Sticky black substance leaking from leaf springs joint

Kipcl · July 12, 2016

I have a 2014 LT Silverado 5.3 litre, Sport Edition, with approx 80,000 miles. Today I noticed a pool of black, sticky substance below the right, rear of the truck. I looked under the vehicle, and found black splatter marks all over. The viscosity thickens as it dries. After cleaning the underside, I think was able to find the leak. It is coming from the front joint on the leaf springs. Forgive my ignorance, I do not know a lot about auto repair, and that is the best way I can describe the problem. None of my gauges are signaling that there is an issue. It might be helpful to know that approximately 2 weeks ago, I ran over a metal ladder on the freeway, which blew out my tire. But, I didn't notice any other damage.

I have attached some pictures. Can anyone tell me what the problem is, cause, how to fix, is it a diy project, etc??

Thank you,

This is my first ever post. I'm not even sure that I am doing this correctly.. I apologize in advance

Pics 1, 2, 3 - (Leak 1-3) - Leak from leaf spring joint

Pics 3 and 4 - Just showing splatter marks from leak

Pics 5, 6, 7, and 9 - Different angles of the leak

Pic 8 - Overview of leaf springs

Thomcat · July 13, 2016

There is no oil or grease fitting for the leaf springs and the rubber bushing is a dry component.

Look like oil trailing from somewhere else, bad shock or oil leak air blown across the undercarriage from somewhere else, .i.e engine or tranny seal, "stickyness" likely caused by oil combined with the tarry snot coating the frame.

redwngr · July 13, 2016

Was it ever serviced after a complaint about a squeek from the rear?

(may have had soem type of lube applied to stop the noise)

Any chance the truck drove over something that contained the material?

I think I'd start by a clean-up at a coin-op car wash and see if substance returns.

dave07 · July 13, 2016

The only thing that has oil back there would be the rear pumpkin and brake fluid. Diff fluid could be getting on the driveshaft and flinging it. But I doubt that is your issue. Brake leak, your pedal would be spongy, check your fluid level anyway. Probably more like you hit some oil bottle or puddle on the highway.

Clean it up and keep an eye on it!

J rod · July 13, 2016

Looks like asphault oil to me but like they said de tar it and clean it up real good and see off you get any more flinging underneath

Boardmember · July 13, 2016

"Tarry snot." So THATS what it's called...yes, I was looking under my new GMC and touched the frame. That's exactly what it was. And it doesn't come off easily.

Sorry kipcl, I hope you clean up and the suggestions above are all it is.

BigBadSierra · July 13, 2016

If the dealer made the mess they can clean the mess!!!!!!!

Kipcl · July 13, 2016

There is no oil or grease fitting for the leaf springs and the rubber bushing is a dry component.

Look like oil trailing from somewhere else, bad shock or oil leak air blown across the undercarriage from somewhere else, .i.e engine or tranny seal, "stickyness" likely caused by oil combined with the tarry snot coating the frame.

Kipcl · July 13, 2016

Your theory makes sense. I discounted oil due to the thickness and stickiness. But, oil combining with the stuff under the vehicle is plausible. Also, about a month ago, I changed the oil myself, for the first time ever, on any vehicle. Oil changes are so cheap, that I've always had it done. I've replaced brakes, alternators, starters, etc but never oil. Only reason I did this time is because Walmart had full synthetic, 0w20, 6 gallon box for $13. (Had to be miss marked).

Anyways, presumably (I will check in a few) I would see the oil leaking from the pan or the filter, if your theory is accurate??

Thomcat · July 13, 2016

Your theory makes sense. I discounted oil due to the thickness and stickiness. But, oil combining with the stuff under the vehicle is plausible. Also, about a month ago, I changed the oil myself, for the first time ever, on any vehicle. Oil changes are so cheap, that I've always had it done. I've replaced brakes, alternators, starters, etc but never oil. Only reason I did this time is because Walmart had full synthetic, 0w20, 6 gallon box for $13. (Had to be miss marked).

Anyways, presumably (I will check in a few) I would see the oil leaking from the pan or the filter, if your theory is accurate??

Doesn't have to be a leak..oil plug and filter are likely intact or you'd have a much bigger mess than that...even if you are careful when you change oil or when you remove the filter, oil is spilled, splashed or leaks onto the frame. Unless you wipe the areas of the engine around the filter housing and the top surfaces of the cross member and frame free of oil, it will eventually find its way to the floor or blown by air when you drive and end up somewhere on the rear. Wipe a paper towel on top of the frame/crossmember areas to see if it contains residual oil crud from the change.

Dnt · July 14, 2016

I think I saw that mashed up dog body in the road the other day. You should not have run over it man it leaves a mark LOL.... Just joking, others have given excellent advice do a thorough cleaning of the area and recheck in a few weeks to see if you have an actual leak or if those were just smashed dog guts.

On the oil change thing I have been buying the mobile1 on the cheap at Wally World myself and my local oil change place changes the oil and filter for me for 20 bucks. just a bit of peace of mind that I know that the correct oil and filter are used plus these silly things hold over 8 quarts of oil just creates a big hassle to recycle. I let the pros (grease monkeys) do that.

ata3001 · July 14, 2016

Leaking muffler bearing!

Thomcat · July 14, 2016

I think I saw that mashed up dog body in the road the other day. You should not have run over it man it leaves a mark LOL.... Just joking, others have given excellent advice do a thorough cleaning of the area and recheck in a few weeks to see if you have an actual leak or if those were just smashed dog guts.

On the oil change thing I have been buying the mobile1 on the cheap at Wally World myself and my local oil change place changes the oil and filter for me for 20 bucks. just a bit of peace of mind that I know that the correct oil and filter are used plus these silly things hold over 8 quarts of oil just creates a big hassle to recycle. I let the pros (grease monkeys) do that.

OK as far as that goes. But, true piece of mind can only be obtained when you actually know for certain that the Mobil 1 goes into your vehicle instead of bulk crap from a 55 gal drum with just a quick wipe of the outside of the existing oil filter.

Dnt · July 14, 2016

I use a local small mom and pop oil change they let me into the work area to supervise. Would not have it any other way

Dnt · July 14, 2016

Leaking muffler bearing!

Whaaaaaaaatt no way man those muffler bearing seals NEVER leak. More likely than that would be a blinker fluid leak, most people do not know that you must take your truck back to the dealership to have the blinker fluid changed on a regular basis.................