There has been a fair bit of discussion lately about the use of Urethane bushes in front beams.
As I have recently scored a few Ball Joint beams for reconditioning I thought a thread on this topic was in order.
There is quite a few who wish they had never gone away from needle rollers and others who claim they are fine if installed correctly.
What are your thoughts?

Nolathane is okay in it's place IMHO.
But it is not always the answer for every application.
And is often installed incorrectly, adding to the grief.

I guess, if I was starting with a newly fabricated beam then I would be using nolathane.
I would assume that most of them are manufactured to suit.

Does the Nolathane bush replace both the inner and outer needle roller bearing too?
Or do you need the inner bush as well?
If you eliminate the inner bush then the grease is going to fill the whole beam before lubricating the outer bush.
That's a heck of a lot of grease, folks.
It's gonna make a mess, surely!

I'm not 100% sure without checking My Manuals, but I would presume there are two sets of needle roller bearings for each suspension arm..
and they do Hold some grease too.. I just filled one up when replacing a front end..
so, that would mean one roller and one nolathane Urethane bush on each side...??
Needle roller bearings are an excellent bearing that can withstand all the ups & downs in a front end for over 40 years.

they do need the grease as recommended by VW though
Lithium based MOLY Grease..
Urethane bushes are NOT that hard and are more flexible than needle rollers which have no flexibility at all.

so, You have one soft urethane bush and one very hard needle roller bearing.. ??

I don't know if the grease can get past the urethane bush??
and urethane doesn't twist... [like rubber]
so, no grease until they start wearing put ???

I don't like them and I haven't evened opened the packet yet...

My thoughts

LEE

Maybe You replace Both needle rollers...?? still BAD..

I am no expert however I know the inner bearing is not a needle, it is called Micarta. It is really a bush. You can leave the Micarta bearings in and just have urethane to replace the rollers or you can get a urethane bearing that is a long tube which replaces both the needles and the Micarta.
I have just been advised to use needle roller bearings rather than urethane by an experienced VW shop when I get Avis adjusters welded in to a stock beam. There is another post on here where it was explained that the urethane need to be reamed to work correctly. If you were building a new beam, by far the easiest method would be the long urethane which also use a different type of grease as well as far as I am aware.
It will be interesting to hear from urethane users though because urethane does make a very good bearing/bush according to a suspension specialist I deal with for my 4by
Cheers.Wayne

The needle bearing have less resistance than the urathane and will move more freely under load resaulting in a better ride, i replaced the inner and outer bearings on my early beetle front end with some silicon aluminium bronze bushes the i machined up to suit, these also worked with the car still riding well, i would not use the urathane as it does not have the characteristic's of the bearing you are replacing and will always have more stiction.

If longevity is the key, then take it from Frog my baja, yesterday discovered that teh shimmy in teh front end was from dead Urethane front torsion bar bush (empi brand). It just got that distorted that it allows movement of the torsion arm in the beam and thus doesn't hold the torsion arm firm. Scary when i jacked up the wheel and found out. (was the lower passenger side bush). It was properly and regularly greased too.

The bloody bushes only saw 12 months of the road, and hadn't even had a hardcore offroad trip yet. I'm going back to needle bearings. I'm sick of repeating work due to crap aftermarket parts, particularly if the needle bearings can last 40 years, compared to the 12 months out of the urethane.

Lee, that's my point. It makes a very good bearing because it doesn't flex much, but if you need some compliance like in a shocker bushing, it creates a lot of harshness. Some people with 4by's reckon that is good, but not me.
Used in a beam, it is not supposed to be compliant, so it works ok, but will, like any bearing, require lube

Yes I agree especially the lubrication
otherwise it cannot work

Lee

sent from My Samsung Galaxy

I'm running delrin bushes. Just too add more. " what ifs" to this discussion

and you're right, micata is more of a bush, looks, feels and works like bakerlite. not sure if you can even buy it anymore? I like needles, except if the rolling surfaces of your arms are worn, in with case reaming bushes to suit the current size of those surfaces may bring a better result. even if they do need replacing more often.

I really like the full bronze bushes idea, becuase delrin is brittle, very little resistance though. i swear i have broken one already

YIKES
haven't heard of Delrin for many years..
and have never heard of the inner VW bush material
but know what bakelite was and looked like..

