Is the Timbren Suspension Enhancement System Compatible With Sulastic Shackles?

Question:

I have a 2021 F350 SRW with Sulastic Shackles. Can I use the Timbren SES jounce stops with this configuration? I have a fairly smooth ride unloaded with Sulastic, but more sag than I would like when I tow my 5th wheel. Are they compatible?

asked by: Paul J

Helpful Expert Reply:

You will be able to use the # TFR350SDJ Timbren Suspension Enhancement System with your Sulastic Shackles as long as you still have the correct clearance. The Timbren attaches to your frame rail in place of the existing bump stop.

According to Timbren, there should be 1/2" to 1-1/2" of clearance between the rubber spring and the contact point on the axle. The # TFR350SDJ is 7-1/2" in overall length. If you measure from your existing bump stop attachment point to the axle and it is 8-9" then this will work for you.

If for some reason the gap is larger than 1-1/2" you can use a spacer like the # TA25722-90P00 1/2" spacer or # A25723-90AH00 1" spacer to reach the necessary gap. If you do need to use the spacer then you also need to get new hardware as the supplied hardware isn't long enough. This can be acquired at a local hardware store and requires 8, M10 bolts.