very old nos grubee (pre stage 2 gear box?)

Discussion in 'Transmission / Drivetrain' started by hinz57, Dec 25, 2013.

  1. hinz57

    hinz57 New Member

    All oldtimers!
    I purchased one of the first grubee gb years ago and life got in the way. I seem to remember getting some notification of a recall/exchange which I did not follow up at the time. May have been around 2006. Can anyone remind me what the issues were? I am considering attempting to revisit using this nos box. Also condidering a more current option. Sure would like to know what the problems with this early box were. Looks like a stage 2, but seems to have preceded it. Any and all input appreciated! Thanks, hinz57

  2. crassius

    crassius Well-Known Member

    sorry, can't recall anything, but just sold an old one that was lying around here for some years - had the NT carb with the solid brass slide

    it seemed to run OK with nothing strange in clutch or drive shaft tho
  3. BigBlue

    BigBlue Active Member

    I have an old Stage II that I have had for sale. Like you, I never installed the kit. I bought it sometime between 2004 to 2006.

    If you search the forum on Stage III installation/reviews, you may be able to find what is the recall/issue with the Stage II kits. I am thinking it has to do with the way the clutch engagement mechanism works.

    You may want to contact Bird Dog Distributing ( and ask them if they know of any recalls/issues with the Stage II kits.

    FYI. there's a forum member that has had a Stage III kit installed for several years with no issues. He recommends the stickiest marine grade grease for the transmission.

    Here's what I found when researching the Stage III: "Stage III –Internal gear and centrifugal clutch parts are same as Stage II except for shift lever & cover." Also the Stage II doesn't have an oil seal on the output drive ball bearing pocket.

    Here's the reference on the Stage III: III.htm

    Good Luck,

    AKA: BigBlue
    Last edited: Dec 25, 2013
  4. butterbean

    butterbean Well-Known Member

    The OP is referring to a gearbox for a 4 stroke, not a 2 stroke.
  5. hinz57

    hinz57 New Member

    Thanks for the info and direction. I had planned to call bicycle to see if they had any info about what the issues were. I'll probably just clean it up good and give it a thorough inspection. I have access to a very good machine shop and could effect repair as necessary. It would be a bit easier if I new the issues to begin with, otherwise measuring will ensue! I had read many of the threads on this site referring to stage 2 & 3. These are helpful. Thanks again. Or...I may just buy another gear box. Kind of like the EZ choice, possible the 4G. We'll see.
  6. hinz57

    hinz57 New Member

    I found a thread discussing some former dealer with a bad reputation from Arizona. Augi had written a letter to Don Grubee addressing the issues. Don replied and referenced a group of stage 2 gb, that had not been run on cnc. Apparently these boxes were very noisy. They had an offer to exchange with a different cnc'd box. A distributor named Barsanco was also referenced. I remember now that is where mine came from. Now I would like to know how to identify if my box is actually one of these. Thanks!
  7. HeadSmess

    HeadSmess Well-Known Member

    pop it apart :)

    manual machining looks different to CNC. especially when its done quick and cheap, rather than painstaking, time intensive hand crafting...

    things like...are the gears a nice slide fit on shafts? are machined curves slightly faceted(a sign of fast cnc work) or smooth? (spun on a rotary table or similar) any flat surfaced face....should, but not always, spiral in or out to keep the tool cutting in one direction while manual will tend to take straight cuts all in one direction (depending on machine).

    any complex profiles and or chamfering thats obviously not hand filed... CNC.

    no sudden changes in heights. no obvious change in toolmarks as it enters /exits a corner... no crashes, cus usually a crash on CNC means scrap metal, whereas an observant machinist will stop before the fan gets all covered in...excrement...

    its hard to be definite, cus theres so many types of machines out there... and operators!
    CNC will still make a mess if the machines badly maintained or the programs wrong or the jig has been bolted down a few degrees out of line... etc etc... (read...boss forgot about 14 inch boring bar on station 3, and didnt retract tailstock before doing a rapid retract with toolchange to station 8 on the other side of turret...OOPS!)

    nothing wrong with having a look see anyway, you might find a few glaring faults that are easier to fix now rather than later...

    maybe...just maybe...spin it up with a drill and see what sort of howling obscenities it tries hurling at you?
  8. hinz57

    hinz57 New Member

    Called birddog, very courteous, but no help.
    Emailed Don Grubee, again very courteous, only suggestion was to give it a try. Apparently, all were cnc parts, qc sampling let some through. No way to id the bad parts. Also no info as to which parts were bad, or what dims were off.

    So, after Christmas, I bolted it up to my Honda ghx50. Almost locked up tight! Loosened 4 bolts to motor and box spun freely. I have determined an interference fit fron the cc gear to the idler shaft gear. The gear mesh from ider to output shaft gear is probably ok, if not a bit loose. So..... either the idler shaft bearing bore location is off, or the bolt pattern and bore to mount the gb to motor is off. The only practical solution, as I see it is to throw the box on the Bridgeport and elongate the mounting holes to allow proper gear mesh from cc gear to idler shaft gear. Then make certain that that any clutch bell to housing interference is addressed. Only other options include welding up idler bearing bores and remachining. Not cost effective. Or replacing with an alternative gb. I'll give the simple fix a go first!
    Other problem I found is the clutch bell rubs on the engine case when shaft bolt is snug. The bell extends past the clutch shoes by about 0.100. I plan to spin about 0.060 off the bell for clearance.
    I think that these changes will either make it usable, or let me see what else needs to happen.
    In case you wonder, I have spent many years in fab and machine shops, including manual and cnc. I appreciate any input. Thanks!
  9. HeadSmess

    HeadSmess Well-Known Member

    yers, ive got one of these boxes...well, a box from some horrid kit that i just wanted the engine from... well, i did try the box on the bench for a minute first, of course....

    its a bunch of badly dressed and finished gears, shafts with no shoulders to prevent sideways movement.... dodgy welds here, nasty lumps there... shafts arent even sliding fits in the gears, the amount of work required to get anything decent makes me want to pull a pitbike/honda gearbox apart instead... its ok for a personal project but commercially, complete waste of time.

    if youve done this stuff before...then youll be all to familiar with the mess a rapid retract can make! :jester: and lack of backlash eliminators on a climb job. :eek: