Creak when put in reverse?

[badbowtie03]

hey yall, when I put my 86 k5 in reverse randomly i will hear a loud creak... or if when in reverse... and you throttle fairly good it will creak... yall think a bad motor mount maybe or body mount? Anyone had this problem? Thanks!

 

[SpeedlabDan]

U joints bad

 

[badbowtie03]

Good idea I will check them

 

[diesel4me]

Could be loose rear U bolts on the springs too..or worn bushings at the shackles & other end of the spring..
I've had shocks make weird noises ,but not while driving so much,you notice it more shifting from drive to reverse or while parking..

Another thing that can cause it is a dry slip yoke,the splines can make noises,but on an '86 I doubt that is your source,the older models with fixed yoke on the transfer case had the slip yoke made into the drive shaft were the ones that did it,if those don't get greased often they'll rust up and creak & groan..your '86 probably has a NP-208 with a car like slip yoke made into the tail of the T-case...those run in ATF and don't usually give any grief .

 

[badbowtie03]

So both motor mounts were broken horribly! I replaced them this afternoon... not much fun to work on them but boyyyy what a difference! I just did stock replacements. Feels so much better idling and shifting now... but still... the idle seems high.... working on that...

 

[rampage]

So both motor mounts were broken horribly! I replaced them this afternoon... not much fun to work on them but boyyyy what a difference! I just did stock replacements. Feels so much better idling and shifting now... but still... the idle seems high.... working on that...

Just an FYI, people on here have had bad luck with replacement rubber bushings saying they don’t last long so don’t be surprised if the rubber fails on them.