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Discussion Starter #1
Sunday afternoon fun playing with Comet revealed VERY sloppy steering linkage was caused by every steering tie rod bushing having turned to junk. Those bushings or bearings, which ever term you prefer, are plastic. Yet their application causes them to take quite a beating. Ford diesel trucks with manual transmissions ran unsuitably-soft bushings on their clutch disengagement linkage which fail at a furious rate until the owners replace them with something other than the stock plastic junk bushings. These Snapper tie rod bushings appear to be another circumstance where plastic bushings were specified by some engineer where they should have used some tougher material.

The dealer is closed Sundays anyway. I decided to see if any candidate materials I have might make better replacements. The second thing I tried was some fairly thick-walled hard copper tubing. The tie rod fits inside the tubing's inside diameter. The tubing's outside diameter fits inside the bearing holes. Both fits leave very little clearance. I flared one end of the copper tubing to prevent it from migrating around the tie rod bends. That's exactly what parts of the original plastic bushings had done. Pieces of them had actually slid around the tie rod curves so they were floating along the tie rod's long dimension, where they could do no good. I don't think this fairly-tight-fitting copper tubing will do that.

After flaring and cutting four short copper tubing lengths and swapping them in for the original plastic bearings, the steering clearance is almost tight. I expect these copper tubing replacements would last longer than the original plastic bushings they replace. Many of you have the needed flaring tool, some hard copper tubing and a cut-off tool. If your steering feels sloppy, consider making this improvement. It only takes a few minutes and bending some cotter keys.

My front tires are now both aiming straight ahead rather than angling away from each other. That was causing them to scrub on the ground as they fought against each other for steering dominance.

If this description isn't adequate, tell me. I'm willing to shoot a couple photos. This really tightened up my Comet's loose steering a lot.
John
 

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Nylon bushings for the front end of your Snapper are so inexpensive that they're sold in quantities of ten, and can be replaced over and over again without causing wear of the parent metal.
 

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Discussion Starter #3 (Edited)
Your point is well taken. For me, I would have been required to wait one day for the dealer to open, then drive 18 miles in and 18 miles back, all of which seem convertible to additional costs. Even then, I suspect the hard copper tubing replacements will last longer and also will not abrade away the parent material. Sometimes I try things that don't work out well. Sometimes simple & easy substitutions work out very well. For instance recently while restoring a Lawn-Boy "D" series engine pull starter to operation I discovered that the parts pile was missing the "slip ring spring," which is just a springy metal wire bent into a very specific shape. Our family occasionally buys take-out orders of flavored rice from a Chinese place and I had noticed that they were using what appears to be very stiff stainless steel wire for their package swinging handles, so I'd saved a few of them. About 2 minutes of re bending one of those wire handles duplicated the original Lawn-Boy pull starter slip ring and it works very well. I don't know that those same stainless steel wire handles are available nation wide, so others might not be able to duplicate that substitution. But hard copper tubing and tools are available nation wide. So for those who might want to save some driving time and expense yet produce a repair that seems at least as good and perhaps better than stock, just as many Ford diesel manual transmission pickup owners have done when too-soft plastic OEM Ford bushings begin showing signs of failure every time about 3 months have passed after their repeated replacements, this report seemed like a suitable forum conversation topic.

