Shocks/Dampers rebuilding (Questions)

[CFritz7001@aol.com]

I'm in the process of rebuilding a Girling shock absorber/damper, (my first attempt at this.) I've removed the recuperation chamber, the end plugs (caps), and the domed plug in the side of the body, but have not pressed out operating shaft, so the piston(s)are still in place. While cleaning out the gunk from the interior, I found the mangled & broken fragments of at least three spring clips (horse-shoe-shaped items that we call "circlips" here in the US --- I don't know what they are called in the UK and elsewhere). The cross-section drawings I've seen do not show any circlips, as far as I can see. My questions are these: 1) Where could these circlips have been located? How many total? 2) Is there another one somewhere which did not break & fall out? 3) Can or should I proceed to press out the operating shaft & its lever arm, or is there still another circlip (or fragments of one) that must be extracted before this pressing can be done without damaging something? Any suggestions will be much appreciated. Carl Friz TC 6756 Gainesville, Florida

[C. Knight]

CFritz7001@aol.com wrote:

> > I'm in the process of rebuilding a Girling shock absorber/damper, (my > first attempt at this.) I've removed the recuperation chamber, the end plugs > (caps), and the domed plug in the side of the body, but have not pressed out > operating shaft, so the piston(s)are still in place........ > My questions are these: > 1) Where could these circlips have been located? How many total?

The circlips hold the recuperation valves and the metering valve in the piston assembly. Sorry I can't remember the number or exact configuration.

> 2) Is there another one somewhere which did not break & fall out?

Probably, but as far as I can remember they should all be attached to the piston assembly which can be slid out after you have pushed the lever arm out.

> 3) Can or should I proceed to press out the operating shaft & its lever > arm, or is there still another circlip (or fragments of one) that must be > extracted before this pressing can be done without damaging something?

Yes you should be able to press the lever arm shaft, complete with the lever arm, from the "core plug" hole. There should be no circlips on that shaft. The shaft seal is not available (in the UK) so you may have to improvise with a modern seal and a re machined housing when you rebuild. We also call them circlips in the UK. Best wishes Cliff Knight

[Jorolibb@aol.com]

Carl, If I remember correctly, there should be an excellent article in the technical section in the TABC website on rebuilding the shocks along with pictures and seal info. If you can't find it, let me know and I will mail you copies. John Libbert J2 3118 TC 2138 MGA 70528

[Roger Furneaux]

Re: [mg-tabc] Shocks/Dampers rebuilding (Questions) Hi Carl - there is also a very good article in the latest "Sacred Octagon", pp. 29-34 by T.J. van Parys. He says nothing about the innards (obviously his were good) but has good detail on replacement seals. BTW, I belong to the NEMGTR solely for the benefit of receiving TSO (along with only 18 others in the UK, one of whom is a certain Barry Walker - now I wonder why he is interested, if it is not for the Cars & Spares section, although the $ is rather too strong against the British Pound, although that could always change!) oc[b]T[/b]agonally Roger Furneaux John Libbert also wrote:

[quote]Carl, If I remember correctly, there should be an excellent article in the technical section in the TABC website on rebuilding the shocks along with pictures and seal info. If you can't find it, let me know and I will mail you copies.

[/quote]

[DAI]

Hi Carl, By a happy coincidence I have been reworking my dampers all weekend. The article on the T-BAC special files site, by Terrance J. Van Parys is an excellent start. I followed most of what Terrance wrote, but I may add some additional text for those who wish to fully dismantle the dampers. The circlips you refer to are shown in one of the rare cross-section figures of a damper and it is in the Brown book. You will note that the circlip is shown located between the two pistons. There are lots of tiny arrows that help the reader understand the fluid mechanics of the damper when operated. The circlips orientation, and that of the pistons themselves are important and can be determined from the Brown book. Regarding the core plug - I removed this by drilling several 5mm diameter holes through the plug in a horizontal line, such that with 4 holes, the diameter of the plug was compromised in strength and can be levered out. Under the plug is a red/maroon coloured seal (as per Terrance's article). There is nothing else holding the shaft in place. The shaft is an interference fit only, between the splines of the lever shaft and the actuator arm that moves the pair of pistons internally. I did not use a machine shop to press the shaft out. Rather, I used a 6 inch vice and an arrangement of two old shackle bolts (with nuts attached) positioned one over each damper mounting hole and a small socket to fit over the shaft end (as revealed under the core plug. By application of the vice, this provides thrust directly along the lever shaft. I was concerned about the bending moment when tightening the vice, so applied additional lifting force by driving wedges in the ~4mm gap between the lever arm and the damper body. Two such wedges, plus the pressure from the vice (all coordinated - need 3 hands!) was sufficient to safely drive the shaft out. Once free, the actuating arm inside the damper and between the pistons can be extracted. Then with the end caps also unscrewed, the piston assembly can be withdrawn complete. Please note the orientation of the piston assembly - there is a 'way-upness' to them. Also note, that the circlip has a way-upness as well (see Brown book). There are 4 circlips - in two pairs, arranged with one pair on either side of the piston pair, joining them in the center and either side of the actuating arm. Further, there is a thin rectangular plate that is trapped underneith each pair of circlips on either side of the actuating arm to provide a separation limit between the pistons. The circlips provide a thrust pulling the piston towards the actuating arm. Once the pistons are removed, each has a valve at its end. There is a flat sprung steel plate that can be prised free, under which is located a round brass plug of about 5mm in diameter. Remove the plug and a circular thin sprung steel valve can be removed from a circular backing plate with holes. This plate can also be removed, to reveal a brass gause mesh/filter. The rest is straight forward. On reassembly, be careful to check that the lever arm splines find the correct position relative to the piston actuating arm splines, as this orientation defines the arms neutral position. It is worth noting the full extent position on a second damper and use this to define the limits of the repaired damper before you repress the level arm shaft fully back into position. The travel limits of the level arm should not be less that the vertical travel limits of the axle between top and bottom bump stops, and should be the same on both sides of the car. Sorry this has been a long discorse. Hope it helps. Regards, DAI TC6132 --- CFritz7001@aol.com wrote: > I'm in the process of rebuilding a Girling shock