[bakelite was used as the rubbing block on points years ago]

[nolathane]
and if its not rubber like the originals it needs lubrication

cheers

LEE

I don't know why so many people seem to think that they know better than the VW engineers who spent years designing it in the first place. If the standard beam setup works, why change it?

100% correct, the urathane might seem a easy option but is not the correct choice of material for the job it needs to do.

i have always used delrin (trade name acetal ) for all the beams i have done and i think it is the best for this application
you can finish the id/od to size and press it in to give you about .i5mm clearance on the arm
the only critical thing is to have a seal on the outside to stop shit getting in and use a good grease(moly or a teflon based)
leave the micata bush if it is ok, if not put a delrin bush in
acetal is an engineering plastic designed for making bushes although there is some others but they are quite expensive

No urethane for me.
100% needle rollers and fabbed internal if necessary.

Thanks, Matt.
What you say is where i am heading.
I'll put some pic's up shortly.

Those nice RED colored Nolathane bushes in the clear packets look so good...

and they weren't designed over 40- 50+ years ago....

so these NEW HEAVY DUTY bushes MUST be the best....


Well not for this little black duck...

LEE

Here is a picture of a beam with the outer nedle rollers removed.
No surprises there.

1/ Same beam cut behind the inner bushes with the metal bush removed.
2/ Note the plastic bush that mounts the metal bush still in place inside the beam.
3/ The inner metal bush.

thanks for the pics

Lee

This is a pic of two worn trailing arms.
The one on the left has flat spots from the needle rollers (not that common).
The one on the right has wear from the inner bush (common occurrence).

Neither would be reusable with OEM bearings.
Nolathane would be able to be used here as it supports over a larger area.
The wear spots wil actually help lubrication by trapping grease.

Checking the bushes of a rebuilder beam.

The trailing arm is lightly greased and installed in the beam without the springpack.
Make sure the arm is in roughly the position when driving - this is where the wear occurs.
Hold the trailing arm where the grease seal sits and move the balljoint back and forth.
I am using the edge of the table for reference to the shock mount bolt.
No movement felt = good.

Slight movement (less than say 0.5 mm) = potential problem. Try to differentiate between inner and outer movement.

If the needle roller and load surface on the trailing arm look ok then they probably are.
The movement is most likely the inner bush
Probably not worth pursuing. Grease it up and drive it!

Too much movement (2 mm or more) = repair time.
If the inner trailing arm load surface is torn up, then the slipper bush will probably be in the same condition.

I believe that these bushes are torn up when a previous owner has driven a long time without lubrication.
Correctly lubricated. the OEM system will last almost indefinitely.

The beam above measured up as;

LH upper and LH lower trailing arms, no movement detected.

RH lower trailing arm showed about 1.5 - 2 mm.
More than I would like but if it was the only problem i would probably live with it. Especially as it is on the right.

RH upper arm showed 3 to 4 mm movement.
No good in anyones eyes, I am sure.

So I am looking to remove both RH needle rollers ( and reuse them if possible) and make two Delrin (or similar) replacement inner bushes.
The lower arm will be okay to reuse but the upper arm is shot. That's the one pictured here (and earlier).

Thanks Lucky Phil for all the great photos and information. I now understand a lot better how my Bug beam all fits together and what to look for when I pull the beam apart to get Avis adjusters welded in
Cheers....Wayne

You are welcome Wayne. Stay tuned - there should be plenty of good stuff to follow.

Not everyone is fortunate enough to come into a bent beam to slice up.
I don't think I could have ruined a good beam just for a look inside.

Here's a pic of the needle rollers out.
They took a bit of a dent on the inside from the slide hammer, but they are okay to use again.

Great pics and info for everyone. Some points to note is that while all ball-joint beams are like this (and type 3 although they are different sizes), king-link early beams have no needle rollers at all, just the plastic/bakelite material for inner and outer bearings, although the outer can be replaced with the needle bearing as the OD's are the same, and then the later king-link '62(?)-'67 was needle outer.
It's also important to note the way the factory tooling worked. The inner bushes are small on the ID, this is because the inside of the beam is not true dimensionally, that is, it's not a machined accurate bore, so the bushes get pressed in and then reamed to size so the hole is accurate. The reamer uses the internal torsion bar location in the centre of the beam and the needle roller location at the outside of the beam as guides to ream the bushes true to the beam.