Getting Slop Out of MTD Steering

[mhavanti]

Delrin is an excellent choice. I keep the threshold savers from new door units. Its very hard, has a great lubricity and wear factor.

I wouldn't have thought you should have to remove the engine to get to everything you need to. But then, it may be easier and faster. Just take your time and think it thru, you'll overcome.

 

[Roger B]

Ron,

The steering in my MTD Yardman was much the same as you have described. It seemed to have been designed that way. The only major effort I made was to make a steel bushing that fit over the pin on the steering gear arch, that the steering rod end would still slip (tightly) over. That improved things, but as you and mhavanti have discussed, all of the steering components fit together very loosely. I have considered building up the ends of the remaining tie rods with weld and then hand shaping them to improve their fit, but I got involved with rebuilding the transaxle and stopped worrying about it. I can steer it and the bushing I made improved things enough to satisfy me. I will be interested in reading about how the improvements you've made work out.

Roger B

 

[Ronno6]

Delrin is an excellent choice. I keep the threshold savers from new door units. Its very hard, has a great lubricity and wear factor.

I wouldn't have thought you should have to remove the engine to get to everything you need to. But then, it may be easier and faster. Just take your time and think it thru, you'll overcome.

The bolt for the bushing in the arc-shaped slot is way back from the edge of the support plate, which is mounted closely under the mower frame.
This makes things virtually impossible to access with a wrench (maybe a specially bent wrench) due to angles and interference with the engine.
And, in order to repalce the main drive belt, the engine pulley has to drop down so that the belt can clear the keepers. Even though I used never-seize
when I replaced that pulley the first time,it still won't budge. Hence another reason to pull the engine, which really isn't that bad of a task.
Thanks again..........

Ron,

The steering in my MTD Yardman was much the same as you have described. It seemed to have been designed that way. The only major effort I made was to make a steel bushing that fit over the pin on the steering gear arch, that the steering rod end would still slip (tightly) over. That improved things, but as you and mhavanti have discussed, all of the steering components fit together very loosely. I have considered building up the ends of the remaining tie rods with weld and then hand shaping them to improve their fit, but I got involved with rebuilding the transaxle and stopped worrying about it. I can steer it and the bushing I made improved things enough to satisfy me. I will be interested in reading about how the improvements you've made work out.

Roger B

I can't help but think that some slop was intended.
However, sometimes the critter just won't turn as sharply as I think it should.
I have found that a tad of toe-in helps the turning radius, but things have become so sloppy that action is required.
And, sometimes when the steering is turned to right or left lock, one wheel will flop into a right angle position
and the whole shebang comes to a halt. Very disturbing.
I may get some bushings for the rod ends to do as you did, then capture them with larger washers over and under.
That's probably gonna be another McMaster Carr order...........
Thanks for your comments, and I will advise the ultimate outcome.

Thanks for your comments!

 

[mhavanti]

Roger and Ronno,

Would it be alright to reply to both of your last comments and use this so as to cover both with one reply? I'll just call you two Rog-O and that should get you both! lol

Roger, the steel shim can cause extreme wear to your gear segment, that is why I recommend the plastic below the gear segment to raise it to the top of your bolt built in washer shoulder and provides a friction relief between the frame and the gear segment keeping the gear segment flat precluding the rocking motion. The gears are required to have some clearance but not as much as the stamped gear comes with. You could cut the frame loose in that area of the raised section on your frame if it is the gears above the frame, move the piece toward the pinion gear on the shaft and weld the frame back up and that would solve a great deal of movement between the two teeth. You would also have to consider the piece would have to be flat during welding and the weld ground smooth afterward. I've done it, but, it isn't a lot of fun.

Ronno,

On the toe in, you should toe outward to help your steering. Plus, to gain a tighter turning radius for both directions, toe out gives you a greater Ackerman in the steering right and left. It will also make your mower track more accurately. Back to the Ackerman. Ackerman is: Turn your wheel to lock in one direction, the inside tire should now have a tighter turn than the outer tire. You want this because the inner tire is traveling a shorter distance than the outer tire. This will gain better fuel mileage and less wear and tear on your engine and tires. Plus, you can run it wide open and not have the mower wander all over the yard or pavement. ( as though you were going a hundred miles and hour )

Now, Rog-O

For the tie rod tightening. Take a 1/4 inch flat washer, put it into a vise, cut one side until you twist it just enough to slide it over your tie rod ball shaft. Now, twist it back until it is surrounding the shaft over the ball equally, bend it down over the outside of the tie rod housing if you can. Weld it to the outside of the tie rod housing and now your tie rod will not have any slack in it and most of your slop will be gone.

Here is a youtube on how to do it: http://www.lawnmowerforum.com/showt...-Slop-Out-of-MTD-Steering?p=253452#post253452

 

[Ronno6]

I understand the principles involved in inner/outer paths when traversing a curve.
In most instances I believe this is addressed in the design and geometry of the steering system.

I have found that having a bit of tow-out seems to be really detrimental to turning radius.
I have observed the tracks taken by the front tires when steering a tight turn, and the outer tire
seems to be the one controlling the turn.This causes the inside to drag and not grip, a bit like
what the NASCAR drivers would describe as "push."
Maybe I'm not actually inducing a tow-in, just less tow-out. Dunno.
However, as sloppy as the steering has been, it is difficult to actually determine
what actually is happening.
I certainly hope that I can achieve a better grasp on the situation once this exercise is completed.

 

[mhavanti]

Now we're talking. I've been designing, building and racing cars, motorcycles, trucks (including diesel rigs at Indianapolis), bar stools, Go Karts, lawnmowers, RC cars, you name it, I've built and raced it also including my race guns. More rounds per trigger pull the more fun they are. lol.

