TC Steering: Understanding End Assemblies

It’s that time of year where many are working on their cars for the driving days ahead. Most inquiries I get cover the full spectrum of car servicing. However, this past month I have had a surprising number of questions concerning the TC steering rod end assemblies. Specific problems surfaced with: “Can’t get it apart, can’t get it together, what needs to be replaced and most importantly, what is the correct assembly order?” The overall problem is that the end assemblies are confusing. Let’s make it simple!

Identification: There are 4 end assemblies. 3 tie rod end and 1 drag link end (also referred to drop arm end). How do you tell which is which? You must be able to first identify which type of end you are working on, as the assemblies are different.

Quick ID: Tie rod ends (TRE) have a cross slot (X) in the end adjustment plug. The drag link end (DLE) has only a single slot. Simple! One additional quick ID is that the TRE barrel slot is a small figure 8 and the DLE slot is elongated.

Drag link end assembly
Tie rod end assembly

Assembly Order: The drag link end is assembled differently than the tie rod end. To keep it simple: The DLE has the spring on the outside and the TRE has the spring on the inside.

Tie Rod End Assembly: Starting with the inside of the barrel housing the assembly order is: spring, cup (w/ tiered back), TRE ball, and cup/end plug (the end plug is also the cup). Remember the plug has a cross slot (X).

Drag Link End Assembly: From inside out, cup (w/ flat back), drop arm ball (tapered), cup (w/ tiered back), spring, and end plug. Remember this plug has a single slot.

Confusion: So far, this seems simple. However, there are some confusion factors that you need to be aware of:

• The TRE ball has a straight shaft. All 3 TRE balls are alike. The DLE ball has a tapered shaft. Very much distinguishable.

• The TRE inner cup is also the same used in the DLE outer cup. So you will have 4 of these. Visually, it has a tiered back that fits into the spring. The DLE inner cup has a flat back. There is only one on the TC inside the DLE.

• The TRE outer cup is also the end plug. 3 of these on the TC. However, the DLE plug does not have a “cup” side. Only 1 of these on your car.

• TRE housings are threaded differently for the rods. There are 2 left hand threaded barrels for left and 1 right hand threaded for right. Sometimes the barrels are stamped L/H or R/H. If not look at threads.

Help!! “I can’t get the drop arm ball out” (or in): The tapered drop arm ball cannot be assembled by simple putting it in or out of the “figure 8” slot. It has to be slid in through the end of the barrel housing and then out the slot. This is for safety reasons in case a spring breaks and the ball comes loose. It cannot fall out. And what about the springs?

Originality: Here is an interesting finding that has also added to confusion. According to the Factory parts manual, the spring in all 4 end assemblies should be the same (same parts number). However, replacement end assemblies have a longer spring in the TRE compared to the DLE spring. (approx. ¾” vs. ½” tall). A study of some “original?” end assembly barrels show that they often varied in depth when measuring the depth of the machining for the internal components. So a different length spring is required. Therefore, if you cannot get the correct adjustment on the end assembly, be mindful to check to see if a different spring length would be better.

Examples of TRE/DLE springs

Adjustment: The ball adjustment on all ends is the same. Tighten as much as possible and then back out the end plug a half turn and install the split pin (cotter). When you thread the complete end assembly onto the rod shaft, count how many turns. Then do the same number for opposite side. This will keep the adjustment capability equal and preclude wondering why you run out of toe-in adjustment. (Believe it, this has been a reported problem!)

Inspection: Finally, what do you look for when inspecting? The obvious answer is looseness. Jack up your car and give the steering a shake. If there is any sign of end play, it’s time for inspection. Common fail items are broken internal springs. And if you don’t keep it lubricated the balls will wear as in the photos, causing steering issues. Most importantly, DO NOT trust the assembly order from the prior owner. It is not uncommon to find it wrong, which has created many of the problems mentioned above.

Two examples (on the right) of ball joint wear

Wrap Up: The intent of this writing has not been to make you an expert in TC steering but to make you aware of the end piece differences and how to check your car. When the time comes to actually disassemble your car, you can find a “ready reference” for the DLE/TRE assembly in steering section of the catalog at:

Please check your steering this winter.

Doug Pelton

Editor’s comments: The set-up is, of course, the same on the TA and TB, except that the neck of the ball joint which connects with the drag link (drop arm) is a parallel fitting as opposed to a taper fitting on the TC.

One cannot be too careful with the examination of the components which make up the steering assembly. I have heard it said and seen it written, that one way of taking out the wear on the ball of the ball joint is to turn it so that the cup receives an unworn face of the ball. Well, if you want to dice with death for the sake of a few quid, go ahead! Indeed, you might find yourself ‘going ahead’ on a bend in the road with a vehicle coming straight at you in the opposite direction. I exaggerate to shock, but I’m sure you get my drift!

Another useful check if you are disassembling the steering or perhaps doing a rebuild is to have a really good look at the complete tie rod and drag link assemblies. This includes carefully inspecting the barrels (or tubes, if you like) of the assemblies, the importance of which is instanced by the following experience at an MoT test.

Those of you in the UK are well used to sitting in the car and obeying the commands of the Ministry of Transport (MoT) vehicle examiner while he marvels from below at the suspension and steering set-up of your car. He will tell you to rotate the steering wheel hard in each direction to enable him to check for wear in the joints. On one such occasion, a friend of mine was told by the examiner that the drag link end was moving vertically up and down before moving the road wheels. A ‘fail’ certificate was issued and the owner drove the car home slowly.

Upon disassembly it was found that the inner shoulder in the “tube” that supported the cup had worn away allowing the cup to tilt, which in turn moved the tapered peg over at an angle. This caused the slot in the casing to wear away, allowing the ball to protrude through the slot which would have eventually popped out.

The reason why this happened must have been due to a combination of insufficient land width within the “tube” and/or the outside diameter of the cup being too small. This would result in there being inadequate support behind the cup. A serious matter!

One, other examination – check your steering rods for straightness. Recently, when working on my J2 I found all three spare track rods I had were bent!

3 thoughts on “TC Steering: Understanding End Assemblies

  1. dirk w dondorp says:

    Hi Doug, on my dismantled DRE I found it had a TRE housing and a cross slotted cup with a tapered ballend!
    Could it be that some suppliers are cutting corners by using the TRE housing and internals also for the DRE part?

  2. Neil Pope says:

    Hi Doug,
    A very interesting and for me topical article! Having just dismantled the TRE and DRE assemblies from my TA I found them to be exactly as described in your article – except – the drop arm ball DOES pass through the figure 8 hole in the barrel housing.It is a firm fit and shows little wear so I do not think it has worn the hole at all. There is no way it would pass through the end as described. Am I right to assume that the TA did not have this safety feature that you describe for the TC?

  3. stuvw says:

    Hi Doug,

    I just removed my steering box and column.
    I disconnected my drop arm from the steering box no worries. I removed the cotter pin and bolt from the drag link ball assembly, but the drop arm will readily not come off the tapered pin.

    Has anyone else had and solved this problem. I don’t want to get too agressive and damage anything in the process.

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