Larger rear wheel, decreased power

["Manic-Mechanic" 1,192]

I had ordered up a set of 16” rear wheels with 32” ag tires.Running them with push blade or tiller is fine.

However, the 3pt finish mower seems to be a burden?

wheels too large?

[Lee1977 6,245]

It's that big mower, don't think the wheels have anything to do with it. With thick damp grass you might be going too fast. 

[8ntruck 6,399]

The larger wheel/tire combination effectively lowers the final drive ratio.  You have traded some pulling power for speed.

["Manic-Mechanic" 1,192]

17 minutes ago, Lee1977 said:

It's that big mower, don't think the wheels have anything to do with it. With thick damp grass you might be going too fast. 

I wish that were the case, I cannot go up an incline even with the mower off and up.

["Manic-Mechanic" 1,192]

Just now, 8ntruck said:

The larger wheel/tire combination effectively lowers the final drive ratio.  You have traded some pulling power for speed.

Yes, she can get going, thinking about going back down but they do look nice!

[kpinnc 10,829]

56 minutes ago, "Manic-Mechanic" said:

I cannot go up an incline even with the mower off and up.

 

Short of your wheels being 6 feet tall, this should not ever be the case. Your hydro is obviously getting weak. 

 

Sundstrands can be rebuilt. It may be nothing more than a valving issue, but something is definitely wrong if 16 inch wheels steal that much torque.

[953 nut 51,899]

7 hours ago, "Manic-Mechanic" said:

I cannot go up an incline even with the mower off and up

Was your  going up inclines without any problems before you installed the new tires? Is the engine speed decreasing noticeably when going up a hill or is the transmission just not being responsive. Is the hydraulic lift good and strong? Is the problem more noticeable when the transmission is hot? Is the loss of power problem as bad in reverse as it is in forward? These questions can help narrow down the problem.

The larger rear tires are only about 10% bigger than your previous tires +/- and shouldn't present a problem. As @kpinnc said I am inclined to think the Sundstrand needs some attention.

[squonk 38,987]

You can try going from 10/30 oil to 10/40 and see if it improves. It helped my C-160 on inclines.

[Pullstart 59,828]

 more for a weak transmission.  @Skipper has proven that with a strong hydro, tire size doesn’t much matter.

 

 

["Manic-Mechanic" 1,192]

37 minutes ago, 953 nut said:

Was your  going up inclines without any problems before you installed the new tires? Is the engine speed decreasing noticeably when going up a hill or is the transmission just not being responsive. Is the hydraulic lift good and strong? Is the problem more noticeable when the transmission is hot? Is the loss of power problem as bad in reverse as it is in forward? These questions can help narrow down the problem.

The larger rear tires are only about 10% bigger than your previous tires +/- and shouldn't present a problem. As @kpinnc said I am inclined to think the Sundstrand needs some attention.

Yes, everything leans towards the pump, especially if the tire size shouldn’t effect the torque all that much.

The travel speed in forward is excellent but set slower in reverse deliberately.

Yes, the wine is the same either direction.

using the tiller is no problem, same with the blade.

Only the 3pt mower is difficult on inclines.

I have a nice rebuilt pump with really clean spline shaft, just tearing down is needed and procrastination has set in! Lol

Really was researching the wheel size effect. So, probably won’t benifit to reduce rear wheels at this time?

["Manic-Mechanic" 1,192]

32 minutes ago, Pullstart said:

 more for a weak transmission.  @Skipper has proven that with a strong hydro, tire size doesn’t much matter.

 

 

Thank you for sharing Skipper’s post, very thorough and interesting for sure! Yes, all signs are leading me back to the pump, guess in denial?

[Pullstart 59,828]

23 minutes ago, "Manic-Mechanic" said:

So, probably won’t benifit to reduce rear wheels at this time?

My guess is what’s done is done.  Bandaids on bandaids don’t do much for ya.  

[Sailman 1,134]

2 hours ago, squonk said:

You can try going from 10/30 oil to 10/40 and see if it improves. It helped my C-160 on inclines.

 

My C-120 Hydro was getting slow using the blade to push gravel when it got hot. Figured the pump or trans was getting worn. Put the 10/40 in and have not had the same issue since.

["Manic-Mechanic" 1,192]

49 minutes ago, Sailman said:

 

My C-120 Hydro was getting slow using the blade to push gravel when it got hot. Figured the pump or trans was getting worn. Put the 10/40 in and have not had the same issue since.

Now there’s a thought, a whole lot easier than switching out the pump that’s for sure!

[Pullstart 59,828]

For a while at least..

[kpinnc 10,829]

2 hours ago, Pullstart said:

For a while at least..

 

Agreed. It's usually a short term fix.

[squonk 38,987]

I'm on 5 years with the 10/40 fix.

["Manic-Mechanic" 1,192]

2 hours ago, kpinnc said:

 

Agreed. It's usually a short term fix.

I’ll check it out, worth a try

[jeremi3210 688]

In my experience with d's if the pump is worn the motor is also. They are easy to rebuild just a little time consuming. I've  done a few of them and they are all running strong!

["Manic-Mechanic" 1,192]

30 minutes ago, jeremi3210 said:

In my experience with d's if the pump is worn the motor is also. They are easy to rebuild just a little time consuming. I've  done a few of them and they are all running strong!

I have another pump totally rebuilt with new shaft. However, finding parts is null & void, especially this day an age!

[jeremi3210 688]

There is some very good threads on them here on red Square! Bout the only thing you may need would be a new gasket. Just buy some gasket material the same thickness and cut one out of it. With a rebuilt pump you are more than half way to a new hydro! Also I think you could separate the pump and motor from a c series hydro and use the motor from that. I've never tried it but just looking at em they look like they'd work!

["Manic-Mechanic" 1,192]

14 hours ago, jeremi3210 said:

There is some very good threads on them here on red Square! Bout the only thing you may need would be a new gasket. Just buy some gasket material the same thickness and cut one out of it. With a rebuilt pump you are more than half way to a new hydro! Also I think you could separate the pump and motor from a c series hydro and use the motor from that. I've never tried it but just looking at em they look like they'd work!

Yes, both units will work, however the pump from a C will need changed around

I have had the units apart and did find materials to rebuild the pump.

There are a couple really good rebuild posts on here that look at a total polish and keeping the slippers assigned correctly.

I was more so curious about wheel size as there is a 6” increase. Now am looking at changing oil to 40

I have had the divorced system apart flushed and find it fairly easy to reassemble.

should the 40 wt not pan out then my total rebuild is on the shelf

Edited May 6, 2023 by "Manic-Mechanic"