Note: this post has been updated with more images and information added.
We totally know we’ve got a queue of jobs to get through this winter. But we thought it might be useful and that it’s about time we get into some details about why we dwell on fixing the seat foundation before any new foam and skins get fitted.
You will never get a great driving seat despite how fresh your seats look unless the foundation is fixed. In some cases, seats were not even made comfortable from factory.
Seat foundation is like house foundation. But you don’t drive your house around and get a sore back or bottom.
The example we’re using here is XC seats, using XA/XB as additional examples for comparison.
If you would like to know what to look out for in investigating why your seats are uncomfortable, these are some of the more common problems that we have encountered during our jobs. It goes without saying that welding repair and spring replacement are required well before the fitment of any upholstery.
Frequently observed issues: cracked / fatigued metal, worn/twisted (or sometimes missing) weld nuts etc., fatigued / saggy springs, worn or broken spring clips, metal wear from fatigued / unsupportive springs, collapsed (or sometimes broken) edge wire(s) …
You can right-click on each image to view it in detail.
Driver back rest issues
Look for metal fatigue / cracks as they can be hard to spot.
Even on the less worn out side (inside) of the driver seat, spring clips could be worn.
The head rest part usually doesn’t suffer too much stress, but a weak spring could continue to wear out itself, and/or other parts of the frame that it comes into contact with. Note that not every single spring needs to be replaced. Broken ones should be, but sometimes factory springs just need to be reinforced.
Fatigued and/or broken edge wires and/or springs are very common. If left unaddressed, edge wires / springs will continue to hit and wear the metal out, and springs/wires could eventually snap. Your seat sags and collapses and the broken metal parts poking out for example would also damage the foam and fabric covers. All in all a very unpleasant experience obviously.
Driver cushion base issues
Look for worn/twisted (or sometimes missing) lock nuts,
Keep inspecting every spring because sometimes they look okay and unbroken until some pressure applied, then you’ll know they’re fatigued. They stop functioning as springs and will not provide any support or comfort when used.
Comparisons between upgraded XA/XB vs. yet to be restored XC seat bases:
We hope this post is helpful in demystifying why your seats are uncomfortable.
Note: the images and information below have been added to illustrate some details that I missed before. Furthermore the driver seat now has all broken and fatigued spring replaced.
XC Back Rest with New Factory Spec Springs
Lower headrest spring has been replaced – this will give better support to the driver head rest especially when the seat skin has a wire that needs to be hog ringed down to the spring.
Lumber / mid-section spring has been replaced with a handmade, factory-spec spring. It is made with spring wire and in fact a slightly thicker gauge, with the expectation that it will offer an even stronger spring and therefore better lumber support. This mid section is also where the seat skin needs to have the listing wires hog ringed down to springs.
XC Cushion Base with Upgraded Spec Springs
Below are some more detailed photos that should have been included in the post.
Just a final note …
It is really important to check symmetry and squareness of the frames. A seat that’s had (accident for example) damage and has been trimmed without addressing the fundamental problems may look twisted and would feel really uncomfortable when used.