C Bushing Question

[txhawkeye]

I am getting ready to bolt the front axle back up and I have a question. I am installing a stock height suspension kit and it has 4 degree C bushings and rubber degreed radius arm bushings in the kit. I also have 2 degree bushings and urethane non degreed radius arm bushings on hand as well so I can install either one. Everything I see the later would be the right choice but the kit was probably set up that way for a reason. What would you do?


Sent from my iPhone using Tapatalk

 

[Bronco Maniac]

My buddy has no suspension lift and had 2 degree bushings. He bought 7 degree bushings as recommended by someone. When we took it apart we determined he had put the 2 degree bushings in wrong. We put the 7 degree bushings in and he loves the way it drives.

 

[DirtDonk]

With zero lift I would install the straight-cut radius arm bushings, instead of the degreed type.
The angled ones are to help with lifted trucks, but you're the best judge being there with the vehicle.
And in spite of rubber having an advantage in that position, most likely though, the standard ones will work best even though they're polyurethane.

The question of which C-bushings to use is why we often recommend having the caster checked before you pull it all apart. But since we don't have that option, you can go with either the 2 or the 4 degree bushings with little likelyhood of any negative effects.
But what year is the Bronco, and do you have manual or power steering?
If you're going to be running power steering, I would just use the 4° setup and head on down the road.

Paul

 

[txhawkeye]

With zero lift I would install the straight-cut radius arm bushings, instead of the degreed type.
The angled ones are to help with lifted trucks, but you're the best judge being there with the vehicle.
And in spite of rubber having an advantage in that position, most likely though, the standard ones will work best even though they're polyurethane.

The question of which C-bushings to use is why we often recommend having the caster checked before you pull it all apart. But since we don't have that option, you can go with either the 2 or the 4 degree bushings with little likelyhood of any negative effects.
But what year is the Bronco, and do you have manual or power steering?
If you're going to be running power steering, I would just use the 4° setup and head on down the road.

Paul

It is a 66 I will be adding power steering, so I guess I will go with the 4 degree. Thank you for the help.


Sent from my iPhone using Tapatalk

 

[DirtDonk]

Ok, pretty sure a '66 can benefit from the added caster. Most of the early models, and in fact most up to about '76, had very low caster numbers from the factory. First because a lot of caster just wasn't necessary they felt for a little utility vehicle that wasn't going to be out autocrossing or driving the autobahn, and with manual steering, less caster was easier to steer.

As blu pointed out, keep an eye on your front u-joint after the C-bushing swap, to make sure it's not binding.
This is likely not going to be any issue in your case. But like anything else, and since every Bronco is different, it never hurts to keep it in mind and test after the install.

Paul

 

[tirewater]

My '76 with stock height suspension and C bushings has pretty close to zero caster. It drives fine because cross caster/camber is nearly zero as well.

I'll be replacing my C bushings with the 4 degree bushings as the resulting caster should still be in the listed spec.

 

[DirtDonk]

Yoza. That's low for a '76. When we were tracking this about 10 years ago or so, all the guys with '77 EB's, and most of them with '76's were the lucky ones with big positive caster numbers compared to the rest of us.
Some few of the '76's were lower though, more like the earlier models. We did notice that the numbers were all over the place no matter what year though, which led us to believe that Dana wasn't exactly using carefully made jigs to weld all their stuff together on.

Looks like you got one of those lower '76's, but even more so. Just out of curiosity, was yours an early build? What month was it produced?

Thanks

Paul

 

[tirewater]

Marti says vehicle was built 12/5/75. I'm guessing it's in the middle of the build year. Although I don't know when in '75 Ford started selling the '76s.

My alignment spec is about as stock as my bronco will get. All non C bushing suspension & steering components are new (tie rods, radius arm bushings, springs, shocks, ball joints, track bar bushing, etc...). I removed camber correction shims between the knuckles and a caster correction bushing when replacing the ball joints - so I was somewhat surprised that caster & camber were about equal side to side.

 

[blubuckaroo]

Great news Paul!
Maybe that's why my '77 will cruise at 70 hands free with a 2.5" lift and using 2* C bushings.

Back when I installed my first lift, 2* C bushings were recommended for a 2" to 2.5" lift.
Now days, a 4* C bushing is recommended by all our vendors. Some even go to 7* Cs.

As you already know, my opinion on this is a matter of record. Proper driveline angle is important. Make sure you check yours before ordering your C bushings.

 

[DirtDonk]

Yeah, the camber is actually great. Even though the spec calls for between 1 and 2 degrees positive, having less than 1 degree (but not below about .4°) is very desirable.

I think that '76 was another one of those delayed years, where '75 production went up until October of '75, instead of the more common August change.
If that's the case, then yours is still somewhat early. Not exactly right at the beginning, but not that far down the road either for that year.

Thanks for the info. Let us know how it drives after the bushings go in.

Paul

 

[DirtDonk]

Yeah Mark, it was only in more recent years (about the last 10 or so) that we've been pushing more and more bushing correction for less and less lift. If you look at most of the websites, I think we still "officially" use the old recommendations. But when you talk to a human we usually err to the larger bushings these days, based on our customer's experiences.
Most of that change was driven by finding the earlier models with crappy caster numbers even after bushing changes. But also because lifts and tires were getting bigger and bigger, and power steering was getting more and more prevalent, and more powerful too.
Heck, I ran manual steering with mine for almost 40 years with less than 2° total caster and it did pretty darn good.

Also people's expectations of these things have changed drastically in the last decade or so as well. Where we accepted low numbers before, more and more caster is being searched for to get rid of some of the old quirks.

You're always correct to mention the pinion angle. I think it's more than a little luck that keeps u-joints from binding on most Broncos using 7 degrees of correction. But most do tolerate it. You just don't want to be "that one guy" who's Bronco doesn't when nobody warned you!
And nowadays I bet most Broncos never see the Lock side of a hub knob anyway.

We'll probably keep recommending more bushing, so just keep reminding us to watch out for binding.

Paul

 

[blubuckaroo]

We'll probably keep recommending more bushing, so just keep reminding us to watch out for binding.

Paul

I'll do that. But the shake when you drive on the road, with the hubs locked, will always be a reminder that you should have checked.

 

[sykanr0ng]

On the other hand; with so many Broncos being made into street only use, how much need is there to be concerned with the front driveshaft binding?
For those owners steering on the streets and roads is everything.