i recieved my new pdr hx35 turbo on friday and when i went to install it yesterday , i noticed than the front blades would spin independantly of the rear (my stock turbo didnt do this). at this point i realized that the small nut (10mm) that holds on the compressor wheel(front) was loose-so loose that i could unscrew it by hand! i tried to call piers -but they are not in on the weekends. does anyone know what the proper torque would be -or if i need to use loc-tite on it? i'd hate to grenade my new turbo! its the small 10mm nut that holds the front on and its reverse threaded.

 

If it's a 6 point nut, 142 in-lb. A 12 point nut is 135 in-lb. You can download all the service literature here. http://www.holset.co.uk/flash/index.html
Take care though as I think some of the compressor wheels are balanced to the shaft. There might be marks on them to line up. I know my stock turbo is marked. Good Luck.

 

ugh! uh-o ! i didnt see any marks on the inlet side- i did see a paint mark on the exhaust side though--is that the mark that you were talking about? if so, i may be ok. the exhaust side was installed ok i guess- they grind on the nut and shaft after assembly to ensure that it doesnt come off.

 

Wouldn't it also have a small key to heep it from spinning on the shaft??? If it where mine, no way in heck would I install it and risk ruining it, get a hold of Piers on Monday and find out WHY it's this way, sounds to me like it was assembled on a Friday and someone was in a hurry to clock out.

 

The compressor wheel does not have a key. The threads on the shaft are reverse of the rotation to keep it tight. Still best to check.

 

Yeah, my Cummins book shows no key, but says there should be alignment marks on the shaft and turbine. BTW, they grind on the rear nut to balance the turbo. My old H1C is hardly touched, but my WH1C has dang near half the nut ground off.

 

Like said before, talk to Piers and see what they say.

 

thanks to everyone for their advice! and thanks to berner for the holset link. i was able to go onto holsets site and download the entire service and repair manual for the hx35w(all 72 pages) . it is very detailed and helpful- id recommend for everyone to save it too. according to the manual, since i have the bi-hexangonal nut(12 point) instead of the hex(6 point) nut, it will not have an alignment mark to line up cause the two units are balanced differently. it just gives me the torque spec and in the assembly section -tells me exactly what to do.

 

There's a whole bunch of ways to balance things, but you also have to consider the tip speed, the rotors in the turbos, would have to be what we call an investment casting, to be poured this close, only .001 or so out of tolerance, but to have to grind most of the nut away, would tell me that one or the other rotor was out of tolerance. I wish I could take my turbo off the motor, spin it up, and put our SKF analyzier on it to see just what it was doing. But there again, manufacturers CAN make a engine that is balanced and won't give problems, but where would be the profit in this, the motors would last too long and they'd lose $$$$ on repair parts