The built-in kickstand is one of the best features of older Schwinn bikes, and is much stronger and more durable than any aftermarket bolt-on replacement I've seen. Fortunately even if they have become loose over the years, they can be made to work like new, in many cases without even replacing any parts.
See the diagram showing the Schwinn kickstand parts here
. In it you will see the cam and dowel pin that Jeff was referring to. While both can wear, in my experience the dowel pin wears much more readily than the cam, especially when they have not been regreased over the years. Fortunately by the nature of the design the dowel pin wears against the cam on one side only, so an easy fix to tighten up these kickstands is to rotate the dowel pin 180 degrees in the hole. To do this compress the washer and spring using a vice as seen here
, then using a pliers rotate the dowel such that the worn side is against the washer, which will leave the fresh side against the cam. If you can't twist the dowel pin with a pliers, then remove it with a punch and reinsert it with the worn side facing the washer. Be sure to remove all the old grease from the entire kickstand assembly and regrease before reinstalling.
If that doesn't help, then replacing the dowel and/or cam is the next option, and that should make it work like new. For the record the dowel is a 3/16" diameter solid steel pin that is 3/4" in length. For maximum durability it should be hardened steel: http://www.grainger.com/Grainger/Dowel-Pin-2MB61
The cams you can find on eBay
, however you need to be careful as there are two different types, which I'll call "1970-" and "1971+" since those are the years they were installed on new bikes (yours is obviously the latter). They both fit the same frame tubes, but they require different kickstands and so are non-interchangeable. The 1971+ cam was designed to allow less kickstand travel, keeping the stand more vertical in relation to the bike when it is deployed. The corresponding kickstands were changed in length and/or angle. This change was made because when people would sit on bikes with the older style cam/kickstand deployed it would put excessive rotational force on the cam in the frame tube, rounding out the frame tube in some cases. A kickstand repair kit (p/n 57 050
) was even sold expressly to fix the rounded frame tube problem.
You can tell the improved 1971+ cams and kickstands apart from the 1970- models by virtue of the markings. The 1970- cam has a single notch in the base of the drive-side triangular end, while the 1971+ cam has 3 notches. You can see these markings in the pics below, with the 1970- cam on the left and the 1971+ cam on the right. The matching 1971+ kickstands can be identified by three slash marks on either side of the stamped number, which are the last three digits of the part number. Your Suburban should have a p/n 57 350 kickstand.
Looking on eBay right now there are 4 auctions with NOS cams being sold separately, of those 3 are the old 1970- type (like this one
) and only this one
might be the newer 1971+ type, but it is hard to be 100% certain from the bad picture.
Before you go replacing any parts try rotating the dowel pin 180 degrees and regreasing the assembly first, let me know if that fixes the problem.