What I was told was when servicing dampers with replaceable cartridges to put a couple ounces of light oil in the housing before sliding the cartridge in. That way the cartridge would be better thermally connected to the outer housing. Actually I think the factory recommended procedure for VW's was to use antifreeze, but I prefer oil to prevent rust.
Threading is usually done at modest RPMs, so balance is not a real issue. What you need is a lathe that has a short enough spindle so the suspension bracket can hang out the rear of the lathe spindle while the top end of the strut is in the chuck jaws. Otherwise, you need a lathe with a HUGE spindle through hole to clear the bracket. I don't know how big the bracket is, most small-shop lathes have fairly small through holes, between
3/4 and 1.5", say. My 15" Sheldon has a 2.25" through hole, and the spindle is about 29" long from the back to the tips of the chuck jaws.
And what happens when you need to turn the spindle in reverse? In my case, that would work too, because it is a lever closing drawbar, with a lock to keep it from rotating relative to the spindle, but for handwheel style closers, I would expect problems. (An example of when you would use this is when using a tap or a die in a tailstock or carriage holder and need to back it off or out.) But -- I also have the releasing tap holders for the bed turret, so it allows the tap to free-wheel until I can stop the spindle and reverse it. Yes, I do tap under power with this setup.
If it comes to that, have a look at this piece I made to hold a depth stop in my lever type collet closer tube. You could just as easily clamp a crank in it.
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A socket set screw in the 1/4-20 hole expands the body in the closer tube, a socket head cap screw in the 10-32 clamps on the stop rod (or crank).
"> And what happens when you need to turn the spindle in reverse?
Don,
I have a Royal hand closing drawbar with a round handwheel on the outside end. My expandable arbor has a 10 in. crank. The expander is cranked into position with the lathe "in gear" usu. in the slowest threading speed. The crank is turned until it expands enough to begin turning the spindle against the heavy drag of my lathe (13 x 40). Then, with the lathe taken out of gear the spindle can be easily cranked by hand. In my machine, the lead screw remains engaged when "out of gear." Hand cranking makes for a very handy and sensitive setup for slow operations in the lathe.
I find it to be a good "cutoff starter" as well, particularly when working with larger stock. The ideal cut-off speed for larger pieces is usu. much slower than the min. 105 rpm of my machine. Hand cranking can take a lot of fear out of cutting off.
If ever I encounter the situation where there is enough resistance to unscrew the expandable arbor, I should expect to lend some other assistance such as barring the spindle backwards via a wrench in the camlock holes or etc. With a screw-on back plate I would still expect to lend some extra backing effort if the need arose.
Follow up to original post below... please note that this is crossposted to alt.autos.porsche.944
Cliff's notes/background: I purchased a used (read: junk) pair of each flavor of strut off eBay for the express purpose of mock> Hopefully some machinist will read this who also has enough knowledge of
Well, I just got my early struts a few minutes ago... it looks like they would bolt right on to my car EXCEPT that the lower mounting hole is about 1/4" or so off from the later ones. Just enough that I wouldn't feel comfortable opening it up/welding a washer on - it would be awful close to the edge of the bracket.
At a glance, the only other major difference I can see is the strut bearings (obviously) and the brake line bracket (welded on at a different angle.) The tubes appear to be similar in diameter so I'm still keeping my fingers crossed.
One of the late struts appears to have been in a fire - fuel line maybe? - spring is sagged and bump stop is melted but the other appears to have been recently rebuilt (bump stop and little plastic cup are intact, and I swear there's cosmoline around the cap threads) so I have high hopes that I will be able to unscrew the cap and extract the cartridge for a trial fit in a late style housing.
I'm going to try to work on this tomorrow as I am leaving for a Studebaker meet in South Bend, IN on Tuesday; if I can get all my questions answered I might be able to leave my pieces parts with a machinist friend that lives in Fort Wayne.
Note to self - make sure camera is in car when going over to friend's garage to destroy these @$%^ late struts!
Stay tuned...
nate
-warming up the angle grinder and other implements of destruction - woo hoo!-
-this is what happens when you let a cheap ass Studebaker owner work on a Porsche-
Bad news... doesn't work. To make a long story short, the strut assemblies are at a glance identical, but upon closer examination are subtly different in almost every dimension. I had to try, however, because I just hate getting a "good" idea and not following up on it.
- the tubes of the struts are slightly different in diameter. The
87-88 ones are about 1/8" larger in diameter than the earlier ones.
- the bolt pattern is different, the holes in the early struts are slightly closer together.
- the pocket that the steering knuckle fits into is slightly wider on the early struts.
- the tubes are slightly longer on the late struts. (that alone wouldn't have been a problem; I could have just cut them shorter)
So... it appears that for an 87-88 owner there are only two options.
1) buy original Sachs/Boge struts for about $240 apiece - I don't consider this to be an acceptable option because of the bad experiences I've had with Sachs/Boge products in the past.
2) Get the Koni inserts designed for the late struts - there was a how to with pics posted just a couple weeks ago on these.
Option 2) makes me a little nervous as it seems that once you go down that road you're at the mercy of Koni for as long as you own your car; they're the only one that makes inserts for the late struts. But right now it looks like the only game in town.
I'll post pics later tonight just to clarify the above, but I didn't get very far as as soon as I knocked the cap off the first Sachs strut, I could see that I was done.
I saw that; I was really hoping to put Bilsteins on the front so I didn't have to replace my rear shocks. I guess I will just have to see how the Konis work because they look like the only came in town. Alternately I have a good used set of stockers with tweaked mounting points, I will see if I can get a friend with a press to try to untweak them for me. At least the shafts on those are straight unlike the other ones I got :(
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