How do you know when it's torsion bar time?

[69B5]

I have a 69 RT and it seems the front end is worn, ball joints very much so

I was going to redo the front end and was just going to replace it with the stock RT size torsion bars, .92 same as what I assume must be on it just to know the front end is set and straight

However......as I start adding up my budget sheets, it would seem it wise not to spend on anything needlessly, since I have a long to do list besides the front end

Is there anyway to know if the bars should be replaced? Also, oddly the .96 (I assume larger bars) are ever so slightly less then the .92. Has anyone gone from the .92 to the .96, and if so, was it a more bone jarring experience?

Also, do people change upper control arms "just because" also?

Appreciate your input

[303 Mopar]

Beside looking at your worn parts, what are the issues of your front end that is causing you to want to rebuild?  Most torsion bars do not "need" to be replaced but if you do I would highly suggest going big like 1.10 Hotchkis or Firm Feel bars. Chances are you need to look at your ball joints, bushings, etc.  You should check your UCA and LCA to make sure they are not cracked, but again unless you are doing some serious slalom track time you don't need to replace them.  I would also look at your steering linkage.

[69B5]

Well I took it to a front end shop and they said the whole thing looked original to them, like 50 years old. They said while they could do just the ball joints, if they did, they would expect the next thing to fail, then the next then the next so they said just bite the bullet and do it all. Of course, they are in sales at this place it's a chain and they make commission

Car seems to sit OK but the front wheels were bowed where the bottoms stuck crazy out like Red Foxx the actor from Sanford and Sons.

I may have body stress on the car from a past accident, and the car being raced, would larger torsion bars put more stress on the unibody?

I was thinking about new control arms, the ones I was looking at always has some parts installed on them but really I was planning to use the Moog  

[green69rt]

You can do some simple tests to see if stuff needs replacement.  On some things, all you can do is look and make a guess.  
Ball joints may be hard to check without a dial indicator.  In the old days, mechanics would put the car in the air, yank the tires around from side to side and announce the ball joints needed replacement.  That was a load of .......!   You need a dial indicator to see if the ball joints are worn.  

Do look at all the rubber on ball joints, bushings, strut rods, tie rod ends and anything else.  If they are torn, cracked or missing then chances are that joint needs replacement.

Look at the place where the strut rods go thru the k-member.  That is common failure point.  You might see that the k-member around the strut rod end is cracked or torn.  This is a major repair!

Finally remember that the original suspension on these cars was pretty mushy and loose.  So don't expect a lot from a few replacements with factory grade stuff, it will help, just not enough to make it drive like you wife's Toyota.


I know you said that there are other priorities now but here's what can really make a diff if you want to really upgrade the suspension if you want.

Offset bushings on the upper control arm and then a more modern alignment spec.  Old specs were for bias tires vs modern radials.

For the TBs, go BIG.  Unless you want to maintain originality then go 1.00 inches or bigger.  If you want to stay with the originals then you can send you original TBs to Firm Feel and they will heat treat and restore yours for a fee.

Shocks, shocks, shocks.

There are simple fixes for the steering box that go all the way from cheap (pressure adjust) to total replacement with an after market unit such as Borgenson (sp?)

Front sway bar is the same.  Go original or after market such as Hotchkiss.  

Now you start to get into some items that really require a total removal of the front suspension and that's a big subject on here with lots of advice and opinions.

Now, I'm sure that others will chime in.

[Mike DC]

 
I went from stock 0.90 bars to 0.96 bars and the difference was pretty minor.  0.96 certainly won't be any big jump from 0.92 bars. 
 
But if you're thinking of going any bigger, bear in mind that the stiffness ramps up more dramatically as the bars get thicker.  1.00" bars are about 140% as stiff as 0.92 bars.  1.10" bars would be twice as stiff as 0.92" bars. 

[green69rt]

Mike makes a valid point.

Here's a seller with some stiffness info....

http://www.firmfeel.com/b_body_mopar_torsion_bars.html

[c00nhunterjoe]

If you are rebuilding the front end and already pinching pennies... may want to sit back and start saving up. We are talking 50 year old parts and debating over spending 200 bucks.
  If this is an accurate resto- put the stock parts in.
If this is a spirited cruiser, 1.0 bars and new tubular uppers for inreased caster. Im not a fan of using the offset bushings.

[69B5]

If it's a good idea to replace them as they may need 50 year old parts, them I'm all for changing them out

Being aware they CAN wear, they are getting swapped

[green69rt]

If you are rebuilding the front end and already pinching pennies... may want to sit back and start saving up. We are talking 50 year old parts and debating over spending 200 bucks.
  If this is an accurate resto- put the stock parts in.
If this is a spirited cruiser, 1.0 bars and new tubular uppers for inreased caster. Im not a fan of using the offset bushings.

