UCA pivot bar removal

[Raindem]

Hi all.  Have a question on my 1973 UCA.  Once it is removed from the vehicle, how do you get the pivot bar out?  I'm going to be changing the bushings, which seem simple enough to press out.  But before I can get it positioned into my press the bar has to come out.  The wide sections where the bolts go through appear too big to pass through the outer metal bushing sleeve.  When I did the LCAs the pivot shaft was easy to press out.  But on the upper, it just doesn't look like it has the clearance. 

I did search, btw.  All the posts on UCA bushing I found assumed the bar had already been removed.

Thanks

Curt

[Raindem]

I've been doing some more searching and can't find any good info on this.  All the examples of UCA bushing replacement either show the pivot rod already removed, or more commonly they show the type of UCA with pivot studs, not the full length bar.

So I'll start cracking away at it tomorrow.  First I'll remove the rubber and see if the rod slips through the outer sleeve.  If that don't work we'll see.  Any suggestions are welcome.

[redgum78]

Hey Raindem,

I did my 73 a couple years ago. From what I remember you are correct. The pivot bar will not pass through the bushes in either direction. From what I recall you need to remove at least one of the bushes with the pivot bar in place. I think even then it wont pass through the UCA. You have to push it through the hole left from the removed bush as far as it will go, then cock it to the side and slide it back out the other way (may even have to part remove the other bush as well). To remove the first one I think I made up a basic jig and pressed on the pivot bar which then pushes on the opposite bush.

Make sure you do the reverse (have the pivot bar in place) when you press the bushes back in otherwise you wont get the pivot bar back in!

If you get stuck I might have a photo somewhere.

[Raindem]

Thanks for the info, redgum.  I managed to get one of the UCA's disassembled today by using the pivot bar as a driver.  It wasn't too bad once you get a method down.

First, remove the hardware from the ends of the pivot bar.  Then, assemble a bolt, nut, and 2 large washers (one on each side) through one of the pivot bar mounting holes.  The thick washers from the ends of the pivot bar work good for this, as do the stud and bolt from the mounting plate.  I put the A-arm into the press with the bolt/nut/washer side down and pressed on the opposite end.  The pivot bar will slide in the bushings and the large washers will seat against the inner shoulder of the bushing shell.  Keep pressing and it pops it loose.  You can get the bushing half way out with this method.

To get it all of the way out, remove it from the press and clamp the pivot bar in a vise.  I used a generic gear puller to grip the outer shoulder and pull the bushing the rest of the way out.  At that point the A-arm wasn't gripping it very much and it came out easy.

The pivot bar can now be withdrawn.  I just pulled it back and inserted a large washer on the end.  Then I put it back in the press and used the pivot bar to drive out the other bushing.

At this point the inner bushing sleeves will be stuck on the pivot bar.  I noticed they were already split so it wouldn't be difficult to chisel them off.  However, I happened to have a HF bearing splitter set laying around and used that to pull off the inner sleeves.

If anyone needs photos let me know before tomorrow.  I'll be doing the other UCA.

[redgum78]

Thanks for the info, redgum.  I managed to get one of the UCA's disassembled today by using the pivot bar as a driver.  It wasn't too bad once you get a method down.

First, remove the hardware from the ends of the pivot bar.  Then, assemble a bolt, nut, and 2 large washers (one on each side) through one of the pivot bar mounting holes.  The thick washers from the ends of the pivot bar work good for this, as do the stud and bolt from the mounting plate.  I put the A-arm into the press with the bolt/nut/washer side down and pressed on the opposite end.  The pivot bar will slide in the bushings and the large washers will seat against the inner shoulder of the bushing shell.  Keep pressing and it pops it loose.  You can get the bushing half way out with this method.

To get it all of the way out, remove it from the press and clamp the pivot bar in a vise.  I used a generic gear puller to grip the outer shoulder and pull the bushing the rest of the way out.  At that point the A-arm wasn't gripping it very much and it came out easy.

The pivot bar can now be withdrawn.  I just pulled it back and inserted a large washer on the end.  Then I put it back in the press and used the pivot bar to drive out the other bushing.

At this point the inner bushing sleeves will be stuck on the pivot bar.  I noticed they were already split so it wouldn't be difficult to chisel them off.  However, I happened to have a HF bearing splitter set laying around and used that to pull off the inner sleeves.

