changed fluids now gears 1& 2 have slipped twice

[rprothero]

I changed out the tran and rear fluids and on my ride today (aprox 10 miles) my first and second gear popped into neutral. I had been riding for about 20 minutes before it happened but am wondering if this is normal as a break in period for the new fluids or something I should be concerned about..I walked the bike and nothing appears to be leaking ..Bike has little less than 12k on it so seems weird to run into this...you guys run into anything like this?

[low944]

I just did both fluids on my 04 rockster and have put about 60 mile on it. It seems to shift better, and no slips. What fluid did you use? I put Mobil 1 75w140 in both.

[rprothero]

I used Liqui-Moly Synthetic Racing Gear Oil, 75W-90, purchased at beemerboneyard..used the same oil for both rear and tran..

[gregor]

As said elsewhere, oil threads can get a little heated. Just make sure that all the specs are suitable for the purpose (not just the viscosity). From memory, gearbox oils and final drive have different requirements. GL5 is a must for the final drive IIRC.
Just be glad that you do not own an air head- there were three lots of transmission oil in those.

[Rider Rick]

Just a wag, but maybe you can check the state of your shift lever. I heard of one poster's experience and the shift lever had worked loose. Also, is it possible you are putting any pressure on the lever with a larger than normal boot, etc, or can you confirm your foot is not touching the shift lever at any time during the episode? Tranny gears, or perhaps more accurately the dog gear arms should not pop out of the holes because of low friction. I can see them popping loose if the tranny was flexed or badly worn, or very out of alignment. I've now exhausted my small store of data on this matter .