Case 1370. Please explain this text in the manual.

The shop manual for Case 2090-2594 says alittle bit more than the manual for Case 1370 about the engine oil pump, but it is still a bit strange.
It says:
68. R&R AND OVERHAUL. The
engine oil pump is attached with front
main bearing cap screws and is shim ad-
justed to provide recommended gear
backlash of 0.006*0.011 inch (0.152-
0.279 mm). With oil pan removed as
outlined in paragraph 67, remove inlet
tube, gallery pressure sensing tube (if so
equipped), then unbolt and remove oil
pump. Note number of shims upon
removal.
Model 2090, 2290, 2094 and 2294
engines use a single large drive gear,
while Model 2390, 2590, 2394 and 2594
engines were equipped with a small
drive gear and an idler gear. See Figs.
60 and 61.
Install by reversing removal procedure
using the removed shim pack. If parts
are renewed which might affect drive
gear backlash, install carefully and
tighten mounting bolts finger tight; and
turn engine over by hand and check for
binding of drive gears. If binding occurs,
install additional shims (6—Fig 60 or 61)
and recheck. Shims (6) are available in
0.005 inch (0.127 mm) thickness only.
After front main bearing cap screws are
properly tightened to a torque of 200-
210 ft.-lbs. (271-285 N • m), instaU intake
tube (1) and tighten compression nut to
90-100 ft.-lbs. (122-136 N • m) torque.
If backlash on Model 2390, 2590, 2394
or 2594 engine oil pump drive and idler
gears exceeds 0.008 inch (0.203 mm) or
gears are damaged, renew pump. Pump
is available as an assembly only.

First it says that the backlash should be 0,006-0,011 inch.
In the end it says that I should renew pump if it exceeds 0,008 inch.
And they say "drive gear". Should it not be a backlash on the idle gear to?

This pump has one drive gear and one idle gear.
When I reinstalled the pump after installing new main bearings, I have no backlash at all on the idle gear.
I guess they mean that it should be backlash on the idle gear?

There is only one gear clearance that can be adjusted, idler to crank. The other is fixed. As you know, shims are provided for idler to crank and should be set as instructed. If there is no B/L between the idler and pump gear it is as manufactured unless something is bent or damaged.

Although I cannot explain the no B/L between the idler/ pump gear it cannot be changed and I assume has ran that way since new. Does the pump/idler turn freely without any catching or tight spots during rotation when off the engine, if so there is not much you can do to change that.

I guess if that is the case that there is no B/L between the two gears mounted to the pump body it was either built that way or is it possible that the idler shaft has been bent by improper installation pushing the idler gear and oil pump gear together? Those are the only explanations I can think of without actually seeing the pieces.

Mel

No, between the pump gear and the idle gear it is a correct backlash.
It is the backlash between the crankshaft and the idle gear that is incorrect.
I tested to install the pump without O-ring. Then it will be a little backlash. The new O-ring press the pump a little to the side, that affect the backlash.
There are 3 shims, each 0,13 mm. I cant get a new one now because I have to wait for it for some weeks so I will make a new shim thas is 0,5mm, that will be like 4 original shims.

Throw a piece of beer can in there and try it again. It is not rocket science.