Sullair 250018-551 Aftermarket Flexible Coupling Element

Sullair 250018-551 is the six-bolt hexagonal rubber drive coupling element between the motor and the air end. It is used on Sullair Series 12, Series 16 and HH rotary screw air compressors (as listed by replacement sellers). This aftermarket version is made to the same mounting and connections as the original, so it fits where the old one came off.

Sold as one unit. Check the number on your old part, or in the parts manual for your machine, before ordering.

Technical properties & sizes

Applications & use cases

Cracked or split rubber
Heat and torque cycles crack the rubber between the bushings. A split element puts shock loads on the motor and air end bearings, so change it at the first cracks.

Knocking at start up
A worn element lets the coupling halves wind up and knock as the motor starts. Check the element when you hear it.

Black rubber dust in the coupling guard
Rubber dust round the coupling means the element is wearing, often from misalignment. Replace it and check the alignment.

Fitting tips
Isolate and lock off power before removing the guard. Fit the element on clean bushings, tighten the bolts evenly to the maker's torque, check the motor to air end alignment, and refit the guard before starting.

Price beat guarantee

We check what other aftermarket sellers charge for this same part. Their prices on the date we checked:

Our price of USD 99.71 is 26% to 89% less than these sellers.

Found this part cheaper somewhere else? Send us the listing and we will beat it by 5% under our Price Beat Guarantee. Every order is also covered by our 30 day money back guarantee.

Frequently asked questions