JD-3520 MFWD "driveshaft" faulty?

[tugboat-2]

My 2006-JD-3520-Cab,... just racked 900 hours and on its third,..(3rd) MFWD "driveshaft". The shaft that comes forward from the transmission to the front differential.

Its splined-end meets the splined shaft coming out the back of the front diff. The two slide into a short,(3") common, internally splined "sleeve",..(with a pin through the centre).

Load-Match and 4WD engaged constantly unless in transport or mowing. I dig and move lots of earth, "working" my machine, but never purposely abuse it.

First shaft went (last year) suddenly. The next gave a quick warning. Driving down a steep, 20ft hill, filling my bucket and "backing" up the hill all afternoon,.. no problem.

Went down scooped a 1/2 load for front ballast, scraped up a pile with rear blade,.. filled the bucket and crawling up frontwards (low gear @2500 RPM) felt a quick slip'n'grab, slip'n'grab and detected a faint clicking as I came over the top. Dumped my bucket and parked.

Slid under checking "everything" for "anything", shafts, linkage, pins etc. Removed dash panel to check "travel" and freeplay in the MFWD "lever". The "Brail-method" confirmed lever engagement of detent spring-balls that "hold" it in gear,...yet there was NO drive at wheels! Checked oil levels and anything else I could think of, All OK. The driveshaft "felt" tight.

Testing,..(smooth and quiet) in 2 wheel, but 4WD,..."Nothing"!! So dropped grader blade and bucket, connected RFM and mowed a couple hours without incident.

Next day, drove 'er the quarter mile to my dealer. The shaft and sleeve splines, were rounded off, warn and chewed like you'd expect from "softer" metal.

New shaft and sleeve wouldn't be so bad,..but the "other" shaftspline was just as bad,....EXCEPT:..it's the back end of the front "pinion" gear (one solid, short shaft) which means dropping the front axle, splitting the case, pulling out the carrier, (Crown and pinion, side gears and bearings etc), and replacing the pinion,...which is a pre-set "package" with bearings etc complete!!!

They suggested the alternative: "welding" everything solid, to save a major expense. But agreed the possibility of "heat" damage through the short pinion shaft to seals and bearings was not a good choice. (good idea on an old beat up tractor,...but WHOA!! This Baby is still brand new to me,..still shines up to a Beauty!!!) So I authorized a full and proper job. This is precision work in a clean shop with the right tools and not for my dusty, gravel floored drive-shed. (Note: no paper gaskets,..just metal to metal with liquid sealant spread thin with an ink roller and torqued! A sterile operation for the OR!!)

Meanwhile I have my tractor back, up and running,...but am walking on eggshells,..hesitant to go back to anything heavy. Perhaps having a brand new machine made me a tad "over" confident??

Well OK, now that you've endured another long winded "tug-tail",...."IF" you're still with me,......have any of you experienced anything similar?? AGAIN: This is an (Xmas) 2006 JD-3520-Cab,...(my beautiful Rolls! Cab still has that "new-car" smell,..ha,ha!)

I'd appreciate your thoughts...?
. . tug

 

[sunnyside360]

I've never had a burp with my 3720 engine or drive train but I only use 4 WD when the wheels are slipping or when on a very steep hill to give 4 wheel traction and/or braking. Otherwise, it's always in 2 wheel drive which is 99% of the time. I don't recall anyone else reporting this type of problem. I personally don't think it is good for the drive train to keep it in 4 wd all the time due to the stresses put on it.

 

[Cocre]

Have you got a matched set of tires? From what I understand the front and rear have to be sized to rotate at the ratio of the MFD, just something to check.

 

[RogerH]

A couple questions:

1. Are the rear tires filled with fluid?
2. How heavy is the blade on the rear?

The reason I ask is that in my experience many angle type blades and lighter box blades are not enough weight on the back to properly ballast the tractor. When using the loader, most of the weight ends up on the front wheels and all the power is going through the front axle. This can wear out the front axle and MFWD drive components quicker.

When I take apart anything that is splined, I like to lubricate it with a "moly" grease when I reassemble it. I have read where that helps prevent spline corrosion, which accelerates wear.

 

[tugboat-2]

sunnyside360: Thanks for the reply, I must agree with you on the idea of stress and keeping in 2WD as much as possible. I've been digging and climbing a lot and need the traction for both aspects. However, I'll take your advice and try to disengage 4WD when not really necessary. Definitely a good "habit" to form!!

