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I recently bought a 42” fabricated deck Toro, model 75747. I am extremely pleased except for the rear tires. I am having traction issues in a several of places in the lawn. Looking at the other Toros, the next deck size up has a two inch jump in tire size and looking across the zero turn market, my mower has the smallest tires sold, 18x7.5-8. The next size Toro mower has 18x9.5-8. They both use the same hydros. In measuring that mower’s wheel/tire, I’m pretty sure I can use that assembly by adding one inch wheel spacer. The left tire will be even with the trim side of the deck while the right side will be inside of the deck. Thoughts, potential problems that anyone sees with this change??? Has anyone done this???

The 18x9.5-8 will not do much in the way of better traction a taller tire will help. 20x10-8 would be better.If you do this you have to be able to lower the back of the deck or raise the front to get a even cut. They also make a 20x8-8.

I’m new to this process of changing tire sizes on a mower. How does a taller tire help me with traction? My thought process with a wider tire was to have more surface (contact) area.

What pressure are you running in your rear tires?

12#.

All of the parts are ordered and should be here within a couple of weeks. Once completed, I’ll post pictures of the before and after in case anyone is interested in making the same type of changes.

BudLight said:

All of the parts are ordered and should be here within a couple of weeks. Once completed, I’ll post pictures of the before and after in case anyone is interested in making the same type of changes.

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so what size tires did you decide on?

Going to 20"ers will add rotating mass (weight) to the hydros. Being they are the EZT 2100, I would excersize caution.

should be ok good luck.

I ordered the 18x9.5-8. That’s the same diameter but two inches wider than my original. It’s the same wheel/tire assembly used on the Toro 75750 (next size mower up from mine). That mower has the same hydros (2100) as mine. I don’t know what the weight is for the one inch wheel spacers but expect it to be minimal.
The tire/wheel assembly is coming from Mower Parts Group. The wheel spacers from Titan Wheel Accessories.

First input here from a long-time reader. I have this mower and I agree that the traction is not good when mowing slopes for sure. I am not sure that larger tires would solve the problem since the same weight will be distributed over a larger area so your putting less PSI on the ground. Isn't a more aggressive tread or more weight over the tries what you need?

So now with Super Swampers on the mower, how are you going to level the deck?

I looked at more aggressive tread designs and was concerned that they would damage my lawn during a turn. Again, I’m new to the zero turn world. Is my assumption accurate?? Also…. I anticipate that my deck will be level or close to it with the new tires. They’re the same diameter as the originals. Not the gumbo monster mudders! Ha!

BudLight said:

I looked at more aggressive tread designs and was concerned that they would damage my lawn during a turn. Again, I’m new to the zero turn world. Is my assumption accurate?? Also…. I anticipate that my deck will be level or close to it with the new tires. They’re the same diameter as the originals. Not the gumbo monster mudders! Ha!

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Don’t assume, check the deck level and pitch.

Tire assemblies and one inch wheel spacers are in. A dry fit reveals that I didn’t measure correctly or the offset of these wheels are slightly different than those on the 75750 Toro mower I measured at the dealer. The tire on the right side just barely touches a fender support bracket. Now in the process of swapping the one inch spacers for two inch spacers. I attempted to download a photo but the system says it is too large (3mb).

BudLight said:

Tire assemblies and one inch wheel spacers are in. A dry fit reveals that I didn’t measure correctly or the offset of these wheels are slightly different than those on the 75750 Toro mower I measured at the dealer. The tire on the right side just barely touches a fender support bracket. Now in the process of swapping the one inch spacers for two inch spacers. I attempted to download a photo but the system says it is too large (3mb).

Click to expand...

Shrink the file.

Took your advice and downloaded a photo application which allowed me to compress the file.

The more you hang those wheels out farther adds stress on the axles.. Just saying..

7394 said:

The more you hang those wheels out farther adds stress on the axles.. Just saying..

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Believe me, I thought about this a lot before starting this project. I came to the conclusion (perhaps the wrong one), that the extra stress would be created by the weight of the spacers. The wheel/tire assembly I’m using is the same as a 75750 and my 75747 mower has the same HG 2100 hydros. The two different mowers also have the same part numbers on their axles. I had considered this swap as a potential option to the wheel spacers. The other thing I wanted to look at but couldn’t find was the difference in total weight between the two units, or even load capacities..

The wheels out further is like adding leverage on the axles when you hit bumps etc.. Probably be ok, but just my .02

Load capacity can be found on Hydro-gear website for your 2100's.

