Setting thrust bearing clearance.

[Mike70gtx]

Tore motor completely down. When putting crank back in, how do I set the thrust bearing clearance? I did a search but it didn't get specific. Do I keep caps a little loose then hit crank forward? It has main caps and was line bored. Everything was good before tear down. Anything else I need to remember or keep in mind when putting back together. Have done bearings several times after headgasket blown. This is the first time I had crank all the way out. Trying to get motor back together the next 3 days so I can make pinks all out in Dallas.

 

[johnplogii]

You can't really set the clearance, you can check it. If it's too tight you can touch the thrust surface to gain clearance. You have the right idea on setting the caps, I usually whack it a time or two from each end hitting it from the rear last with the hardware snug so it can move. I use the handle of a plastic hammer & hit it with another hammer. A good plastic mallet would probably be better if you have one.

John

 

[Mike70gtx]

It just moves a hair. So I'm trying to center it between the movement, which is minimal.

 

[turbodave231]

The proper way to "Set" a thrust bearing:

Install the crankshaft
Install all your main caps and seat them in their registers with a deadblow hammer
Torque each main caps to spec
Measure crank end play before and after torquing each cap
(this is not required but it may help you find other issues with the crank or bearings. The end play should NOT change, if it does, you have a problem)
Back off #2 main cap bolts/studs and then re-tighten just snug
Strike the crank snout rearward with a deadblow hammer
Strike the crank flange forward with a deadblow hammer
Torque #2 main to spec.
Measure end play with a dial indicator

Your last hammer blows should be in the same direction as the thrust generated from the transmission.

Dave

 

[Mike70gtx]

Excellent. I guess I will undo #2 and do the hammer thing.

 

[bmackinnon]

The proper way to "Set" a thrust bearing:

Install the crankshaft
Install all your main caps and seat them in their registers with a deadblow hammer
Torque each main caps to spec
Measure crank end play before and after torquing each cap
(this is not required but it may help you find other issues with the crank or bearings. The end play should NOT change, if it does, you have a problem)
Back off #2 main cap bolts/studs and then re-tighten just snug
Strike the crank snout rearward with a deadblow hammer
Strike the crank flange forward with a deadblow hammer
Torque #2 main to spec.
Measure end play with a dial indicator

Your last hammer blows should be in the same direction as the thrust generated from the transmission.

Dave

This is correct, and according to the FSM... :wink:

 

[Slix]

You can't really set the clearance, you can check it. If it's too tight you can touch the thrust surface to gain clearance. You have the right idea on setting the caps, I usually whack it a time or two from each end hitting it from the rear last with the hardware snug so it can move. I use the handle of a plastic hammer & hit it with another hammer. A good plastic mallet would probably be better if you have one.

John

Yeah worked like a charm...

 

[Slix]

The proper way to "Set" a thrust bearing:

Install the crankshaft
Install all your main caps and seat them in their registers with a deadblow hammer
Torque each main caps to spec
Measure crank end play before and after torquing each cap
(this is not required but it may help you find other issues with the crank or bearings. The end play should NOT change, if it does, you have a problem)
Back off #2 main cap bolts/studs and then re-tighten just snug
Strike the crank snout rearward with a deadblow hammer
Strike the crank flange forward with a deadblow hammer
Torque #2 main to spec.
Measure end play with a dial indicator

Your last hammer blows should be in the same direction as the thrust generated from the transmission.

Dave

Yep that's a good way

 

[bison]

I do what is mentioned above. First I measure endplay with no #2 cap. Whatever I get has to be repeated when the #2 cap is torqued down. I’ve seen a couple instances where it wasn’t. Usually due to the main studs shank interfering with the holes in the cap. If you run into this you can use a long end mill and just plunge the hole offset in the direction clearance is needed. Usually only .010-.015 is needed to get the clearance needed. The important part is that the thrust is exactly the same with and without the cap. If there’s less with the cap you need to figure out why and correct it or the thrust will fail rapidly


Sent from my iPhone using Tapatalk

 

[Slix]

The proper way to "Set" a thrust bearing:

Install the crankshaft
Install all your main caps and seat them in their registers with a deadblow hammer
Torque each main caps to spec
Measure crank end play before and after torquing each cap
(this is not required but it may help you find other issues with the crank or bearings. The end play should NOT change, if it does, you have a problem)
Back off #2 main cap bolts/studs and then re-tighten just snug
Strike the crank snout rearward with a deadblow hammer
Strike the crank flange forward with a deadblow hammer
Torque #2 main to spec.
Measure end play with a dial indicator

Your last hammer blows should be in the same direction as the thrust generated from the transmission.

Dave

wondering if this can/should be done when rods are connected to crank shaft?

 

[jay dcpt]

Not needed. Thrust should be set with just the crank in place.