Offset Bushings

[Lelo 500]

Is there any advantage to installing offset upper arm bushings before ever driving or having the car aligned? 65 Coronet 500- The body is very solid but the donor front end (K-member on down) was pretty beat up. I am currently replacing all wearable parts and I'm not sure if I should just get the standard bushings or what.
I thought the offset bushings were a corrective thing but after a bit of reading on the net some people are saying they are a upgrade?

 

[Lelo 500]

:moparts ghost:

 

[Darter6]

I say yes. I just did my 63's front end and didn't use the off set bushings.Max positive caster was 1 degree. Now the manual steer cars spec it is in range but I would have liked to have more.Also to get that I had to go with 1/2 degree positive camber.Little more than I want but should be ok.

 

[1970GTX]

I installed the offset bushings in my '70 and was able to get 3 degrees of positive caster.

 

[dvw]

After doing alinments for 30 years I would NEVER build a Mopar witout using offset bushings. You can never have enough adjustment. Remember these cars were designed to have between -1/2 (manual) and +3/4 (power) caster readings. Those were taken with the car level. Now add chassis rake. For every degree of rake forward you lose 1 degree of caster. Put a digital level on your lower rocker. Most modern "Hot Rods" will have around 2 degrees give or take. Now your stock readings are -2 1/2 to -1 3/4 degrees. You have to try and adjust back to a desired +2 to +3 degrees. See where I'm going? Put them in now, save yourself time and money on wasted alignments.
Doug

 

[hm427donzi]

dvw, I just rebuilt the K-frame on my Belvedere and it's hanging on a stand ready to be re-installed in the car. When I bought my rebuild kit from PST, I asked about the offset bushings and the tech man told me if I wasn't road racing just go with the stock ones. After reading your post do you feel like I may need to dis-assemble and put offset ones in? Thanks.

 

[nm9stheham]

All depends on how you want the car to feel in steering. If you like the more modern steering feedback, where the wheel has a very distinct self-centering action when you turn it even a bit off-center, then you want to go with more caster with the offset bushings. New cars are all pretty much this way and most drivers strongly want the modern steering feedback; the old style drives many people nuts.

The stock steering action of that old day was for very little self centering action. The reason was that the older manual steering box cars took a lot of steering effort and it was hard to sell them to the ladies unless the steering was as light as possible. Designing in near zero caster achieved that but the cost is that there is very little directional feedback in the steering; you turn the wheel slightly to make a steering correction and you feel little to no self-centering action. It made for manual steering box cars that felt like power steering going down the road.

I kept the original alignment specs in my '62 Dart as it is almost 100% original. And I have no issue adjusting to the little or not feedback feel. (I can adjust OK after many years of lots of off road and rally racing, where your steering is very often more by throttle and the steering is more often than not very loose due to the gravel road surfaces.) But it seems like most drivers these days do not like it at all, and never adjust to it. So you likely will prefer the increased caster settings of the offset bushings.

 

[hm427donzi]

nm9stheham, that was a very informative response. I've been driving this car since I was 16 in 1977. I know exactly what you are describing as far as a manual box feeling like power steering going down the road. I actually have always liked that, to me that's how those cars are supposed to feel.

 

[dvw]

dvw, I just rebuilt the K-frame on my Belvedere and it's hanging on a stand ready to be re-installed in the car. When I bought my rebuild kit from PST, I asked about the offset bushings and the tech man told me if I wasn't road racing just go with the stock ones. After reading your post do you feel like I may need to dis-assemble and put offset ones in? Thanks.

I would absolutely install them in the forward location. If you want the "old school" feel you can still set it to the early specs. But I guarantee it'll steer better with more caster. It's a quick , cheap, easy thing to do. You won't be sorry. I've been building Mopar Hot Rods over 40 years. Learned a few tricks along the way. This one has off set bushings, drives great at close to 150 mph. Notice the camber even in the air.
Doug

 

[Lelo 500]

So are 4 offset bushing required? I see kits that include 2 bushings.

 

[hm427donzi]

I think we are talking about 2 bushings in each upper control arm. I will take dvw's advice and change to the offset bushings while everything is out and easier to get to. I can see that it makes since to have more adjustability even if I decide not to use it.

 

[nm9stheham]

Well, you don't get more adjustment once the offset bushings are pressed in place... it is just that you can get more total adjustment if you include where you orient the bushings prior to pressing in. But once the offset bushings are pressed in place at the desired orientation, you have the same range of adjustability as before, just centered across a different range of settings.

(IMO, having a good camber at full droop in a drag car as pictured is not a bad idea for steering when the front is light. But far a street car, that only happens if you put about 15-20 sacks of fertilizer in the trunk. And 0 camber at full droop means a non-stock camber at static height. So don't think offset bushings magically somehow keep camber constant....)

 

[dvw]

Well, you don't get more adjustment once the offset bushings are pressed in place... it is just that you can get more total adjustment if you include where you orient the bushings prior to pressing in. But once the offset bushings are pressed in place at the desired orientation, you have the same range of adjustability as before, just centered across a different range of settings.

(IMO, having a good camber at full droop in a drag car as pictured is not a bad idea for steering when the front is light. But far a street car, that only happens if you put about 15-20 sacks of fertilizer in the trunk. And 0 camber at full droop means a non-stock camber at static height. So don't think offset bushings magically somehow keep camber constant....)

It adds range because you will NEVER use the inside 1/2 of the front cam adjustment with stock bushings. And with proper set-up you'll see my camber at ride height is good as well.
Doug

 

[nm9stheham]

You mean you never will set for +caster? LOL I see your point.....!

I believe you on the camber....but it is not the offset bushing and caster adjustment that does that, correct? And I am curious as to what you did for that. (I think of control arm lengths and angles for that.)

 

[dvw]

You mean you never will set for +caster? LOL I see your point.....!

I believe you on the camber....but it is not the offset bushing and caster adjustment that does that, correct? And I am curious as to what you did for that. (I think of control arm lengths and angles for that.)

Never set for Negative caster.

You are exactly correct, control arm angles. Obviously upper control arms are shorter than lowers. The upper arc is a smaller radius. In my case the control arm is tilted slightly upward. As the suspension starts to droop it gains a slight amount of camber then loses itit as the arms pivot downward. Road race style would like to gain negative camber on the outer whell and positive camber on the inner wheel. All can be achieved. just depends on how much relocation you want to do. For a normal street Hot Rod the bushing are a big step in making the car drive and handle better.
Doug

 

[nm9stheham]

Makes sense. I have a design set up for my Opel rally car that does that: puts a slight upward angle on the UCA; does wonders for putting positive camber on the inside wheel in a turn. Look at the upper control arm angles on an F1 car and it will be the same, for the same reason. Requires a new front end support so I may never get around to building it. And it puts a lot of localized stress on the area supporting the control arms since the pivots get closer together. Glad to see someone else has this implemented for a good reason.