Increasing rear tire size on Toro 42 inch Timecutter

[Imajkrsl]

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.

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

 

[packardv8]

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

 

[bertsmobile1]

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

 

[packardv8]

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

 

[MParr]

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

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

 

[Imajkrsl]

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

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.

 

[VRR.DYNDNS>BIZ]

I would have tried 9 PSI first! and learning about zero turn traction issues. Talk to a seasoned operator who operates on side slopes. Zero turn = zero traction in comparison to a tractor when backing and spot turning and most noticed backing up a slope.

 

[Gravelier]

I would have tried 9 PSI first! and learning about zero turn traction issues. Talk to a seasoned operator who operates on side slopes. Zero turn = zero traction in comparison to a tractor when backing and spot turning and most noticed backing up a slope.

For what it’s worth, I have a summer home on a lake and slid my dixon cone drive into the lake. I needed 3 extra people to get it out of the water. I switched out the tires for ATV tires. I need to be conservative on the turns or I burn the grass. Other than that, I’ve had no repeats. I can back up any hill that I have.

 

[Auto Doc's]

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???

Can you add a weight box of some kind to the rear of the unit? Lowering the rear tire air pressure a little also help.

The problem with bigger tires is you change the overall stance of the machine, and the deck may not have enough adjustment to correct for the problem.