NH 7635 Dual Command Issue (also slow loader)

[monkspill]

Hello,

Wondering if anyone has come across this issue before, we have a 1997 NH 7635 (Similar to a TL100) which has the 24x12 gearbox with the dual-command switch on the gear stick. We previously had the Dual-Command switch working after the tractor went in for some work, I was topping with the machine around a year ago and hit a bit of a grip which shook the tractor somewhat and then she flicked back in to the low range and would only work in the High range if I held the left handle shuttle lever forward (suggests a switch as these are only designed to have the splitter in foward range) and then after some time it stopped working altogether. Can't find a lot of information on wiring etc for this machine, wondered if anyone else had encountered similar issue? It wouldn't bother me that much but she is restricted to about 30k without the splitter for the odd occasion I do venture onto the road.

Also, (unrelated) the tractor has a bomford c3618 loader on it which is painfully slow unless giving it plenty of revs, the back end lifts and operates quickly, as do the spools if running auxiliary functions although they have become extremely stiff and somewhat temperamental, for example when folding up set of hydraulic harrows/tipping trailer if you push the lever forward fully the trailer wont tip as quickly as when holding the lever 3/4 open. The spools will lock into the detent position fine but as said are extremely stiff. Tractor has a closed center hydaulic system I believe and you can hear/feel her straining when the loader is engaged.

Something else to note, the joystick for the loader has a float function but works when you pull the loader towards you all the way as opposed to knocking it forward in to float.

Thanks in advance, any advice is much appreciated.

 

[monkspill]

Anyone got any ideas?

 

[agrimax]

Had a similar problem with a TL100a dual command. There was a broken wire below the floor rubber just in front of the gear lever with the switch on it. Maybe the same problem with yours.
Don't know about the hydraulics though. Are you sure they're closed centre on a 7635?

 

[monkspill]

Thanks I will have a look at that, yes may have got that the wrong way round, the pump is gear driven & loader needs to be engaged for use (other functions then don’t work) so that would make it open Centre as opposed to closed wouldn’t it.

 

[agrimax]

Yes, all gear pumps in these..... Open centre only.

 

[monkspill]

Any ideas on the above folks ?

 

[Half Pipe]

Thanks I will have a look at that, yes may have got that the wrong way round, the pump is gear driven & loader needs to be engaged for use (other functions then don’t work) so that would make it open Centre as opposed to closed wouldn’t it.

How do you engage the loader?
Is it plumbed into a rear spool?
Any chance it's plumbed back to front when float only works in raise direction!?

 

[monkspill]

How do you engage the loader?
Is it plumbed into a rear spool?
Any chance it's plumbed back to front when float only works in raise direction!?

Yes plugged into rear remote/spool. Float detent is in raise direction guessing joystick just wrong way round, I bought it off an equestrian yard and they did drop a bale over the front of the machine previously they told me so I was wondering if they had someone change something to slow it down.

 

[Half Pipe]

Does the rear spool that operates loader have the flow adjuster on it? Just out back window on the right.
Or is this the spool you say powers other equipment at reasonable speed

 

[Half Pipe]

Are all the rear spools stiff and temperamental?
It could be the lever linkages needing some lubricant, but we once had a hydraulic coupling break up and a bit of metal went into the tractor (tl100) spool, it jammed, so we had to take it apart and managed to get the it moving, but was never right after that

 

[monkspill]

Does the rear spool that operates loader have the flow adjuster on it? Just out back window on the right.
Or is this the spool you say powers other equipment at reasonable speed

Yes 2 on there, 1 has snapped off but if I plug it into one of the other spoils it still operates at the same speed.. unless of course the spools are left/right pairs as opposed to above/below as I thought in which case I could plug in to a different one to try. Engagement levers are incredibly stiff to the point of them bending on of the levers if you try and pull it as oppose to tap it

 

[monkspill]

Are all the rear spools stiff and temperamental?
It could be the lever linkages needing some lubricant, but we once had a hydraulic coupling break up and a bit of metal went into the tractor (tl100) spool, it jammed, so we had to take it apart and managed to get the it moving, but was never right after that

How did you sort this out? How is best to lubricate them?

 

[monkspill]

As you can see I have now plugged into the bottom left spool which is slighter faster, when revving the tractor almost flat out the loader takes around 8-9 seconds to cycle from the ground to full height, takes around 6 to come back down. Is this about right? Just remember my old zetor 6245 when in “1000” pto was a lot faster. The loader is faster when flow control is in the min position, on the other spool it is snapped off and was in the max position. Maybe I’m just used to the telehandler and excavator speeds...

The rams are double acting so would expect them to be similar speed coming up/down.

 

[Thomas5060]

As you can see I have now plugged into the bottom left spool which is slighter faster, when revving the tractor almost flat out the loader takes around 8-9 seconds to cycle from the ground to full height, takes around 6 to come back down. Is this about right? Just remember my old zetor 6245 when in “1000” pto was a lot faster. The loader is faster when flow control is in the min position, on the other spool it is snapped off and was in the max position. Maybe I’m just used to the telehandler and excavator speeds...

The rams are double acting so would expect them to be similar speed coming up/down.

Is that a new joystick you have fitted? If so make sure cables are adjusted properly

 

[monkspill]

Been on there since we’ve had it but must be relatively new as the loader is plumbed for electric 3rd service but there’s no buttons.

 

[Half Pipe]

Double acting rams always retract quicker as the rod takes up space, so needs less oil.

Are both of the rear spool valves sticky?
Do you know if the loader will have been used a lot?
The bit of metal I presume kept the spool open looks like it doesn't hold spool fully open, this would heat it up more than necessary, and could cause valve to be sticky!
The proper way would of been adjust the detent so it stayed open, easily done with a flat screwdriver and a spanner.
Will try get a photo for you.
But the loader valve should really have been connected to the tractor pump pipework.

 

[monkspill]

Double acting rams always retract quicker as the rod takes up space, so needs less oil.

Are both of the rear spool valves sticky?
Do you know if the loader will have been used a lot?
The bit of metal I presume kept the spool open looks like it doesn't hold spool fully open, this would heat it up more than necessary, and could cause valve to be sticky!
The proper way would of been adjust the detent so it stayed open, easily done with a flat screwdriver and a spanner.
Will try get a photo for you.
But the loader valve should really have been connected to the tractor pump pipework.

Thanks for the response,

That’s a seperate spool it’s on now but the detent does keep it open, thanks I appreciated that. The return for the loader (I’m guessing) goes straight In to the back end.

 

[Half Pipe]

It looks like the return from loader goes in the oil filler pipe.
Can just see it in your photo of rear couplings.

 

[monkspill]

It looks like the return from loader goes in the oil filler pipe.
Can just see it in your photo of rear couplings.

Indeed it does yes!

 

[monkspill]

It looks like the return from loader goes in the oil filler pipe.
Can just see it in your photo of rear couplings.

Is this a bad way of doing things? Looking at some other machines (7635/Tl100) they appear to be plumbed direct or not in to the rear remotes..