greasing upper control arm ???

[harmony]

While giving the old girl ( '48 Windsor) a grease job, one of the upper control arm grease nipple wouldn't take any grease.  I thought it might just be a matter of removing the nipple and removing some hardened grease, either in the nipple or the end of the upper control arm bar.  Not so.

Fortunately I have a spare assembly out of a parts car I disassembled a few years ago.  So I started to investigate and took it apart to see how it all worked.  To my surprise, it seems like the up and down motion of the control arm assembly is based on the rotation of threads on the upper control arm bar and the end bushing that screws into the ends of it.  The weird thing is that the only way for grease to lubricate the movement is for it to work its way between the threads.  

The end bushing that the grease nipple is threaded into, has threads on the inside of it and on the outside of it.  The inside threads match up to the threads on the end of the control arm bar.  The outside threads on the bushing, threads into the control arm.  

I would have thought that there would be a flat spot on the threads on the control arm bar, so that the grease could easily work its way down the threads.  But not so.

The other interesting thing I found is that the outside threads on the bushings are not conventional threads.  They have a very "soft" low profile thread so to say.  More like rolling hills and valleys than threads.  They don't look like they have been worn this way, but rather manufactured this way.  For whatever reason that is illuding me. 

So once these end bushings are threaded in tight, they move with the control arm.  Obviously the control arm bar is bolted in place.   So the rotational movement of the upper control, which is about 1/4 turn (I'm guessing) is achieved by means of the outer thread of the control arm bar, and the internal thread of the bushing.

 

With all this in mind, I'm thinking I need to unthread the bushing.  I should really take it right out and clean up the threads.  I'm a little concerned about any pressure that is on the assembly.  I'm thinking the way I have it, which is the wheel removed and the car supported by jack stands to the control arm assembly is hanging down.  I'm thinking that that would create a downward force on the control arm, putting a downward force on the top of the control arm bar. So I have wedged between  the bottom of the control arm and the frame.  My thinking is that should relieve any pressure on the bushing as I unthread it.  

 

Any thoughts on that, or contradictions to my way of thinking?

[Ivan_B]

Not sure where the grease is supposed to go in this joint, etc., but if it is stuck, try to take out the zerk and spray some WD 40 in there, a few times. It should go through, eventually. Once it does, grease it to push the old stuff + WD 40 out. Repeat every 1000 miles, or seasonally, to keep things in good condition

Also, the Chrysler master tech video shows the car being greased-up with the wheels in the air. And I suspect that this is the default position (on the lift). On my car, you cannot even reach the rear upper fittings with the car on the ground.

 

If the joint is a complete no go, there are things you can attach to the fitting and hammer on it to push the liquid oil through at high pressure.

 

I just greased my suspension, yesterday. Despite owning a couple classic cars before, this was actually my very first complete grease job ? All of the fittings took the grease right in, and seemed to be well lubricated before. On one hand this is very good, on the other - there was absolutely no change in ride quality, afterwards ?

[harmony]

33 minutes ago, Ivan_B said:

Not sure where the grease is supposed to go in this joint, etc., but if it is stuck, try to take out the zerk and spray some WD 40 in there, a few times. It should go through, eventually. Once it does, grease it to push the old stuff + WD 40 out. Repeat every 1000 miles, or seasonally, to keep things in good condition

Also, the Chrysler master tech video shows the car being greased-up with the wheels in the air. And I suspect that this is the default position (on the lift). On my car, you cannot even reach the rear upper fittings with the car on the ground.

 

If the joint is a complete no go, there are things you can attach to the fitting and hammer on it to push the liquid oil through at high pressure.

 

I just greased my suspension, yesterday. Despite owning a couple classic cars before, this was actually my very first complete grease job ? All of the fittings took the grease right in, and seemed to be well lubricated before. On one hand this is very good, on the other - there was absolutely no change in ride quality, afterwards ?

Once the grease nipple is removed, the distance from the edge of the opening where the grease nipple starts to thread in, to the end of the control arm rod, is about 1/8th of an inch.  In the one picture you can see the end of the control arm rod with a countersunk end to it.  So like I said, the grease goes in the grease nipple and fills that 1/8th inch cavity and then has to work it's way around the threads and eventually it gets pushed out the other side where the dust boot is.  

[Ivan_B]

Yes, I've read that. As you've said, one would expect some grease holes/channels along the threads but, apparently, Chrysler engineers had a different design in mind

[harmony]

 

3 minutes ago, Ivan_B said:

Yes, I've read that. As you've said, one would expect some grease holes/channels along the threads but, apparently, Chrysler engineers had a different design in mind

I would have thought that they would have designed it totally different.  To be honest, I'm surprised that the grease actually flows out the other end when I grease the other nipples.  The grease has to travel at least an inch between the threads before it comes out the other end.  When I thread the bushing on to the control arm rod ( my spare one).  The two thread surfaces are not loose, so you would think the design wouldn't even work. 

I don't really want to heat up the bushing on the one fitting that won't take grease, because I am bound to destroy that rubber dust boot.  I haven't even tried to put a wrench on the bushing yet, to see if it will loosen up.  It probably will, but then I need to decide if I want to take it right out and give it a good cleaning, or just loosen it enough to get some grease flowing through.  At this point, I'm curious why just one is refusing grease.  I suspect that the lower control arm bushings are the same, so that's 8 altogether, 7 of which take grease easily.  Very strange.  

