BGB leak and play

[mike_sdak 1]

Al mentioned checking play in the BGB in another thread. I have the motor removed from my 917H. I put on the driveshaft for the 16 Hp briggs, and noticed a drop of oil on the driver's right side (transmission drive) pulley on the BGB. I assume that shaft seal is leaking a bit on the BGB. Also, when I turn the input shaft, there is a portion of a revolution of play (for lack of a better turn) before movement on the output shaft occurs. So my question is twofold - How do you check the play in the BGB? How much is too much? and, How to replace the seals? Or can I band-aid the seals in some fashion?? Thanks in advance,

[PhanDad 1,401]

See these posts: http://www.simpletractors.com/club2/topic.asp?TOPIC_ID=112639 http://www.simpletractors.com/club2/topic.asp?TOPIC_ID=112066&SearchTerms=bgb http://www.youtube.com/watch?v=_2cwAUP0Gjw&videos=xGw74R--zCM

[mike_sdak 1]

Bill, Thanks. Those posts look like they will get me started in the right direction. Any comments on how much backlash is too much? I think in one of those threads, a member mentioned 3/8" travel on the outside of the main output pulley.

[donmoore1904 0]

I have two similar tractors, one has a perfectly quiet and well performing BGB, and the other has one that chatters and the driveshaft vibrates. The main problem in the latter is the ball bearing on the front shaft was going bad. But there was also about twice as much lash in this one due a worn BGB gear key. My memory is that on the output pulley, the noisy one had about 1/4" of lash. The good one about 1/8". I think I had about 7 degrees of lash on this one, and 3.5 degrees on the "good" one, which translates fairly well. As far as that leak - after seeing the damage done by low oil I would suggest fixing the seal. The Simplicity procedure says to assemble the BGB and put the seals in last. Maybe you can pull them somehow. The trick I have used on a crankshaft is a self tapping screw and pliers - but the small seals are pretty narrow.

[mike_sdak 1]

Thanks for the thoughts. I checked the backlash last night. I would guesstimate about 1/8" plus or minus, seems pretty tight to me. I think I'll try to replace the seals and leave the box alone for now.

[larry8200 0]

Have you checked to make sure the BGB isn't overfilled? The dipstick should just touch the gear oil when set (not screwed into) the fill hole. It sounds like it's nice and tight, and if there is only a "drop" I'd be in no hurry to do anything.

[Willy 0]

As long as the BGB is out of the tractor I would replace the seals and the needle bearing on the front shaft while they are easy to get at.