Taylormade

Pitman Arm and Drag Link

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24 minutes ago, Spinneyhill said:

 

 I can't use the Chev ends because I have two springs each end, not one - unless I modify it.

 

Interesting.  My drag link uses a single spring at each end.

 

IMG_3436.JPG

 

IMG_3437.JPG

 

 

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If that is the order in which it came apart, it is not what is shown in the drawing on p. D-2-G in the Master Parts List. The inner seat or bearing goes in first. The flat topped pin should be under the end plug, on that end. The other end is the way you show, hence the offset in the holes in the body.

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My original drag link parts looked about the same from the 1929 Studebaker President.  I got the front axle assembly and the steering column from a parts car, but they had torched the drag link rod and all I had were the ends.  As it was, I couldn't find new ball studs with a 1.08" diameter ball and/or the right taper and threads.  That's what drove me to use modern Jeep Wagoneer tie rod ends, because the taper and threaded section were the same as the old ball studs.  On the Moog web site, you can find tie rod/drag link ends listed by dimensions for the tapered section and thread size.  But, there are no drawings with dimensions, like the length of the threads, etc.  Moog refuses to provide that kind of information, probably because they don't want any liability for misapplication.  You can tell them a car brand name and model and they will tell you the part number intended for that car, period.  But, for old cars that didn't use the modern style ends, they can't help.

 

The o.d. on the ends of my drag links is about 1.5" while the main tube was 1.125".  Expanding the tube would have thinned the 1/8" wall by about 25%, but even the large diameter end still had 1/8" wall, tapped for about a 1-5/16 -16 thread.  The length of the expanded section was about 3".  A hydraulic tube expander, of the type used in muffler shops, could do the expansion but would thin the walls.  The drag link builders must have had a machine that would simultaneously expand the tube while compressing the ends to maintain wall thickness.  I'm not sure of the safe limit for expanding a cold tube without risking cracks in the metal, but 25% stretch sounds like a lot.

 

Sorry about the confusion of tie rods versus drag links.  I mentioned it because my tie rod was swaged down and threaded on the tube ends to screw into the tie rod ends.  The tie rod ends used the same style of captured ball stud with spring-loaded cups as the drag link ends.  I think the swaging-down operation is much like the tube expander.

 

Here a link to a YouTube video of a tube expander in operation:

 

1929 Studebaker reach rod ends.jpg

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21 hours ago, Spinneyhill said:

If that is the order in which it came apart, it is not what is shown in the drawing on p. D-2-G in the Master Parts List. The inner seat or bearing goes in first. The flat topped pin should be under the end plug, on that end. The other end is the way you show, hence the offset in the holes in the body.

 

You're correct.  I accidentally showed two photos of the same end.  The pitman arm end came out like this and, according to my Instruction Book, is correct.

 

IMG_3425.JPG

 

The tie rod end came out like this.  I have a sneaking feeling I laid this out wrong.  I took this shot in March of 2014, so I can't be sure.  According to the Instruction Book, it should be a drag link bearing, then the drag link ball, then another bearing, then the spring, then the spring seat.  So, it would appear I have this end laid out incorrectly - the exact opposite of what it should be.  Or, perhaps it was rebuilt and put in wrong, but I vote for my error.

 

IMG_3436.JPG

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My machine shop and Dodge 8 Guru told me on Saturday that welding steering gear is illegal in NZ except by an appropriately certified welder. There is one in Christchurch apparently. So I will look for another drag link before proceeding much further. The inside of mine is very worn and the ball etc. can almost be pulled out.while assembled. The RHD drag link is different to your LHD version.

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4 hours ago, Spinneyhill said:

My machine shop and Dodge 8 Guru told me on Saturday that welding steering gear is illegal in NZ except by an appropriately certified welder. There is one in Christchurch apparently. So I will look for another drag link before proceeding much further. The inside of mine is very worn and the ball etc. can almost be pulled out.while assembled. The RHD drag link is different to your LHD version.

Can you post some photos of your drag link and an end to end dimension? I have an extra drag link that I don't know what it is for. it is supposed to be for a DB about 1930 or '31.

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Thanks. Photos attached.

 

DC-8-DragLink-RHD.jpg

 

DC-8-DragLink-RHD-2.jpg

 

Notice the ends are symmetric and longer than Taylormade's 1932 DL versions because there are two springs in each end.  Overall length is 798 mm = 31.42". LHD links bend the other way of course.

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RATS! It slipped my mind that your stuff is reverse of the stateside stuff.

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Taylormade . to me ,I think layout is wrong on both . when finished the neck down area of link should hold the ball so it will not pull out. Making it the side without spring . Spring pushes ball to restricted side .  The spring is tighten to solid and backed off to next notch of cotter pin , per my  manual .  

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I agree with Tom. That is what is shown in the part book diagrams. Body, seat, ball, seat, spring, T-pin, plug, bent cotter, grease nipple. I am not sure why the T-pin is there, perhaps to prevent the spring from buckling laterally and wearing on the housing.

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With two springs, mine is tightened fully then backed off one and a half turns of the plug.

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Now I'm totally confused! :huh:  I got out the dependable Instruction Book (no Shop manual for 1932) and took a look.  This is the diagram for the two ends of the drag links.  It appears to be exactly the same as the PDF Tom posted for his truck.

 

drag link.jpg

 

My first layout (on the tie rod end of the link) was the one I thought I had laid out wrong.  This is how I had it compared to the book.  This was not correct - I had the spring on the wrong end.DL 1.jpg.

 

I did a bit of Photoshopping and this is the correct layout.

 

DL 2.jpg

 

I still think I had the Pitman arm end of the link laid out correctly.  It seems to match the book.

 

DL 3.jpg

 

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Sorry for confusing the issue. :(      Now you have it sussed, the big question is, what is the plan? It is difficult and there seems to be no easy solution.

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Yes , I Think you have it right now, I was half wrong . See how the back of keyed slot is farther from back of enlarged tube . This gives room for spring and will accept shocks inward . Take  the end pieces only and assemble with pitman arm in ,if it can not be pulled out of keyed slot it should be safe . Do same test on other end ,with out spring . Use Tee inner of spring ,I agree with Spinneyhill it reinforce and if spring breaks stops ball from coming out . Tells you if wear in keyed slot is in need of repair , the way I see it .

Edited by ArticiferTom
spellin (see edit history)

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1 hour ago, Spinneyhill said:

Now you have it sussed, the big question is, what is the plan? It is difficult and there seems to be no easy solution.

 

I sent the pitman arm and my drag link to the gentleman who did the Auburn pitman arm in post #10.  I also sent him a one inch ball bearing.  It will probably be a month or more before I get everything back, but I will post the results.

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Interesting, the drag link pdf on post #37 and illustrations at post #39 show the springs to be inside by the tube at one end and outside by the adjuster at the other end .  My GM shop manuals show the springs always on the inner side.  Seems interesting that engineers at two different major manufacturers come to opposite conclusions.

Edited by Tinindian
spelling error (see edit history)

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