82 R65LS

[jgp1854]

What is the CW on transmission fluid, weight, synthetic vs non synthetic.  Needing to change the transmission fluid to switch out the the neutral safety switch

thanks

jgp

[tvrla]

The standard 85/90 is the best. Synthetics work just fine and I've heard that these boxes last longer with it. But if your fluid is still good, why not pour it back in? Normally it gets changed due to contaminants (metal particles) rather than lubricity issues, so filter it and re-use.

[Bob_Roller]

I think the main concern regarding transmission oil, would be water contamination, from sealing issues with the speedometer drive cable boot, where the speedometer cable goes into the transmission .

That would be my main reason for replacing the oil on a regular basis .

Other than that possible scenario, I don't think these transmissions are very tough on lubricants .

They are 'farm implements' after all !!!!!

To put things in some sort of perspective, if you ever owned a manual transmission car, how often did the transmission oil get changed ?

Probably every clutch change, at best !!!!

[Barry]

I've filtered very low mileage gear oil and put it back in. Why not if it's good quality oil and there are no contaminants. Filtering using proper filter paper in a funnel can be slow and tedious when the oil is cold so If I'm going to do it I filter it while it's still hot and thin.  

[nhmaf]

I just use new every time - it isn't so expensive or require so much that I can't afford an extra oil change every couple years or so.

[badbmwbrad]

I use non-synthetic 90 weight gear oil spiked with a small quantity of DowCorning Gear M additive (molybdenum disulfide).  Gear M cannot be used with systhetic oil
 

What is the CW on transmission fluid, weight, synthetic vs non synthetic.  Needing to change the transmission fluid to switch out the the neutral safety switch

thanks

jgp

[tvrla]

I agree on the water issue, though frequent running will heat up the oil enough to burn off small accumulations. That doesn't negate the importance of sealing off the speedo cable, though.

[Barry]

What is the CW on transmission fluid, weight, synthetic vs non synthetic.

If you ride in a moderate climate I would use something thinner than straight 90W particularly for use below 5 Deg C. BMW recommend 80W for winter use, 90W for summer use and 80W/90 for year round. The 90W oil has a very high viscosity at 0 deg C which will result in a fair amount of drag. 80W/90 is typically half as thick or less and synthetic 75W/90 is only 1/5 the viscosity of the 90W.  

[tvrla]

Besides the drag of the thicker oil, the cold lubricating abilities must also be considered. There's a bearing fed only by splash into a channel along the transmission's roof - and that's the one that tends to dictate when a rebuild is needed. If the oil is thick it's possible the lubrication abilities when cold won't be sufficient.

As usual, it's always a good idea to take it easy at least the first few miles after the bike's been first started.