Intermediate Shaft / Oil Pump Indexing

[5DIGITS]

The topic listed below was posted within the tech area but the method also has additional significance within the T-III engine due to the increased shaft speed and the potential for accelerated wear.

Intermediate Shaft / Oil Pump Indexing

For those who have ever had intermediate shaft or oil pump gear devastation, there is a method to improve gear meshing and component longevity.
As much as we'd like to believe that these components are precision machined to strict standards, they unfortunately are mass produced components with a wide quality acceptance band.
This means that the journal, gear tip, and tooth cutting processes for both components in addition to oil pump gear centering on the shaft and the distributor hole machining in the block can all amount to a noticeable uneven mess, between the components.
This can be observed during the engine assembly process as variation in the rotating effort required to turn the intermediate shaft sprocket upon installation in the block.
This is typically caused when 'minor' non-concentric high spots on the oil pump gear are aligned with high spots on the intermediate shaft.
Although, there are a few easy steps to reduce the chance of component failure and a catastrophic event should either gear shear and cause a total loss of oil pressure.

1. With the oil pump installed, Loc-tite on the oil pump attachment bolts, and the oil pump attachment bolts near snug; install the intermediate shaft
2. Rotate the oil pump housing in its mounted position to realize how much the oil pump housing can be turned to the left and right, while visually noting travel relative to the mounting bolts
3. With the level of travel determined, clock the oil pump as close to the center position that was determined by the previous step
4. Torque the oil pump attachment bolts, per the manufacturers recommended specification

NOTE: The previous steps have minimized the chance that the oil pump is preloaded to one side of the engine block distributor/oil-pump hole because the oil pump mounting flange surface is not always 'true' to the oil pump center-line.

5. Install the intermediate shaft retaining cover without the anaerobic sealant and lightly tighten the bolts that hold the cover in place
6. With the intermediate shaft key in place, install intermediate shaft pulley
7. Rotate the shaft by turning the pulley while noting the consistency in rotating effort, throughout several rotations

If the rotating effort is not smooth and/or consistent throughout several rotations, proceed to step 8, otherwise proceed to step 9.

NOTE: If the following steps are repeated numerous times without improvement, thoroughly inspect each component for obvious signs of significant manufacturing defect and replace as needed.

8. Re-clocking the intermediate shaft

Remove the intermediate shaft pulley
Remove the intermediate shaft cover
Note or index the pulleys/shafts current position
Remove the intermediate shaft, re-clock the shaft to one/same direction, by 90 degrees
Reinstall the intermediate shaft
Return to Step 5


9. Remove the pulley, intermediate shaft retaining cover bolts, and cover
10. Complete the final installation of the intermediate shaft cover and pulley hardware per the manufacturers recommended specifications

The above process can provide the best possible component mesh and gear loading by improving awareness to minor manufacturing variation, aligning those variations in a manner that minimizes excessive component loading, and minimize the resulting wear.

[DOHCRT]

Thanks Ken, Awesome information, right up there with timing belt tension, idler relocation and light weight retainers...

[Lotashelbys]

right up there with timing belt tension, idler relocation and light weight retainers...

And the latest thing I have been thinking about,drilling the head for the center oil drain-back to be used(and the head gasket if not using modded 006) I know you need to delete the PVC port in the center drain-back bore but just think of how much more oil would be poured onto the I-shaft and oil pump gears by doing this...... 8valves and Masi heads have center drain-back hole pouring oil onto the gears with no real issues how could it not help the TIII. Thoughts Ken???

[DOHCRT]

Not a bad idea Jackson, I am already using the 9296PT gasket @ 20# without any problems; so opening up that drain back wouldn't be a big leap. I was going to hit up Warren for one of his drilled shafts and see how that worked.

[iTurbo]

Damn, is there anything you guys haven't thought of? I will be incorporating this into my next build thank you very much.

[5DIGITS]

And the latest thing I have been thinking about,drilling the head for the center oil drain-back to be used(and the head gasket if not using modded 006) I know you need to delete the PVC port in the center drain-back bore but just think of how much more oil would be poured onto the I-shaft and oil pump gears by doing this...... 8valves and Masi heads have center drain-back hole pouring oil onto the gears with no real issues how could it not help the TIII. Thoughts Ken???

Understanding that 8V applications can realize shaft/pump failures while benefiting from both normal speed and the drain back lubrication; properly setting or adjusting intermediate shaft/oil pump gear-mesh is first and foremost.
With consistent mesh set, anything to improve oil lubrication or efforts to reduce the T-III intermediate shaft speed (coupled with eliminating the balance shafts) will help the rotating assembly survive.
Additionally, a 2.4L oil squirter (or equivalent) could be added to provide 'targetable' oil delivery, if supplemental lubrication is desired.