Power steering loosing power

[NIXON]

I've been following this thread since it began . It seems like your dealer is trying to dodge the issue . You've got a lot of patience in my book . I keep coming back to this thread hoping to read that it's been fixed . JD has a good reputation and I'm sure it will be taken care of by them . Have you gone over the dealers head yet ? Good luck , John

 

[higgy]

I just went through this with my bota. I zeroed out a front tire this last week end when moving snow. I could not get a new tire of the same brand as stock and the bota dealer said that he could not get one with out a rim in it!? I went to the local tire supplier and we looked at what he had. The front tires are 10-16.5 and when we put them next to each other there was about a 1 inch difference when not inflated. I was worried about that much difference and the possible binding it could put on the transfer case, and I would need two new fronts as not to drive the diff all the time.

The rule of thumb that the tire people go by here is 5% allowance on 4x4 between front and back when looking at the damiter. That made the 1 inch in 30 3%.

One thing of interest in the 3130, the stock tires are only 6 ply from the dealer, man, that is a light tire.

We put the new 10 ply tire on the rim and inflated the tire and there is very little difference when mounted. Bought two and off we went.

The tires that I put on are anvil wall, 10 ply, stronger and less expensive the stocker ones.

I have been very happy with the new ones.

Any way I got off track. Measure the diameter of both the front and the back and do a calculation, is it with in 5% (rule of thumb here)?

If it is as them what the allowable difference is, or maybe the poster that is a JD tech could let us know what JD thinks as it would be a number supplied by a non biased reference.

If it is with in the 5% or the allowable difference that JD states then you have weakened their argument.

Did the dealer remember you talking to them before changing the rear tires?

Sorry that this is so long.

Dane

 

[Trev]

</font><font color="blue" class="small">( Measure the diameter of both the front and the back and do a calculation, is it with in 5% (rule of thumb here)?)</font>

Hi Dane,

Not sure I'm following you here.. and this is probably a dumb question.. but when you have BIG tires on the back, and little ones on the front, like most of the CUTs, how do you derive the 5% figure you mention? Is it from what the manufacturer states the diameters *should* be?

Tks,
Bob

 

[higgy]

That is the way it was explained to me. Each tire is made with in a range as not all tires are the same in dimension from the different manufactures. When the calcs are done for the ratio of front tire to back tire there is a 5%(rule of thumb, please check with your manufacturer) range that will not cause problems in the drive line.

I would think if this true and the tire even though not the same as new are with in the range there should not be a problem.

By doing a calculation the range of tire heights that should work can be gotten.

For example if the stock tire is 100 inches 5% would be 5 inches which would give a range of 97.5 to 102.5 as workable tire heights.

In my case after mounting and inflation to 40 psi there was only a 0.5% difference, even though when looking at the tires it seemed like a big difference.

I have put 10 hours on the new tires with no problem at all.

 

[Trev]

</font><font color="blue" class="small">( In my case after mounting and inflation to 40 psi there was only a 0.5% difference, even though when looking at the tires it seemed like a big difference.)</font>

Thanks, that makes sense. But, 40 PSI?? I run mine at around 12... /forums/images/graemlins/smile.gif

Best.............Bob

 

[keeney]

As far as steering losing power, I have noticed that my machine would occasionally lose power steering when trying to move the maxed-out loader and trying to back out of a low spot at the same time, or some similar combination. I think it was just at the limits of the power steering pump pressure.

Other times, on side hills, sometimes, it seems like the power steering pump is starved for fluid. I checked the level and it seemed fine. I plan to change the filters and fluid out soon - maybe that will help mine.

My understanding is that the JD OEM tire combinations are intentionally chosen to give a slightly higher ground speed on the fronts than the rears to help with steering traction and response.

- Rick

 

[higgy]

I change mine depending on the surface that I am working on. With the new tires I can go all the way to 60 if I want, Can’t say that I have many reasons for doing so but hey at least I have the option.

When operating of dry ground and using the loader I run higher pressure to keep the tire wall from distorting to badly, this can cause high torsion on the tire and I have had them fail when doing sharp turns with less air in the tire.

The worst was on my plane, as it was a taildragger, lock one wheel to turn and the torsion on the pivot wheel is very high.

What does this have to do with tractors< when using differential breaking you set up the same types of forces on the back tires.

Haven't done that in a lot of years, but I am careful not to do it anyway.

 

[tc35dforme]

<font color="blue"> My understanding is that the JD OEM tire combinations are intentionally chosen to give a slightly higher ground speed on the fronts than the rears to help with steering traction and response.
</font>

Now that's something I can't understand. If the front has a higher ground speed, won't the tractor eventually become very long. I would imagine the ground speed ( speed of the unit relative to the ground ) would be the same for any point or object on a tractor in motion. Are you talking rotational speed of the wheel / tire ?. Obviously, the smaller the circumference the faster it has to spin to cover a given distance.

Big tire / slow rev = distance = fast rev / small tire

 

[higgy]

DaneI think that would be rotational speed, a slight slip in the front under 4x4 drive.

The specs must be very close I would think not to have a problem with the drive train.

I have replace diff parts in many 4x4 trucks and they need to be well matched not to bind the drive system, but tire ware, slightly different sizes from the factory etc. will all add to making the rotational speed slightly different so there must be slop built into the drive system.

As these are open diffs in the front the pressure may be released as the power shifts from side to side or when you go around a corner and the inside outside tire rates change. Don't know for sure.

Dane

 

[keeney]

Sorry, your are right, I used the wrong term. I meant the speed at the surface of the tire, not including slippage.

Maybe I should have said "relative tangental speeds of the front tires in comparison to the rear tires, as measured at their respective effective radii under nominal loads and at nominal inflation pressures" if that helps make it any more clear.

Maybe "effective tangental speed"?

Or just "speed"?



- Rick