Discontinued Inner Tie Rods - A Solution

[Ludworks]

EDIT: Pictures are here https://www.theeaglestore.com/tierodpictures

Many of you are probably aware that inner tie rods have disappeared from the market. I've been looking into this and I've come up with a workaround. It's not perfect, but it's cheap and easy.

First some specs:
Inner and outer tie rods are identical except for the fact that the inner tie rod has counter-clockwise (left-hand) adjusting threads.
Adjusting threads are 5/8-18 - common GM size
Stud threads are 7/16-20 - common GM size
Stud taper is 1.5"/1' also called 7° or 7.15° - common angle across many makes
Taper minor diameter is approximately 0.495" (possibly spec'd at 1/2") - varies between brands - uncommon size
Taper major diameter is approximately 0.575" (possibly spec'd at 9/16) - varies between brands - uncommon size
Length of taper engagement is approximately 3/8" when hand-tight - varies between brands.


Hornet/Nova Hybrid Solution:
Outer tie rods from Hornets, Spirits, Concords, Gremlins, Javelins, etc. have the correct taper, and thread sizes. They also have correct counter-clockwise adjusting thread. The only issue is that they are shorter than the Eagle inner tie rods. A simple and inexpensive solution for this is to use a longer adjusting sleeve.

The adjusting sleeves on my Eagle are 4.25" long. I've seen many for sale which are 4.5" long. I cannot say which is the correct original length.

One of the attached pictures shows three tie rods, two with adjusting sleeves. The top is a GM tie rod. The middle is a Hornet Outer tie rod. The lower is an Eagle Inner tie rod.

The lower tie rod has my original adjusting sleeve on it. The middle tie rod has an adjusting sleeve from a 1970 Chevy Nova (along with about a dozen other GM models) part# MOOG ES350S or DELPHI TA5458. It's just over 6" long. The overall difference in length is approximately 1/4".

Without exact specs on material properties and construction, it's impossible to say how much thread engagement is actually necessary for the tie rods. To be safe, I recommend no less that 1 times the diameter, or 5/8"; for theoretical maximum strength 2 times the diameter, or 1 1/4".

I've been unable to locate a 6 1/2" tie rod adjuster but that length would probably be ideal for maximum thread engagement..

There are a number of companies which have 5/8"-18 tie rod adjusting sleeves available in custom lengths. They are mostly jam-nut locking as opposed to the split sleeve style of the OEMs, but they could be a good alternative if more thread engagement is needed.


GM Solution
Older GM Vehicles (60s-80s) often used tie rods with 5/8"-18 adjusting threads and 7/16"-20 stud threads. They are available in a myriad of lengths and clockwise/counterclockwise threads depending on the vehicle and the tie rod position. The taper angle is also generally the appropriate 1.5"/1' (7°). The only issue with these tie rods is the taper diameters. The angle is the same, but overall the tapers are bigger, causing the tie rod end stud to have less engagement.

One of the attached pictures shows a comparison of the GM taper with the AMC taper. The AMC taper has approximately 3/8" engagement length, while the GM has approximately 1/4" of engagement. That's a reduction of 1/3. However, they still fit and can still be used. Long term durability is unknown.

A way around this is to ream female tapers on the Eagle to accept the slightly larger GM size. 7° reamers are readily available and fairly easy to use. This modification has been done by others with good results so I'll say no more about it.

[vangremlin]

Thanks for these solutions!  They seem like good workarounds!

[89 MJ]

Awesome!

[Ludworks]

Thanks fellas.

If the 6" tie rod sleeves are too short for most people I can have custom ones made for the store. Somebody with an intact steering system and shot tie rods just needs to test this out and let me know, my steering is all dissembled and while the mock-up looks good I can't be 100% certain there's not some minor unforeseen problem.