BadPax New Reader
8/31/18 12:23 p.m.

BadPax is quickly starting to equal Bad Post or Bad Question....but I am looking for advice on repairing a rubber bellows or boot.  In the process of repairing the shift linkage on my 91 Corvette with the ZF 6 Speed transmission, the large rubber bellows that shields the linkage on the underneath side of the car developed a straight tear along the bottom center part of the bellows (about 3 inch long tear).  I believe the bellows may be NLA, but in any case I don't think I could replace it with the transmission in the car.  So I am looking for suggestions on how to patch over the tear, to try and keep as much road debris out of the linkage as possible.

My initial plan would be to use a piece of inner tube and glue it to the bellows using 3m window weld superfast urethane adhesive/sealant (same stuff that is used to install front windshield).  I have not used the 3m stuff before, but it was recommended to me.  Does this sound like a plan with at least a chance of success, or would there be a better route?  Appreciate any suggestions the hive might have.


GameboyRMH MegaDork
8/31/18 12:29 p.m.

Your plan mostly sounds good but I think rubber cement (like in a bicycle inner tube repair kit) would be a better bet than window-weld.

BadPax New Reader
8/31/18 12:40 p.m.

In reply to GameboyRMH :

I haven't worked with very much with rubber cement, but I was concerned that the heat might cause issues with rubber cement.  The rubber bellows is only 6 inches or so above the cat.  There is a heat shield on the cat, but it still must get pretty warm up there.

Fueled by Caffeine
Fueled by Caffeine MegaDork
8/31/18 12:46 p.m.
BadPax New Reader
8/31/18 12:56 p.m.

In reply to Fueled by Caffeine :

It's not either of those parts.  I am probably using the wrong term, but it is a large rubber bellows or boot that is on the underside of the car that is covering where the shift linkage shaft connects to the transmission shaft, I haven't seen a setup like it before.  Then on the interior of the car there is a traditional rubber shift boot that goes around the bottom of the shifter along with a leather shift boot cover that goes over the rubber shift boot.

BadPax New Reader
8/31/18 12:59 p.m.

Looking back over the email that I had received about  using the 3m window weld; that was for gluing the cracked pieces together, rather than applying a patch over the cracked area.  Maybe rubber cement would work?  If it is too hot for the rubber cement, then it would probably also melt the inner tube patch I had in place.

Fueled by Caffeine
Fueled by Caffeine MegaDork
8/31/18 1:54 p.m.
Mezzanine Dork
8/31/18 2:39 p.m.

Rubber cement with some bike inner tube for sure. Rubber cement works brilliantly on the stuff; just apply to both surfaces and let dry for 3-5 minutes before sticking them together. If the rubber won't melt from the temps, the rubber cement won't either.

02Pilot SuperDork
8/31/18 3:48 p.m.

Window Weld dries hard - that's why cheap people like me use it fill the voids in rubber mounts. You don't want that here.

SkinnyG SuperDork
8/31/18 4:15 p.m.

I used "Wonda Fix" that I got off a co-worker who imported it from South Africa years ago.  I'm sure it can be found elsewhere.

I supported the back side, gooped it with Wonda, and it held just fine for years until gasoline leaked onto it, and it dissolved.

BadPax New Reader
9/3/18 10:14 p.m.

To finish this up...I ended up using a piece of automotive inner tube and attached it using Weldwood Contact Cement.  I was very happy with the way the patch adhered, now I will just have to see if it can withstand heat over time.  Thanks for all of the input.



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