Can't turn the key every few cycles

[nthach]

A friend's Tahoe had a problem where his ignition wouldn't turn - it would lock up every few key cycles. I replaced the ignition cylinder and I noticed a mechanic unhooked the park lock cable, hence why he was able to shift the truck into D to turn the key. I hooked up the cable and replaced the cylinder. The truck has been starting fine until recently - what would happen is that he turns off the truck but he can't turn the key unless the truck is sitting for a while. I took apart the cylinder, lubed it up with GM's recommended Super Lube grease and replaced the BTSI. Truck was starting fine until he was stopped at Ikea to return something and the ignition wouldn't budge immediately. He eventually got it to turn.

I'm thinking the lock housing might be bad - I did notice the park lock cable was retracted in P, but the cable end moved along with the shifter - so I think the shift mechanism is fine. The lock was turning smoother after I lubed it. Do lock housings in these trucks go bad?

 

[andyd]

How many keys are on his key ring? The start position on my son's beater 528e was getting iffy. I replaced it with a starter button. His keyring had a jillion keys and a leatherman tool. The Rats igniton lock is worn out and requires occasional fiddling. GM keys of old were practically universal. An older GM mostly didn't need a key after about 10 yrs.

 

[nthach]

Just 3 keys, the old ignition key which operates the locks and his house ones.