I don't mean to be overly critical of Snapper's steering design. But if they had configured it so each front steering wheel produced a normal straight-back "trail" or "caster" direction and dimension, both steering wheels would be independently self-centering. Instead some Snapper designer elected to create this Mickey Mouse configuration which causes both steering wheels to continually convert rolling resistance into outward-splaying force. They or someone else specified tie-rod bushings that aren't sufficiently durable for loads and conditions those bushings endure. Every old Comet that hasn't had its front end repaired should not necessarily be sloppy and loose. Yet that undesirable result is the certain and predictable result of Snapper's poor steering design decisions made years ago. Joining two inherently self-centering mono-track steering wheels makes a much better performing and more durable front end than joining two inherently unstable-steering mono-track steering wheels through pressure-loaded links joined by four, too-soft, wear-prone plastic bushings to balance their inherent instabilities. I didn't invent this situation. I'm just reporting what is clearly obvious to any student of good design. Take off your Comet's tie rods, then roll it forward one foot. See what happens. Without tie-rod bushings resisting each side's inherent steering instability by balancing those designed-in loads, those front wheels instantly splay out to maximum left and maximum right aiming. Every dip or bump either of those front wheels hits produces a momentary rolling-resistance spike which this linkage configuration converts into a hammering load that passes through those 4 plastic bushings. All this would have been avoided by better steering geometry design.
John
 

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Poor design. It's simple, effective and stands the test of time. Yes they get a little sloppy but so what? The bushings are cheap and they are very durable. Takes many many hours of use to get the bushings to wear out.

Poor design. Wow! Never heard that one before.....

I do have to say though that is a clever idea for someone in a pinch such as your self. I would actually do this if I wasn't so close to the dealer on a daily basis.
 

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Hate to disagree with you on this, K. Beitz, but a Snapper rider will outlast several box store tractors. When I was a Snapper dealer, it was not uncommon for these machines to last 20 years or more, with parts being cheap and readily available. Since their design is not constantly changed, the old units never become obsolete. The nylon bushings, for example, will fit a new machine or one made 30 years ago- same part.
 

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I considered replacing the plastic bushings with copper but just tightened them up instead with a couple wraps of electrical tape. I think heat shrink tubing would work OK too.
 

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When I was a Snapper dealer, it was not uncommon for these machines to last 20 years or more, with parts being cheap and readily available. Since their design is not constantly changed, the old units never become obsolete.
IMHO, the Snapper RERs have been obsolete in design for many years, perhaps since the 70's. For a $1000, I could buy a Craftsman that is much smoother to operate, and with maintenance, would last just as long. The smallest Snapper RER available cost $1500 for the obsolete design.

As for parts being 'cheap', I recently bought a smooth clutch housing and muffler that cost $82, nearly 10% the cost of a new Craftsman. To buy all the parts for a Snapper at retail would cost many thousands of dollars.

Nothing cheap about maintaining an old Snapper, or any other mechanical device, but it is fun.
 

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Sunday afternoon fun playing with Comet revealed VERY sloppy steering linkage was caused by every steering tie rod bushing having turned to junk. Those bushings or bearings, which ever term you prefer, are plastic. Yet their application causes them to take quite a beating. Ford diesel trucks with manual transmissions ran unsuitably-soft bushings on their clutch disengagement linkage which fail at a furious rate until the owners replace them with something other than the stock plastic junk bushings. These Snapper tie rod bushings appear to be another circumstance where plastic bushings were specified by some engineer where they should have used some tougher material.

The dealer is closed Sundays anyway. I decided to see if any candidate materials I have might make better replacements. The second thing I tried was some fairly thick-walled hard copper tubing. The tie rod fits inside the tubing's inside diameter. The tubing's outside diameter fits inside the bearing holes. Both fits leave very little clearance. I flared one end of the copper tubing to prevent it from migrating around the tie rod bends. That's exactly what parts of the original plastic bushings had done. Pieces of them had actually slid around the tie rod curves so they were floating along the tie rod's long dimension, where they could do no good. I don't think this fairly-tight-fitting copper tubing will do that.

After flaring and cutting four short copper tubing lengths and swapping them in for the original plastic bearings, the steering clearance is almost tight. I expect these copper tubing replacements would last longer than the original plastic bushings they replace. Many of you have the needed flaring tool, some hard copper tubing and a cut-off tool. If your steering feels sloppy, consider making this improvement. It only takes a few minutes and bending some cotter keys.

My front tires are now both aiming straight ahead rather than angling away from each other. That was causing them to scrub on the ground as they fought against each other for steering dominance.

