What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Let's talk Dana 44 steering arm studs/bolts

MTBLAZER89

MTBLAZER89

3/4 ton status
 Premium
GMOTM Winner
Joined
Aug 14, 2001
Posts
8,162
Reaction score
2,739
Location
Kalispell, MT
Let\'s talk Dana 44 steering arm studs/bolts

Ok been following all the posts about sheared studs and what to use as replacements. I have seen mentioned using bolts of various grades. Anyway got to talking about it yesterday with a guy, and he brought up an interesting point. When using a bolt with the conical washers the washers will squeeze the bolt as they get tighter...correct? The steering arm studs are supposed to be torqued to a specific value right. Wouldn't the "squeezing" of the bolt by the conical washer actually give an erronous tourqe value? I was just thinking that studs were meant to go there how "right" is it to use bolts in place of them? Am I thinking correct?
 
Re: Let\'s talk Dana 44 steering arm studs/bolts

I don't know for sure but I don't think there is a difference on the torque value. The area of the stud that the conical washer is on is just like a bolt. It is on a solid round piece of steel. It is not overtop of a threaded ares. So both a bolt and a stud should have the same 9/16" round steel surface underneith them. The only difference you might have is the bolt will probably be zinc coated.

Harley
 
Re: Let\'s talk Dana 44 steering arm studs/bolts

I was just thinking there would be because with a stud you are torquing the nut down on top of the conical washer, and with a bolt you are actually torquing everything down into the knuckle and the conical washer will be trying to squeeze the bolt you are turning where as with a stud thats stationary you are only torquing the nut. /forums/images/graemlins/dunno.gif
 
Re: Let\'s talk Dana 44 steering arm studs/bolts

Brian, The conical washers do not compress on the bolt, they have clearance around the bolt so that it passes through freely. The conical or tapered washer provides a press fit that holds the arm to the knuckle even after the bolt is removed. The reason for using studs instead of bolts is to assure that a bolt does not bottom out on the threaded hole and give a false torque reading.
 
Re: Let\'s talk Dana 44 steering arm studs/bolts

OK makes sense. Just trying to clear some of this stuff up. I'm going with the ARP studs. /forums/images/graemlins/peace.gif /forums/images/graemlins/waytogo.gif
 
Re: Let\'s talk Dana 44 steering arm studs/bolts

[ QUOTE ]
The reason for using studs instead of bolts is to assure that a bolt does not bottom out on the threaded hole and give a false torque reading.

[/ QUOTE ]

I agree w/ this... but I also think there's another advantage to using studs.

If a stud is used, then the threads bottom out into the knuckle and the exposed shear diameter of the stud is the "major" diameter of the bolt- say in this case a 9/16" - which is prolly close to 0.5600 or so.

However, if a bolt is used, then the shear plane falls on the threaded section of the bolt, and so the shear diameter is the same as the "minor" diameter of the bolt - in this 9/16" case - ~ 0.4943.

That's a significant reduction in area...!! /forums/images/graemlins/yikes.gif

Now... This is not to say that I haven't used bolts /forums/images/graemlins/ignore.gif for this exact application, and the grade of bolt used is gonna really affect the life of the connected joint.

Marv
 
Re: Let\'s talk Dana 44 steering arm studs/bolts

[ QUOTE ]
[ QUOTE ]
The reason for using studs instead of bolts is to assure that a bolt does not bottom out on the threaded hole and give a false torque reading.

[/ QUOTE ]

I agree w/ this... but I also think there's another advantage to using studs.

If a stud is used, then the threads bottom out into the knuckle and the exposed shear diameter of the stud is the "major" diameter of the bolt- say in this case a 9/16" - which is prolly close to 0.5600 or so.

However, if a bolt is used, then the shear plane falls on the threaded section of the bolt, and so the shear diameter is the same as the "minor" diameter of the bolt - in this 9/16" case - ~ 0.4943.

That's a significant reduction in area...!! /forums/images/graemlins/yikes.gif

Now... This is not to say that I haven't used bolts /forums/images/graemlins/ignore.gif for this exact application, and the grade of bolt used is gonna really affect the life of the connected joint.