7394 said:

The wheels out further is like adding leverage on the axles when you hit bumps etc.. Probably be ok, but just my .02

Load capacity can be found on Hydro-gear website for your 2100's.

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Thank you very much. That website is excellent.
I agree with you completely on the added leverage caused by pushing the wheels out.
In looking at the specs, it looks like the maximum GVW is 900 lbs per hydro unit.

Cool.

The two inch spacers are in and everything is installed. I’m fairly certain I could have gotten by with 1.5 inch but considered the clearance too close for maximum movements on rough terrain. I’m extremely pleased with how this has turned out. The right tire sticks out less than one inch beyond the blade travel. The left tire is just inside the trim side of the deck, probably even with the blade travel. I can’t tell any difference in handling or turning with the mower. I still need to check and adjust height, level and pitch. Overall I think this is going to be a good modification to my mower. Time will tell on excessive wear and tear, although I’m not sure how I might access that. Before and after pictures.

Like pics. I think the "After" pics are 1st tho. Do you still have warranty ?

Sorry for the reversal on the photos. You’re correct. I posted the revised photos first.
Regarding the warranty…. I started this process at my dealer. He advised on the axle information that I posted previously, he had the 75750 at his store and helped measure the wheel offset. He quoted somewhere around $300+ for the “Toro” factory wheel/tire assembly (I purchased online). At no time was there mention of a warranty issue.

No biggie, Pics are self explanatory on size.

Dealer won't mention warranrty, unless this causes a problem.. Just enjoy.

We have had a lot of rain over the past few weeks and I was finally able to cut my lawn. These oversized tires have pretty much solved all of my problems. I’m now able to cut across the slopes of my side yards which are about 18 +/- degrees without sliding downhill or tearing up my lawn by spinning my tires in the grass. Not absolutely perfect but they’ve certainly exceeded my goals for improvement.

Awesome work, wheels look great. I have the 34" deck and the rear wheels leave much to be desired. I thought about taking on a similar project, not so much because of a loss of traction but because the narrow wheels leave impressions on my thick St. Augustine grass. The added traction would be a nice benefit however. Around how much did all of this cost?

shurguywutt said:

Awesome work, wheels look great. I have the 34" deck and the rear wheels leave much to be desired. I thought about taking on a similar project, not so much because of a loss of traction but because the narrow wheels leave impressions on my thick St. Augustine grass. The added traction would be a nice benefit however. Around how much did all of this cost?

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$160 for the wheels/tires plus $42 for the two inch spacers. If you’re buying smaller tires and spacers, the cost would go down.

You wanna go expensive, look @ "Tweels" ......... Not my style, but just threw it out there.

BudLight said:

$160 for the wheels/tires plus $42 for the two inch spacers. If you’re buying smaller tires and spacers, the cost would go down.

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I have the 34" deck 75734 (to get through my gates) but I would seriously consider doing the same mod as you did one day. I know its an entry level ZT but rear wheel size still seems like the biggest weak point on this mower, mine are even smaller than your stock ones (18” X 6). I have the same 2100 hydros on mine too.

Would you go 1.5" spacers if you had to do it again? Whats the model number for the spacers that you used? Did the mod throw off the level of your deck at all?

Thanks

shurguywutt said:

I have the 34" deck 75734 (to get through my gates) but I would seriously consider doing the same mod as you did one day. I know its an entry level ZT but rear wheel size still seems like the biggest weak point on this mower, mine are even smaller than your stock ones (18” X 6). I have the same 2100 hydros on mine too.

Would you go 1.5" spacers if you had to do it again? Whats the model number for the spacers that you used? Did the mod throw off the level of your deck at all?

Thanks

Click to expand...

If I had the opportunity, I would go with 1.5” spacers. They would provide adequate clearance on my mower and I assume less pressure on the hydros. I looked on Amazon and the two inch spacers I used aren’t showing up. What you need is a 4x4 spacer with at least a 57mm bore and 1/2x20 studs with nuts. The thickness is your choice. The back set on the wheel you’re going to use along with existing clearance defines the required thickness. The ones I considered were designed primarily for golf carts. I screwed up and ordered one inch spacers which were too narrow. And that was after I measured a 75750 mower at the dealers. The frames, the fender supports and the wheel offsets are different on all of these mowers. Measure twice, order once.

7394 said:

You wanna go expensive, look @ "Tweels" ......... Not my style, but just threw it out there.

