300ft lbs/400nm torque... Any suggestions?
 

The specs state the crank bolt (27mm) on the crankshaft should be torqued to 300ft lbs/400nm torque on my 92 400se.

I have several torque wrenches, but none that will torque at this high of a value.

Do you think I can give a long breaker bar a good "heave hoe" and call it good, or should I be concerned about bringing the bolt to the correct torque spec.

The price of a torque wrench that will accomplish 300ft is very expensive and I don't think I'll have much use for it after chaning the water pump.

Russell

Check with a local rental yard and see if you can obtain a "torque multiplier." It has been a long while since I needed to use one so I cannot say if they are still available, I do know that I rented it due to cost.

If you are unable to locate one then perhaps a heave hoe will do..............you do the heave and I'll do the hoe :D

Find a sturdy pipe that will slip over the handle of your 3/4" drive breaker bar. Stand on the pipe according to your weight. E.g., if you weigh 150 lb, stand 2 ft away from the socket center. If you weigh 200 lb, stand 1.5 ft from the socket. When the socket no longer turns, you are at spec.

Steve

yep, that's just what I did when I rebuilt my 617. You're pretty smart sbourg - how'd you know I weigh 200lb??

[QUOTE=Pete Burton]yep, that's just what I did when I rebuilt my 617. You're pretty smart sbourg - how'd you know I weigh 200lb??[/QUOTE


Good try, maybe get close, but wrong thinking. Your method assumes the bolt will stop turning at the specified torque. Probably not.

Mark

>Your method assumes the bolt will stop turning at the specified torque. Probably not. >>

That is the whole concept ... when the bolt stops turning , you have attained that specific torque...if it does not stop, you do it again until it does...

Of course, thank you Arthur.
regards,
Mark

M
HERE IS HIS BASIC CONCEPT..

The Torque on an object about some pivot point is due to the action of a force on the object.

Magnitude of the Torque:

t = "Force" times the "Lever Arm"

= (Component of the Force perpendicular to Lever Arm) x (Lever Arm - the distance between the pivotal axis and the point where the force is applied) = Fp l
..OF COURSE , ONE MUST BE PERPENDICULAR TO USE THIS , SO THAT CAN CAUSE A SLIGHT VARIABLE AS ONE TRIES TO STAND ON A BREAKER BAR IN BETWEEN THE RADIATOR ...::))

I guess someone should chime in and let you know that you don't have to take that bolt out to do the waterpump job. You can undo the pulley and leave the hub still connected to the crankshaft. There are six bolts inside the pulley that once removed will allow you to work the pulley and damper off the front. It should be noted that the pulley and damper are a tight fit on the hub and will require effort to remove after the bolts are out. It is however a lot less effort than removing the whole hub/pulley assembly together. :cool:

PS Don't forget to align the pulley to the tdc mark and then mark the pulley as well in this position. The bolt holes are not symmetric and the pulley seperates from the damper once off the hub.