QUESTION: any problem adding larger front tires?

[MtnViewRanch]

I've spoken with about 10 different Massey dealerships, & I also called AGCO directly ... each place has said not to change the tire size, because the rear and front tire sizes are supposed to work together with a Certain Ratio in mind.
However, none of them could tell me if there was any room in that ratio for adjustment, however small, to go up or down a tire size.

None said that there was not any room for adjustment, but they all said they did not know.

I I know some of you have mentioned to just not use the 4 wheel drive, but that would not work at all, as I use the front drive wheels all the time for doing loader work. Just would not be practical to not use 4 wheel drive

I still say to figure out what the ratios are for the 2 different OEM sets of tires and confirm that they do indeed use the same gearing on the tractor for those 2 ratios. Anything between those 2 different ratios should be fine.

Good luck.

 

[ovrszd]

My vote is that any tire size change has an affect on wear and/or potential damage. How much is to be determined thru use. No chart will answer that. That is why no dealership is going to tell you that it's alright. If you value your warranty, don't change tire size. Or if you do change tire size, keep that a secret and have the original tires onhand to reinstall before going to the shop for ANY type of service.

RDrancher and I have similar history with this subject. Our history is all based on actual experience and results. Not determined by any chart that might or might not be right. I'm sure we both have played with gear ratios and tire sizes more than most posters in this thread. That doesn't mean we are smarter. It means we are more experienced.

GManBart's charts are pretty. They give you all sorts of mathematical information that might or might not mean anything in practical application. I also doubt that GManBart has ever changed gear ratios or tire sizes in a modified vehicle of any type.

But then maybe I don't know much. Yet, I do know that if you change tire size or even tire air pressure unevenly, you just changed the gear ratio of vehicle in question.

 

[/pine]

My vote is that any tire size change has an affect on wear and/or potential damage. How much is to be determined thru use. No chart will answer that. That is why no dealership is going to tell you that it's alright. If you value your warranty, don't change tire size. Or if you do change tire size, keep that a secret and have the original tires onhand to reinstall before going to the shop for ANY type of service.

RDrancher and I have similar history with this subject. Our history is all based on actual experience and results. Not determined by any chart that might or might not be right. I'm sure we both have played with gear ratios and tire sizes more than most posters in this thread. That doesn't mean we are smarter. It means we are more experienced.

GManBart's charts are pretty. They give you all sorts of mathematical information that might or might not mean anything in practical application. I also doubt that GManBart has ever changed gear ratios or tire sizes in a modified vehicle of any type.

But then maybe I don't know much. Yet, I do know that if you change tire size or even tire air pressure unevenly, you just changed the gear ratio of vehicle in question.

You're right, some of us may not have the experience that you claim...but one thing I do know is that with the above statement (in red) you're inducing fraudulent behavior...

 

[SPYDERLK]

I've spoken with about 10 different Massey dealerships, & I also called AGCO directly ... each place has said not to change the tire size, because the rear and front tire sizes are supposed to work together with a Certain Ratio in mind.
However, none of them could tell me if there was any room in that ratio for adjustment, however small, to go up or down a tire size.

None said that there was not any room for adjustment, but they all said they did not know.

I I know some of you have mentioned to just not use the 4 wheel drive, but that would not work at all, as I use the front drive wheels all the time for doing loader work. Just would not be practical to not use 4 wheel drive

Our L3450 has excessive lead built in. AG tires ...We bought it used and the front tires were worn to nubs. When we replaced them with identical tires it became evident why when I noted that the fronts "scratched" the gravel drive when 4WD was in use. The tractor handles great with this setup and has now about 2200 hrs and the front drive is fine. I would be concerned if we were operating on hard pack but our use is turf/farming. Also of concern would be extreme weighting of the tractor on both ends which would lock the wheels harder to the ground and inhibit the slip needed. The 7520 OTOH has essentially 0 lead and turns rather poorly. The BX1500 has oversized tires front and back. This increased front lead too. The dealer advised against it. The tractor turns great and no trouble over 2000hrs. NOT a loader tractor tho, so no excessive weighting conditions.

