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SkyTrak problem

Joined
May 6, 2017
Messages
9
Location
Dardanelle Arkansas
Hey guys....I have a 1997 8042 SkyTrak that I bought about 2000. I'm in the residential construction business and it has been an invaluable piece of equipment with only a few very minor problems over the years. However....as of late, it has decided that it doesn't want to move forward or backwards, unless you extend the boom or maybe operate the tilt. Once you get going, you can let off the boom and it will continue to move. This can be a herky-jerky type motion from moving to stopped to moving to stopped, etc. Very strange and very aggravating. I've asked every "expert" I can find in my "neck of the woods", but I seem to be at a dead end. I'm no mechanic, but I'm willing to tackle almost anything this might be.

Thanks for your advice.
CF
 

icestationzebra

Senior Member
Joined
Jun 21, 2009
Messages
366
Location
WI
Does it have a prox sensor that cuts out the transmission when the boom is above a certain angle? I think they do but can't remember for certain. If so sounds like it is going out or you have an intermittent connection. ISZ
 

92U 3406

Senior Member
Joined
Jan 3, 2017
Messages
3,100
Location
Western Canuckistan
Occupation
Wrench Bender
Last place I worked had a fleet of Skytraks (newer though) and we had a couple issues with the brake pedal switch under the dash burning out. Depending on what options are on the machine the switch could control brake lights as well as transmission functions? Or something to do with stability/boom? Its been a couple years since I last worked on one. I do remember for sure that we had an 8042 that shifted super harsh and had a few transmission quirks and it was all caused by that brake pedal switch. I would start by checking that switch if your machine has it. Under the dash, above the brake pedal.
 
Joined
May 6, 2017
Messages
9
Location
Dardanelle Arkansas
Last place I worked had a fleet of Skytraks (newer though) and we had a couple issues with the brake pedal switch under the dash burning out. Depending on what options are on the machine the switch could control brake lights as well as transmission functions? Or something to do with stability/boom? Its been a couple years since I last worked on one. I do remember for sure that we had an 8042 that shifted super harsh and had a few transmission quirks and it was all caused by that brake pedal switch. I would start by checking that switch if your machine has it. Under the dash, above the brake pedal.

Hmmmmm.... could be. I'll check it out this morning and report back. Thanks for the tip.
 
Joined
May 6, 2017
Messages
9
Location
Dardanelle Arkansas
Last place I worked had a fleet of Skytraks (newer though) and we had a couple issues with the brake pedal switch under the dash burning out. Depending on what options are on the machine the switch could control brake lights as well as transmission functions? Or something to do with stability/boom? Its been a couple years since I last worked on one. I do remember for sure that we had an 8042 that shifted super harsh and had a few transmission quirks and it was all caused by that brake pedal switch. I would start by checking that switch if your machine has it. Under the dash, above the brake pedal.

Hmmmmm.... could be. I'll check it out this morning and report back. Thanks for the tip.
 
Joined
May 6, 2017
Messages
9
Location
Dardanelle Arkansas
NO brake pedal switch under the dash. Maybe because it's an older model. I dunno.

I took off on it this afternoon and all seemed good. For about 5 minutes. And then BAM...just goes into neutral.
 

92U 3406

Senior Member
Joined
Jan 3, 2017
Messages
3,100
Location
Western Canuckistan
Occupation
Wrench Bender
I'm drawing a bit of a blank. I'm thinking its likely an electrical issue. Seems to me those Skytracks had the ZF transmission with a solenoid block to control the clutches. Maybe check the wiring to the coils. IIRC those machines had a bunch of hoses and wiring jammed between the frame and the transmission housing and they liked to rub along that area.
 
Joined
May 6, 2017
Messages
9
Location
Dardanelle Arkansas
I'm drawing a bit of a blank. I'm thinking its likely an electrical issue. Seems to me those Skytracks had the ZF transmission with a solenoid block to control the clutches. Maybe check the wiring to the coils. IIRC those machines had a bunch of hoses and wiring jammed between the frame and the transmission housing and they liked to rub along that area.

Could be an electrical issue. There was a time when the tilt was not working correctly -turned out to be a broken wire under the cab. And there are a LOT of hoses and wires jammed up between the frame and tranny. In fact, I've had to replace a couple of the hoses due to wear just where you are talking about. I'll check it out. Thanks.
 

xgiovannix12

Senior Member
Joined
Feb 22, 2012
Messages
474
Location
New York
Occupation
Operator/Mechanic/Truck driver
I have a skytrak 5522 that did this. my main power wire that fed the ignition on the alternator was loose. do you loose power to everything else when it goes to N
 
Joined
May 6, 2017
Messages
9
Location
Dardanelle Arkansas
I have a skytrak 5522 that did this. my main power wire that fed the ignition on the alternator was loose. do you loose power to everything else when it goes to N

No...it still runs. Never dies. It's like it just drops into neutral. And only activating the hydraulics seems to kick it into gear. Very inconsistent. Sometimes it runs fine for a bit and other times I can hardly get it moving. I think you and 92U are right in that it's most likely an electrical issue.
 

xgiovannix12

Senior Member
Joined
Feb 22, 2012
Messages
474
Location
New York
Occupation
Operator/Mechanic/Truck driver
my machine would stay running but would not move. With the vibration of the boom it would knock the wire loose. I believe the transmissions are solenoid driven so no power no forward or reverse.
 

Junkyard

Senior Member
Joined
Jun 5, 2016
Messages
3,621
Location
Claremore, OK
Occupation
Field Mechanic
Where is the fuse panel located on it? My JCB 508C does silly crap all the time. The panel sits below a little cubbyhole in the dash that holds water, water runs down into the fuse panel area and I constantly fight corrosion and poor connections. When it acts up I can reach down and wiggle fuses and the offending issue usually goes away. I'd say something silly like that is going on. Not a pinpoint diagnosis but might help steer you to the culprit.

Junkyard
 
Joined
May 6, 2017
Messages
9
Location
Dardanelle Arkansas
Where is the fuse panel located on it? My JCB 508C does silly crap all the time. The panel sits below a little cubbyhole in the dash that holds water, water runs down into the fuse panel area and I constantly fight corrosion and poor connections. When it acts up I can reach down and wiggle fuses and the offending issue usually goes away. I'd say something silly like that is going on. Not a pinpoint diagnosis but might help steer you to the culprit.

Junkyard

Fuse panel is located in the lower right part of the cab under the levers that operate the hydraulics. I looked and it stays dry in there. Fuses and panel look good.
 

skata

Senior Member
Joined
May 10, 2007
Messages
1,541
Location
midwest
Where is the fuse panel located on it? My JCB 508C does silly crap all the time. The panel sits below a little cubbyhole in the dash that holds water, water runs down into the fuse panel area and I constantly fight corrosion and poor connections. When it acts up I can reach down and wiggle fuses and the offending issue usually goes away. I'd say something silly like that is going on. Not a pinpoint diagnosis but might help steer you to the culprit.

Junkyard
i had that same issue on a jcb 506c. i lifted off the gray plastic cover and sprayed the backside of the fuse panel with dielectric grease. and replaced the fuses with new uncorroded ones. havent had any issues in years since.
 
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