About ten years ago we put a 30' flexhead on a 7720 Titan II. We had a local machine shop add 4' to the unload auger and never had any problems with it.
We use a extension on our 2388's that is called The Extender it fits on the end of the auger and has the different boot at the end we have been very pleased with it we run 36 foot MacDons and it clears the cart very easily
We have installed The Extender on our 2188 and love it. It keeps the cart away from the header much better than the factory spec length. Took us 1.5 hour to complete the job. Highly recommeded. No problems so far.
I installed the 3' one that goes next to the unloader elbow. It has an auger with it that is splined on the gearbox side but the other end has a smooth machined pilot that goes in your existing auger. You must overlap the flighting and weld the flighting and the two augers together. I don't think that the extra liner comes with the kit(where the auger sets in the cradle),if it doesn't order it also. It more difficult to install but it works great. BTW I put it on a 2002 2388.
loewen manufacturing makes unloader extensions for Gleaner in 30"-36". The 30" inch bolts on at the base with black tube connecting to your existing tube, then you attach the auger to the end. Seems to be well built, ordered mine from Worthington Ag. www.loewenmfg.com
Thank you 4-Star! I will check into that one! It sounds better as you describe it, than the add on the end one from Stewart, not saying Stewart may not make a good product. I have not seen the loewen unit.
Huper II has a cheap way of installing a stop on the cylinder by installing a pipe coupling over the cylinder shaft which stops the unloading auger sooner which gives you more height. You will have the move the limit switch on the collar to enable the auger run interlock. Hyper II did this to my N6 and it made a big difference in getting over the side of carts and wagons. lots cheaper than an extention plus the longer the auger the more stress on that pivot collar coming out of the hopper. Hopefully Hyper II will respond with more details. Pete Hinrichsen