more creep

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bluffcam

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Joined
Oct 6, 2007
Messages
14
well this 843 with an isuzu has been an interesting project. Supposed to be an easy u-joint repair. The machine was run with the u-joint failing for as long as possible i figure. The rear engine mounts vibrated a square groove 1/4" deep in frame, the wobbling u-joint broke hydro pump shaft, and the plate holding engine and starter was cracked. With some help from this forum its running, moving and lifting. It started without any pursuasion or bleeding and sounds great.
any tricks or hints on adjusting creep, this unit has the hydraulic servos(don't know if this is good or bad) I put new bushings on the servos where they bolt to the arm. I read the book and found it a bit confusing so i made some adjustments on rod ends. didn't help much. One side goes forward at a pretty good clip and the other moves backwards slowly. Any way to check if servo are working properly?
The lift cylinders both have a small drip at base of cylinder, haven't pulled yet but figure they are cracked and wonder if they can be welded? pretty sure leak is not at hose connection.
thanks---some picture under 843 rebuild if interested.
 

skidsteer.ca

Well-known member
Joined
Jan 20, 2006
Messages
3,853
Put the critter on blocks so wheels can turn,start her up and watch them go. My 853 has the servos and is conected to the steering levers by morse cables. I just unhook the cables and make adjustments until the wheels stop.This is done right on top of the pump.
Then adjust the cable to get equal stroke in both forward or reverse. It a patience thing. Also be sure worn parts are not preventing repeatable centering of the steering lever.
If the cylinders are infact cracked and are steel (some have cast ends) they can likely be welded, so long as the crack is not right where the seal slides back and forth. You will have to pull them off and get a good look at things. Pressure test them on the bench and grind out the crack carfully. It would be good to get some hi tensile welding electrodes for the repair, or you may want to take it to a pro.
I have welded a few fittings back on and even shortend one cylinder by taking a piece out of the barrel and welding the bottom/ back end on again and shortening the rod.
Worse case new cylinders can be made, but I'd certainly try a repair first.
Ken
 

Fishfiles

Well-known member
Joined
Feb 8, 2007
Messages
1,698
Put the critter on blocks so wheels can turn,start her up and watch them go. My 853 has the servos and is conected to the steering levers by morse cables. I just unhook the cables and make adjustments until the wheels stop.This is done right on top of the pump.
Then adjust the cable to get equal stroke in both forward or reverse. It a patience thing. Also be sure worn parts are not preventing repeatable centering of the steering lever.
If the cylinders are infact cracked and are steel (some have cast ends) they can likely be welded, so long as the crack is not right where the seal slides back and forth. You will have to pull them off and get a good look at things. Pressure test them on the bench and grind out the crack carfully. It would be good to get some hi tensile welding electrodes for the repair, or you may want to take it to a pro.
I have welded a few fittings back on and even shortend one cylinder by taking a piece out of the barrel and welding the bottom/ back end on again and shortening the rod.
Worse case new cylinders can be made, but I'd certainly try a repair first.
Ken
Skidsteer , I am pretty sure the servo steering in the 843 was totally different from the 853 , it was very hard to set netraul on that machine , it has little cylinders with hydraulic lines going to them , kinda like power assist , really crammed in there , not all of the 843 had that type of steering , seems I only seen 2 or 3 that had a servo steer set up which I think he is talking about -----can't remember what the adjustment procedure was
 

Tazza

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Dec 7, 2004
Messages
16,819
Skidsteer , I am pretty sure the servo steering in the 843 was totally different from the 853 , it was very hard to set netraul on that machine , it has little cylinders with hydraulic lines going to them , kinda like power assist , really crammed in there , not all of the 843 had that type of steering , seems I only seen 2 or 3 that had a servo steer set up which I think he is talking about -----can't remember what the adjustment procedure was
I think i see the servo. It looks sort of like a power steering setup. I just wonder if it may need a new set of seals or something to assist in it holding centre. Even possibly air stuck in the system causing it to be sort of spongy? wanting to favour one direction more than the other? I am just guessing as i have never fully understood how hydraulic assisted steering works, but as far as i was aware it does have a small amount of internal by-pass that will purge any air that may have been in there.
 

skidsteer.ca

Well-known member
Joined
Jan 20, 2006
Messages
3,853
I think i see the servo. It looks sort of like a power steering setup. I just wonder if it may need a new set of seals or something to assist in it holding centre. Even possibly air stuck in the system causing it to be sort of spongy? wanting to favour one direction more than the other? I am just guessing as i have never fully understood how hydraulic assisted steering works, but as far as i was aware it does have a small amount of internal by-pass that will purge any air that may have been in there.
Ok good to know, might be best to sweet talk local dealer out of a few photo copies.
Ken
 
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bluffcam

Member
Joined
Oct 6, 2007
Messages
14
It is the gizmo(servo) with the two small hydraulic hoses. I got a feeling this setup didn't work out too great as the manual has about 5 changes in this steering depending on serial number. There is a large bushing and bolt that bolts to pintle on hydrostatic pump. then there is two 1/4" hydraulic rams on other end of servo. One ties to a fixed point on the frame and the other hooks to the steering arms with a centering spring. Common sense would say disconnect the end points and get wheels to stop moving then reconnect adjusting the lengths to keep wheels from moving. It sounds like it may take a bit of doing and experimenting to get it right. image 3 in the 843 rebuild folder shows the servo laying off to the left of the pumps.
 

Fishfiles

Well-known member
Joined
Feb 8, 2007
Messages
1,698
It is the gizmo(servo) with the two small hydraulic hoses. I got a feeling this setup didn't work out too great as the manual has about 5 changes in this steering depending on serial number. There is a large bushing and bolt that bolts to pintle on hydrostatic pump. then there is two 1/4" hydraulic rams on other end of servo. One ties to a fixed point on the frame and the other hooks to the steering arms with a centering spring. Common sense would say disconnect the end points and get wheels to stop moving then reconnect adjusting the lengths to keep wheels from moving. It sounds like it may take a bit of doing and experimenting to get it right. image 3 in the 843 rebuild folder shows the servo laying off to the left of the pumps.
Bluffcam , I'd would almost bet that your machine is a high flow machine as the units I seen with servo assist were , one of the first of it's kind , you made me remember an old guy thats gone away now that had one , it is still sitting in a lot here and was flooded over the roof in Katrina ---------the servo cylinders I doubt are your problem , if a remember right there is a plate on the side of the pump , this plate is just like the pintle plate that sits on top of the newer machines , there should be some 9/16 headed bolts holding blocks under the plate , the adjustment is made there , as stated get the machine jacked and blocked and I think you can barely loose the bolts and take a hammer and tap the heads one way or the other to take up the slack between the block and the steering pintle while you pull the level in the direction you need to stop the creep till you get it right , seems I remember that every action has an opposite reaction and the servos really throw things off -------good luck
 
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