Just a little hijack.  Why no offset bushings.  I already have them installed so.....?

[c00nhunterjoe]

Because its the same stock dimension steel insert with an inner ring that has been molded offset in the rubber to within the ragged edge of metal on metal contact when brand new and uncompressed. Some love it, i do not.

[green69rt]

Because its the same stock dimension steel insert with an inner ring that has been molded offset in the rubber to within the ragged edge of metal on metal contact when brand new and uncompressed. Some love it, i do not.

 So, A better solution might be to buy UCAs with more castor designed in instead of the bushings?  I can see that.  Any UCA's for our cars designed with more castor?  I only saw tubular Adjustable UCA's but those, usually, had those funny joints (Heim?) which some people recommended against, not to mention costing a lot.

Edit: just took a quick look at Firm Feel and they have them in tubular style with stock type bushings but still pretty pricey.   

[Ryan.C]

I have a set of firm feel tubular UCA's and PST 1.03 torsion bars these parts completely changed the handling of the car. For the better I should say, worth every penny. 

[ODZKing]

I've been told. torsion bars are either broken or not. However, they say that if you replace one side the other side is not far behind to break.
Just what I have been told. 

[Mike DC]

 
IIRC they sag down and lose their height, not their spring rate.  If you can still adjust them high enough (and you still like the stock stiffness) then they're usable. 


They break when they get damaged.  Nicked/gouged.  A crack starts to grow at the damage point until it snaps.  Coil springs are prone to the same problem, they just don't break as often because they don't get struck as often.  Coils are tucked up away from road debris unlike torsion bars.

If you find any minor shallow nicks/gouges on your T-bars, polish them down smooth.  (It's the same principle as drilling holes at the ends of a crack to prevent it from growing.)  If you find any bigger knocks in them, replace them. 

[b5blue]

  IMO just do a simple overhaul, new aftermarket UCA's come with ball joint and bushings installed. (Just be sure to check, some complained of loose parts, mine were fine.)  New strut rod and LCA bushings with Lower ball joints. RR as needed tie rods and pivot parts. The reason to do now is alignment, I just shelled out 88.00. You'll need alignment after fixing most of what I listed so pay for that one time and keep the car safe while protecting the front tires.
  Most rubber parts of bushings have failed and are gone a lot sooner than expected, I've seen T-Bars cranked pretty far to compensate for rotted bushings. If money is tight reuse T-Bars and get 4 new Monroe Matic's from Rockauto for 60.00 delivered if your shocks kinda crappy. This way your driving sooner safely.     

[69B5]

Well I am now approaching the car like I am keeping it forever (and I might)

What I got thus far is from Mancini Racing  (they are local here)

* largest Mopar torsion bars they had, which was .96 (apparently .92 was stock)
* B body full front end rebuild kit, MOOG
* The arms for the steering not in the kit (since it is drive train specific)
* I had to get the sway bar center bushings form Energy as MOOG only sells the ends now
* Bliesten shocks from PST
* manual drums to power disc brake conversion kit, not a giant sized kit
* I found a screaming deal on used 2 piece American Racing Custom Shop rims, custom set up for B body 15" in case I can't get the Magnums on after the brakes (and they said don't count on it)

....and I have been buying other parts not related to this, like headlight parts, etc

This should keep us chewing on it for sometime, as we look to beg or borrow tools, etc. BUt all the while I will sell it, at a decent loss, with the trunk full of parts as I am borrowing time from nowhere to do this work

Wish it was easier to post pics, I'd do so, I am old and not computer savoy. I just take them off my phone and this site won't take them.  Thank God for this forum, and the great people behind it  but the file sizes seem to be from the dial up AOL days. I like this site best (um.... B Bodies Only) but I am not sure why you can upload whatever you want there but not here. I 'll need to find a kid to figure out how to do it  

[Kern Dog]

"   How do you know when it's torsion bar time?"
When your torsion bars measure UNDER 1 inch !

[Vegas_Nick]

My personal opinion is do a full front end rebuild including the torsion bars. I cannot say enough about the guys at Firmfeel and their help in building up my front end. Everything is new from the start. Do it that way and chances are you won't replace another part in your lifetime.

Here is a little article about the one that I just did.

http://ratrageous.com/building-a-race-car-for-the-road/k-member-and-front-suspension-build/

[Nacho-RT74]

straight to the question:

when you can't set anymore the correct ride height without get the adjusting bolt allmost fully in.

after that you can get performance upgrades.