790 wheel swapping

smilingreen · Jun 12, 2002

Hey, I tried the neatest trick today with my 790. I rotated the two front wheels and gained what looks like about 10" on my front wheel base. WOW!! What a difference in stability and ride smoothness. Oh, guess I should clarify. I have R4's on my MFWD 790. Anybody tried this? Any problems you have encountered doing it?

MJB · Jun 13, 2002

You might want to check your owners manual to see if JD recommends flipping the tires around. Putting the front wheels in the wider position will greatly increase the stress on the front wheel bearings, especially if you have a FEL. The manual for my 4300 specifically states that the front wheels should not be switched to the wider position, at least for the R4 tires. Hope this helps.

HalseyGreen · Jun 13, 2002

I also tried the same thing on my JD790, agree with you that it added much stability, but as you were not sure if it was a good idea. I looked at the owners manual and couldn't find anywhere that said don't do it, but also didn't tell you it was acceptable. Theres a whole section about rear wheels, and if it was permitted for front, I would think that there would be a section on them. I then looked at the parts and service manual and at how the front wheel hubs were supported, decided that the extra stress of FEL work may cause parts failure. If you look at the parts, there is not the traditional 4x4 style front axle stub with the hollow center, the hub is supported by bearings on the interior of the axle housing, and the interior parts also provide the gears for driving the hub. Asked my dealer and he had not hear of anyone doing this and didn't recommend it for the same reasons as stated above. I switched them back after about 3 hours of use. I'd also like to hear anyone elses experiences.

Ledgemere Farm · Jun 13, 2002

Again, talk to your dealer. The axle might take the stress, but the hubs might not. The manual for my Cub states that you need to make sure of the valve stems being on the outside. I am not sure why. I dished out the back wheels and gained quite a bit. I am certain that you can do the same with your Johnny if you have adjustable rims.

smilingreen · Jun 15, 2002

I looked in my owners manual and could not find anything, either. I have a FEL and that is why I switched them around. In my landscaping business, I get the tractor in all kinds of weird positions when moving & distributing dirt and gravel and the extra stability from the width sure comes in handy. (kinda cuts down on the pucker factor, too/w3tcompact/icons/blush.gif ) It seems to ride a lot smoother also with out all the rocking motion back and forth when going across bumpy, uneven ground. I have not asked my Deere dealer about it, though. It comes in handy when loading and unloading on the trailer. Before, with the wheels in factory position, my rear tires hung off both sides of the ramps, and my fronts were in the middle of the ramps. Now, both front & rears are completely on the ramps. For saftey sake, I like this much better. I wonder what Yanmar would say about this? This tractor is very well built and one would think that they would over-engineer something like the front end, which takes the majority of the weight and pounding with a FEL. I wonder how much bearings are??? /w3tcompact/icons/eyes.gif

Ledgemere Farm · Jun 15, 2002

All very good questions. I would very much like to swap my front wheels around, but am reluctant to do so. My brother-in-law, who owns a dairy farm, suggested that I not swap them. Again, all compacts were not created equal...(ahem),. He has an old Bolens and the front end was making some noise. We took it apart and the guts of it were all shot to $%#@!. While I have no doubt that your Johnny is 10x the tractor that Bolens is..er..was, It still may be be advisable to talk to your friendly John Deere mecahanic.

smilingreen · Jun 21, 2002

Well, I have been running my 790 about a week now (35 hours) /w3tcompact/icons/grin.gif with the front wheels swapped. No problems so far and the more I think about as I have all this seat time/w3tcompact/icons/grin.gif, the more I think it will not harm it.
My reasoning: The wheels do not have a spacer between the rim and the hub, so the center of the wheel rim still bolts on at the same distance as it was before in the factory position. The only difference is the wheel width is wider on the outside of the rim instead of the inside. It still has tire support on the inside, just not as much as before. I could see it damaging the axle or bearings if I had put wheel spacers on, due to added stress from the extended distance the rim was from the axle hub. What do you mechanical engineering guys think? /w3tcompact/icons/clever.gif

MJB · Jun 21, 2002

The critical distance to consider when figuring the amount of stress that the wheel puts on the axle is the distance from the axle center pivot point to the center of the tire. If the tires are further out, they are placing more bending stress on the axle. You might be able to run it that way forever without causing damage,/w3tcompact/icons/smile.gif or maybe not./w3tcompact/icons/frown.gif

Ledgemere Farm · Jun 22, 2002

I finally called the dealer about this yesterday. The mechanic said doing thid would DEFINITELY harm the front end and is not recommended. I agree that it adds stability and have been contemplating doing it to my tractor, but now I won't. Who wants to buy a new front end?

smilingreen · Jun 24, 2002

Ok, guys....
Directly from my dealers mouth....I finally asked him about swapping the front two wheels around on my 790 today, and he said" Absolutely, you can turn them around. Quite a few of my customers have done it and it does not void the warranty. It also makes your tractor more stable". So, I feel better now, since I have been running them for about 2 weeks now that way. So guys, if you have a John Deere 790 MFWD with R4 tires on them, you can reverse them with no consequences. Evidentally, Yanmar did over-engineer the front end alxe and hubs on this model of machine. /w3tcompact/icons/cool.gif Enjoy your new stability!!