U-BOLT TORQUE CHART
|
SIZE |
MATERIAL |
TORQUE |
|
(Dia x Thread) |
GRADE |
(Ft. Lbs) |
|
3/8 x 24 |
T5 |
28-38 |
|
7/16 x 20 |
T5 |
44-58 |
|
1/2 x 20 |
T5 |
66-84 |
|
9/16 x 18 |
T5 |
93-116 |
|
5/8 x 18 |
T8 |
161-197 |
|
3/4 x 16 |
T8 |
279-330 |
|
7/8 x 14 |
T8 |
441-511 |
|
1 x 14 |
T8 |
665-757 |
|
1-1/8 x 12 |
T8 |
943-1059 |
|
1-1/8x12 |
T8 |
1300-1443 |
Removed U-Bolts should NEVER be placed back onto the vehicle, they should be thrown away. Suspension U-Bolts are manufactured with a smooth rolled thread, while the mating Hi-Nuts are manufactured with sharp cut threads. When a U-Bolt is tightened to it's recommended torque level, the U-Bolt threads stretch as they mate with the Hi-Nuts. Although, not always visible to the naked eye, this damages the threads. Removing the Hi-Nuts from the U-Bolt will cause a cross-threading that will not allow the U-Bolt to be adequately re-torqued. A common practice in most maintenance facilities is to use a impact wrench to tighten U-Bolts. Consistent, accurate torque is next to impossible to obtain with a impact wrench, and in most cases an over-torqued fastener is the result. We recommend using a torque wrench when installing U-Bolts. New U-Bolts should be torqued after 2 weeks of usage.
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