Chevy & GMC Vans

The gasket stuff sounds right.

Thanks Dean. I will use it. I was looking at various diff covers and the way they picture putting the silicone on to form the gasket was sort of a wavy line that would always go past the bolt holes on the inside of the hole. Is that approximately correct? There really isn't much description on the tube.

When I have helped Dean apply silicone to make a gasket we always put the silicone on in a straight line and around all sides of the bolt hole. Never can have too much silicone to make a great seal. I also know some that we have used has had to cure a bit before we put the two parts together some are immediate. Guess you will have to tell from the directions to see what kind yours is. Hope this helps.

So far you've done a great job. Don't be afraid to modify tools to make them do a specific job. When I use RTV sealer I always clean the mating parts with carb cleaner. In order for RTV to bond properly the parts must be perfectly clean. On the diff cover I use two very small beads. One on the inside of the holes and one on the outside of the holes. That provides a backup seal just in case the inside seal fails. Keep up the good work. For those of us who have been doing this for a very long time there's a great feeling of satisfaction when a job has been done successfully.

Sounds good to me.

Smiliesafari wrote:So far you've done a great job. Don't be afraid to modify tools to make them do a specific job. When I use RTV sealer I always clean the mating parts with carb cleaner. In order for RTV to bond properly the parts must be perfectly clean. On the diff cover I use two very small beads. One on the inside of the holes and one on the outside of the holes. That provides a backup seal just in case the inside seal fails. Keep up the good work. For those of us who have been doing this for a very long time there's a great feeling of satisfaction when a job has been done successfully.

I'm with you on the sense of satisfaction. As I grow in ability, I grow in confidence.

The job is almost done.

Oh, would brake cleaner work as well as carb cleaner? I ask because I have the brake cleaner

Yes, thats what we used to give a final clean up of my diff cover and it worked great, spray away

What Zam said. Truth be known, they're probably the same solvent.

I have the cover cleaned up with brake cleaner. There are a couple of very small spots of the old gasket right by the bolt holes that is putting up a fight trying to stay on the cover. I have run out of time for this weekend, so it will have to wait until Monday, unless I find an extra hour a little later. Then put the RTV on it, put it back on, fill with oil. I don't have it in front of me, but may have it somewhere, what should the diff cover be torqued up to.

How long before it it drivable? The tube I have doesn't really give a good answer to that question. Time to set up or time to full cure?

I wouldn't torque the cover bolts any more than 15 ft lbs. Actually just a little more than a good snug will do. It's not a structural piece so true torque isn't necessary. Clean all of the old gasket off and hammer all of the bolt holes flat if they have been distorted. Complete cure time for RTV is usually about 24 hours. If you don't need to use the van then let it sit overnight before you add the lube.

That is about what I expected. I will have to check the holes and see about hammering them flat, once I find something to hammer them flat on.

I got the cover back on, just now. It turned out I have the wrong stuff to do the gasket. So off I went to get the Ultra-black gasket maker instead of the Black sealant/adhesive. Now I need to wait an hour and tighten the bolts up 1/4 to 1/2 turn.

Last night my wife was asking if the van would be drivable today. I said if I had the right stuff I could get it to a running condition, but that would require driving to London to the 24 hour Wal-mart to get the gasket stuff. She didn't think that was worth it. So I guess we wait until tomorrow for the gasket to set up completely.

So I am figuring jacking up the front end will be the easiest way to get the van level just leaving the back up on the stands since my drive is not level so that I can refill the diff. So how level do I have to get it?

Also, I figure based on how the fill opening is located, I fill it until the oil starts to leak back out the hole.

The van isn't high enough to make any difference. Fill it where it sits.

DONE!!!

Better yet it actually still drives