Torque clarification/sequence rear control arm bushings

[DaveR]

So I have combed the manual, and while I am sure its clear there for you guys I am not confident I have the following torque specs and sequence correct.

I am wanting to know how to torque the rear control arm bushings, and what sequence it should be done in to reduce squeaking and unintended performance.

Specifically:
1) the two bolts on the Front differential support cross member surrounding the bushing
2) the end bolt on the control arm facing the front of the car (by the front diff support)
3) the end bolt on the control arm facing the back of the car (by the rear traverse link mount)
3) the two bolts, long and short sandwiching the lower control arm bushing, rear mounted to the rear traverse link mount

I have attached the relevant torque page, and would appreciate some help making sure I get the right numbers for these bolts.

Thanks all

[Zed Head]

The basic idea is that when you torque the bolts down the rubber of the bushing is clamped in to place.  It flexes rotationally forward and backward, internally in the meat of the bushing material, as the suspension moves, but the outer and inner surfaces stay locked in place.  So there's no sequence, it's just a matter of getting the outer and inner surfaces located at the normal ride height of the car.  Basically, you leave the bolts loose, set the car down, roll it back and forth to get the wheels to spread to their normal position, rock it up and down a few times, then lay on your back and reach underneath to torque the bolts.  Or drive it up on ramps so you can get under it.

If you're using polyurethane bushings, none of this matters because they rotate inside the mounts.  They need grease to stop squeaking.

[grannyknot]

You can go ahead and tighten down the 4 large control arm bushings that you have circled, just make sure they are slid on as far as they go. When those are clamped they will continue to rotate on the inside tube of the control arm. Then do exactly what Zed Head says before torquing down the 4 large end bolts and 4 nuts for the spindle pins.

[Captain Obvious]

Are you using stock style rubber bushings, or poly?

Because (as Zed Head mentioned above) if you're using poly, then the sequence doesn't matter at all. Snug everything up and then do your final tightening in any order you want to. No difference.

[DaveR]

They are stock bushings, not yet replaced in the rear. Decent shape though. I know the loading for the rear bushings matters, but I was a little concerned about having enough access under the car to get a wrench (preferably torque wrench) in there to snug everything down once its on the ground. Especially the front large end bolts on the rear control arm.

Hopefully I will have enough room, the car is only slightly lowered.

Still hoping I can get the right torque specs. I think the large outside bolts are 100 ft-lb, and tightened at the very end once the car is on the ground. Still unsure about the brackets that hold the bushings up (cross members)

Edited August 26, 2016 by DaveR

[Captain Obvious]

Gotcha. Stock rubber bushings. Then you do need to pay attention to the order of events. Here's the summary:

First tighten up the eight small bolts (the ones you circled).
Second, load the suspension.
Third, tighten the four large bolts that thread into the control arms.

As for loading the suspension, there are several options (ground, ramps, etc), but I do something a little different.  I use a pair of small moving dollies with 2x10 planks across them. I lower the rear tires onto the planks/dolly combos and not only does this give me enough height to crawl under and tighten stuff, but the dollies allow the rear suspension to squirm around under load to equilibrium in a loaded position. Kinda like the alignment platters they use under your wheels on the alignment rack, only taller (and cheaper). JUST MAKE SURE YOU PUT THE FRONT END ON JACK STANDS OR AT LEAST CHOCK THE FRONT TIRES. You don't want your car rolling away on the dollies.

Also, while you're under there, I'd take the time to loosen and retighten all four of your spindle pin nuts too. They need to be done with the suspension loaded as well, and you don't know what the previous owner did.

[DaveR]

Great thanks. I compared the steps in the manual to their names, and matched up these torques for those bolts.  (The slightly different phrasing of everything has been hard for me to follow even though I am familiar with all the phyiscal pieces.)

8 small bolts you mentioned are:
-Link mount rear bracket (4x at U brackets holding the rear most control arm bushing in place) - 23-31 ft-lb
-Front Diff mount install nuts (4x) - 23-31 ft-lb

4 Large bolts are:
- Transverse link inner bolts (4x) large bolts on the front and back of the control arms = 101-116 ft-lb

Spindle pin nuts (transverse link outer self lock nuts - 54-69 ft-lb
Spindle pin lock bolt - 7-9 ft-lb
 

[Captain Obvious]

Yeah, sometimes everyone uses different terminology than what's in the manual and that can make stuff hard to find. It looks like you have successfully cross referenced the colloquial names to the official manual names.

And I found a pic of the plank/dolly combo that I use when loading the suspension. These allows the suspension to find it's "at rest" position before tightening the suspension bits into place. I think this is better than ramps because the dollies can squirm around as you jounce the suspension:

Just make sure you block the other end of the car from moving in some way when you do this so it doesn't roll around. And by no means ever try to do this on all four corners at the same time unless you've got a very level floor. DAMHIKT.

Edited August 27, 2016 by Captain Obvious
Can't speel

[Namerow]

Although I have not tried this, another strategy that I read about involves placing each tire on top of a pair of sheet-metal pads.  The contact surfaces between the two pieces of sheet-metal are lubricated so they'll slide.  I seem to recall that sand was used, but grease might be a better -- albeit messy -- solution. 

Plus: car can be rolled onto the pads without needing a jack, and both ends of the car are at the same level.  Minus: less clearance to get at the bolts you're trying to torque.

[Captain Obvious]

I've seen that sheet metal plate idea used for people who are doing home alignments. I've not tried it, but it sounds simple enough. I would be a little concerned though that the suspension really develops a lot of positive camber when the wheels are completely off the ground. You'd have to be careful that the plates were large enough to insure you didn't completely slide one off the other.

Maybe people jack up each corner using the control arm so you keep the suspension compressed and then slip the metal plate sandwich under the tire?

[grannyknot]

Funny that you guys should be talking about this now as I just put together 2 sets of these for measuring bumpsteer. Stainless steel plates I had sitting around, buffed up the mating surfaces with fine steel wool and then add a very thin lubricant, lithium in this case. I tried oil and grease but white lithium had the best action.

 

[Captain Obvious]

Nice. So how did you account for the large initial squirm without slipping the top plate completely off the bottom plate? Did you lift by the control arms, or is it just not as severe as I'm picturing?