Rear Hatch issues

So when I first bought my truck, the rear hatch would open about halfway and needed help rest of the way up and when u let go at the top it would fall til about 75% mark. Might I also mention they were not OEM struts, made in USA however.
A buddy of mine is parting out his 1999 4Runner (because it had 300k+ miles and was worth more in parts) so I bought his (KYB, I assume to be OEM) rear hatch struts from him, which worked perfectly fine with no help on his Runner, and installed them today on mine.
Now the hatch wont lift at all without help however any position I put it in it will hold stiff as a rock all the way to the top. So my question is now… why wont my hatch open on its own lol.
Thank you in advance for any helpful replies.

 

Grease your hinges?

 

Get new OEM struts? Regardless whether yours are original or not, your buddy's are 24 years old. That tailgate is heavy, and comparing one set of used ones to another on two different old trucks may not be the best idea. As negusm said, grease the hinges, too.

 

Hey yall, thank you for the replies. So yes, greasing the hinges made a difference. Wont fully open on its own but it moves up more freely and Im sure after another few days or so soaking it in wd40 it might be okay!

 

WD40 will evaporate and it will be worse.

You want a grease of some sort that will hang around.

 

I agree 100% on the WD-40 comment.
The WD is the initials for water displacement.
For that WD-40 is awesome.
I use it on rigging equipment and whatnot that has gotten wet.
How this product has come to be known as a lubricant is somewhat of a Jedi mind trick in my opinion.

 

WD-40 is a very handy SOLVENT that is very good at being a general purpose CLEANER.

When something is stuck and you displace the water and clean out whatever is causing the bind...it fools you into thinking you are lubricating!

You need to re-apply it religiously or get a proper lubricant.