Rear sway bars (anti roll bars) what got them and what didn't?

[SUBURBAN5]

Blue Streak is the bomb! Just do not drop it! Pun intended LOL! Seriously, the blue plastic is brittle. Check the parts out when you get them, and look at the box to see if it's been damaged too.
Mom and I have had extra work the last 2 weeks. Got to go this evening and do a couple work projects that couldn't be fit into yesterday. Some of our co workers seem to only work when they feel so inclined....and don't bother to let the boss know until Friday afternoon. Most people that are on call 24/7 make a bit more $$ per hour than we do.....

Yeah lot of that going on cause of the pandemic. Our company had to tell employees a while back if they didnt come back to work then there terminated. Lot of guys saying home cause of the benefits or "there sick" now were short handed with drivers

 

[HotWheelsBurban]

Yeah lot of that going on cause of the pandemic. Our company had to tell employees a while back if they didnt come back to work then there terminated. Lot of guys saying home cause of the benefits or "there sick" now were short handed with drivers

I agree with that. But I know one of these dudes from a former job we both had and sometimes he's just lazy. When he does come in, most of the time, does the bare minimum of job requirements......tired of cleaning up after him. Our company is going to make major transitions in what we merchandise in mid October. Boss thinks most of the poor workers will go with the company that's taking some of the things we're no longer doing. Hope he's right.....more work for mom and I, less diaper duty......sometimes it seems like I have 50 kids.

 

[SUBURBAN5]

Lol that's us. We got a bunch of guys at work that I swear are still kids

 

[sewlow]

Just a note to begin with.
GM installed larger front bars on these trucks that only came equipped with the front bar. GM's method of compensating for not having a rear bar.
Trucks with both front & rear bars had a smaller front bar than the ones just equipped with the single front one.

The rear bar from an SUV is more than adequate for C1500's.
Going too large & the trucks get tail-happy. Especially over stutter bumps such as railroad tracks. The rear suspension becomes less compliant.
Too large of a rear bar will also cause a vehicle to 'push' in the corners. A rear bar has to be somewhat compliant so as to allow the weight of the vehicle to transfer onto the outer front wheel, resulting in that tire being 'planted' as opposed to sliding over top of itself during any type of aggresive manouevering.

Sway bar technology is a science all unto itself, with many trains of thought such as 'soft suspension/ large stiff bars' to the other end of the spectrum of 'stiff suspension/small lighter bars'.
Track guys all have their various views & opinions. It all depends on the final usage of the vehicle, driver personal preference, & most importantly, track times.
Testing of such is also important. Comprimises abound. A vehicle that turns in a great 'G'-force meaurement on a 200' skid pad may not be the best in a slalom course. Alternatively, a vehicle that does well on a slalom may not generate the best of skid pad numbers. Usually, it's the vehicles that combine 'not-the-best' in each measurement that are the ones that shine in actual real-world usage. ...and generate the best track times.

Then there's the bars themselves. Solid. Hollow. Semi-hollow, (Solid centers/hollow ends.) This tech is a giant can of worms!

The install of a factory rear bar under these trucks is not done with the idea of creating a race car cabable of stellar handling performance equal to that of an actual track vehicle.
Nope. But, it will improve the handling over & above that which was not available from the factory. Allows for more confidence in the vehicle when evasive moves are suddenly required.
Throwing on some good shocks is a good idea. A vehicle is suspended by the ...ahhh...suspension. (!) Shocks control the motion of the suspension.

A rear bar will also help when towing.


To install a GM sway bar on a non-factory equipped truck you'll need...
- The sway bar from an SUV. This includes the end links, the frame mount brackets & the nuts & bolts for the brackets.
The nuts & bolts are important. There's a key on the nuts that prevents the nut from turning inside the frame when tightening or removing. Like a fender nut/bolt combo. It's near impossible to get any type of wrench/socket in there to hold them.
- 2x 3" Heavy Duty muffler clamps. H/D because they're longer & of a heavier gauge. Regular M/clamps are not long enough to get everything that's going to be mounted on them to fit.
- I also recommend to replace the bushings on the end links with urethane.
I got the ones for mine from the local auto parts store. Take one of the the originals with you. The replacements were in a divided plastic container of various sizes allowing me to pick & choose the ones I needed.
The factory rubber ones are one piece. The urethane ones are of a two piece design. So, you'll require 8 pieces.
For the diff mounts, they also were also replaced with urethane. They are a split design so that they just slip over the bar. No need to slide them on over the ends of the bar. The came with shells equipped with grease zerks.
The ones I used had the same bolt hole center-to-center measurements as the c-to-c measurements of the muffler clamp U-bots.
I took one of the original rubber ones with me to figure the size. You could also just measure the factory bar with a dial caliper to get the right size.

