Wheel hub bolt grade ?

[Retired Sparky 526]

I'm looking to replace the bolts that hold the wheel hubs on the rear axles of my '86 310-8. Can someone tell me what grade of bolt to get,

     the old square headed bolts don't offer much info. This time I'm going hex head.                                  

                                         

                                                  Being hex head, I now have a torque value I can use.

 

 

 

[WHX?? 50,782]

i would suggest a grade 8 and believe they are a 3/8-18 thread. I have a one that is twisted off and is gonna be real fun to get off. grade 8's might not do that.

[stevasaurus 23,086]

Those are special bolts...they are indented on the bottom to better grab the axle without damage.  They are actually a set screw...3/8 - 16 x 1".    Suggest you get a 12 point socket that fits the 1/4" square head for more torque.

Edited August 22, 2016 by stevasaurus

[WHX?? 50,782]

 

2 hours ago, stevasaurus said:

they are indented on the bottom

oh forgot about that...could a guy grind that cup in bottom??

[stevasaurus 23,086]

Could maybe use a drill...but why not use the right thing with the right socket?? 

[pfrederi 18,341]

The set screws should be alloy steel trying to grind a cup would be a lot of work and wouldn't be as good a real one.  Also 8 pt sockets are less likely to round off the head.

 

 

Edited August 22, 2016 by pfrederi

[Achto 28,806]

You can also find set screws in 3/8 16 with an allen  head on them. Then you can use a 5/16 allen socket on your torque wrench.

[Jerry77 1,218]

6 hours ago, WHX7 said:

i would suggest a grade 8 and believe they are a 3/8-18 thread. I have a one that is twisted off and is gonna be real fun to get off. grade 8's might not do that.

JIm - you might check with a local machine shop - I got a 1/8 inch x 3 inch long cutting bit made for tool and die makers from a friend - I was restoring an antigue car with a number of bolts that were broken or too stubborn to remove - you put that bit in a die grinder and just drilll right down into the bolt and ream it out - gets thin enough it will remove easily - go slow, it is easy to  get into the threads of the casing....if you can find one, you won't believe how easy it is to remove a broken bolt..

[gwest_ca-(File Mod) 11,252]

Set screw torque is listed in this manual and it is also on the first page that opens which is readable below.

Just snug up the jamb nut. Any more and it tends to pull the set screw back out. After a few hours recheck the torque because they always seem to loosen as parts seat in. Keep checking until you are satisfied they are staying tight.

Don't forget to apply Never-seize to the axle and hub.

 

Garry

[WHX?? 50,782]

14 hours ago, Jerry77 said:

JIm - you might check with a local machine shop - I got a 1/8 inch x 3 inch long cutting bit made for tool and die makers from a friend - I was restoring an antigue car with a number of bolts that were broken or too stubborn to remove - you put that bit in a die grinder and just drilll right down into the bolt and ream it out - gets thin enough it will remove easily - go slow, it is easy to  get into the threads of the casing....if you can find one, you won't believe how easy it is to remove a broken bolt..

Sounds interesting Jerry we may need a pic of that cutter. Going to try welding the jamb nut on to what little is left of the set screw and try to carefully back it out. If that don't work yours is plan B.

Edited August 23, 2016 by WHX7