Quote:
Originally Posted by Sirrotica
If the bearing fails from lack of lubrication, not putting grease in will make it last longer? Then you have the fact that they leave one side of the bearing exposed. If you wanted a sealed bearing, why is one side open? So dirt can enter?
You stick to your theory, and I'll continue doing it the way I've done it for 50 years........... 
Hopefully you don't replace tapered wheel bearings using the same theory.
I'm wondering why someone would stake the bearing, when it can't move unless the transmission is removed?.........  It's pretty much captive as soon as the input shaft is installed.
If someone was worried that it didn't fit tightly, a couple hits with a prick punch on the interior of the crank bore can tighten it in the bore.
Most times I install the bearing, grease it as outlined, and finish the job. |
well its not "my theory" its what ive been told for years by many reputable life long mechanics & when i asked the tech dept at a bearing company. i used a pilot bearing for my car & when i saw the open back & thin clear grease i thought the same thing about adding grease, they said do not do that as its not designed for random grease to be injected at an unknown or excessive amount, they use a special grease intended for the purpose. there is a lot of info out there supporting that & they all say the same thing, that thick grease in a roller bearing like these makes the balls not rotate as designed & they will skid along the race causing excessive heat, wear & shortened life. so i chose to go with what the manufacturer recommended & trust what my mechanic friends say... im not suggesting the bearing will fail right away by adding grease & im sure its worked for you in the past, but its not what the manufacturer says to do & apparently a lot of other people & mechanics that have been doing this just as long as you know about it too.
not much dirt is able to get into the area of a pilot bearing, when i removed mine at ~50k miles & 40+ years old the inside of the crank bore was basically spotless & the bearing itself was very clean looking. these pilot bearings arent designed or needed to be sealed...
& a tapered wheel bearing is completely different than a roller bearing... they are designed for thick wheel bearing grease & operate a little different than a ball bearing, the comment about "hope you dont replace tapered bearings using the same theory" makes no sense since they are not the same type of bearing & obviously dont come pre lubed with a specific grease & require packing with wheel bearing grease.
lots of people do things different than what the manufacturer or repair manual says to do, i do it too sometimes & it usually "works" ok, but that doesnt mean its what the engineers & manufacturers of the part recommend to do.
EDIT: i just called timken to confirm what they suggest for this, spoke to the auto tech dept & asked about greasing a pilot bearing for a 1978 firebird & he looked up the part #. he said they specifically do not recommend adding any grease to these, they are supplied with a special synthetic grease that lasts the life of the bearing. i asked if it would be ok to put some other grease like chassis or wheel bearing grease & he said its not recommended & then repeated what ive heard & mentioned above, it will or can cause the ball bearing to not roll & rotate right & cause heat & premature wear. straight from the horses mouth. do what you want but i will leave my pilot bearing as designed & if/when it fails or the grease dries up i will buy another one for a few bucks.