Crankshaft Installation Instructions
|Please read installation thoroughly before starting work. When they are completely understood proceed with installation|
Clean and prepare the engine block
Please clean carefully the engine block and all components to ensure perfect bearing placement. By far the best way to remove all gallery plugs and all the dis-assembled engine to soak in a agitated chemical bath. This way all the sludge and dirt accumulations are removed. If chemical cleaning facilities are unavailable, you can use the less desirable method with a solvent such as Kerosene. It is imperative to ensure that the entire lubrication system is completely clean and free of obstructions.
Check NIP and back contact
Check oil clearance
Check end float (Thrust clearance)
A. Clean the Crankshaft very well, after that blow with dry air to clean oil holes thoroughly. Make sure oil holes are flow free!
B. Inspect all journals to make sure the crank is free of nicks, scratches, and hairline cracks.
C. Spread plenty of oil on all journals before assembly. Do not lubricate the thrust faces of the thrust bearing at this point.
D. Check proper oil clearance and make sure the direction of rod and bearing are corrected. A 0.50mm-0.715mm side clearance is required
E. Once you have measured all your journals and matched them to their specific bearings, you are ready to lay the crank in place. Before doing that, however, spread a coat of assembly grease on the bearings to protect the crank.
F. Now position the crank on the block without installing any of the caps, just yet. Install a dial indicator on the nose of the crank to measure endplay. You should be able to move the crank back and forth by hand. The clearance must be as suggested by the engine’s manufacturer.
G. When you make sure you have the correct amount of endplay, go ahead and install the rear main seal before bolting on the main cap.
H. The next step is to bolt up and torque all the main cap except for the cap containing the thrust bearing. Make sure you add oil on the thread of the bolts first. Check your endplay again. If you don’t have enough play, one of the caps is out of alignment. You can adjust the cap location slightly by tapping it lightly with a dead-blow hammer and then tightening the bolts back down.
I. Again, if the endplay is correct, you can install the last main cap-this one with the thrust bearing. Tap it into place but do not torque the cap bolts. Instead, knock the crank lightly, either forward or back, to align the thrust faces of the two bearing shells. Now tighten the bolts to the proper torque specs.
J. Once you have reached this point, most probably the end play has tightened up a bit. You can use a screwdriver placed between one of the main caps and a counterweight to help you move the crank. Be careful and do not use excessive force.
If there isn’t enough endplay, you may need to reduce the thickness of the thrust face of the thrust bearing slightly. This can usually get you a thousandth or so. Lightly rub both faces of both halves of the thrust bearing on super-fine sandpaper that is being lubricated by a constant stream of fluid in your cleaning tank. It’s also a good idea to use a surface block (or even a pane of glass) underneath the sandpaper to make sure you are sanding on an even plane. If the endplay is too much, you must use oversized thrust washers.
♦ We “strongly” recommend that you balance the crank and flywheel together.
♦ All 4340 cranks are nitrited with plasma gas. DO NOT polish journal in any circumstances
It is necessary to check the NIP or crush fit of the new bearings in their housing and also the back contact if the old bearing backs have any bright, shiny areas. The procedure of this operation is:
a. Apply a coating of the bearing “blue” to the cleaned tunnel seating and the joint faces of the case or cup.
b. Clean and try the bearings and apply the bearing “blue” to the joint faces on one bearing. Assembly the bearings in to the housings, tightening the holding bolt evenly to the correct tension. Threads should be oiled.
c. Accurately measure and right down the assembled internal diameters of each pair of bearings, then release the bolt or bolts on one side only. This should allow the joint faces to separate on this side. A feeler guide of 0.10mm to 0.15mm should be accepted into the opening.
d. Release the remaining bolts and dismantle the bearing unit completely. An examination of the housings and the bearings should reveal an even transference of “blue”
i. Tunnel bores to back of bearings.
ii. One bearing joint face to the other.
iii. The cap joint face to the case joint face or vice-versa.
An uneven transference of blue indicates some “off standard” condition to be investigated and corrected.
With tunnel sizes correct to specification and shaft journal unworn or correctly ground undersize, ACL finished-to-size bearings will provide a correct operating clearance which can be quickly confirmed on assembly with the use of flexi gauge. Where doubt exists, or in special case, oil clearance should be checked by accurately measuring and writing down each journal diameter and then subtracting this from the corresponding internal bearing diameters that where noted when checking the amount of nip. The difference between the two diameters represents the vertical oil clearance and this must fall within the specified tolerance shown against each part number in the alphabetical list.
It is advisable to check the thrust clearance at both thrust faces to ensure an accurate measurement.
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