256]

Thanks for everyone's suggestions. I tried the "threaded rod" suggestion I got from Team Camaro this and it worked. By cranking on the nuts, I was able to squeeze the control arm down the 1/8 inch I needed.

Now I need a suggestion on the type grease to use on the ends of the bushings as I drive the control arm into the subframe. These are stock type rubber bushings

I would think standard grease would degrade the rubber. I know that silicone grease would be good but when I look for "silicone grease" on the auto part store websites, all I see is liquid sprays. I have also read where something like Mobile 1 synthetic grease would be good.

I just don't want to put anything on there that will hurt the rubber.

Thanks.....Dave

[JohnZ]

Now I need a suggestion on the type grease to use on the ends of the bushings as I drive the control arm into the subframe. These are stock type rubber bushings

You don't need ANY kind of grease on the ends of the bushings - none is either required nor specified; when you torque those bushing through-bolts with the suspension at design ride height, the serrated ends of the hardened inner sleeves bite into the subframe pockets and lock that center sleeve rock-solid - you don't want it to move or help it move.

There's also no movement between the outer sleeve and the control arm - it's also locked solid; all rotational movement between the control arm and the subframe takes place in the rubber element of the bushing, which is bonded to the O.D. of the inner sleeve and to the I.D. of the outer sleeve, so no movement = no lubrication required.

[DAVEN1256]

Hi John, I see the serrated edges on the inner sleeve of the upper control arm bushings. The edges of my lower control arm inner sleeves appear to be smooth. On both the replacement Moog bushings I have and the originals. That being the case, I just wanted to verify that the inner sleeve of the lower control arm bushing is supposed to be clamped between the sides of the subframe crossmember so it can't rotate.

Then only reason I was considering the grease is because so many people seem to have problems getting the lower control arm bushings in. Everyone seems to be greasing them and then beating them with a big hammer.

How did they get them in at the factory?

Thanks.....Dave

[1968RSZ28]

Then only reason I was considering the grease is because so many people seem to have problems getting the lower control arm bushings in. Everyone seems to be greasing them and then beating them with a big hammer.

Thanks.....Dave

The removal & installation of the control arm bushings can be found in Section 3 (Front Suspension) of the 1968 Chevrolet Chassis Service Manual (ST 130-68).

Paul

[scoop]

From what I can see from the pictures is that both bushings are pointing same way. If they are both installed from the outside going in they will fit with no binding. Thanks, Scoop

[DAVEN1256]

The picture is deceiving. Both bushings are installed from the outside pointing in.

[DAVEN1256]

Thanks for tip on the chassis service manual but I don't have one of those and I have to get these control arms in tomorrow.

Dave

[JohnZ]

Hi John, I see the serrated edges on the inner sleeve of the upper control arm bushings. The edges of my lower control arm inner sleeves appear to be smooth. On both the replacement Moog bushings I have and the originals. That being the case, I just wanted to verify that the inner sleeve of the lower control arm bushing is supposed to be clamped between the sides of the subframe crossmember so it can't rotate.

Then only reason I was considering the grease is because so many people seem to have problems getting the lower control arm bushings in. Everyone seems to be greasing them and then beating them with a big hammer.

How did they get them in at the factory?

Thanks.....Dave

Big hammers and wedge-type tools were used frequently to install the control arms to the subframe. When that bolt is torqued, it locks the inner sleeve solid to the walls of the pocket in the subframe - that's why the Assembly Manual has the note to torque them with the suspension at design ride height (so the rubber element in the bushing doesn't become preloaded in torsion when the car is on wheels).

[Petes L48]

Thanks for tip on the chassis service manual but I don't have one of those and I have to get these control arms in tomorrow.

Dave

May be too late, but looks like you can still download the 67 service manuals here, probably little to no difference between a 68.
http://www.camaros.org/forum/index.php?topic=9433.0
 

[DAVEN1256]

Thanks for all the replies and suggestions. I did manage to get the lower control arms installed. First, I put the threaded rod back in them and cranked on them as hard as could to try to narrow them some more. They were better after that but it still wasn't quite enough to get them in. Even using a hammer. Then I remembered that my Hotchkiss front sway bar came with a vial of white grease to lubricate it's rubber mounting bushings. I put a very, very light smear on the outside of each bushing and they went in.

I tried to heed John's advice and avoid using grease but they just weren't going to go in other wise. At least with the tools I had to work with.

I will definitely wait until everything is installed and the car is at it's ride height before doing any tightening.

Thanks.....Dave







Thanks.......Dave

[firstgenaddict]

If you use a spreader bar in between the inside of the two bushing holes it makes the pressing go much easier, same goes for the distance where the bushing actually passes in the A arm rail. If you space this with a precise spacer it keeps the deflection down, the deflection in the steel of the A arm rail is what is causing your binding and not allowing the bushing to press in without so much work.

What happens is the outside support wall flexes toward the opposing wall and even when you think it is home it isn't squarely home, so when the tension is released the wall flexes back and the busing is proud of it's proper placement. Keeping all the walls square to one another is the key to pressing bushings with as few problems possible.  

You don't need grease put a little palmolive liquid soap on them if you need a lubricant to allow them to slide into the pockets.