Re: Differential pinion depth
Posted: Tue Jan 22, 2019 10:42 am
This is a reproduction CWP showing contact patch almost as good as it gets with engineers' blue and a bit of oil:
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Hawksfield wrote:promotor
Al
That's a good contact result
I found getting the consistency of the paste was critical, you have got it correct in this example
Your experience is obvious
2cams70 wrote:Whilst that's the correct way to calculate pinion torque (force x distance) your specification seems wrong (too low fortunately so you won't require a new collapsible spacer). Ford specs. for new bearings as follows:
20 to 26 lb.in (including oil seal drag)
13 to 19 ib.in (excluding oil seal drag)
halve these figures for used bearings.
Note that later Ford manuals do not quote a figure for torque including oil seal drag. They advise that the oil seal drag be determined by measuring it with zero preload on the bearings. Presumably this is to account for different seal suppliers and types used during manufacture. Early seals were leather and later were synthetic rubber.
Note also that it is easier to measure pinion torque and oil seal drag using a direct reading spring balance unless you have a variety of weights or are comfortable sliding the weight over an adjustable distance to determine torque.
Once you have reached the correct preload it is strongly recommended not to back the nut off again as you have done here unless you use a new spacer.
The pinion torque figures in the manual are for the pinion by itself - i.e not meshed with the crown wheel.
davidj wrote:Afternoon,I recently replaced the input seal and crush washer on my diff using a (very expensive!) torque gauge to measure the rotation torque of the pinion, and set it at 22 lbf in (with the seal). This is the figure from the Haynes Escort manual and various forums - the Escort uses the same diff. However, the is no mention of using half the figure for used bearings and indeed the manual assumes the original bearings are being used. Do you think I have over tightened the assembly?Yours worried, David