Fitting new ball joints and new lower A-arm bushings. One side at a time. No problem pressing out the old bushings, but with all the cautions I’d read about the fragility of the A-arms, I took the new (IPD rubber) bushings to a trusted local garage for installation on A-arm #1. When I picked it up, the guy advised me that the bushings seemed pretty loose and recommended he tack weld them in place as he often did in those cases. Obviously, “loose” is a relative term and they certainly didn’t wobble, nor could they be moved by hand. Unfortunately, I had an incomplete idea of how these things actually worked, so I declined and brought the thing home. But, before I installed it I gave it a more thorough think and concluded he might be right. So the project is now on hold.

It looks like the long bolt that goes through the bushings gets torqued pretty high and squeezes the interior cylinder in the bushings tight against the subframe tube. They become immobile. The outer cylinders of the bushings, press fitted into the A-arm apparently are supposed to be immobile relative to the A-arm itself. So, really, the only thing that’s supposed to move is the rubber itself. Which is why you final torque that long nut after the wheel is on the ground.

As such, I’m concerned about his concern. Don’t want the A-arm rotating on the outer cylinder of the bushing, and inclined to take it back to him and have him tack the bushings outer cylinders to the A-arm. This guy yearly inspects my 1800 and has aligned the front end once or twice. I feel strongly he knows what he’s doing when it comes to bushings. Assuming that my above-stated understanding of how this is supposed to work is correct, does anyone have any input that might dissuade me from having him tack the bushings?

How do you judge loose on a 10 ton press.......The new.bushing just went in square and easily. I wrap all other bushing I'm replacing with "kevlar"cloth and a strap when using my 20 ton press. Pressing is like a loaded gun...need to be careful. Lower your car ,Dave before the final tightening.

First let me thank everyone who has chimed in. To tack or not to tack…that is the question. Perhaps, more important is what my mechanic, John, meant by “loose.”
When I got the A-arm back on Friday, even though I’d provided the old through bolt (I have newer spares that I plan to use), when I attempted to put one of the new bolts through the newly place bushings they didn’t quite align. A few taps with a mallet quickly cured that. And it’s got me thinking that the narrow lip on the inside of the A-arm through which the barrels of the bushing project may have been designed that way to enable just a bit of axial play so that as everything is tightened up and the A-arm flexes just a bit, everything still aligns without binding. On the other hand, if those bushings were tacked in place, that tiny bit of axial play might not be available.

After reading your comments last evening, I got some channel locks and carefully tried to see if there was any radial play in the bushings inside the A-arm. Admittedly, I wasn’t capable of exerting the type of forces at play when the vehicle is operating. But, they certainly weren’t loose. Add in that (thanks, Ron, for making me do some actual measuring instead of just a visual comparison) the new bushings are a bit more than a half millimeter greater in diameter than the ones I removed and it would seem that the interference fit achieved would have to be at least as great as before.

I really did like the video Derek provided, although it was a bit confusing in that he pushed out just the center parts of the bushing. Perhaps the poly bushing system is different than the rubber bushings I have, but I thought the rubber in mine was bonded to both the inner and outer cylinders. Ron uses the terms “loads” and “unloads,” which I guess refer to compression rather than deformative rotation.

So, it’s Super Bowl Sunday, and with some un-seasonably warm weather headed our way tomorrow, I’m gonna sleep on this one more night. Then I’ll stop by and ask John to define “loose” and, if he simply meant that they went in pretty easily, I’m going to skip the tack welding, put my trust in Volvo engineering, and get on with my life. Thanks for all the help, and any other that may be forthcoming

Dave;

IF you were going to tack the bushings in-place for fear of an insufficient interference fit, alignment of the two being kindof important(!), the ONLY way, and time, this should be done is with the bolt aligning them in the first place!

