Torque spec question:
Thread Starter
Drifting
Joined: Sep 2004
Posts: 1,372
Likes: 321
From: Clarksville TN
Torque spec question:
I just read a C5 tie rod end torque spec that refers to 3 passes. They are: 15 lb-ft, 160 degrees and 35 lb-ft. I interpret that to say torque to 15, then tighten nut a bit less than half a full turn and finally finish with a torque of 35. Would you agree with this plan? I’ve not seen a spec given this way before.
FYI: I asked my question on this forum because I currently have only a C2 and I value the expertise on this forum more than on C5 or C7.
FYI: I asked my question on this forum because I currently have only a C2 and I value the expertise on this forum more than on C5 or C7.
Last edited by vipervetteguy; Feb 14, 2019 at 08:51 PM.
Melting Slicks
Joined: Sep 2009
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Likes: 1,258
From: MI
2023 C2 of the Year Finalist - Unmodified
2022 C2 of the Year Finalist - Unmodified
2017 C2 of Year Finalist
The 15 ft lb pass just ensures that the taper is seated. The 160 degrees rotation from that point ensures that once the taper is seated, the two pieces are drawn together a certain distance, thus causing the internal taper to expand within its elastic limit. I believe, (though I never wrote a spec saying "three passes") that the 35 ft lb spec refers to the minimum torque that should be achieved during the 160 rotation, not a separate tightening step.
Thread Starter
Drifting
Joined: Sep 2004
Posts: 1,372
Likes: 321
From: Clarksville TN
The 15 ft lb pass just ensures that the taper is seated. The 160 degrees rotation from that point ensures that once the taper is seated, the two pieces are drawn together a certain distance, thus causing the internal taper to expand within its elastic limit. I believe, (though I never wrote a spec saying "three passes") that the 35 ft lb spec refers to the minimum torque that should be achieved during the 160 rotation, not a separate tightening step.
Melting Slicks
Joined: Sep 2009
Posts: 3,382
Likes: 1,258
From: MI
2023 C2 of the Year Finalist - Unmodified
2022 C2 of the Year Finalist - Unmodified
2017 C2 of Year Finalist
In all likelihood, the 35 ft lbs is there only to ensure that the 160 degree rotation didn’t yield the internal taper. If, after rotating 160 degrees, you haven’t acheived 35 ft lbs, the internal taper must have stretched beyond its yield point, meaning it is permanently deformed and can’t acheived the desired attachment integrity.