[harmony]

1 minute ago, harmony said:

 

I would have thought that they would have designed it totally different.  To be honest, I'm surprised that the grease actually flows out the other end when I grease the other nipples.  The grease has to travel at least an inch between the threads before it comes out the other end.  When I thread the bushing on to the control arm rod ( my spare one).  The two thread surfaces are not loose, so you would think the design wouldn't even work. 

I don't really want to heat up the bushing on the one fitting that won't take grease, because I am bound to destroy that rubber dust boot.  I haven't even tried to put a wrench on the bushing yet, to see if it will loosen up.  It probably will, but then I need to decide if I want to take it right out and give it a good cleaning, or just loosen it enough to get some grease flowing through.  At this point, I'm curious why just one is refusing grease.  I suspect that the lower control arm bushings are the same, so that's 8 altogether, 7 of which take grease easily.  Very strange.  

Question is, why won't it take grease?  It's functioning just like the opposite end.  The bushing is tight to the control arm, and moves with the control arm when I raise and lower the assembly with a bottle jack.   So that means that the two thread surfaces inside are rotating back and forth or up and down rather, meaning it's not seized, so why won't it take grease?  After I pulled out the nipple I got in that small amount of space with a curved pic, and cleaned out any grease,  then I sprayed it with brake cleaner, and got in there with half a dozen Q-tips and flushed it out again with brake cleaner and air.  So there is no dried grease at the entrance to the threads.  It's a mystery.

[Ivan_B]

Even a tight thread is not completely tight to hold pressurized liquids, etc. Think about all those fittings where we use the thread sealant so that they do not leak... If the grease is not going in, there must be something in its way. Despite the fact that the bushing is still rotating, I can see where the new grease passage could be blocked. I would still try to use light oil to dissolve and wash-out what ever could be stuck in there.

 

Try threading your grease gun directly into the zerk hole to see if you can apply some extra pressure to this joint this way.

Edited January 24 by Ivan_B

[harmony]

5 minutes ago, Ivan_B said:

Even a tight thread is not completely tight to hold pressurized liquids, etc. Think about all those fittings where we use the thread sealant so that they do not leak... If the grease is not going in, there must be something in its way. Despite the fact that the bushing is still rotating, I can see where the new grease passage could be blocked. I would still try to use light oil to dissolve and wash-out what ever could be stuck in there.

 

Try threading your grease gun directly into the zerk hole to see if you can apply some extra pressure to this joint this way.

I just had a thought.  Perhaps the blockage, is at the exiting end, where the dust boot is.  This would give the impression that it isn't taking grease.  When in reality, the threads are actually well greased. 

[Ivan_B]

Technically, the new grease is expected to go in and come out from the other side, pushing the old grease + dirt out of the joint. So, if you push but do not see the grease coming out from anywhere except the zerk or your gun connections, it is not good

[harmony]

Today I got brave and I put a 1 inch box end wrench on the bushing, as it is called in the manual, and then a 3 foot pipe on the end of the wrench and after a couple grunts it came loose.  I loosened it out about a full turn, pumped in some grease.  Only a small amount would go in.  Then I re-tightened up the bushing.  That tightening procedure also forced that small amount of new grease in a little further.  I repeated the procedure a few times and each time loosened the bushing just a little bit further, and I was getting a little bit more fresh grease in there each time.  After awhile the grease was going in and coming out the other end of the dust cover nicely. 

As usual, patience and persistence is the key with these old girls.

[lepic56]

Hi Harmony

 I have the same problem on my 51 Dodge,, I bought a "Grease joint Rejuvenator" on amazon.  did not try it yet,  but sure I will try your way and maybe a mix of both ways to unclogged. One full turn out with the bushing, use to Rejuvenator, screw back-in,  and do it again until it works like new.. lol   Thanks for the information.. 

 

 

[Ivan_B]

If you are going into the joints, etc., just remove, disassemble, and clean them properly

[p15-1948]

From some 1949 literature

[harmony]

17 minutes ago, lepic56 said:

Hi Harmony

 I have the same problem on my 51 Dodge,, I bought a "Grease joint Rejuvenator" on amazon.  did not try it yet,  but sure I will try your way and maybe a mix of both ways to unclogged. One full turn out with the bushing, use to Rejuvenator, screw back-in,  and do it again until it works like new.. lol   Thanks for the information.. 

 

 

Thanks for that info on that rejuvenator tool.  I didn't even know it existed.  Let us know how well it works.

[harmony]

21 minutes ago, p15-1948 said:

From some 1949 literature

Gotta love how Chrysler referred to this method as a "stunt" right there in print.   lol!

[lepic56]

the Bushing  , from 1949 tech bulletins 

[andyd]

A trick to installing grease into these type of bushing is to jack the car up and have the suspension sitting at roughly halfway between its arc, ie, more or less at the same angle it would be when driving down the road.......in theory this position should give enough clearance to get grease into the bushing.........its also worth pointing out that this type of bushing was/is quite common in suspensions of most makes of US cars up to when rubber bushings began to be used, around the late 50's, mid 60's.......I've had arguments with the so called local mechanics over the years when I have to get my 1940 Dodge getting its annual registration check..........sometimes they jack up the car...and find what they think is excess wear ...........o/k.here we go again I say.........lol...........regards from Oz..........andyd