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Oily residue on back of truck?

4K views 18 replies 8 participants last post by  RivMan 
#1 ·
Hey guys, got a question!

I've put about 1000 miles on my truck since I picked it up 3 weeks ago. I washed it about 300 miles ago, and when I was filling it up today, I noticed the entire back of the truck had a thin oily film on it, from the back tire back. Is this a normal thing these trucks do, or do I have a leak to track down?

Thanks
-Rob
 
#2 ·
Is it on both sides? It could be from too much tire dressing being applied. is it on the tail gate or only after the exhaust? Check all your fluids to be safe
 
#3 ·
It's on both sides and tailgate, only behind the rear tires. No tire dressing ever on the these tires, so that's not it.

Thanks
-Rob
 
#4 ·
well then, check under neath and see if fluid is maybe heaving out the rear diff?
 
#5 ·
If it is under warranty, take it in. Sounds like you may have a leak of some kind. Check the ground where you park it over night and see if there is any evidence of a leak there. It has been cold the past few mornings here in SE Michigan. Something that may seal well when it was warmer may not be sealing as well now. This is the time of year everyone begins to notice their trans cooler lines leaking. Keep us posted.
 
#7 ·
Thanks guys! The truck is an 07 LBZ with 108k, so no warranty here.

It seems as though I'm one of the lucky ones. I'm guessing these are the trans cooler lines, passenger side under the bumper.



Are they a tough fix? Do they normally leak enough to cause a huge problem?

Thanks
-Rob
 
#8 ·
They can leak enough to cause big problems, a few of the vendors like alligator performance have an aftermarket line kit that is easy to install and will take care of your problem, it will be money well spent.
 
#9 ·
Thanks guys, I've seen the Alligator kit, and the Husker diesel kit. Are there any others out there I should consider?

Thanks
-Rob
 
#10 ·
Allseason makes a good one.

I just took the lines off and took them to a hydrolic line shop and had them recover the ends and hard lines, then had them smooth crimp new stainless braided hose onto my lines so they will last forever now. Plus, it was cheaper than new lines from GM that I know will eventually leak again................
 
#11 ·
Yours look like they are leaking pretty bad.

One day i was driving home from work at a LBZ went flying past me with a mist coming from the bottom of his truck which was splattering me well... I gunned it to catch up to him trying to get him to stop to tell him about his lines.. I think he thought i was being a dick.. flipped me off then sped off. :(

If you want give me a call and i can get you hooked up on a set of lines
 
#13 ·
Thanks guys, I just checked the trans fluid, 3 qts short. Never noticed a puddle under the truck, so I'm guessing it's only coming out while driving.

Michelle, has there been any re-design of these lines, or would any line I purchase through the dealer have the same deficiency in the crimps?

Thank you
-Rob
 
#15 ·
So HELLO is in order from me... first post... I have a 03 Dmax that I have driven 108k loving miles... bought new in 2003. Noticed film of oil on the tailgate when I arrived home after driving a 2000 mile round trip to South Dakota to shoot pheasants... I was in need of an oil change so when I dropped it off at the local chevy dealer to have the oil change they called and said the transfer case had a hole the was worn from the inside out... wanted $1,300 to repair it... what should I do?
 
#16 ·
Look into "Pump Rub". If the T-Case isn't trashed from lack of fluid yet, there's a repair kit available from merchant automotive. $75 for the kit and $300 for a new housing I think.

-Rob
 
#19 ·
Once it starts leaking, that's the fix (Or taking it to a skilled welder). The Merchant kit only prevents it from happening again.

-Rob
 
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