Tie Rod End Testing & Development
Roadsafe 4WD are a leading supplier in the automotive industry, supplying to a broad customer base throughout Australia and internationally. The Roadsafe 4WD chassis parts components are manufactured in Taiwan, using only the highest quality materials, under a TS Quality System.
We are continually researching and identifying ways we can improve our product over and above a genuine OE item and other products in the marketplace. One of the reasons for this daily exercise to better our product and work toward constant improvement, is due to the fact that these steering & suspension components, when fitted to 4wd’s, are generally fitted to highly modified vehicles pushing the boundaries of the original design.
As an example, when we first designed and manufactured the replaceable Tie Rod Ends for Nissan Patrols we based it on the original Nissan specifications at the time. This design was used to supply individual ends as well as our range of Roadsafe 4WD Patrol steering arms, this was the case for many years without issue. As vehicles and the 4wd scene evolved and larger tyres were fitted with higher quality suspension allowing the vehicle to travel faster in difficult terrain, Roadsafe identified a requirement for a stronger Tie Rod End.
There are 2 main factors to consider with a heavy duty Tie Rod End:
- Pull Out – where the ball stud has the ability to pull through the housing and separate
- Shear Strength – the load required laterally on the ball stud resulting in bending or breaking
Amongst other features and qualities these 2 tests are performed to determine comparative strengths in various designs.
The Nissan Patrol has 3 main Tie Rod Ends for vehicles 1988-2016. These being TE135HD, 8520HD & 8570HD. The original genuine design had a diameter of 13.5mm across the neck of the ball stud.
With thousands of ends sold using this design based on original equipment, up to 2013, we had 5 reported cases of a failure at this common point. Based on these 5 failures we progressed to a redesigned ball stud with a 14.5mm diameter neck, working to ensure we had a heavy duty variant. This change was completed using the same housing we had always used with no issue. During a Roadsafe development meeting it was identified that the 4WD scene was still progressing, with vehicles getting higher lifts, larger tyres and venturing into more difficult terrain, and we should consider a completely new design offering increased strength and features.
March 2014 saw the biggest change to the tie rod ends with a fresh new design being released and used on all steering arms supplied by Roadsafe and other companies throughout Australia and abroad.
The new design incorporates a completely new housing offering increased articulation of the joint reducing binding through the suspension cycle, while having an increased neck diameter to 15.5mm, negating any reduction in physical size, providing 12% more material directly to the load area reducing fatigue and compounding the strength.
Then a further upgrade (July 2014) to a massive 18.5mm solid no-neck style ball stud on the TE8570LHD/RHD & TE8520LHD/RHD and 17.85mm solid no-neck style ball stud on the TE135LHD/RHD – a material increase of up to 25% (8570). The maximum neck size is restricted by articulation specifications per application.
We prove these results by rigorous testing of each ball stud, each design undergoes multiple shear (lateral load) tests as can be seen in the below videos. Please click on the image to see the relevant video.
All tests result in the same force being applied – =456kgw=4468.8N
- First is the OE V2 ball stud design @ 14.0mm neck – Resulting in a deflection of 12 degrees
- Then we have the original Roadsafe Heavy Duty version with 15.5mm ball stud – Resulting in a deflection of 7 degrees
- Finally we have the solid Roadsafe Heavy Duty version 18mm ball stud – Resulting in a deflection of 6 degrees
Further to the shear (lateral load) tests we also perform a pull out test. Please click on the image to see the test results.
From the testing video and report, we can report that the OE ball stud is pulled out from its housing at the force 4284.99kgf. On the other hand, the Roadsafe ball stud stay’s in the housing at the force 10,054.98kgf, until the test tooling failed (broke). If we have a stronger test tooling we would see the Roadsafe ball stud can withstand even greater force than this result, at over double the result of a genuine item.
Roadsafe take quality of product and reputation very seriously, as indicated above we do act on factual data supplied to us with regard to the integrity of our products to ensure the products are of a high standard. Based on sales volume Roadsafe have a return rate of less than .5 of 1% over the entire range of product, which includes things like…
- Stock protection
- Incorrectly ordered product
- Genuine Warranties
- Good will credits
- Failed components due to misuse/abuse, incorrect installation etc.
Roadsafe products are distributed through a variety of stores and resellers with some of these being private labelled, all of which are encouraged to report any credible product issues so we are able to identify batch issues, manufacturing defects or otherwise – and act accordingly.
At Roadsafe we want to provide a high quality product, that will evolve & improve over time. As new technologies and manufacturing techniques become available, Roadsafe will incorporate these into product design if it enhances the product features and benefits. At the end of the day, the Roadsafe goal is to supply a high quality product at a competitive price.