If the deck is clean, blades new, tire pressure set, engine rpms set- it is likely time to adjust the deck pitch. The Dixon manual may give a spec, say 1/4 lower in the front- but that won't always work well on a given lawn. First thing is to measure and record the measurements now in case you worsen the quality of cut. You can try exaggerating the pitch lower first and test cut. For that matter you can create a pitch where the deck is actually lower in the rear to solve some issues. All kinds of conditions can come up.

as I stated in my original message, all that has already been checked and done by the dealer and me with no success.
any other suggestions?

Sounds to me like you do not have the right blades on it, too short. Have you checked the overlap between the blades? I'd almost say you have 42" blades on a 44" deck. I service one of those regularly and it does not have that problem.

Walt Conner

I have a number of suggesions, but as you stated in your original post "all that has been already checked and done", I'd say your screwed.

If you don't take the time to do QOC protocol on your property it will likely never be solved. Possibly not even then. Are there technical bulletins by the company that may have addressed this issue? This has been going on for 8 years now or is the machine new to you? Your original post touched on very little.specific information.

Thanks very much for your suggestions and help.
I have had the unit since I purchased it new in 2005.
I will check the blade length and make sure they are the correct ones even though the dealer sold me replacement blades that did not solve the problem. Even though the three blades are off-set triangularly, blades that are too short will cause the problem.
the unit runs good and smooth, no vibration, just like it was new, but its mowing/cutting is inadequate. the dealer has witnessed the problem, changed the blades, adjusted the engine speed, and adjusted the deck with no success - he has no other suggestions and can not explain why this is happening. he says there are no field bulletins on this problem.
I would appreciate any other suggestions.

" changed the blades, adjusted the engine speed, and adjusted the deck with no success -"

Well none of this is likely to have any affect and he should have known it. I do not have the figure here for 44" Ram blades but the 42" Dixon blades are about 14-3/8" long. 44" blades are going to be 15+"

Walt Conner

This may or may not be applicable to your situation. Hard to say without personally observing your stripes.
I had a "similar" issue with a 60" tri-blade welded deck. It "appeared" to be leaving two strips of uncut grass on both sides of one of the blades. The deck was checked multiple times for side to side level and various deck pitches were made. New blades were installed. Spindles were checked for damage and were checked to insure they were perpendicular to the deck and that all blades were level. All to no avail. The problem turned out to be that one spindle/quill (and consequently, the blade attatched to that spindle/quill) was almost 1/8" of an inch higher than the other two quills/blades. It wasn't that the deck was leaving tow stipes, it was the small difference in mowing height between the adjacent blades and the resulting difference in grass height that gave the appearance of the stripes. Problem was resolved by adding a 12 guage shim between the quill and the deck to correct the blade height. There's more to the story with the dealer--but that's not relevant here. Probably not the source of your problem, but a possibility that you may want to eliminate.

Well I wonder what the outcome was.

Walt Conner

I checked the blade diagonal length and they seemed to be ok, but I couldn't account for the wear. So I went to the dealer and purchased new blades that were 1/8" longer, installed them, and verified that they did not hit each other or the deck. the problem with the two strips of grass that were not being cut completely is mostly solved, but the mower still doesn't cut certain types of grass, like bahia, as well as others in my large 1.3 acre yard, but I think that is typical of all mowers. any advice?
Thanks for your advice.

Note that blades from Dixon MAY not be the best blades to use. You do not say what the length is. You want the longest blades you can get that do not hit each other. I have found that certain aftermarket blades work best on my Dixon because they are longer. Also, the more lift they have the better - unless you are on very sandy soil.

Walt Conner

I purchased new Oregon blades as follows:
P/N: Length:
491-530; 14-15/16"
496-399; 14-15/16"
They both solve the problem, but I couldn't find the length of my Dixon's to compare to them - at the Dixon website or in my owner's manual and my old Dixon's were too worn to measure the diagonal length.
Any comments?

What was the length of the "gator" and the other blades that you tried that didn't cure the problem?

I own a Gravely 42 ZT and it leaves strips of uncut grass, called the dealer I bought it from and he said he's never heard of such a thing(He's full of BS), It's just hard for me to believe you spend thousands of dollars on a mower that is suppose to be so good and the cut is horrible.
I emailed Gravely and they told me I was cutting to fast, or letting the grass get to high. I owned a "cheap Scotts Riding mower that I paid $900 for 15 years ago from Home Depot and it will out cut a Brand new Gravely Zero Turn, I am just totally amazed a $4500 mower cuts like crap.