I should (and "do") know better,...just got into the bad habit of leaving 4WD engaged due to the terrain I'm working much of the time. "Costly habit that"!!
THANKS~~~~~~~~~~~~~~~~~~~~~~~

Cocre: Thanks for the reply, and thank you for a great suggestion. I have always been cognizant of that fact and although I've changed front tires a couple times,..I'm very strict about sticking with what tires were recommended for the tractor when it was new,..they are matched but I agree that is a very excellent point, (especially for those new to 4WD!)
THANKS~~~~~~~~~~~~~~~~~~~~~~~

RogerH: Item: 1. Yes, the rear tires "only" are filled with good Canadian Beet Juice. Item: 2. Relative my rear grader blade, I'm not sure of the actual weight, but it's quite old, had it for years. Extremely heavy compared to modern ones. Was likely sold as EXTRA Heavy Duty when new.

However, you do conjur up an excellent point. The work I was doing, (and quite a bit of it), was driving forward down a fairly steep grade, filling the bucket with damp, heavy earth, . . then "backing" up the hill. At this point the weight would be on the front wheels, . . and the weight of my blade was more than likely inadequate to countre the stress?

The hill was of such steepness that more than once I stopped and rocked the tractor slightly to see if it would lift the rear and balance on the front, but not a chance. I guess the combined loaded tires and blade held us firm. (I have the two-way tiltmeter, unsure how to read the fore'n'aft but it sat on 1.5 and more,. if we have an interpreter aboard?)

Regardless, . . I see the stress I was placing on the entire front assembly as I "backed" up the hill. Climbing slowly "forward" up the hill perhaps wouldn't be quite "as" stressful but certainly too much on a continuous basis! And it "was" the forward climb that stripped the splines,...or at least was the "coup-de-grace" for them.
THANKS~~~~~~~~~~~~~~~~~~~~~~~

TO ALL of you who responded thus far: Your combined input is of great value to me (and hopefully to others), so please accept my sincere thanks!

CHEERS for now !!
. . tug

 

[kennyd]

A couple questions:

1. Are the rear tires filled with fluid?
2. How heavy is the blade on the rear?

The reason I ask is that in my experience many angle type blades and lighter box blades are not enough weight on the back to properly ballast the tractor. When using the loader, most of the weight ends up on the front wheels and all the power is going through the front axle. This can wear out the front axle and MFWD drive components quicker.

When I take apart anything that is splined, I like to lubricate it with a "moly" grease when I reassemble it. I have read where that helps prevent spline corrosion, which accelerates wear.

I agree with Roger here...sounds like a ballasting problem.

 

[Cocre]

I never (well almost never) take my 3320 out of MFWD, but I also have a 1000 pound backhoe hanging off the rear most anytime I am using the FEL. I have been meaning to load the rear tires too, I will probably do it for sure now.

 

[sunnyside360]

I never (well almost never) take my 3320 out of MFWD, but I also have a 1000 pound backhoe hanging off the rear most anytime I am using the FEL. I have been meaning to load the rear tires too, I will probably do it for sure now.

My neighbor has a 4X10 with FEL (no backhoe) and he used to keep it in MFWD all the time until he had trouble. He had to replace some gears and bearings in the front axle housing. He now uses MFWD only when needed.
I personally am not so sure he had the problem because it was in MFWD all the time but he thinks so.

 

[Spudland_Dave]

I personally am not so sure he had the problem because it was in MFWD all the time but he thinks so.

I'm gonna agree with you, most if not all the machines I know about (friends & family) of various color pretty much LIVE with the MFWD engaged.. My dad has 900 hours on his orange L2900 and I think probably only 5 of those hours have been in 2wd...Also quite a few green machines that for all intents & purposes you could engage MFWD and then unhook the linkage...

 

[LBrown59]

My neighbor has a 4X10 with FEL (no backhoe) and he used to keep it in MFWD all the time until he had trouble. He had to replace some gears and bearings in the front axle housing. He now uses MFWD only when needed.
I personally am not so sure he had the problem because it was in MFWD all the time but he thinks so.

I don't think so either it's something defective.
.

 

[Cocre]

I just got off my 3320. I tried to use it without the MFWD engaged. On flat land things are fine, I can use the FEL with no issue, but as soon as I point the nose of the tractor down a mild slope and try to back out of dirt pile with a loaded bucket all the rear R4s will do are spin. I engage the MFWD and out I come. Perhaps I could use the differential lock, and sometimes I have to do that too, but that sure takes the fun (and speed) out of moving dirt. I have 1000 pounds of ballast (a backhoe) on the rear. I think I'll just leave it in MFWD.