Marv

[/ QUOTE ]

That must be why Marv is a "Failure Analysis Engineer" /forums/images/graemlins/thumb.gif
 
Re: Let\'s talk Dana 44 steering arm studs/bolts

[ QUOTE ]
Brian, The conical washers do not compress on the bolt, they have clearance around the bolt so that it passes through freely. The conical or tapered washer provides a press fit that holds the arm to the knuckle even after the bolt is removed. The reason for using studs instead of bolts is to assure that a bolt does not bottom out on the threaded hole and give a false torque reading.

[/ QUOTE ]

Ummm, that's not right. The washers tighten up against the studs to hold the arm on. If you use bolts and remove them the arm falls off. I don't see your logic?????

Using bolts will give you an incorrect torque reading on a D44 arm. This is part of the problem with using torque to measure when a bolt is tight. The best way is to measure bolt stretch, but that's easier said than done, so we use torque values.

Andy
 
Re: Let\'s talk Dana 44 steering arm studs/bolts

Yes the design of the cone washer is to clamp down on the stud and keep tention on the arm. D44/10B arms are designed on a friction fit not a shear fit. When using bolts the washer compresses and could catch the bolt before it is actually at proper torque. As to marvs mention on size, this is true. But the average shop does not sink the threads in the knuckle at all as to allow the stress riser (transition from shank to thread) to be buried in the knuckle.

As for harleys breakage, I have been thinking of how, why, and how to stop it all week. I have come up with a few problems.

1) Using a spacer will allow a larger diagonal force to be placed on the stud. It is now supporting a shearing force as well as a tension force. If the stud streched at all due to the tension load the frincion force (between the knuckle/arm) would become lower and in turn cause the steering to put its load on the shear of the studs instead of the friction of the inteface.

2)A x-over arm appears to have less area on the knuckle. I noticed this after comparing most x-over arm's outline with a stock arm's outline.

3) The 3 bolt patern creates a triangular pendulum between the TRE hole and the arm base in stock formation, where as a linear pendulum is made in x-over formation.

I might be overthinking this though due to my current summer classes.
 
Re: Let\'s talk Dana 44 steering arm studs/bolts

Is the difference in area actually .5600 with a stud though. If the stud hole was counter sunk for the stud slightly I think it would be but as of now it really isn't. This would still be putting the load on the thread area which is the smaller area. That is where my studs sheared. Right at the transition. It ripped right at the first thread on the studs which is right at or just below parallel to the knuckle surface.

Harley
 
Re: Let\'s talk Dana 44 steering arm studs/bolts

We don't really need to be concerned with the shear area here, if the studs are loaded in shear, it's going to break. It's the clamp load that keeps it all together and that's generated by the torque tension relationship in the bolt. When that's overcome by the side leverage, the strength goes only to the shear strength of the fasteners and off it comes. By the time you lose your clamp load, the stress in the fastener is so high that any side load will snap it.
I wouldn't spend too much time wondering why a grade 5 stud broke, put an appropriate grade fastener in there with a good torque spec and I think you'll be OK.

There might be a problem with the crush on the sleeve when you use a bolt, I didn't think about that part. You might be able to measure up how much it would crush and figure out if it will clamp on the bolt shank. If it will it will definitely affect the torque value. I wouldn't hesitate to use bolts as a get by but without more time figuring it out it may not be an optimum setup.
 
Re: Let\'s talk Dana 44 steering arm studs/bolts

Stephen is absolutely correct in that sense. Friction between the arm and the knuckle is what keeps the bolts from shearing. When that friction is broken, the bolts will most likely shear reguardless of the size of them.

That is essentially why making sure they're torqued sufficiently is most important. If the bolts are not properly stretched, the clamping force required to create that friction between arm and knuckle will be insufficient.
 
Re: Let\'s talk Dana 44 steering arm studs/bolts

Then what would you think of something like lock-tight sleeve retainer between the knuckle and steering arm (being carefull to not get any on the cone washers)?

I think I read somewhere that stuff has a shear strength of like 3500psi.
 
You must log in or register to reply here.

Latest Posts

Top Bottom