Front Differential Side Bearing Preload

[eMULe]

I'm replacing the front differential on a 1993 FG439. I have the service manual Fuso issued back then in three printed binders. The rear axle section has a spec for torque needed to rotate the differential after preloading the bearings, but the section for the front differential does not. It only says:

"tighten the side bearing nut within the nominal value of the backlash and apply preload to the side bearing. The preload should be applied so that the sum of the amount of tightening of the left and right side bearing nuts is within one notch of the lock plate hole and the lock plate is set within this range."

I 'translate' this to mean adjust the ring-pinion gear backlash to the nominal value (0.15-0.20mm) with no end play or preload on the side bearings then tighten both a cumulative (both sides added together) max of one notch.
That doesn't seem like much preload.

I was wondering if later editions of the service manual added a spec for the front differential like the rear where you wind wire or string around the differential and use a spring scale to measure the torque needed to rotate it.

I'm asking people with later printed or CD ROM versions to take a look. Thanks in advance.

 

[alan]

normally one notch each side then recheck backlash and tooth pattern.

 

[mog]

Specs from the 1996-2001 Fuso manual for front differential:

Starting torque of wheel hub bearing 3±1 N·m {2.2±0.7 lbf.ft, 0.3±0.1 kgf·m}
— Tangential force at hub bolt 18 to 34 N {4.0 to 7.7 lbf., 1.8 to 3.5 kgf}

I posted a copy of that section of the manual here for you:
http://996.i8.com/FusoFG-front%20diff.pdf

 

[eMULe]

Re:

Mog, I'm talking about the tapered roller bearings on either side of the differential case itself that holds the ring gear. The spec and pdf you reference are for the hub & its tapered roller bearings that hold up the tire/brake drum on either side of the axle. The differential I'm talking about would be a few pages away in the same section of the manual. In my early printed version its "Section 5 REDUCTION AND DIFFERENTIAL.

 

[mog]

Mog, I'm talking about the tapered roller bearings on either side of the differential case itself that holds the ring gear.

Ahhhhh. My manual is the same as yours, it does not list specs for the front diff.
I would think you would be safe using the specs for the rear diff which are listed. These are from my manual;

Starting torque of side bearing 1.96 to 2.94 N·m —{1.4 to 2.2 lbf.ft, 0.20 to 0.30 kgf·m} Adjust using adjusting screw
• Tangential force at 152 mm {5.98 in.} point around outer periphery of differential case: 25.5 to 38.2 N {5.7 to 8.6 lbf, 2.6 to 3.9 kgf}

 

[SkiFreak]

This is from the FG84D manual...

 

[eMULe]

re: (2)

Thanks for the input from later manuals.

Reading this again I think Alan managed to condense the careful Japanese translation down to 10 words.
Alan do you have any of those beautiful aluminum wheels if I happen to win a lottery?

 

[alan]

Hi,
Yeer i'm not big on words.
Yes I still have 5 stud alloy wheels in stock, and will shortly have the later 6 stud wheels available soon, they are being made at the moment and a sample is coming this week for test fitting.