Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

my old  1980 Yardman let me down  while clearing  or so inches after work today.    It  started after about   6-10  pulls   it would sputter and black smoke would come out the muffler.   Anyway  it finally started and I i warmed it up and started to clear the drive   I made the first pass and punched through the EOD.  I turned the blower and put it in reverse.... Nothing!  it wouldnt move.  I tried all 5 forward speeds ans both reverse   but the wheels didnt move one bit.    Motor was running fine and augers were moving.  it was too dark to work on it tonight  .I ended up using my 4.5hp single stage to finish the job.   So what do you all think caused this sudden drive failure?  I will work on it this weekend   .What should I be checking. ?

FYI for those who dont know   this is a 5hp 1980 yarman  two stage blower.

OK. Now I'm confused.  LOL 
Anyway, I ended up just putting a new 3/16 x 1 1/2 roll pin back in the two axles.

"BTW, Kevin, you will not find a bolt to fit in that spot that will last very long.  Small bolts like that will shear very easily.  Only a roll pin or a spring pin will fit."

 Well, first of all, I could not find a #8 hard 3/16 x 1 1/2 bolt at the store. I guess they start at 1/4. I would have had to drill the axles out. Not so sure I wanted to do that. Thats why I just put the roll pin in.

Ken, My blower does have a variable-ratio limited-slip differential, but I'm confused there too. My left wheel has the large wing nut on it. Turn clockwise to reduce slip or lock the wheels. Turn the wingnut counterclockwise to unlock the wheels and increase the slipping action of the differential for easy turning. I've tried to unlock the wheels by the directions in the manual, but they still stay locked. I can move the machine around fine, but would like to try it without the wheels locked. Any reason why they won't come unlocked? Any suggestions are appreciated.
                                                                                                                                       Thanks,  Kevin

Kevin,
i know nothing about your machine.

A # 10 bolt is about 3/16. Most socket head cap screws are grade 8 or better. Mcmaster-Carr or any fastener supply house will have them.

robmints wrote:

Apparently, neither do I, but I'm working on it.   LOL                               

That locking mechanism has a habit of seizing up with time. Usually in the locked position as that is where most people leave it.   That.......completely defeats the purpose of having a diff. equipped machine.   I have a couple of friends that have the very same machine as you, Kevin.  Both were seized up.  Once they were freed up and working properly again, the machines were nicer to operate.

You should not need a hardend bolt in that application.  I DO NOT recommend drilling out the holes and putting in a 1/4" bolt ,as the sides of the connecting rod are pretty thin already with the 3/16" holes in them.  I have broken that rod a couple of times from "regular use"  and it has ALWAYS  snapped where the holes are.  I keep a spare around now.  But that is just me, I can't have any down time.  Sounds like you have a bit of tinkering to do.  To me, that is almost as fun as playing (I mean) working  with your snowblower!

BTW............you will know that your diff. is working properly when you make a 180 degree turn (say left, with the machine not running and the clutch not engaged) and the left wheel is rotating backward and the right wheel is rotating forward.

HTH,

Ken

Hi Ken. I didn't want to drill the holes out for the reason you stated. As far as the diff, are there any tricks I can try to get it loose or just hope it does it on it's own? I just loosened it up today. Perhaps just running it around in this next storm may do it. We'll see.

                                                            Thanks for your help,   Kevin