I know this topic has been discussed often, but during assembly I began to second guess myself. I always thought you wanted to have a clearance, or 'negative' preload between the lower unit tapered roller bearing and the race pressed into the intermediate housing.
After taking numerous measurements, I have confidence in the height of the race placed over the lower unit tapered bearing -aka "A" according to Volvo, and the depth of the intermediate housing where the race is pressed - "B".
B is greater than A.
The manual (DP-E) states: "add 0.02 mm to the clearance dimension to establish preload." See below:
I do not feel comfortable preloading this tapered bearing. It will spin at +3700 RPM at WOT and I suspect this angular velocity will create significant heat, which will lead to expansion thereby creating greater friction, aka heat.
I plan to create a shim stack that will leave a clearance / void / slop, between the tapered bearing and race by 0.020- 0.030 mm.
Can you guys weigh in here?
My math is:
B = 8.0340 mm
A = 7.4828 mm
Clearance = 0.5512 mm
In theory, a 0.5512 mm shim stack would create zero preload. Creating a shim stack GREATER than 0.5512 mm creates a POSITIVE preload and creating a shim stack LESS than 0.5512 mm creates a NEGATIVE preload.
My intent is to create a shim stack between 0.5258 - 0.5131 mm.
Rummaging through the shims on my bench I cannot achieve this, so I will place an order. Evidently Volvo only sells shims in the following thickness: 0.05 / 0.10 / 0.20 / 0.35 mm.
So it looks like my stack will be: 0.35 + 0.10 + 0.05 = 0.50 mm. Maybe they will mic out a bit thicker and I can achieve the desired 0.52ish.
Thoughts?
Thank you.
After taking numerous measurements, I have confidence in the height of the race placed over the lower unit tapered bearing -aka "A" according to Volvo, and the depth of the intermediate housing where the race is pressed - "B".
B is greater than A.
The manual (DP-E) states: "add 0.02 mm to the clearance dimension to establish preload." See below:
I do not feel comfortable preloading this tapered bearing. It will spin at +3700 RPM at WOT and I suspect this angular velocity will create significant heat, which will lead to expansion thereby creating greater friction, aka heat.
I plan to create a shim stack that will leave a clearance / void / slop, between the tapered bearing and race by 0.020- 0.030 mm.
Can you guys weigh in here?
My math is:
B = 8.0340 mm
A = 7.4828 mm
Clearance = 0.5512 mm
In theory, a 0.5512 mm shim stack would create zero preload. Creating a shim stack GREATER than 0.5512 mm creates a POSITIVE preload and creating a shim stack LESS than 0.5512 mm creates a NEGATIVE preload.
My intent is to create a shim stack between 0.5258 - 0.5131 mm.
Rummaging through the shims on my bench I cannot achieve this, so I will place an order. Evidently Volvo only sells shims in the following thickness: 0.05 / 0.10 / 0.20 / 0.35 mm.
So it looks like my stack will be: 0.35 + 0.10 + 0.05 = 0.50 mm. Maybe they will mic out a bit thicker and I can achieve the desired 0.52ish.
Thoughts?
Thank you.