If this description isn't adequate, tell me. I'm willing to shoot a couple photos. This really tightened up my Comet's loose steering a lot.
John
Possibly a few of us would appreciate your closeups of those copper bushings
 

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Sunday afternoon fun playing with Comet revealed VERY sloppy steering linkage was caused by every steering tie rod bushing having turned to junk. Those bushings or bearings, which ever term you prefer, are plastic. Yet their application causes them to take quite a beating. Ford diesel trucks with manual transmissions ran unsuitably-soft bushings on their clutch disengagement linkage which fail at a furious rate until the owners replace them with something other than the stock plastic junk bushings. These Snapper tie rod bushings appear to be another circumstance where plastic bushings were specified by some engineer where they should have used some tougher material.

The dealer is closed Sundays anyway. I decided to see if any candidate materials I have might make better replacements. The second thing I tried was some fairly thick-walled hard copper tubing. The tie rod fits inside the tubing's inside diameter. The tubing's outside diameter fits inside the bearing holes. Both fits leave very little clearance. I flared one end of the copper tubing to prevent it from migrating around the tie rod bends. That's exactly what parts of the original plastic bushings had done. Pieces of them had actually slid around the tie rod curves so they were floating along the tie rod's long dimension, where they could do no good. I don't think this fairly-tight-fitting copper tubing will do that.

After flaring and cutting four short copper tubing lengths and swapping them in for the original plastic bearings, the steering clearance is almost tight. I expect these copper tubing replacements would last longer than the original plastic bushings they replace. Many of you have the needed flaring tool, some hard copper tubing and a cut-off tool. If your steering feels sloppy, consider making this improvement. It only takes a few minutes and bending some cotter keys.

My front tires are now both aiming straight ahead rather than angling away from each other. That was causing them to scrub on the ground as they fought against each other for steering dominance.

If this description isn't adequate, tell me. I'm willing to shoot a couple photos. This really tightened up my Comet's loose steering a lot.
John
Photos please?
calrec
 

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Discussion Starter #12
I finally remembered to take a camera to the Snapper project mower. Here's a view of the tie rod bushings made from hard copper tubing as described.

John
 

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Since their design is not constantly changed, the old units never become obsolete. .
You know, they keep changing and "improving" modern lawn equipment, but the grass hasn't changed in a bazillion years. If we didn't need cup holders and 23hp 30 years ago, why do we need it now?
 

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Your point is well taken. For me, I would have been required to wait one day for the dealer to open, then drive 18 miles in and 18 miles back, all of which seem convertible to additional costs. Even then, I suspect the hard copper tubing replacements will last longer and also will not abrade away the parent material. Sometimes I try things that don't work out well. Sometimes simple & easy substitutions work out very well. For instance recently while restoring a Lawn-Boy "D" series engine pull starter to operation I discovered that the parts pile was missing the "slip ring spring," which is just a springy metal wire bent into a very specific shape. Our family occasionally buys take-out orders of flavored rice from a Chinese place and I had noticed that they were using what appears to be very stiff stainless steel wire for their package swinging handles, so I'd saved a few of them. About 2 minutes of re bending one of those wire handles duplicated the original Lawn-Boy pull starter slip ring and it works very well. I don't know that those same stainless steel wire handles are available nation wide, so others might not be able to duplicate that substitution. But hard copper tubing and tools are available nation wide. So for those who might want to save some driving time and expense yet produce a repair that seems at least as good and perhaps better than stock, just as many Ford diesel manual transmission pickup owners have done when too-soft plastic OEM Ford bushings begin showing signs of failure every time about 3 months have passed after their repeated replacements, this report seemed like a suitable forum conversation topic.