Click to expand...

I spoke several times to a guy who owns a small lawn service company about changing my wheels/tires. He brought up the tweels for his commercial mowers. When I told him they cost about $2K I thought he was going to throw up.

"Tweels" ain't cheap, & I have seen pics of some that did break down in time. (after warranty ending, naturally)..

BudLight said:

If I had the opportunity, I would go with 1.5” spacers. They would provide adequate clearance on my mower and I assume less pressure on the hydros. I looked on Amazon and the two inch spacers I used aren’t showing up. What you need is a 4x4 spacer with at least a 57mm bore and 1/2x20 studs with nuts. The thickness is your choice. The back set on the wheel you’re going to use along with existing clearance defines the required thickness. The ones I considered were designed primarily for golf carts. I screwed up and ordered one inch spacers which were too narrow. And that was after I measured a 75750 mower at the dealers. The frames, the fender supports and the wheel offsets are different on all of these mowers. Measure twice, order once.

Click to expand...

If you decide to move forward with your project and need a set of one inch spacers, let me know. I’ve got a set that is brand new that I’ll sell to you cheap. I bolted one of them onto my mower which prevented me returning them to the company.

BudLight said:

If you decide to move forward with your project and need a set of one inch spacers, let me know. I’ve got a set that is brand new that I’ll sell to you cheap. I bolted one of them onto my mower which prevented me returning them to the company.

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Will keep that in mind. Thanks

@BudLight - Just curious how you are liking this setup after a year. I'm looking to do this for my 42" Toro as well as I'm having a similar slope issue on my yard. Could you share the part numbers and sites you purchased the wheels and adaptors from?

Beehbs said:

@BudLight - Just curious how you are liking this setup after a year. I'm looking to do this for my 42" Toro as well as I'm having a similar slope issue on my yard. Could you share the part numbers and sites you purchased the wheels and adaptors from?

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Did you ever get a reply, or take the leap and go with something else? I'm dealing with the same slippery tires on my 4260. They're several years old and getting worse. Not wanting to replace them with the same thing.

My apologies, I didn’t receive notice that additional responses came in and just stumbled on these two questions. Here’s a screenshot of the tire/wheels I ordered. It gives the part numbers all. The spacers I ended up using are two inch. Got them from Amazon if I remember correctly. I just looked and don’t see them listed anymore but any two inch spacer (golf cart) with a 4x4 pattern will work ok. If you can use a one inch spacer, I’ll sell the originals that I bought and were too narrow for my application. Brand new.

Also have a 4235 with the 18 x 7.50 - 8" tires and wheels.

I saw another machine with 20 x 10 - 8" setup; anyone know what width wheel is needed to run those tires?

FWIW, the first two internet whores who paid google to have their site at the top of the search are actually "out-of-stock" on the tires, but waste your time hoping you'll click on something else on their site.

jack vines

packardv8 said:

Also have a 4235 with the 18 x 7.50 - 8" tires and wheels.

I saw another machine with 20 x 10 - 8" setup; anyone know what width wheel is needed to run those tires?

FWIW, the first two internet whores who paid google to have their site at the top of the search are actually "out-of-stock" on the tires, but waste your time hoping you'll click on something else on their site.

jack vines

Click to expand...

One thing you have to be aware of is the offset of the wheel. In other words, when you mount the new tire and wheel, will it rub the frame or fender? That’s the issue I encountered resulting in the requirement for 2” spacers to clear frame.

Agree, if one is changing wheels, knowing the offset of both OEM and replacement wheels is critical.

If one is just replacing the OEM tires with a taller, wider tire, each tire is rated for use on wheels from XX to XY widths. With automobile tires, that specification is furnished by the manufacturers. With all the small machine tires coming from Asia and mostly China, the wheel width specs are thus far impossible to find.

jack vines

packardv8 said:

Agree, if one is changing wheels, knowing the offset of both OEM and replacement wheels is critical.

If one is just replacing the OEM tires with a taller, wider tire, each tire is rated for use on wheels from XX to XY widths. With automobile tires, that specification is furnished by the manufacturers. With all the small machine tires coming from Asia and mostly China, the wheel width specs are thus far impossible to find.

jack vines

Click to expand...