,,,Your condition is uniquely yours and you have to weigh the variables as best you can. ... In truth however; a little front lead is good [practically essential], and with robust driveline more is better, but the line delineating too much is very dependent on your machine and use conditions.
larry

 

[GManBart]

I've spoken with about 10 different Massey dealerships, & I also called AGCO directly ... each place has said not to change the tire size, because the rear and front tire sizes are supposed to work together with a Certain Ratio in mind.
However, none of them could tell me if there was any room in that ratio for adjustment, however small, to go up or down a tire size.

None said that there was not any room for adjustment, but they all said they did not know.

I I know some of you have mentioned to just not use the 4 wheel drive, but that would not work at all, as I use the front drive wheels all the time for doing loader work. Just would not be practical to not use 4 wheel drive

That's the critical point...they simply don't know. Why is that? it's possible that it's because the acceptable range is a lot bigger than people think it might be.

The tires wear over time, causing different ratios. You can change tire pressures which causes a different ratio. They offer different size tire rear tires with the same fronts, which makes for a different ratio. It's a safe bet that the ratio on AG tires is different than the one for R4s.

With all of that, if it was SOOOOO critical, why isn't there a section in the manual, or in the dealer's technical guides, that covers acceptable combinations that will keep the front/rear ratio in the suitable range?

Either they don't care, or the acceptable range is broad enough that they don't worry about it.

 

[GManBart]

GManBart's charts are pretty. They give you all sorts of mathematical information that might or might not mean anything in practical application.

I didn't post any "charts", and they aren't mine. I posted a link with the formula, and process, for correctly determining front tire lead, which is what we're talking about. If the front tires turn slightly faster, within a range, there isn't going to be any damage. That doesn't require years of experience to figure out...it just requires some careful measuring, and the correct process.

I also doubt that GManBart has ever changed gear ratios or tire sizes in a modified vehicle of any type.

Why would you assume that? I'm not all that old, but I think the first time I started messing around with that was nearly 30 years ago....don't think math, and ratios have changed much since then.

But then maybe I don't know much. Yet, I do know that if you change tire size or even tire air pressure unevenly, you just changed the gear ratio of vehicle in question.

True, and that's why there has to be an acceptable range of ratios that will work perfectly. If the range was so narrow that it couldn't handle uneven wear, replacing tires unevenly, or changing up or down slightly in size, they would have sections covering the topic in user manuals and shop manuals, but they don't.

 

[ovrszd]

Why would you assume that? I'm not all that old, but I think the first time I started messing around with that was nearly 30 years ago....don't think math, and ratios have changed much since then.

Then in your experiences over the past 30 years what did you find to be the acceptable variance without damage???

 

[RDrancher]

The OP already made his decision, but Gman's going to argue it into the dirt anyway.

Time to unsubscribe from this one.

 

[skyhook]

It's obvious to me that the dealers suggestion is,,
if you want bigger tires, trade your machine in...
Tractors and trucks are a different bread,
first off, tractors don't go that fast,
if your mainly on snow or gravel, i don't see a problem, as long as there's a margin for "slip'.
If your on dry pavement, switch to 2x4 and use the 4x4x only when needed.
But then again, I have no warranty on mine, so i just use common sense.
I mean, as stated earlier, why are they offering two "different" rear sizes for the same machine.
Doesn't make sense, does it, or does it.

 

[Fordman1981]

You're right, some of us may not have the experience that you claim...but one thing I do know is that with the above statement (in red) you're inducing fraudulent behavior...

Here is the way I see it. If you want to change the tires you can. But do not try to hide it or be secret about it. If you have a failure which I doubt you will it is on you. A warranty is a good thing to have but use it as it was intended do not try to get warranty to cover something you did. I'm not saying the OP will try to do this just saying some people have suggested it and it's wrong.