Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

dieselman

Fiber Disk

Recommended Posts

dieselman
Im ready to mount my engen tonight after I drill 2 holes. Im gona try to get it as square and inline as I can with the drive but im wondering it it is off aluttle how hard it will be on the fiber disks. Thanks

Share this post


Link to post
Share on other sites
HubbardRA
I've swapped several engines. To be honest, I've been out of line by as much as an inch and never seen any additional vibration. Don't try to angle the engine to compensate. The critical element in a drive shaft is that the input shaft and the output shaft, coming to and leaving from the joints, be parallel (even if not directly in line), regardless of the driveshaft angle. If you don't believe me, look at one of those jacked up 4x4 trucks. The driveshaft has an extreme angle, but the shaft coming out of the transmission and the pinion shaft of the rear are always parallel (aligned to the same angle). A flex disk works the same as a universal joint, but it will be overstressed and tear itself apart if the angle is too extreme.

Share this post


Link to post
Share on other sites
dieselman
HubbardRA by being paral you mean by haveing the engen and gear box level with one another. Im not as worried about the hight as i am haveing the engine and bevil box not strat with one another. or haveing the engine in the frame a hire crooked. I just came in from messing with it and i have to bend a spot out on my frame a luttle so the bolt heads dont run but otherwise It looked like i had it strat.

Share this post


Link to post
Share on other sites
John_RI
Don't count on the coupling disks to make up for offsets. You should line things up as best as you can - don't expect a piece of plastic to take the place of good sense. Bearings in the engine and bevel box will suffer if the alignment is not correct.

Share this post


Link to post
Share on other sites
HubbardRA
Guys, I knew several of you would question my remarks. I will agree that the shaft should be as straight as possible with as little angle at the joints as you can get. I ran a 12 Hp Cub Cadet engine sitting on spacers to make the oil pan clear the frame of my 61 wards for several years in tractor pulling. This was with a set of flex plates that I had removed from and AC 716 tractor. The engine shaft was about 1 & 1/2 inches higher than stock. That engine was later changed to a 14 Hp Kohler flat bottom type like Simplicity uses. Still nearly an inch higher than the original 7.25 Hp B/S. Same joints and still running. The angle if it is large enough will fatigue the joints and make them come apart. I don't know what the critical angle is, since I have never had one fail. The load on the engine itself from the increased driveshaft angle is much less than produced by a belt drive like the other makes use. When I say keep the shafts parallel, I mean keep the engine square in the chassis. Don't try to point the engine shaft directly toward the BGB shaft if the engine sits higher. This will create unequal angles in the input versus the output and produce a vibration. When there is an angle between the input shaft and the drive shaft, this makes a pulsation in the drive shaft. If the output is sitting at the same angle with the driveshaft, the pulsation is removed. It is very difficult to explain the mechanism behind this in words on this forum, but it plays true with flex joints same as universal joints. If you had constant velocity joints, then this doesn't happen. Biggest cause of failure in these joints is pulling them into tension when bolting them to the engine. This is why I always loosen the set screws on the BGB yoke so that it can move if necessary when bolting up the engine, then tighten afterward. I've built two pulling tractors from the ground up, with motorcycle engines. I've built circle track cars and drag cars. It worked on all of them. This advice if "free". Use it as you wish.

Share this post


Link to post
Share on other sites
RickS
While I cannot explain it as well as Rod can. He is correct the angles must match. As he states, if you point the motor at the shaft the angles will be different and you will get a vibration. I had an old jeep with a 2.5 inch lift, the only way to get rid of the driveshaft vibration was to make the angles the same. Once that was done I never had a problem with the u-joints. Another way to explain it would be to state the joints must be in phase with each other.

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.

  • Who's Online (See full list)

    • rokon2813
    • SmilinSam
    • GregB
    • littlefan
    • Chris727
    • CarlH
    • bowhunt4life
  • Today's Birthdays

    1. dbulkley62
      dbulkley62
      (59 years old)
  • Recent Status Updates

    • jbrooks

      jbrooks  »  Talntedmrgreen

      Josh
       
      folowing  this from a link at the downloads.  I just rescued an AC 920 with the lambodini diesel. I can' t download  yet .  Where did you find the PDF copy you posted. . I would like to figure out how to adjust the injection pump. 
      I assume it's a bosche, correct
      · 0 replies
    • dav-1

      dav-1  »  Talntedmrgreen

        Over a year ago, you answered a question I had about the tool bar for my FDT. In your reply dated Dec 31, 2019  you said the spacer, part #16, goes in the bar to allow for up and down depth adjustment. does this mean the bolt has to be tightened at whatever depth desired or does the bolt slide up and down, allowing the lower hitch to free float?
         If it is tightened so the lower hitch and the bar are rigid, then is the depth to be controlled by the shoes? Or by the lift handle?
        Is there any kind of user directions for the tool bar? The Outdoor Power Manual basically shows how to assemble the bar but not how to use it
      · 1 reply
  • Adverts

×