4wd issue. Replaced vacuum line harness, check valve, solenoid and locking hubs. Installed using vacuum pump to avoid damage to the diaphragm. Drivers side keeps repeatedly failing. Vacuum reading in the lines ranges from 19-25 at idle. Drivers side locking hub will not hold vacuum meaning diaphragm is damaged. What would cause repeat failures?!

 

Guess is Assembly procedure.
It has some precautions and requirements to be followed to be sure nothing is forced during assembly.
Good luck.

 

By procedures are you referring to putting 15-20in-hg vacuum to the locking hub to avoid damaging the diaphragm and making sure the teeth are aligned. I've completed this exact job several times on multiple vehicles. The truck this time is my personal vehicle. I've measured vacuum at every possible place and it all checks out. After replacing iwe it'll be fine for a few hundred miles and then it'll grind. Switch from 2wd to 4wd and back to 2wd it'll go away for another couple hundred and bam out of nowhere it'll grind. Repeat same process and so on until it won't make it 10 ft without grinding horribly. Once the cold hit it was basically bypass the drivers side and plug the line leaning it permanently locked in which keeps the grinding away but wears out the hub prematurely. Of course I can solve a customer's problem without issue. For some reason I can't get mine solved. I've looked into alignment issues and it's within spec and drives straight.

 

From your original post, it was Guessing.
If you did the procedure many times to success, you have to be missing something.
Good luck.

 

I am guessing that you think that if grease is good on the IWE that more grease is more gooder.

 

i put a small amount of grease on the axel but not more than a thin film for installation but i do not pack grease in the iwe. Anyone even partially mechanically inclined should know better. That's like throwing grease in an oil bearing.. makes no sense. I work on them everyday. For over 12 years. Not implying I know everything about everything because I learn new things everyday but I know a thing or 2. Thanks for the input tho.