Tugboat, you say you have changed the front tires a couple of times on your tractor already at 900 hours. Is this due to wear? I have close to 400 hours on my tires and they look to me the same as when I bought it with 185 hours on it, and they looked brand new then. Something must be wearing them out way faster than normal.

 

[jd110]

First of all, I want to clarify things. Did the shaft fail the same way all three times? Second, Are you saying your tractor is less than three years old? If so, then you should still have a powertrain warranty up until three years or 2000 hours that should have covered this. Third, I think the gear ratio/tire sizes need to be physically checked. Your tires shouldn't be wearing out that quickly unless ratios are incorrect or you are running on paved surfaces in 4wd. Lastly, you could have some kind of alignment problem with the driveshaft, or the front axle could have too much "play" in it allowing it to slide from front to rear. If you raise up the front of the tractor, you shouldn't hae any play front to rear in the axle, and that splined coupling should slide easily on the shaft with no binding. Ask your dealer if he is familiar with solution 72552 which addresses these issues. Good Luck!

 

[tugboat-2]

Hi Cocre ! ...yes, re: the front tires,..at one point digging my lake (pond) I had to work in a wet clay soup a couple days. Somehow a stone got wedged between the tire and rim. I didn't notice till after dark coming back to the house, I lost the air and ran the tire off the rim. It was dark, I was beat and I guess it flopped around a couple times pretty well destroying the bead.

Would have shut 'er down and come back in daylight (not far) but a few kioti were circling me so skidded 'er home on the bucket. I had teased them by chasing them with the tractor earlier so I guess they were angry and I was unarmed at the time. Don't know what they'd have done if I just jumped out waving my arms and hollered and whooped at them. Last time I stopped the tractor and pulled a gun, they took off so fast I never got a shot away!! So who knows?

I fixed the tire but under load it refused to hold air and I had to carry my 12Volt Compressor, so put a tube in but the bead was so badly stretched the tube took a beating and became a pain in the hiney. Dropped it off late at night with a note. Friend has a tire shop on the farm. He was away, his son put the new tire on and after mowing next day, something didn't look quite right,...checked the size,..."wrong"!

Took it back and "naturally",..the kid insisted the difference was too small to worry about. Told him (nicely) to remove the tire as I was not paying for it! He got his dad on the cell,..who ordered the lad to put the proper tire on and make it snappy! Another time I snagged a front on a broken off stub of snow fence T bar and had to replace it. (At least I found that bar before my RFM!)

Aahh, but it surely does hurt to scrap a tire with lots of good tread left!!

But yes, I always insist on the proper tire size match with 4WD. Thanks for your interest,..best wishes.

CHEERS!
. . tug

 

[tugboat-2]

Hi JD110: a couple of clarifications first,..I'm on the 3rd shaft, meaning just 2 have broken. And the tires were not prematurely warn but were replaced as explained to Cocre above.

In respect to the warranty, I was recently told my warranty ran out Xmas of 2008 which is only 2 years from purchase but I'm working on that and my dealer said he'd talk to the Area Rep re: any possible assistance?

Actually I'm lucky to have the dealer I have, most especially for my Service Mgr who has done so much for me over the past couple years. I was hesitant to get into this with you guys as I'm reluctant to cause you worry,..but briefly:

I could write a book on the "serious" problems I've had with this beautiful tractor. They tell me I'm too hard on it,...and if this MFWD thing is any indication,...then perhaps I am? Although, my wife is certain I somehow got stuck with a "lemon",.....but I told her they don't come in green!!

When they first told me that,...I asked why then, would you sell me the tools you did and not "Caution" me to only use them extremely "gently"? When I told them what I was doing, they suggested the heavy duty bucket (the 73") and no one stopped me when I ordered the "tooth-bar" for it. No one warned me against buying the Heavy Box-Blade with Scarifiers and they knew I already had the big old heavy duty grader blade,....but never once has anyone advised me to "go easy",...don't dig solid dirt or hard clay with the toothbar nor did they caution me on the use of blade or box. They took my money and I'm grateful to them. They don't know I have a set of discs!!

