TTY crank pulley bolt - how critical is angle?

[Silver]

I just did a timing job on a 5.4 Triton. I was able to get 45 degrees out of the specified 60 degrees after torqueing the TTY bolt the proper amount. This with an 18" 1/2" breaker bar, I just couldn't get anymore out of it, I simply gave out of strength to hold the crank and push on the breaker bar. Before I though of obtaining a piece of pipe to add leverage I moved on and forgot about it. The truck hasn't been driven but it makes me curious. That was a LOT of force at 45 degrees after torqueing to 37 ft/lb. Do you think that extra 15 degrees is really needed? I mean honestly I've never tightened anything beyond my physical ability and since it's a crank bolt I don't want to strip it. It makes me wonder if I may have goofed up the initial torque spec.

You know what, maybe I should just buy a new bolt and start over.

 

[wpod]

Lets imagine for discussion that 45* is 45 lbft and 60* is 60 lbft. You make the decision as it is your vehicle.

 

[tasch72]

The pulley to crankshaft torque spec steps are:

1. 66 ft/lbs
2. loosen 1 turn
3. 36 ft/lbs
4. +90 degrees

As per torkspec.com

it may help to have the truck in gear/park with the parking brake set.

If in doubt, start over. Not worth losing the pulley

 

[Silver]

That will be an awfully tight bolt. I guess it's just my inexperience with tightening something this tight. It makes me worry about the bolt breaking or stripping out the crank threads. WOW that would be horrible. Doh...

 

[The_Eric]

It'll probably be fine - it's pressed onto the crank anyway, shouldn't take huge amounts of force to retain it. There's the matter of the crank sensor wheel and crank sprocket too, but again, as tight as everything is, I can't image you'll have any problems. As an example, a small block Chevy is something like 70lbs with a 7/16" bolt and they don't come off on their own.

 

[tasch72]

That will be an awfully tight bolt. I guess it's just my inexperience with tightening something this tight. It makes me worry about the bolt breaking or stripping out the crank threads. WOW that would be horrible. Doh...

If you want more peace of mind, you can pick up an ARP 156-2501 for the same application. It is not TTY and calls for 100 ft/lbs torque with supplied lubricant on the threads and the washer where it contacts the pulley

 

[Silver]

It'll probably be fine - it's pressed onto the crank anyway, shouldn't take huge amounts of force to retain it. There's the matter of the crank sensor wheel and crank sprocket too, but again, as tight as everything is, I can't image you'll have any problems. As an example, a small block Chevy is something like 70lbs with a 7/16" bolt and they don't come off on their own.

Makes you wonder how they come up with such drastic differences. I just can't get over how tight it would be and that it's going into the crank makes me anxious even though I feel sort of stupid for questioning it at all.

 

[Jimmy_Russells]

Makes you wonder how they come up with such drastic differences. I just can't get over how tight it would be and that it's going into the crank makes me anxious even though I feel sort of stupid for questioning it at all.

If it's a TTY bolt the torque isn't linear. It will stretch while you're turning that last bit, you just need more leverage.

Ever done a TTY bolt on a wheel bearing? Usually like 90 ft lbs + 180° or something like that. I was standing (literally) on a 24" breaker bar to get it done.

 

[Silver]

If it's a TTY bolt the torque isn't linear. It will stretch while you're turning that last bit, you just need more leverage.

Ever done a TTY bolt on a wheel bearing? Usually like 90 ft lbs + 180° or something like that. I was standing (literally) on a 24" breaker bar to get it done.

I do remember years back as a matter of fact doing a wheel bearing. I don't recall how I left it but yes I could not get it to the 200 ft/lb or whatever it called for. I think if it wasn't the crank I'd have been less hesitant. I will get another bolt and redo it. Thanks.

 

[emmett442]

You sure that bolt is even TTY? I don't remember that being so on the old Mod motors. Don't remember any of the service manuals calling for a new bolt after removal.

 

[Slow Car Sport Mode]

If it's a TTY bolt the torque isn't linear. It will stretch while you're turning that last bit, you just need more leverage.

Ever done a TTY bolt on a wheel bearing? Usually like 90 ft lbs + 180° or something like that. I was standing (literally) on a 24" breaker bar to get it done.

How heavy are you?

 

[mk378]

In any case, you don't need a new bolt since you never fully tightened this one.

Also tighten by angle doesn't necessarily mean it's a torque to yield. Though it's a bit risky to final tighten anything with an impact gun, a lot of people do with crank bolts since then there's no need to stop the engine from turning. Honda crank bolts are not TTY but they also have a tighten by angle spec so you can watch the angle of the socket rather than measure torque.

 

[Kurtatron]

Hardest Crank Pulley Torque requirement I ever did was 184ft-lbs. Being a mid engine vehicle, I could not stand or use body weight. I had to bench press that 24" breaker bar like I was an ape at the gym. I yelled to get that thing on.

 

[Jimmy_Russells]

How heavy are you?

Not light, about 270. I think I decided to stand rather than bench press the bar downwards because I was afraid it would break and smash my teeth out or something.