Oil change, Reccomendations?

[monsterbronc]

Im coming up on my first oil change, right now Its got re-cycled 15-40 diesel engine oil in it (IT WAS FREE) and im having shift issues. lots of secondary neutrals.

What Oil should I use? the books say 10-30, and says nothing about special motorcycle oil. I have a couple of really (really really) high mileage old school engines in my daily drivers (bronco has 401K eagle has 210K) and I am  firm believer in synthetic oils. in the diesel trucking industry I SEE the difference. That bronco of mines been running castrol syntec since I bought it, and that was 250,000 miles ago, never had a head off it.

I'm wondering if synthetic oils will hurt my clutch, I would like to run either casrol Edge, or royal purple. and would I benefit from thicker oil in this older motor, or is that my shifting problem?

Thanks, Steve.

[sgtslag]

I run Shell Rotella T6 Synthetic, 5W-40 in my bikes, and all three of my 4-wheel vehicles -- it simplifies my life by only having one oil type to use, period!  This stuff was amazing in my cars this past Winter, in tropical Minnesota.  I would turn the key in my car, after it sat all day in the parking ramp, exposed to the sub-zero air temperatures, and it turned over like it was July.

The 5 weight, when the oil is cold, helps in easy starts.  As the oil temperature rises, so does the oil weight, to 40 -- no problems with too thin an oil pumping through the engine.  With it being synthetic, I can go 7,000+ miles, between changes.  I used SeaFoam to clean out the engine, and I use it to stabilize the gas, during the Winter storage months, so I know my engine, and fuel system, are clean.  Since the diesel oil has no friction modifiers, it won't affect my clutch (automotive oils, used for the first three years of ownership, had no effect on the clutch, either, but this is still safer).

I would recommend running SeaFoam through the crankcase (add 4 oz. to the oil, run for five minutes on the center stand, shifting through all of the gears, to flush each gear in the transmission), then dump the oil for fresh, with a new filter.  This will ensure there are no carbon, or sludge, deposits within the engine, or the transmission.  With high detergent diesel oils, regularly changed, you will never need to add SeaFoam to the engine again.

I'm no expert, but if you still have clutch problems after that, then I would suggest a clutch rebuild.  Cheers!

[Re-run]

+1 on rotella. I use the t6 synthetic too. It has worked great and I do not need to change every 1000 miles like you have to with regular oil. Being a diesel oil, it contains lots of detergent to keep things clean. It also has a higher level of zddp then your average car oil, which is good for the valve train and gears.