If anyone needs photos let me know before tomorrow.  I'll be doing the other UCA.

Yep that sounds a bit familiar. It was a while ago when I did mine but I do recall a bit of chisel action along with getting the bush half way out then having to change methods the remove it the rest of the way. As you say the first one takes more time but the 2nd one comes out easier once you know how. Glad you got it sorted!
As you have to do an alignment I have a thread on here somewhere that might help with camber/caster set up for 73/74. I will see if I can find it. Basically you want as much positive caster as possible while maintaining some negative camber (1 degree negative camber would be ideal but anything over 0.5 is ok). It is hard to achieve this on the cam style UCAs but our 73/74 slotted UCA adjustment seem to allow a bit more range. My 73 had terrible under steer and bump steer issues. New bushes, some positive caster and negative camber made it a different car to drive. My next job is solid K frame isolators.

[redgum78]

http://www.dodgecharger.com/forum/index.php/topic,122804.0.html


May be of some help for your alignment.

[Raindem]

Thanks for the link.  I plan to pick up some basic DiY alignment tools when the time comes.

So the slotted adjustment is for camber or castor?  The way it is oriented to the k-frame it almost looks like it would affect toe.

Curt

[redgum78]

Thanks for the link.  I plan to pick up some basic DiY alignment tools when the time comes.

So the slotted adjustment is for camber or castor?  The way it is oriented to the k-frame it almost looks like it would affect toe.

Curt

You want to get your ride hight set first as changing that later will effect everything.
Then set camber and castor by adjusting where the pivot bar sits on the slots. Last adjust the toe.
If you do it in any other order your previous adjustments will change.
So to best answer your question- the slotted UCA adjustment is for camber and castor not for setting toe. However they will effect toe if you change them.

Think of it like this, moving the rear of the pivot bar in towards the motor will move the UCR in (which increase negative camber although most likely not enough) and back towards the rear of the car (increasing positive castor). So this is a good starting point as you want to start with Max castor.
You will probably find though in this position you will still have positive camber (wheels wider at the top which is bad).
To get negative camber you will need to move the pivot bar in at the front until you have the correct amount of negative camber. Of course the problem with this is that it also moves the UCA forward and thus reduces your positive castor. This is the tricky bit, getting enough negative camber while maintaining positive caster and keeping it even on both sides.
Once you have managed to do that the toe is easy, just adjust it to anywhere between 1mm to 0mm toe in at the front using the tie rod arm adjusters. A tiny amount of front toe is good as the wheels tend to flare out a little when driving. Also adjust toe in a manner that keeps the steering wheel central.

Until I did my front end I didn't really understand the advantage of tubular UCA upgrades. Now I do! It gives you the ability to add castor (lots of castor) and still have negative camber.

The obvious question for me after all this was why did the factory set up their front ends with the inability to to get good camber/castor figures.
Best answers I could turn up was the following;
Camber- Bias ply tires did not flex in the side wall and therefore couldn't handle much negative camber. Once radial tires became common place it took a while before manufactures took advantage of the added tire wall flex and handling improvements of negative camber.

Castor-Positive castor helps keep a vehicle travelling straight and also will auto correct a car to the straight ahead position (if caster is equal on both sides). However castor also makes steering heavy, very heavy if it is moving slowly. So to the detriment of handling cars did not have much caster as it made parking the thing a little easier. Once power steering became common it was less of an issue but again I suspect it took a few years before manufactures castor habits changed.

I am a truck mechanic not an alignment expert but I did research this and learnt a lot when I did mine. I am sure if I have got anything wrong someone will jump in and correct me.

[Raindem]

Thanks for the info.  I've always considered alignments a voodoo science and wouldn't go near it.  But I'll give it a shot when I get everything back together.

[alfaitalia]

I used to think that but there really is not a lot to it. I own a camber gauge, a tracking gauge (for toe) and a caster gauge...so I don't venture near the alignment shop at all! All those simple tools were picked up dirt cheap on the bay of E...I had to wait a bit but they showed up eventually!

[redgum78]

It is definitely worth taking the time to learn how to set up and align IMO.
If you know a good alignment shop that is much easier but a good shop and tech is not always easy to find. I decided to tool up and do it myself after I had an alignment done and asked the guy what he set the caster at. He told me it was not adjustable!