Custom Tie-rods That Fit Standard Suspension

[Whittie]

Custom Tie-rods for Datsun 260Z

 

As many people in front of me, I have come across the limitations of the front steering tie-rod length on the Zed. With new TTT front control arms with a minimum 3.5Degrees negative camber I have 6 degrees toe-in… You should have heard the tyres protesting on the way home from Wheels World!!

 

So, the challenge was on. Plenty of people said that the only way to go is custom because nobody makes a tie-rod that fits and gives the range of movement and extension we required, about 40mm. So, 280zx tie-rods were no good but still, SOMETHING had to be done.

 

I couldn’t go with a rose joint setup because I still have relatively standard suspension and the huge suspension travel would bind even the highest movement rose-joints I could find. Despite being told it couldn’t be done by plenty of people on this forum, my Father decided that everyone just hadn’t tried hard enough… Sure…

 

We went to about 6 or 7 suspension mobs in town, who all couldn’t get us out of their shops fast enough, before My dad ran into the State Manager for the Pedder’s suspension mob who, after hearing about our poor reception at several of their stores, measured up the standard zed tie rod pitch, thread and thread height and got the national R&D department onto the case. It took them 3 days, but they came back with a solution!

 

A threaded tie-rod off of a Ford XY Falcon!

 

It has the same pitch, thread height and thread as the zed tie-rod. In short, it fits in the standard steering knuckle without any modification!

 

To complete the tie-rod I used:

- 2 RH thread Falcon Tie-rod ends, Pedder’s Part #PTE391R. These come off an XT-XW-XY Ford Falcon from 1968-1972. I don’t know what you could use in the states, but probably something off of a mustang or similar.

- 2 Datsun RH thread rack-end ball joints

- Chrome-molly tube, cut to the extra length you require

- Steel nuts to fit on the tie-rod and the rack end to act as lock nuts and another set to weld onto the chrome-molly tube to fix to the nuts.

 

You then simply tap the Steel nuts and then weld them into the chrome-molly tube. I then had mine electro-plated so the steel nuts don’t rust.

 

Using all Right Hand threads means that expensive and difficult to find 14mmx1.5 LH die’s don’t have to be found to tap the nuts for the LH thread ball joint on the standard Z steering rack. Also, because the ball joint in the rack end can spin the tie-rods can still be adjusted on the car by spinning the ball joint end instead of turning the tie-rod itself, very much the same as the standard suspension.

 

However, the thread on the Tie-rod is a really weird size and nobody in town could supply nuts of the correct thread, they kept telling us it was like a Hydraulic fitting thread. Therefore, we had to have a machine shop make up the nuts and plugs for the tie-rod end of the middle tube.

 

And here are the pics everyone has been waiting for:

New rod next to old one demonstrating the extra length of the new tie-rod.

 

 

The middle section of the rod

 

 

A blown-up view of all the pieces

 

 

And finally, the new tie-rod on the car. The angle look great and I’m not expecting any bump-steer but I’m yet to drive the car so can’t comment just yet.

 

 

Versus the non-modified tie-rod:

 

 

Here is the in-board side of the new rob, showing how it all mates up. Nothing binds even at full droop.

 

 

And here is the clearance with the stock 14†rims and with TTT Roll centre adjusters fitted as well.

 

 

With any luck this mod will be useful to someone looking to avoid going full custom rose-joints on this part of the suspension, as well as fitting on COMPLETELY STANDARD SUSPENSION. Total cost for both sides came in at around AU$300 for all parts and machining, but could be replicated for less given a few hiccups with attempting to get everything to work together.

Edited July 19, 2010 by Whittie

[benitoz]

Nice work, I wasted 3 days trying to come up with stuff here and it was a huge let down, I was trying to buid something very similar, I was wondering if you used hex bar stock and tapped both ends if it would be strong enough ? Does anyone know a site that sells the tubing and the inserts that you can tap ? If I could buy what you just built with m14x1.5 on both ends I would be a happy camper haha.

[JMortensen]

Good job Whittie.What you have done won't affect bump steer at all (unless the position of the outer pivot is slightly lower or higher than the Z car tie rod). It will neither improve or worsen it. The reason that the control arm lines up nicer with your new tie rods is due to the J bend at the end of your new tie rod. It's not the arm that needs to line up, it is the imaginary line from the center of the tie rod pivots and the line from the control arm pivot to the ball joint which need to be parallel. From the pictures it looks like they are the same or very close to the same.