> absorber/damper, (my > first attempt at this.) I've removed the > recuperation chamber, the end plugs > (caps), and the domed plug in the side of the body, > but have not pressed out > operating shaft, so the piston(s)are still in place. > While cleaning out the > gunk from the interior, I found the mangled & broken > fragments of at least > three spring clips (horse-shoe-shaped items that we > call "circlips" here in > the US --- I don't know what they are called in the > UK and elsewhere). The > cross-section drawings I've seen do not show any > circlips, as far as I can > see. > My questions are these: > 1) Where could these circlips have been located? > How many total? > 2) Is there another one somewhere which did not > break & fall out? 3) > Can or should I proceed to press out the operating > shaft & its lever arm, or > is there still another circlip (or fragments of one) > that must be extracted > before this pressing can be done without damaging > something? > Any suggestions will be much appreciated. > Carl Friz > TC 6756 > Gainesville, Florida > > > > Your use of Yahoo! Groups is subject to > http://docs.yahoo.com/info/terms/ > >

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[DAI]

Oh Carl, One other little tip - when the lever arm has been removed from the damper body, it is a good time to replace the rubber bushings. It seems far easier to install them when there is just an arm. I do not have the bush fitting adaptor kit, but found I could insert the rubber bushings first, then drive the shock link stud or arm using a vice and a pair of screw drivers, lubricated with some saliva and copious invective. Also, if part of the purpose of your damper work is to repair the leaking seal around the lever arm, then Terrance's article identifies the correct seals. I bought 8 last June, and a further 8 later last year. They may have some in stock, but it seems from my discussions with the lady (name of Ina, GDFriend@allsealsinc.com) at 'All Seals' in LA, that we MG-ers are the only customers for this partucular item! DAI --- CFritz7001@aol.com wrote: > I'm in the process of rebuilding a Girling shock

> absorber/damper, (my > first attempt at this.) I've removed the > recuperation chamber, the end plugs > (caps), and the domed plug in the side of the body, > but have not pressed out > operating shaft, so the piston(s)are still in place. > While cleaning out the > gunk from the interior, I found the mangled & broken > fragments of at least > three spring clips (horse-shoe-shaped items that we > call "circlips" here in > the US --- I don't know what they are called in the > UK and elsewhere). The > cross-section drawings I've seen do not show any > circlips, as far as I can > see. > My questions are these: > 1) Where could these circlips have been located? > How many total? > 2) Is there another one somewhere which did not > break & fall out? 3) > Can or should I proceed to press out the operating > shaft & its lever arm, or > is there still another circlip (or fragments of one) > that must be extracted > before this pressing can be done without damaging > something? > Any suggestions will be much appreciated. > Carl Friz > TC 6756 > Gainesville, Florida > > > > Your use of Yahoo! Groups is subject to > http://docs.yahoo.com/info/terms/ > >

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[Roger Furneaux]

Hi Carl - that's a good question: I was told once that the rears should be a little stiffer, but have never seen it in print, let alone actual figures for them, or any way of testing them. I never took mine apart to look at the valves, just pressed the shafts out to replace the seals, and moved them around so I had two square tops at the front (the others had the long pressed steel tops and don't look so nice. I tried testing them by clamping in the vice, and hanging several old Crown Wheels (ring gears) on the arms so they would be pulled down. The idea was to time them from the top of the stroke to the bottom, but they all came out about the same! someone out there must know of a more scientific way. ocTagonally Roger

> Thanks for alerting me to the TSO article on shocks. I'm a >"dues-delinquent" member of NEMGTR, so you have just given me another reason >to get paid up! > Cliff Knight gave me the info I wanted re circlips--they retain the >valves, and I can proceed to press out the operating shaft & arm. > BTW, are the front shocks the same as the rear ?? (I just noticed that >the Moss(USA) catalog uses the same part number for all four) >Regards, >Carl

[Chip Old]

The front and rear damper bodies, valving, etc are identical. Only the arms and links differ from front to back. A slightly more scientific (but only slightly) method of testing is to hook a spring scale to the eye of the damper arm and see how much force is required to move it. On Mon, 19 Mar 2001, Roger Furneaux wrote to CFritz7001@aol.com:

> Hi Carl - that's a good question: I was told once that the rears should be a > little stiffer, but have never seen it in print, let alone actual figures > for them, or any way of testing them. I never took mine apart to look at the > valves, just pressed the shafts out to replace the seals, and moved them > around so I had two square tops at the front (the others had the long > pressed steel tops and don't look so nice. > > I tried testing them by clamping in the vice, and hanging several old Crown > Wheels (ring gears) on the arms so they would be pulled down. The idea was > to time them from the top of the stroke to the bottom, but they all came out > about the same! > > someone out there must know of a more scientific way.

-- Chip Old 1948 M.G. TC TC6710 XPAG7430 NEMGTR #2271 Cub Hill, Maryland 1962 Triumph TR4 CT3154LO CT3479E fold@bcpl.net