Grade 7 Bolts for suspension (ball joints)?

[miked]

i bought bolts and self locking nuts to renew the bolts holding the lower ball joints to the control arm. i was asking for grade 8 bolts but the only available is grade 7. i just bought it anyway. but is it safe?

[jick.cejoco]

i bought bolts and self locking nuts to renew the bolts holding the lower ball joints to the control arm. i was asking for grade 8 bolts but the only available is grade 7. i just bought it anyway. but is it safe?

you probably could reuse your old bolts if they are not damaged. the bolts you had probably are not even grade eight. if the bolts are not tension loaded (compression loaded), the bolts might hold and are less likely to fail than when they are tension loaded. unless you are sure the old bolts are grade eight, then you don't have to worry. otherwise, it is better to upgrade to grade ten (high tensile strength carbon steel) bolts

[miked]

you probably could reuse your old bolts if they are not damaged. the bolts you had probably are not even grade eight. if the bolts are not tension loaded (compression loaded), the bolts might hold and are less likely to fail than when they are tension loaded. unless you are sure the old bolts are grade eight, then you don't have to worry. otherwise, it is better to upgrade to grade ten (high tensile strength carbon steel) bolts

thanks.....the upper ball joints are press fitted so no problem...the lower BJs are bolted (3 bolts) and they are the load bearing joints (coil spring in between control arms). are the lower BJs tension- or compression-loaded then?

[jick.cejoco]

thanks.....the upper ball joints are press fitted so no problem...the lower BJs are bolted (3 bolts) and they are the load bearing joints (coil spring in between control arms). are the lower BJs tension- or compression-loaded then?

so the suspension system you have is a short and long arm suspension (SLA). whichever of the two control arms carry the sprung weight or the control arm which has the spring between it and the vehicle frame is the load bearing control arm and the ball joint on it is also the load bearing ball joint. the way the ball joint attaches to the control arm determines if the bolts or fasteners are tension loaded or compression loaded. if the flange of the ball joint is under the control arm, the bolts are only tension loaded because of the torque applied to it and not the sprung weight, which would be not much of a problem if the bolts were downgraded than when the sprung weight plus the fastener torque are imposed upon the fastener

[miked]

so the suspension system you have is a short and long arm suspension (SLA). whichever of the two control arms carry the sprung weight or the control arm which has the spring between it and the vehicle frame is the load bearing control arm and the ball joint on it is also the load bearing ball joint. the way the ball joint attaches to the control arm determines if the bolts or fasteners are tension loaded or compression loaded. if the flange of the ball joint is under the control arm, the bolts are only tension loaded because of the torque applied to it and not the sprung weight, which would be not much of a problem if the bolts were downgraded than when the sprung weight plus the fastener torque are imposed upon the fastener

after further inspection, BJ flange is under control arm. i may reuse the old bolt then and use the new bolts somewhere else....i may use them as carry-around spares on my truck but can i use them on the propeller shaft?

btw, the SLA suspension is a beam type. strut bar in front of lower arm.

[jick.cejoco]

after further inspection, BJ flange is under control arm. i may reuse the old bolt then and use the new bolts somewhere else....i may use them as carry-around spares on my truck but can i use them on the propeller shaft?

btw, the SLA suspension is a beam type. strut bar in front of lower arm.

SLAs come in two versions: double wishbone type (both upper and lower control arms are triangular) and the triangular and straight control arm type (lower control arm has a strut rod to make a triangular support). the type F (the spring is on the upper control arm) SLA had been obsolete because of high profile (higher hoodline)