Install.
- Lube the bushings with synthetic grease. Urethane doesn't like regular Dino-grease.
- Diassemble the end links from the frame brackets & the bar.
- Slip the U-bolts for the muffler clamps through the opening of where the shock brackets are welded to the diff. One will face towards the front of the vehicle, the other towards the rear.
- Slip the other 1/2 of the M/clamps over the U-bolts.
- Install the sway bar bushings over the bar, along the shells.
For this next part, a third hand really helps.
- Install the shells/bushings on to the muffler clamps & bolt them loosely until both sides are installed.
- Once that's done, snug the nuts up tight enough to just hold the bar in place, without it being able to move around on it's own, yet loose enough that it can be moved by hand.
- Align the bar so that is parallel to the diff. The U-bolt ends may get hung up on the shock mount due to their length, which can prevent the bar from being mounted parallel. Trimmage of the U-bolt may be required.
- Once the bar is parallel, tighten down that assembly.

This next part of the assembly requires that the weight of the vehicle is on the wheels. The vehicle needs to be on a level surface.

- Assemble the end links onto the bar with the new bushings.
- Assemble the frame mounts to the end links.
- Swing the ends of the bar with that assembly up to the frame.
- *Important* The end links have to be perpendicular to the bar. Straight up & down. Not leaning forward or to the rear.
- Trace the frame mount position on the frame with an awl or some chalk.
- Mark that front mounting hole for the bracket on the frame. You'll only be able to mark that front one as the rear one is blocked by the end link.
- You may also find that there is a big rivet sitting right underneath where the frame bracket goes. Don't remove that rivet. Drill a larger than required in the frame bracket so that the rivet fits inside that hole.
- Remove the brackets from the end links.
-Place that bracket up against the frame in the marked position & mark that rear hole.
- Drill the four holes for the bracket in the frame.
- Install the brackets using the original specific nuts & bolts. Use some red loc-tite on the nuts & bolts.
- Swing the bar back up into postion & install the end links into the frame brackets.
Go back & check that all the nuts & bolts are tight.
Lube the diff bushings via the grease zerks.

Now, get out there & carve some corners & enjoy the feeling of the truck being more connected, front-to-rear.

 

[sewlow]

Pix! I have pix!

This shows the M/clamp mounted to the diff. This is the same method of mounting sway bars that the aftermarket Co.'s use.
It also shows why the U-bolts may have to be trimmed. This is mine before they were. You can see why as that one leg is just a bit too long for the mount to slide right back inside the shock mount in order to get the bar parallel to the diff housing.

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This pic shows why you can't mark that one hole for the frame bracket with the upright installed. This is under my '97 before I replaced the rubber bushings.
...and I made a bit of an error, not that it matters, but it's the bolts that have the key on them to prevent it from turning inside the frame rail. Not the nuts.

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Finished.

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Now, for you guys with more than a 6" rear drop, you may have to shorten the uprights in some manner. If those are too long, what happens is that bar ends up sitting on too much of angle, too close to the pumpkin cover. On hard suspension compressions, the bar may hit the cover as the bar swings through it's travel. A bit of 'massaging' with a hammer can allow for clearance in that area. Keep an eye on where the bar touches. It's actually more of a scuff. Too much hammering could put the cover into the crown gear. It doesn't take much to get the clearance required.

 

[TacosnBeer]

sewlow - Freakn AWESOME write up and pics! Cant ask for better than that.

 

[98chevy2500SS]

x2! Great write-up with lots of details and pics is a HUGE help.

 

[sewlow]

Thanks guys!

 

[Pinger]

That IRS looks similar to the Jaguars.

It shares the same feature as Jaguars of using the driveshaft as top link (and very wide based lower wishbones). Lotus used rubber 'do-nut' couplings (from Hillman Imps) where Jaguar used all metal UJs. Chapman used drive shafts as top links (with all metal UJs) on his race cars too. He disliked splined shafts as back then they were prone to sticking under torque and locking the suspension mid corner.

Jaguar used inboard brakes and Lotus a variant. If you look closely you can see that the brakes are inboard of the hubs - just not right up with the diff as with Jaguars. It's doubtful the rubber coupling could have withstood brake torque (even if Chapman had wanted the brakes next to the diff (probable though - to reduce unsprung weight)).

 

[Pinger]

Good post.

Too large of a rear bar will also cause a vehicle to 'push' in the corners. A rear bar has to be somewhat compliant so as to allow the weight of the vehicle to transfer onto the outer front wheel, resulting in that tire being 'planted' as opposed to sliding over top of itself during any type of aggresive manouevering.

But I'm taking issue with the above!
Lack of rear bar causes the front to push as without roll resistance at the rear all the roll goes to the front outer tyre and the increased load there increases that tyre's slip angle. When it runs out of slip angle it runs out of grip (assuming the chassis is stiff enough to transfer the roll without flexing). A stiiffer front bar has the same effect as the inner tyre does less having transferred the weight to the outer - increasing its slip angle.
Conversely, the greater weight transfer to the outer rear tyre from the inner rear tyre when a rear bar is fitted increases the outer rear tyre's slip angle and thus the tendency is toward oversteer (loose) - while reducing the weight transfer at the front due it occurring at the rear.

Sway bar technology is a science all unto itself, with many trains of thought such as 'soft suspension/ large stiff bars' to the other end of the spectrum of 'stiff suspension/small lighter bars'.

Not to mention roll centre heights....