Previous owner used Lucas Oil 85-140 wt.
Is this oil ok to use?
Should I change it over to Synergn?
If so where can I buy that?
If I started taking out the copper bolt with nut on it on the drivers side and realized that was not the fill plug and put it back in, would that affect anything?
The fill plug is the other one on the passenger side in the same location?
Tranny makes alot of noise in 3rd gear while lugging. Speed up and it goes away. Is this normal?
Most of riding through the dunes is in 2nd gear.
Thanks for any help.

redline is the best oil to use... the gold bolt is for the ring and pinion adjustment... prolly shouldnt have touched that, hopefully you put it back exactly right... 2d is not a quite tranny but they all seem to have there own noises, if it doest make noise at higher rpm i wouldnt worry about it much

also try to use the higher gears when duning, the higher the gear the stronger and the longer they will last. if you cant dune in 3rd gear your tires are too big or the tranny is geared too tall

I am pretty sure that the plug on the left is for the ring gear to rub against under load and the r and p try to drive each other apart. I have never adjusted mine but someone should know the setting. My guess is finger tight and slightly back it off but that is just a guess.

I think I put the gold bolt back in at the same postion.
Does it affect the ring and pinion if I screwed that bolt out some?

If I remember right a tranny guy told me thats the snubber bolt for the ring and pinion. I believe he said the way to set them is screw it in until it makes contact then back out 1/4 turn and set the nut. You may want to call your tranny guy and ask him to confirm or deny what I said.

Thanks Nic, hopefully Mendeola Transaxles will respond tomorrow.

Previous owner used Lucas Oil 85-140 wt. You may use that, or any other 85-140 wt. oil
Should I change it over to Synergyn? If you can find Synergyn, and are willing to pay for it then yes it is a extremely good oil. We no longer carry it, and carry a equivalent oil that is less expensive and delivers the same protection.
If so where can I buy that? Look on line
If I started taking out the copper bolt with nut on it on the drivers side and realized that was not the fill plug and put it back in, would that affect anything? No, turn it in till it stops then back out half turn.
The fill plug is the other one on the passenger side in the same location? Yes
Tranny makes alot of noise in 3rd gear while lugging. Don't lug your gearbox.Speed up and it goes away. Is this normal? Yes
Most of riding through the dunes is in 2nd gear. You will get faster in time,or you will need to re-gear for the use of all your gears properly.
Thanks for any help.

Thanks Mendeola Transaxle for the response!!!