Have you tried looking for a wheel/tire set that might be available at Tractor Supply or Walmart or even a mower dealer where you could measure the offset to see if or how it would work? I went to a toro dealer and measured the combo size that I wanted. Then located the set for that mower on the internet (shown above). Seems like most of the residential mowers have a 4x4 bolt pattern so you might find what you’re after on a different brand mower. You can get spacers on Amazon.
One more thing. If you’re going to a two inch taller tire, make sure that your deck will allow for you to adjust the deck pitch to compensate for the additional height.

BudLight72 said:

Have you tried looking for a wheel/tire set that might be available at Tractor Supply or Walmart or even a mower dealer where you could measure the offset to see if or how it would work? I went to a toro dealer and measured the combo size that I wanted. Then located the set for that mower on the internet (shown above). Seems like most of the residential mowers have a 4x4 bolt pattern so you might find what you’re after on a different brand mower. You can get spacers on Amazon.

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That works if one wants to spend $250 to increase the tire size.

I have access to a pair of 20 x 10 - 8"s for free if they can be used on the OEM wheels.

jack vines

packardv8 said:

That works if one wants to spend $250 to increase the tire size.

I have access to a pair of 20 x 10 - 8"s for free if they can be used on the OEM wheels.

jack vines

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Ok, now I understand. Good luck on getting this sorted out. Tough to beat free..

Will be a new challenge to the EZT 2100 hydros.

BudLight72 said:

Seems like most of the residential mowers have a 4x4 bolt pattern so you might find what you’re after on a different brand mower. You can get spacers on Amazon.

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Interestingly, I went to a mower scrap yard and every rider there mounted the wheels directly on the round axle and keyway. He didn't have any 4x4 wheels.

Looking more closely at the Toro 4235, it mounts the 4x4 flange on the round axle with a keyway. Doesn't take much leap of imagination to think of mounting a pair of the 20" axle mounted wheels directly. The one factor which must be confirmed is the stop which locates the wheel on the axle so the nut may be tightened to secure it.

However, since Toro spent the money to add the 4x4 flanges, there must be some necessity and maybe the direct axle mount isn't strong enough.

jack vines

five pages.

the real question is why would the manufacturer and engineers go to the trouble of smaller tires on one unit when it would have been easier to make all the units, regardless of deck size, with the same tires. The economics of scale would want all the parts to be the same. Using different parts in production of the same unit takes up time, space, and costs more money stocking inventory at the factory. Smaller tires would require less power, is there a difference in engine size that accompanies deck sizes?

sgkent said:

the real question is why would the manufacturer and engineers go to the trouble of smaller tires on one unit when it would have been easier to make all the units, regardless of deck size, with the same tires. The economics of scale would want all the parts to be the same. Using different parts in production of the same unit takes up time, space, and costs more money stocking inventory at the factory. Smaller tires would require less power, is there a difference in engine size that accompanies deck sizes?

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Yes, No, Maybe. All I know for certain is the manufacturers of less expensive, less powerful tractor style riding mowers usually come with the 20"x10" where Toro chose the 18"x7.50" tires for the 4235 ZTRs.

Smaller tires don't require less power, but a smaller diameter tire produces more pulling power at a slower ground speed. Since ZTRs are seldom asked for a max power dead pull, it's pretty much moot.

A potential downside of a wider tire footprint might be tearing more turf if one often turns with the inside wheel stationary.

FWIW, I just found a source where I can buy a new 20"x10" tire on a new 4x4 wheel for $45 plus shipping.

jack vines

following..

Smaller tires don't require less power, but a smaller diameter tire produces more pulling power at a slower ground speed.

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a smaller diameter tire has the same effect as using a lower gear. So yes, a smaller engine with less torque would move a mower easier with a smaller diameter tire assuming that the PTO pulley size, and transmission pulley size are the same. You did say that the transmission et al was the same. Changing tire diameter would be less expensive than building different size PTO arrangements. So if the engineers wanted a low priced unit they would use an engine with less torque, and then put on smaller tires if they found that the torque was inadequate to use the lessor engine combined with the larger diameter tires.

Plus any change in tire size will require the cutter deck to be adjusted to compensate.

keep in mind that the transmission bears part of the stress, and it converts the energy lost to heat. The fans cool the transmissions. If less power is available, and larger tires are used, the transmission may spin slower causing the fans to deliver an inadequate amount of cooling. It is a stretch but it is a physical possibility. Also, there may be incline requirements when these mowers are made, meaning that they must maintain X RPM climbing Y grade. With a smaller engine it may take smaller tires to maintain that RPM. Think of trying to climb a hill in 4th gear in a VW bus. One has to drop down in the gears to not only have the power but RPM. If the engine turns too slow it loses its air cooling. Only in this case it is possibly both the engine and transmission that are effected if the RPMs fall too low for the amount of heat being generated. It may require putting the larger tires on, measuring things then making a decision if the engine and transmission RPM are adequate at the grades where the machine will be used. However if both the small deck mower and the large deck mower use the same engine then there would be no problem.