 

As to benitoz question, in the US you can buy "tap tube" from any number of racing parts houses, but it isn't set up for 14mm, it's always sized for the more common 5/8" or 3/4" thread we use here. I would imagine that 14mm tap tube would be more common there, as would 14 mm rose joints or rod ends (or you could use the tie rod suggested by Whittie. In the US you might be able to find 14mm threaded tube ends which could be welded to a tube that serves as a turnbuckle, then find a similar tie rod to complete the job.

[Whittie]

Cheers Guys!

 

Thanks for clearing that up Jon. I was thinking about bump-steer and the very little I know about it just today looking over the pics and it also occurred to me that the shape of the tie-rod should not effect it, just the location of the pivots.

 

The new tie-rod pivots around the same vertical height in respect to the turn buckle as the standard tie-rod and so should not effect bump-steer at all.

[NZeder]

Re the tie rod end Whittie has used.

 

For those state side the Ford Falcon XY tie rod Pedder’s Part #PTE391R is the same as......well more research to follow.....I was lead a little down the garden path via and incorrect catalogue and therefore path number.....I will edit this thread/post again.

 

And JMortensen not sure about the guys in Oz but here in NZ we normally use the US/imperial rod ends as they are cheaper and easier to get than the metric items even in this metric part of the world- go figure.

Edited November 26, 2010 by NZeder

[NZeder]

Update time.

 

I will let the pics tell most of the story. But there are 2 type of tie rods for the XT-XW-XY range of falcon. Those known as early Ford and then the later type. Tapers are different but all other dimensions are the same.

 

So for you guys state side the partnumber for Moog items are as follows (used on Mustangs and many other Ford's of the late 60's early 70's)

 

AU/NZ supplier numbers <==> Moog numbers

TE391R <==> ES360RL

TE420R <==> ES387R

 

If you feel so inclined I guess you could also ream out the stock steering arm so the Ford Pinto sizing can be used = 7 degree taper with .554 top and .626 bottom then you can use ES445RL

Edited November 26, 2010 by NZeder

[Mike Mileski]

Here's a source for metric threaded tube ends (it's a UK company).

 

http://www.mcgillmotorsports.co.uk/index.php?page=0&act=viewCat&catId=29

 

Mike Mileski

Tucson, AZ

[Mike Mileski]

I bought a steering rack for my 1971 240Z from Motorsport Auto a couple of years ago and decided to install it and make some adjustable tie rod adjusters for it at the same time. However, I wanted to find a pair of standard tie rods that had the same tapered stud dimension as the stock Datsun so they would fit into the stock steering arms PLUS have one of them right hand threaded and the other left hand threaded. I went to a good old fashioned auto parts store that had a thick Moog catalog, which listed top and bottom taper diameters and started my search.

 

After a while I found a pair of tie rods that fit 1963-1982 Corvettes. ES323R (inner passenger side) and ES323L (outter passenger side). ES323R has a 5/8-18 right hand (RH) threaded shank and ES323L has a 5/8-18 left hand (LH) threaded shank (see pic 1). The taper dimensions were within a couple of thousandths of those listed for the stock Datsun, even closer than the ones listed earlier in this thread.

 

The stock Z steering rack has a 14mm-1.5 LH threaded inner tie rod on the driver's side of the steering rack and a 14mm-1.5 RH one on the passenger side. Since I already taps in both of these sizes, and I liked the style of the threaded tie rod tube ends made by Summit Machine, I ordered a pair of their 5/8-18 threaded ones, one RH and one LH, and, since they didn't sell metric ones, a pair of 1/2-20 ones, one RH and one LH. I drilled out both of the 1/2" ones with a 1/2" drill, which was also the tap drill size for a 14mm-1.5 thread. I then tapped a 14mm-1.5 RH thread in one and a 14mm-.5 LH thread in the other. (see pic 2).

 

I purchased one foot of 4130 tubing (1" OD X 3/4" ID)and cut two pieces to the appropriate length. The tube ends slip right in and can then be welded (see pic 3).

 

I may put some flats on the tubing so they can be turned with a wrench but they turn so easily by hand that I might not. Check out the remaining three pictures for some more details, one has the stock Datsun tie rod in it for comparison.