Cheers

When fitting this type of poly bushings you press out, or burn out, the rubber and centre sleeve. After removing any rubber residue and cleaning up the outer sleeve, which is retained in the arm, you fit the poly bushes as per the video. Poly can be a bit harsh and transmit noise through the body so be aware of that. Only three places I would fit poly, to the upper inner bushes, the cotton reels, as these are small and take a lot of abuse. The original Volvo bushes were much better quality than those available now and can split and collapse after as little as 15k miles. Polys should last at least 100k if they are decent quality. Soft for road and hard for racing where noise doesn't matter. The same cotton reel bush is used at each end of the Panhard rod and you could use poly at the axle end. Using them at the body end does cause noise. Also use them on the anti roll bar push rod ends for a slightly better response.
Renewing all of the bushings and suspension and steering ball joints can transform a car making it much more enjoyable to drive. It's money well spent.

Hello Dave,

I think you're wise to stay away from welding on your control arms. There are valid metallurgical reasons for avoiding welding on steering and suspension components, and I think in many jurisdictions it's illegal.

Peter

Dave;

"fragility of the A-arms" I can't agree with this assertion...Volvo didn't make its off-road reputation with fragile A-Arms"!

Bushing inner sleeve is held against tube in Crossmember when Fasteners are torqued, so it does not turn, and outer Sleeve of Bushing SHOULD be quite snug in A-Arm, having been pressed in there with significant force. If it did not need force to be pressed into place, I fear it was undersized (s**t quality on replacement parts is not uncommon!) were these OE from Volvo or other source...how did they compare old to new...did he measure and compare ODs?...can you post a pic or three...tackwelding outer sleeve in place in A-Arm should NOT be necessary! ...and scares me a little (actually a lot...there should be NO welding necessary!!!)...he should have called BEFORE doing this, for your approval!

Rubber between sleeves does not "move" per se...it only loads and unloads with A-Arm excursions...otherwise you have it right...that is why it must be UNLOADED (suspension in normal position, weighted only, not in compression or rebound!) when hardware is torqued.

Cheers

The bushing will be fine. It get squeezed tight during installment of the A arm.

I think the OP is worried that the standard bush is a loose fit in the arm when it should be a tight interference fit. If that is so, the mechanic is considering a couple of weld tacks to fix it in place. Could be done but I'd rather fit good used or new as a long term cure. Among many other useful videos you can find this which is something that could be considered.
https://www.youtube.com/watch?v=ihJZ0u_v0N4

Hello Dave,

Since you seem to trust your guy, you might want to heed his advice. Just remember it won't be that easy the next time the bushings need to be changed if he does tack weld them on.

The only reason why we have never used tack welds on the bushings is because we have lots of good used arms and in fact you can still buy new lower control arms.

We have welded the bushings on Volvo 240/260 torque rods, but we stopped doing that once inexpensive poly bushings became available as those don't have or need the outer metal jacket.

Qudos on knowing the proper technique for tightening the bolts on metal cased suspension bushings that have center tubes that are vulcanized to the rubber. To make the bushings last, it's critical that the car is level and the suspension has the full weight of the car when the bolts are tightened. I have met seasoned mechanics that didn't know the correct procedure.

--
Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com

I tacked!!! Asked John what he meant by "loose" and he said it was in comparison to other bushings he does routinely (mostly on American cars). In the end, I changed my mind and opted for certainty versus uncertainty. He put two small tacks on the outside flange, positioned so they could be easily ground off in the almost inconceivable possibility that they'll ever need to be changed again. I'll make a note in my maintenance logs so that next guy, or girl, knows to look for them. Put everything back together on the driver's side and took it for a spin. Man, only one side done and already it feels like power steering. Did my best to torque that through bolt to 120 ft/lbs, but that ain't easy. Since I'm going to take it back to John for alignment after the other side is done (and the idler arm bushing - see my next post), all get him to check the torque when it's on the alignment stand.

Again, thanks for all the input. While, at 73, crawling around on a cold, East Coast garage floor is a bit much, the numerous challenges this project presented kept my mind off the inevitable. Can't wait to tear into the other side (and the idler arm).

BTW. When I took the other-side lower A-arm back to John, he reported that the bushings went in properly and there was no need to tack.