Will you be able to adjust the deck height and rake properly after jacking up the rear of the mower like that?

On Toro 42, mine only had 2 adjustment points. One in middle front & 1 on (IIRC) Left side of rear deck, other side is a fixed link.
That would need to be replaced with an adjustable link to deck.

7394 said:

On Toro 42, mine only had 2 adjustment points. One in middle front & 1 on (IIRC) Left side of rear deck, other side is a fixed link.
That would need to be replaced with an adjustable link to deck.

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Not sure I'd agree the fixed link has to be changed until it is proven the two adjustable links lack sufficient travel to level the deck with the larger rear wheels. That may be the case, but it's not a given.

jack vines

Time will tell..

BudLight said:

I ordered the 18x9.5-8. That’s the same diameter but two inches wider than my original. It’s the same wheel/tire assembly used on the Toro 75750 (next size mower up from mine). That mower has the same hydros (2100) as mine. I don’t know what the weight is for the one inch wheel spacers but expect it to be minimal.
The tire/wheel assembly is coming from Mower Parts Group. The wheel spacers from Titan Wheel Accessories.

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Did you ever complete this project and what were the results?

jack vines

packardv8 said:

Did you ever complete this project and what were the results?

jack vines

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Yes I did complete the installation and am extremely pleased with the results. Can’t say that I have identified any negatives from the changes I’ve made. It has provided a noticeable improvement in the overall traction. Especially when wet.

Cool Beans !

BudLight72 said:

Yes I did complete the installation and am extremely pleased with the results. Can’t say that I have identified any negatives from the changes I’ve made. It has provided a noticeable improvement in the overall traction. Especially when wet.

Click to expand...

I did this exact same tire/wheel swap on my Toro 75746 42" Timecutter that I purchased new in March 2023. All I needed was the larger tires/wheels and not the Titan wheel spacers. The inside offset of the wheels of the larger Toro tires/wheels (18x9.5-8) is exactly the same as the inside offset of the smaller Toro tires/wheels (18x7.5-8) that came installed on my mower. The mower does handle much better, and I did not have to re-level the deck after installing the larger Toro tires/wheels. I've listed the links below for the larger Toro tires/whees, as well as the Titan 1.5" wheel spacers (which I did not need). You may or may not need the wheel spacers depending upon your model. Torque specs for Toro rear tire lug nuts is 75/ft lbs. Photos are below. Right side before, right side after and left side after. The space between tires and hydro plate mounts did not change.

Link to tires: https://mowpart.com/tire-asm-139-5848/
Link to Titan 1.5" wheel spacers: https://www.amazon.com/gp/product/B01G40ZEQY/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1

I've asked a couple of knowledgeable mower guys as to why homeowner-size ZT mowers have such small rear wheels compared to tractor-style mowers of the same deck size. No one could come up with a reason.

Also, the big dog commercial ZT mowers have man-size rear tires. One guess is smaller tires and wheels are just cheaper.

jack vines

Cheap low power hydro motors can only suppy a fixed maximum torque
So if yu put a big wheel then you can overload the hydro and it will just sit there and go nowhere

While I don't know it to be true, I've been told the same hydro unit is used on both ZT and tractor mowers, as well as a wide range of motor horsepowers. Anyone confirm?

jack vines

packardv8 said:

While I don't know it to be true, I've been told the same hydro unit is used on both ZT and tractor mowers, as well as a wide range of motor horsepowers. Anyone confirm?

jack vines

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Hydro Gear EZT are used on most entry level residential zero turns. Most tractor type mowers use a Tuff Torq K-46.

bertsmobile1 said:

Cheap low power hydro motors can only suppy a fixed maximum torque
So if yu put a big wheel then you can overload the hydro and it will just sit there and go nowhere

Click to expand...

Ariens uses a larger rear tire on their 42" ICON, bigger than what is used on the Toro. The Ariens has the exact same hydros as the Toro. I don't think that increasing the tire width would have a negative effect on the Toro 42" ZTR, since the Toro 50" ZTR uses the exact same hydros.