Excessive play in front end

[buppy69]

The needle bearings are very loose but the play appears to be where the spindle goes through the upper housing just below the nut and washers. I've tried 3 times to attach the parts breakdown page. The text goes through but the picture doesn't. It doesn't show any bushings as far as I can see.
Eugene

 

[bruce1966us]

The needle bearings should not be loose. That could be a big part of the problem. The needle bearings should be snug inside the gear assembly.

Thanks,
Bruce

 

[reb]

The parts manual shows the housing is two castings with what appears to be a bushing between them. I can't read japanese, so I'm not sure. "TC115 140 15" follows the japanese description. My manual has pages added to show the older 1500D model, which is similar. It uses a different bushing.

reb

 

[roger_scotty]

Can you email me a scan? Every diagram I have is for the US models, but they do go back to 1976. At that time some models used an axial thrust bearing and others got by with a ball bearing loaded in thrust.(at the top of the steering spindle) None of the models used a plain bushing there. Anyway, where the spindle goes through the top of the casting should be tight even if he has to machine the hole out to fit a standard bearing and seal.
Buppy said that the old spindle and bushing was loose enough to cause the wheels to splay, so anything will be an improvement. I wonder if that bushing was a backyard fix or if Yanmar used it.
Agree that it would be nice if the needles were a good fit, but they will get by. The fit of the spindle through the casting is probably more important..... especially if the wheels are splaying out!

 

[gbirky]

reb,
The "TC115 140 15" is a seal number. The numbers are the dimensions in mm. It has an inside (the sealing surface) diameter of 115mm, outside diameter (in casting) of 140mm, and a thickness of 15mm. This has to be the mammoth seal that goes between the upper and lower cast pieces of the steering "knuckle" part of the front axle system (where the tower gears run).

Greg

 

[EFC]

I have the fix. email me buck@efcconstruction.com

 

[roger_scotty]

Finally got to look at the scan of the YM1500D front end. Thanks to Eugene for sending a copy to me. As far as I can see, it is real typical of the early YM series spindles in design. The spindle is bolted to the lower casting, passes right up through both castings and protrudes from the upper to mount the steering bellcrank. The dual pinion bearings run on the spindle supported by needle rollers. The spindle itself has is located in the upper casting by two ball bearings....a large lower one and a smaller upper one that is right below where the spindle protrudes through the casting. I don't see any bushing, and there is the typical large oil seal that separates the castings.

 

[gbirky]

Roger,
So what you are calling the "spindle" is the vertical pivot shaft on which the "tower gears" rotate. In my automotive lingo, the spindle is the shaft on which the brake drum or rotor runs, or is attached to. So on the tractor axle, the "spindle" would be the horizontal shaft which has the mounting plate for the wheel welded to the end rather than the vertical pivot shaft.

Greg

 

[roger_scotty]

Good call. My own opinion - not backed up by anything more than a lifetime of mechanical work - is that mechanical lingo seems to still be sorting itself out.

I call shafts which rotate completely around as "axles" and shafts which have limited or no rotation as "spindles". So what I am referring to in our thread here is what I call the steering spindle - or vertical steering spindle -and in older cars I would call a part which does a similar steering function the "king pin". Though in my lingo the 4wd Yanmar steering spindle has two jobs: Steering plus mounting the drive pinions. Dang! I see what you mean....I almost called that shaft an "axle" just then because it mounts two rotating parts. So I'm not consistent with it either. Thinking on it farther, to me a spindle is usually suppported at one end. When it gets supported on both ends it begins to get into "axle" territory. But I need to call the Yanmar part a spindle because there are two true axles on each side of the tractor and I need to differentiate the steering shaft from those true axle shafts.

In 2wd cars I would also call as a spindle the non-rotating part that projects from the brake mounting plate and which supports the front wheel. In an old style 4wd truck like my old chevy it has a steering spindle, as well as the wheel mounting spindle I just mentioned. But on that truck the wheel mounting spindle is hollow and has a fluted drive axle running through it for 4wd. Whew!

We seem to still be building our mechanical language and it does vary from place to place. By no means to I claim that my terminology is the only way....or even the right way.