Hayden fan clutch hardware

[themechanic]

I don't want to argue, I thought maybe you did not understand how place bolts work. Spend a little time and research place bolts and how they work. They are used in critical areas like flywheels, power steering control valve castings, fan clutchs, stuff you really do not want coming loose.

I never heard of a "place bolt" until you mentioned it. Thanks

However, Earnest Machine offers Place Bolts which feature a special head design that provides a “locking” action between the head of the bolt and the material being clamped. The combination of the special recessed groove under the head and the slots in the top of the head cause the head to flex as it is tightened, illustrated in figure 1. This creates a spring action in the head that provides additional elastic elongation that is not achieved by standard Hex Head Cap Screws. This spring action also provides increased resistance to loosening in high vibration applications.

 

[themechanic]

FYI, I won't be using lock washers with place bolts in the future. However, I will not go back and remove the lock washers that took me 30 minutes to install with the bolts yesterday.

 

[4406bbl]

I agee. I also see the cuts give it less rotational mass so they stay tight, quite the high tech part when you look into it.

 

[SF71]

Hello fellas,

I am facing the same problem and are about to order the bolts. Do 5/16-18x3/4 fit in the clutch and in the waterpump, so I need 8 times the same bolt or are they too long for "fan to clutch" and I need shorter ones? Couldn´t really get out the conversation sorry.

 

[Black_Sheep]

I used studs and nuts to bolt the fan to the clutch, then used factory style bolts to attach the clutch to the water pump. It was difficult but not impossible to get the water pump bolts started.

I had one with too long of a bushing, the issue was easily cured by filing down the bushing.

 

[SF71]

Okay sounds good. But why studs and nuts instead of bolts? Do you still know if 5/16-18x3/4 bolts would fit for clutch and for the waterpump? Or do I need different thread type like UNF (for example 5/16-24x3/4)?

Do you know what lenght will fit for waterpump side? 7/8" of thread too short or too long? And for the clutch rather shorter bolts like 3/4" of thread length?

Don´t have any hardware left over and need to buy new stuff....

 

[Black_Sheep]

Okay sounds good. But why studs and nuts instead of bolts? Do you still know if 5/16-18x3/4 bolts would fit for clutch and for the waterpump? Or do I need different thread type like UNF (for example 5/16-24x3/4)?

Do you know what lenght will fit for waterpump side? 7/8" of thread too short or too long? And for the clutch rather shorter bolts like 3/4" of thread length?

Don´t have any hardware left over and need to buy new stuff....

I used studs and nuts because the factory used studs and nuts. I have used 5/16 bolts in the past without issues. We used 5/16 serrated flange bolts on my brother in law’s 340 because that’s what I had in my stash, he revs the thing to the moon and so far it’s held together.

 

[SF71]

I used studs and nuts because the factory used studs and nuts. I have used 5/16 bolts in the past without issues. We used 5/16 serrated flange bolts on my brother in law’s 340 because that’s what I had in my stash, he revs the thing to the moon and so far it’s held together.

Sounds awesome. And we talk about that coarse thread right? So 5/16-18? And do you know what lengths the bolts were? 5/16 x ??? ? 3/4 too long ?

Gonna use Loctite also just ton make sure it sits tight

 

[Black_Sheep]

Sounds awesome. And we talk about that coarse thread right? So 5/16-18? And do you know what lengths the bolts were? 5/16 x ??? ? 3/4 too long ?

Gonna use Loctite also just ton make sure it sits tight

I just measured the hole depth of a spare I have on the shelf, it is 1/2”. I would use a 5/16-18 x 1/2 to be certain that it’s not bottoming out in the hole, the fan is only 3/32” thick so a 3/4 bolt will be too long.

 

[SF71]

Thank you very much black sheep !! That helps a lot . And out off your mind you know how long the waterpump bolts are ? Because mine are way too long because I had a spacer installed and I think I can’t use the same bolts .

It should be 5/16-18 too right ? Just need to know if 3/4 of thread or longer .

 

[Black_Sheep]

Thank you very much black sheep !! That helps a lot . And out off your mind you know how long the waterpump bolts are ? Because mine are way too long because I had a spacer installed and I think I can’t use the same bolts .

It should be 5/16-18 too right ? Just need to know if 3/4 of thread or longer .

3/4 should do it, the clutch is 3/16 thick and the thickness of the water pump flange and pulley I would guesstimate to be 3/8” to 1/2”. Measure your parts and do the math to verify, if your parts aren’t assembled it will be pretty easy…