greasing front suspension

[DonaldSmith]

In greasing the front suspension of my 47 DeSoto Suburban, I am confronted with three bad fittings that I am trying to repair.

In the process of working on them, and studying the exploded parts diagram, it is apparent that this design looks unlike the modern independent suspension design.

The bushings are not brass sleeves, but hollow steel, with inner threads that engage threads on the pivot ends, and once these are engaged, outer threads that are cut into arm when a bushing is first installed in the arm. The bushings are torqued into the holes in the arm. So as the arm moves, it must thread itself back and forth on the pivot. Starnge.

And somehow. the grease gets pushed through the gap in the threads, to keep the bushing greased. So here we go:

Lower left arm, front bushing:

The grease fitting pushed into the disk that seals the end of the bushing, so that the grease gun wouldn't fit. Yesterday I removed the bushing. (Huge socket and long bar.)

I tapped the hole and installed a new fitting. But then, the grease leaked out betweeen the disc and the bushing. I removed the bushing and sealed the inside of the joint with hardening gasket sealer. I greased the bushing this morning, and it worked.

Upper right arm, front bushing:

The disc was not seated in the bushing, so it wouldn't take grease. Yesterday, I removed that bushing, staked the disc in place, and put the gasket sealant inside, on the joint.

I tried greasing it this morhing, but grease came out the edges of the disc. At least I worked some grease into the bushing before I reinstalled it. But maybe I'll take another shot at fixing it.

Upper left arm, rear bushing:

This is tight against the inner fender. so the straight fitting is inaccessible. It should not have been a straight fitting. Also, it also looks like the disc is not seated properly.

To get at this one, I'll have to unfasten the pivot bar, which is attached with four bolts. (I'll soon know if there are hidden nuts to find.) I think if I re-attach the bar with the inboard holes of the bar bolted to the outboard holes of the frame, the arm may be out far enough to get a socket wernch on the bushing. We'll see.

Anyone else run into this, trying to grease the front suspension?

Edited June 21, 2009 by DonaldSmith

[TodFitch]

Those threaded bushings were introduced in 1933, not sure when they gave up on the concept and when with something cheaper to produce.

The theory is that there is actually more contact area to take up side thrust than a conventional bushing give as each of the thread sides provides side thrust whereas a conventional bushing gives none and all the side thrust is typically taken up by thrust washers. And, the concept goes, with all the side thrust on the washers they wear faster.

In addition, as the spring/suspension component goes through its range of motion the threaded bushing distributes the grease so the all of the moving parts get lubricated.

Not sure how all of this actually worked in practice, but they can be a PITA to work on.

[Andydodge]

Don, the upper inner zerks should be 90degree, not straight,(btw there are no nuts on the upper inner pivot, just 4 bolts that hold it onto the chassis) , also if you can when the car is up on a stand or whatever with the wheel off to get into the zerks, try and jack the actual suspension up a little to take the load off the pin/bush fitting and that may allow a little more space between the pin/bush to let grease in.........greasing these is SO MUCH FUN........lol........regards, andyd

[DonaldSmith]

I got the upper rear bushing out (by temporarily bolting the pivot outboard, using two of the four holes). I re-staked the disc in the bushing, and replaced the straight fitting with a 45 degree. (It should be accessible enough.) I'll let the hardening gasket sealer set overnight, and try greasing the fitting tomorrow.

I'll try jacking up the arms some, to let the grease get in the threads more easily.

Next, I have to check out the tie rods. One of them clicks. Maybe I'll take each tie rod off, record the center-to-center distance to the ends, and take them somewhere to have the ends matched up with new. Actually, three of the ends may be OK, except the grease seals are shot. Anyone sell new grease seals, or have some magic duct tape that will keep the weather out?

[Andydodge]

Don, I bought some tie rod end rubber seals from Andy Bernbaum, they were only a couple of dollars from memory........andyd

[n1gzd_plymouth]

by the way, I recently got an electric grease gun. It is so much easier for me to use that (I have small hands and with traditional grease gun it always seemed like i needed three hands). How I can do it with two easily. I recommend it.

Rebecca

[DonaldSmith]

My tie rod ends were fine. I got some dust boots at a local auto parts store. All together now.

[greg g]

Soometimes a little heat will free up the old grease enough to allow the new stuff to go in and push the old stuff. Shoudn't need a torch hair dryer or heat gun should be sufficient.