Gabriel Rotary Shocks

[Stevemo]

Hi All,

  I am getting ready to do the frame work on my car and I've decided to start with the rotary shocks.  As it turns out nobody seems to have posted much of anything on the Gabriel rotary shocks so I thought I'd start a thread.

  The outer assembly is fairly basic.  There is a nut and star washer holding on a lever arm.  Behind that you will find a dirt shield and a spring to keep dirt from damaging the leather seal and the shaft.

  I took some basic measurements on the shock shaft as follows for a Hupmobile 417W:

• Seal Depth, max would be 0.420", depth could be less or even higher if allowed to stick out
• Seal OD, 1.141", this value cannot be expanded by very much
• Shaft OD, 0.870", shaft will require a sleeve

  It seems like the seal OD is the real limitation.  If anybody knows the part # for the seal that Apple Hydraulic installs in these shocks please let me know.  Their prices for servicing 4 shocks is simply out of reach for many people.

 

  What are people using for fluid in these?  I read that people are using Mobil 15w50 in the Houdaille's.

http://phscollectorcarworld.blogspot.ca/2015/03/tech-series-houdaille-hydraulic-shock.html

 

Thanks, Steve

Edited March 8, 2016 by Stevemo (see edit history)

[Stevemo]

Alright, progress is slow but steady.

 

I am including some information but it is tailored around fixing leaking seals.  If your shocks have not had water get into them they should be pretty easy to maintain.

 

Disassembly:

• Remove plug from shock;
• Lightly seat the adjustment screw under the plug, count how many turns it took and write down the value (front and rear shocks will have different settings);
• Drain the shock into a container so you can attempt to measure the amount of fluid and use it to compare viscosity with other fluids;
• Index the location of the lever to the splined shaft by stamping them with dots;
• Hit the hub with the flats around the edge with a hammer a few times to loosen it up, it is actually a large threaded retaining ring. 
• Remove the retaining ring with a large pair of oil filter pliers;
• Pull on the shaft with enough force to dislodge the face of the shock from the body (probably best done with a slide hammer); and
• Make note of the alignment within the shock, you will notice the shaft and cap are keyed to the body of the shock and cannot be assembled improperly.

Inspection:

• Inspect the tightness of the shaft to its rotating points.  There is a blind hole in the back of the body and one through the cap and they should not have any slop;
  • These could be repaired by installing bushings and machining the shaft to suit;
• Inspect the counterweight like assembly and how it fits against the body of the shock.  I suppose this could be checked with a feeler gauge;
• Take the adjustment screw out and inspect the orifice mechanics for anything unusual; and
• Clean everything up with your solvent of choice.

Parts:

• Seal, SKF 8620, this seal is a bit of a compromise in that it is a couple thousandths small on the OD so it may need to be held in with LocTite; 
  • http://www.skf.com/ca/en/products/seals/industrial-seals/power-transmission-seals/radial-shaft-seals-pt/index.html?designation=8620&unit=imperialUnit
• Quad-ring (similar to a square-ring but more common), Size 4-041 or 4041, 3.000 x 3.125 x 0.070"; and
  • http://o-ring.info/en/technical manual/ERIKS - Technical Manual - Quad-rings.pdf
• Fluid, TBD, I need to do some experimenting.

Reassembly:

• Lubricate the shaft with the fluid you are going to use and drop it in to position;
• Lubricate the quad-ring and stretch it over the cap;
• Install cap;
• Install threaded retaining ring;
• Install lever according to index markings you made;
• Mount shock on car but do not hook up linkage;
• Adjust screw as per findings during disassembly;
• Fill shock to bottom of filler hole and actuate shock several times, refill and repeat
• Install plug; and
• Hook up linkage.

I have not gotten to the point of reassembly yet.  The groove in the shaft where the leather seal used to be may interfere with the lip of the modern seal being installed.  If this occurs the groove may need to be filled in with epoxy and then covered with a Speedi-sleeve.  The Speedi-sleeve to go with the seal is SKF 99087.  http://www.skf.com/ph/products/seals/industrial-seals/power-transmission-seals/wear-seals-skf-speedi-sleeve/index.html?designation=99087&unit=imperialUnit

 

Cheers, Steve

[Stevemo]

Here are some photos, these shocks are amazing devices internally.  There is actually a bi-metallic strip to adjust the shock piston based on temperature.

 

As expected, the seal is loose externally.  I need to get some epoxy to get it to hold in the housing.

 

I also found that the adjustment screw passes through a leather seal.  I did not replace this as it is hard to get to but I think it will be OK.

 

Steve

[30 Hupp]

Interesting thread! Good Luck!!