If you go to any front end alignment shop, you'll find that a street vehicle will wander with straight ahead (zero toe), it will drive terribly wander, dip the tires and push if toe'd in. I do remember a couple of old timers (Chevrolet Dealership) that tried to align my Vette's back in the late 60's and early 70's with toe-in. I couldn't hold them in the road and especially when in a grooved or highway with two percent slant to either side. Any difference in air pressures from one side to the other would take the wheel out of your hands and at the speeds I drove them, not acceptable.

My own father finally took me into his shop, had his front end man set me down and tell me to go get the car, put it on the rack, he is going to teach me how to align my asphalt car as well as the daily driver.

Now, toe in causes many unacceptable factors I've mentioned above, however, to make a vehicle track the very best, you toe in the rear tires about an 1/8th to a 1/4 degree and toe out the front about 1 to 1/2 degree. This doesn't cause push, under steer and there are hundreds of other names we can all it.

Push is usually caused by several factors depending upon the surface of the track, the type of material of the track and actually the set up of the vehicle. Too much wedge in the spring weights is usually the biggest cause. Too stiff front left spring and too light right rear spring. Pan hard bar can be too high below center of the rear axle center line and that will cause over steer and push is going to rear its head. Over inflated rear tires, under inflated front tires or a combination of the two. However, we've only touched on one one thousandth of scenarios that can cause push. Ackerman is a desired factor for both street and has to have it on short tracks in particular.

Toe out if set up for your particular vehicle does not cause noticeable fuel consumption as it is necessary to maintain control over high speed, heavier vehicles in particular. A lawnmower doesn't fall into this category, but, any fuel savings and steering ease is worth it to me.

On my all wheel steer Yardman I have approximately 2 1/2 degrees toe out on each front tire and it drives the guys nuts when they see it. I tell them to take it to their house, jump on and give it a ride and see how it holds the hillside at their place, then tell me it doesn't work. Worst part about that is, then they want me to set up theirs. lol.

Give it a try. I have the hood off mine right now. I will take a shot for you sometime today and give you an idea how much I'm running. Remember, the tires on my mower are the same age as the mower. 1996 and it has never seen anything less than WOT so it runs wide open all the time.

 

[Ronno6]

Had you told me that you worked for Andy and Vince on the #40 turbocar and its successors, I would consider you a lesser god..........

I will try the steering setup you recommend once I get things under control (and a motor back in..)

I am at a loss as to how to set toe in on the rear,tho.........

As for race guns, my son in law owns a MG42...........
I have a Mini-14 for which there is available a trigger which fires 1 shot when squeezed, and a 2nd shot when the trigger is released.....

BTW, a cursory search has turned up nothing as to the wall thickness of a 2 liter pop bottle.
Do you know the material thickness of the plastic?
Thanks

 

[Ronno6]

Well, here's a rather disturbing update.
I knew I had an extra cadaver front axle laying around, so I went searching.
I found that it was not only an axle, but had rod ends,linkages and a dirty but good rack gear.
Playing with it taught me the following:
1.When installed with new bushings the rack gear demonstrated almost NO slop/play. Maybe .010" wobble end to end.
2.There may be no slop between rack and pinion when I receive the new hex-piloted steering shaft bushing.
I believe all present pinion to rack play is due to that bushing being worn...
3.Steering linkage play is greatly reduced, probably due to reduced rack gear slop.
I will have to see how much play remains when I install new plastic bushings on these joints.
4.There is NO room to install the plastic shim/wear plate I was going to fashion from Delrin. Oh,Well....
5.The ends of the rack gear where the linkages attach are not on the same plane with the center of the gear.
I may make some wear shims for those ends, but I may need thinner Delrin.

So, once the new steering shaft bushing is installed, I would not be surprised if things weren't 'bout as good as new.

Then I gotta tighten up those wheels...........

 

[mhavanti]

Since you know the name Granatelli, I'll tell you about one of my cars. It is an Avanti. He took a 289 Cu. In. supercharged Avanti to Bonneville Salt Flats, purely stock from the assembly line other than a few moderations to meet the official's safety requirements. Set a record that still stands today for that class, cu. in., wheelbase, weight, etc.

One hundred seventy-six mph out of the box. The Corvette didn't run that top end with a 327 inch, no top, a tonneau cover and I'd met ole Andy while he was President of STP on several occassions. We were one of his STP distributors. He and my father were a couple of cussin' BS'ers that laughed a lot and both did so many things in their lives. Both were my heroes with the except of that damned Turbo car. We're talking sacrilege. lol

There is a pic of the old Avanti and I thru in a pic of one of my stable of race cars. This one is sitting in Ocala, FL. in the Don Garlits Drag Racing Museum. You'll see my name on the advertising placard.

 

[mhavanti]

Ron,

You could use a water bottle, soda bottle, milk carton, pretty much anything that is about .010-.015 thick. It isn't easy to get it in without testing your faith in the Lord, but, it is doable and you'll be most pleased.

By the way, for the most part, almost all the pinion gears I've replaced, you can turn them 180 degrees and reinstall them and the segment gears then contact in a new area on the pinion gear.

I once had a MG42, a MP38 and MP40, 1921AC, 1928AC, M1a1 Thompsons and many others. But then, I was a dealer and when I retired from all my businesses, the new law passed in 1986 that caused me to tell NRA to lose my name. They endorsed that law and now a race gun can NOT be inherited any longer. You can NOT leave one to a relative or anyone else as it is seen as stray purchasing. With that said, I sold them off to another dealer and his transfer papers come in on 09-11-2001. I handed them over along with his papers before the buildings were hit in NYC and DC. They values increased within fifteen minutes of delivering them, shaking hands and picking up his check. Plus, the folks that attacked us ruined my birthday.