I don't mean to be overly critical of Snapper's steering design. But if they had configured it so each front steering wheel produced a normal straight-back "trail" or "caster" direction and dimension, both steering wheels would be independently self-centering. Instead some Snapper designer elected to create this Mickey Mouse configuration which causes both steering wheels to continually convert rolling resistance into outward-splaying force. They or someone else specified tie-rod bushings that aren't sufficiently durable for loads and conditions those bushings endure. Every old Comet that hasn't had its front end repaired should not necessarily be sloppy and loose. Yet that undesirable result is the certain and predictable result of Snapper's poor steering design decisions made years ago. Joining two inherently self-centering mono-track steering wheels makes a much better performing and more durable front end than joining two inherently unstable-steering mono-track steering wheels through pressure-loaded links joined by four, too-soft, wear-prone plastic bushings to balance their inherent instabilities. I didn't invent this situation. I'm just reporting what is clearly obvious to any student of good design. Take off your Comet's tie rods, then roll it forward one foot. See what happens. Without tie-rod bushings resisting each side's inherent steering instability by balancing those designed-in loads, those front wheels instantly splay out to maximum left and maximum right aiming. Every dip or bump either of those front wheels hits produces a momentary rolling-resistance spike which this linkage configuration converts into a hammering load that passes through those 4 plastic bushings. All this would have been avoided by better steering geometry design.
John
Hi John,
Do you recall what the o.d. & i.d. dimensions are for the 'hard copper tubing?
Thanks
Calrec
 

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I think it was a great idea!! Looks like a "factory job" should look like.:trink40:They'll dig our butts up some 500 years from now and call us the "plastic age",then look at each other and say "What the **** were they thinking"??:biglaugh:
 

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I think it was a great idea!! Looks like a "factory job" should look like.:trink40:They'll dig our butts up some 500 years from now and call us the "plastic age",then look at each other and say "What the **** were they thinking"??:biglaugh:
Think I'll go ahead and mike the tie rod and hole for it in the steering column plate, then look for copper tubing at a hardware store. Can cut and flare the copper at work to make the bushings.
 

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Took the tie rod off the steering column plate: (Cleaned up and measured with digital micrometer.)
Tie rod diameter = 0.370 in.
Hole in steering column plate = 0.485 in.
 

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Sunday afternoon fun playing with Comet revealed VERY sloppy steering linkage was caused by every steering tie rod bushing having turned to junk. Those bushings or bearings, which ever term you prefer, are plastic. Yet their application causes them to take quite a beating. Ford diesel trucks with manual transmissions ran unsuitably-soft bushings on their clutch disengagement linkage which fail at a furious rate until the owners replace them with something other than the stock plastic junk bushings. These Snapper tie rod bushings appear to be another circumstance where plastic bushings were specified by some engineer where they should have used some tougher material.

The dealer is closed Sundays anyway. I decided to see if any candidate materials I have might make better replacements. The second thing I tried was some fairly thick-walled hard copper tubing. The tie rod fits inside the tubing's inside diameter. The tubing's outside diameter fits inside the bearing holes. Both fits leave very little clearance. I flared one end of the copper tubing to prevent it from migrating around the tie rod bends. That's exactly what parts of the original plastic bushings had done. Pieces of them had actually slid around the tie rod curves so they were floating along the tie rod's long dimension, where they could do no good. I don't think this fairly-tight-fitting copper tubing will do that.

After flaring and cutting four short copper tubing lengths and swapping them in for the original plastic bearings, the steering clearance is almost tight. I expect these copper tubing replacements would last longer than the original plastic bushings they replace. Many of you have the needed flaring tool, some hard copper tubing and a cut-off tool. If your steering feels sloppy, consider making this improvement. It only takes a few minutes and bending some cotter keys.

My front tires are now both aiming straight ahead rather than angling away from each other. That was causing them to scrub on the ground as they fought against each other for steering dominance.

If this description isn't adequate, tell me. I'm willing to shoot a couple photos. This really tightened up my Comet's loose steering a lot.
John
Having difficulty finding the 'thick-walled hard copper tubing.' Closest at Lowe's was Type L 3/8"ID 1/2" OD copper. (0.389 ID x 0.507OD)
(Is that what you used?)
 
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