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7120 issues


1958560

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Hi everyone. I finally upgraded to a MFWD 7120 last spring and love it. So last fall, i was looking for a loader for it and ended up buying another 7120 w/ a Great Bend 860 loader on it. But this tractor has a few issues. The mfwd slips when I need it the most. If i lift a little weight off the front end, the tires will spin, but even with no load in the bucket the tires will not spin when going thru deep snow, I nearly got stuck pulling a small hayrack thru snow about 2' deep. The switch light lights up. Is the fwd solenoid behing the lower fuel tank? That seems to be working, but has power when the switch is off then the power goes AWAY when the switch is turned on, is this normal? Also the diff lock doesn't seem to engage at all. Also when its cold, first few shifts into reverse there is a delay about 2-5 seconds before tractor moves. As tractor warms up it shifts sooner. The 3-4 reverse is faster to engage. Can the fwd clutches be removed without splitting tractor? Anybody know how to diagnose these problems. I have a I&T manual, but it seems to be a little vague and has no troubleshooting. Anyone know of a source for a CaseIH complete manual? This tractor has about10300 hrs on it. I am trying to make up my mind as to whether it is feasable to repair this machine or if I should try to trade it on something else. Any help would be greatly appreciated, thanks Rob

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your mfd selonoid is working properly, they are energized when mfd is off.Went through that myself . It sounds like your mfd clutches may be weak but you could try changing the oil in the center pumpkin but be sure you put in 1 pint of limited slip additive with the oil. It is recommended that this be done at regular intervals. Had an MX120 that would slip a LITTLE under heavy loader work, changed the oil-new additive,and it quit. Just my 2 cents,good luck.

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MFD...

The MFD clutch is spring applied, hydraulic released. So, juice to the MFD solenoid when released is correct.

Depends on transmission S/N on how easy the MFD clutch is to repair.

Requires at least a split at the flywheel housing.

Diff lock...

Debris can buildup at the brake valve preventing the brake pedals from returning completely and holding the switches that release the diff lock. An air hose and blow gun usually fixwes that problem. ( easy way to check, sometimes you can hook your toe under the brake pedals and pull back enough to allow the diff lock to engage)

Shifting...

Might (probably) need accumulators charged. The passages that move the oil to shift are small, cold oil does not like small passages.

Jim N.

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Can the fluid be changed in just the center or does the whole 50 gal need to be changed? hard to say if and when the fluid has been changed before, there is nearly 1000 hrs since fuel filter change according to marking on filters, but no marks on hyd filters. Also, this tractor has the second smaller filter that says high performance on it. What is that filter for, it also has the large one that runs vertical behind exhaust stack. The dealer looked in a 7220 book which indicated that the mfd clutch pak can be removed from the right side w/o splitting tractor but was wondering if the 7120 was different. How tough is it to split this? I have rolling stands made for 86 series that bolt to the frame and I just use a 20 ton jack to support the rear, would this be heavy enough? Also have stands that would support the cab. The diff lock switches, are they on the firewall or under the cab? I blew out a couple 5 gal buckets of hay and dirt from under the cab but haven't opened the hood to clean there yet, hood cyls are shot. How does the switrch in the cab work? It has two positions, one that stays in place and a second position that must be held. The book really doesn't say how this functions. Front crank seal leaks also, but I have been waiting for warmer weather to remove loader and pressure wash it before working on it.Weather is starting to warm here ,SD, so hopefully this week I will have time to get started on it, also dealer has his 10% off parts this month. Thanks, rob

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the diff lock switch is pushed all the way forward to engage then stays on when you leave in middle position. flip it back to disengage or touch a brake. the switches on the brakes can be too sensitive as they are on my 7140. i need to adjust mine because they wont allow the diff lock to stay on when i go over the slightest bump.

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I understand how the diff lock works now, and the brake switches are very sensitive on my tractor as well. How are they adjusted? it seems like the first 6 speeds are a little slow to engage also so maybe an accumulator needs to be charged. Are they removable to be charged or do they need the whole tractor? I used the tractor today to push snow away from feedlot fences and thefwd worked better whe n warm, but when I had a full bucket of snow and dug into dirt a little, the front end would stop and the rear wheels would spin, so probably going to have to go into fwd clutches, rob

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I understand how the diff lock works now, and the brake switches are very sensitive on my tractor as well. How are they adjusted? it seems like the first 6 speeds are a little slow to engage also so maybe an accumulator needs to be charged. Are they removable to be charged or do they need the whole tractor? I used the tractor today to push snow away from feedlot fences and thefwd worked better whe n warm, but when I had a full bucket of snow and dug into dirt a little, the front end would stop and the rear wheels would spin, so probably going to have to go into fwd clutches, rob

Before adjusting the switches, make sure there is not dirt build up on top of the brake valve holding the spools from returning all the way. Switches are under the dash.

The accumulators can be charged off of the tractor. They unscrew of off the transmission control valve.

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  • 2 weeks later...

Well , I started to work on the 7120 this week. I thought the front crank seal was leaking, but when I got it washed off and the loader and hoods off, it turned out to be the gasket between the timing cover and the block. So i pulled it apart and replaced the seal and gaskets along with the front cover. Also replaced oil pan gasket as it tore when removing timing cover. Started it up and it ran! I must have gotten the inj pump timing correct. Now on to the mfd. I pulled the suction strainer housing off and found a 2" piece of a blue teflon seal ring on the bottom of the housing. Can anybody give me an idea of where this could have come from based on the color? Dealer couldn't say for sure. This tractor is slow to engage reverse as well so I was wondering which clutch pack should be checked. It looks like I'll have to split the tractor to remove the output shaft for the mfd to get the clutch hub out, dealer said it should come out w/o splitting but was looking at a 72 series manual, you were right Maynard.. If I split it between the speed and range trans would I be able to get at the clutches responsible for the 1-2 reverse? The higher gears seem to work better but was wondering if the first six forward gears share some clutch paks with reverse. While it is split should I rebuild all the clutches that I can get at? Anybody know what clearance the master clutch should have? Up to this point, a 1586 is the biggest tractor I have split, this seems much bigger and is a little intimidating, but its only nuts and bolts right? Any help or direction would be greatly appreciated. Thanks, Rob

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if the first six gears don't work as well as the rest it sounds like your low range clutch pac might be slipping. as for it sharing pacs with reverse yes all the ranges including reverse use the same pacs in the speed trans to make up all 18 gears. :D

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1958560: My 7120 (with only 2500 hours) is in at my dealer right now and they just changed the gasket between the front dover and the block also. The new gasket is much more robust than the old one, so I hope it won't leak again. They also had to change the head gasket as it was leaking antifreeze all around the head when on the dyno test. So a medium size job turned into a much larger job. Discovery work,Bah!!!!

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Friend of mine had the front wheels of his 7230 slipping also. Turns out a snap ring must have snapped for good and it was letting the engagement springs loose. Those front ends should NOT slip. If it does, the solenoid is bypassing oil, or the springs are not tight for some reason. When the light is on, the solenoid should not be energized.

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