Boy oh boy I hope I never snap a rear axle,..they'll blame me for buying 6" wheel spacers "from them",.. giving me an extra foot of width!! lol Crazy I know but it's like buying a Chinese Heavy Duty Torque Wrench, stamped on the handle says: Caution:for your protection do not pull more than 25 lbs!lol

I try to use care and common sense in all that I do and certainly try to NOT hurt or abuse my equipment,....especially since it has been one of my largest investments and I'm very proud to keep it looking and running as new. It gets serviced regularly, "I" am the "ONLY" operator, aside from the JD mechanics. (Same with my GMC truck which hasn't given me "any" trouble in years!! and it gets plenty of 4WD in the winter!)

OH yes JD110 before I forget: I can't really recall how the first shaft went other than it just seemed to stop working,...no click, no noise, not under load at the time, just heading back to the house up a slippery bank and couldn't get 4WD to engage. The second time was as described on the hill under heavy load,..click, click, slip and grab. I should have known by the physical size of the shaft that it was rather,..what,.. delicate? (seems a harsh word,..but, on the other hand,..it fits the circumstances?)

If I relate the problems I've had, you'd likely be inclined to agree that I'm too hard on it, yet some of them have nothing to do with "my" treatment.

JD110 I am grateful for your interest and No,..I am not familiar with what you suggest as: Solution 72552,...but I'll mention that to my dealer. THANK YOU.

CHEERS!
. . tug

 

[Scooby074]

You should be able to use your tractor, as a tractor!

Using the 4wd on soft ground shouldnt cause your problems. Maybe i could see some issues on pavement .

Id be pretty ticked if it was me.

Im sure you keep your machine well greased?Splines on driveshafts can wear prematurely if dirt gets in and contaminates the grease.

Im not familiar with your front end, but Would it be possible for a local driveshaft shop to build you a heavy duty shaft (one with splines not made out of peanut butter) and make it work with your tractor? Might be a more permanent solution if your out of warranty.

 

[jeffster]

I really hope your experience is a rare one. I use MFWD almost all the time as the R4s suck and I can't box blade or use my loader in the clay we have if there is any recent moisture at all. I just turned 100 hours on my 3520 and I bet 80 of them were using MFWD. This is the whole reason I bought this tractor as I need 4wd. I have some large dirt berms that I back up and scrape down the dirt and push it into a remote pile to load with the loader. I can't back up the hill or pull the dirt down without MFWD unless it is very dry out.

On a related note, I did just change my front axle hydraulic fluid and while I saw no shavings at all, the fluid itself was pretty dirty. I feel better having changed it, just for peace of mind.

 

[tugboat-2]

Scooby: ...thanks much for your suggestion. Some old tractors I've had in the past would no doubt benefit by that and the suggestion of the JD shop to simply "weld" the driveshaft to the pinion shaft,...would be good for many of the old junkers I've had,......BUT, BUT,...

Guys, this is my Baby,...my Rolls,...Xmas 2006 (when I took delivery) seems like last week to me!! Even after a hard, dirty days work,....washed and shined up with cab all vacuumed out and dash shined up,...sitting out on the fresh cut lawn down by the lake, . . . it just looks OH,..So Nice, and still so new to "me!!!!! ....remember, after years of junkers wired and chained together, broken welds and even a ripped and faded buggy-top,.. well......

"THIS" is my very first BRAND, SPANKIN, NEW,..right outta the Showroom, ... glistening Tractor with new-car smell in the gorgeous Cab, . and, . . well,... . .

I just prefer,...(at least for a while yet) keepin 'er as Original as possible!! But thanks for the suggestion Scooby, I appreciate your thoughts.

Jeffster: ....and yes of course, I appreciate your thoughts as well, but my turn to ask you a question here: Are your R-4's "loaded",...are you carrying rear ballast of adequate weight? I ask because you sound disgusted with your R-4's on clay?

I also run R-4's, loaded with Beet Juice (Cdn) and found a tremendous upgrade in traction even on wet and slimy clay. (No, not great on wet clay) but surpizingly good with added ballast behind,...(often just my heavy big old grader blade, often wrapped with a mess of heavy old tractor tire chains and the heavy tranny out of a WWII Bren-gun Carrier etc but with all I hear of no traction R-4"s,... I have no complaints,..really!! I hope this helps you a bit!!

Thanks again guys,..much appreciate "all" thoughts and comments,...we're not through with this yet!!

CHEERS!
. . tug

 

[johnesc]

Lost my 4wd and found Front drive shaft coupler and Pinion shaft both worn and slipping. Front drive shaft has to much movement and coupler engaged only half of pinion spline. Bad design, Deere want $750 for new ring and pinion parts.