Help, Jd 410 backhoe won't move fast

[jdm0125]

Hey everyone I got a new project which is a straight JD 410 backhoe. Completely rebuild the entire motor 4cyl diesel. But the mot back in and now she doesn't want to move. She will go into all gears (1-8) and slightly "jerks" like it wants to move but doesn't. I have to put the pedal to the metal before it will start inching forward or backward regardless of the gear. Changed fluids, return filter trans filter and trans screen. Have 162 psi at reverser (with semi warm fluid). Checked linkage into reveres from clutch. Had wife on machine and I used vise grips on link bar to turn. It is going all the way back. I am stuck on this one. The book says it is not susposed to go into reverse in high gear but it does. Book also says when shifting in high gear from stop it should stall in 5 sec which it does not do that either.

I got a steal on this hoe but could not use it when I got it due to motor. Any ideas before I break this thing in half again?

 

[jdm0125]

I also checked the pressure release spring in reverser. I don't think it's the trans pump because hydrolic are working great so I'm getting fluid to hydrolic pump and breaks and steering are good

 

[Tx Jim]

Does it have 160#s in forward? Maybe disconnect clutch(parts key 4) is slipping.

 

[jdm0125]

Yes there is very little pressure change when switching from forward to reverse and neutral it's been a few days since I did test but I had pressure I do know I had 160# on reverser tap port on bottom rear of reverser

Update

I did the pressure test again had 162 # at idol in neutral when I switch to forward and reverse with tires up in air pressure drops all the way down and jumps right back up to 162#. When I put tires on the ground pressure drops to 75# when switching to forward or reverse and slowly drops to 10-20 lbs. when I go full throttle with tires on the ground the pressure then jumps back up to about 160 and tractor slowly tries to creep forward. I checked pressure gauge and noticed it was seeping fluid so I went to snug it up a little more and it stripped out. Now I need to buy another cover.

Any ideas while I'm waiting on cover?

 

[jdm0125]

So if clutch is slipping and I disconnect linkage then it will move at low rpm if that's the problem?

I did put a brand new clutch and pressure plate and throw out bearing when I put motor in

 

[jdm0125]

Ok so I justed pressure in gear to reverser and I'm peaking out at 75# then slow drops in forward and reverse

 

[Cpjlube]

There are two test ports on top of the clutch control valve. Those will give pressures to fwd and reverse individually. Give those a test and report back. There are a few known issues w that machine but start with the top test ports.

 

[jdm0125]

Thanks Cpjlube I will do that. JD is closed today but planning on ordering new reverser cover tomorrow

 

[Cpjlube]

Remember it's just a test port. Unless the housing is broken, you could retap to another size and just plug it up. Just a suggestion. It's not a critical part. Just needs to seal. It's 3/8 -24 I think? Just tap it for course thread and oring the top of the bolt. If it tightens, that's all you need. At least then you could continue with tests. Depending on outcome, reverser might be coming out anyway.........

 

[jdm0125]

Cpjlube
I did try and retap but it was still seeping fluid. New cover will be here tomorrow morning (wed) so I will have the results from test tomorrow evening. After work. Is there anything else I should check tomorrow?

 

[jdm0125]

So I got the cover plate in but they didn't send a gasket so I made one out of an unused water pump gasket which worked no leaks. My challenge is coming in trying to find the right thread/size for the test hole. I bought about 15 different fittings to make sure I had the right one and I cannot get any of them to thread in without force. I took the plug to Lowes and I believe it's 3/8 20 but they don't sell 3/8 20 fittings. I had to use compression. I could get the plug to screw into the female side so I found a male to match but it will not thread in when I got it gone. Does anyone know the exact type and size fitting/thread.

 

[Tx Jim]

Are you referring to test ports on reverser control valve? If so the specs for plugs are listed below.

 

[jdm0125]

Ok so went to JD this morning and got the right piece for the pressure gauge. When I put it in forward or reverse after getting oil hot my psi jumps to 50 #then hangs out at about 25#. I know I should have 100# at accumulator at shift to start shift process. Then it's supposed to get back to 100# within 3/4-1.5 secs. i have tried adjusting the adjustable orfice screw to increase pressure but it does not increase but when I turn it in it does decrease.

 

[jdm0125]

Yes thank you for the specs

 

[Tx Jim]

Ok so went to JD this morning and got the right piece for the pressure gauge. When I put it in forward or reverse after getting oil hot my psi jumps to 50 #then hangs out at about 25#. I know I should have 100# at accumulator at shift to start shift process. Then it's supposed to get back to 100# within 3/4-1.5 secs. i have tried adjusting the adjustable orfice screw to increase pressure but it does not increase but when I turn it in it does decrease.

Sounds as if reverser needs resealing.

 

[jdm0125]

Where exactly on the reverser? It is not leaking on the outside so it would have to be on the inside of the reverser correct?

 

[Tx Jim]

Hyd leaks will be internal. Reverser brake piston seals(parts key 10 & 11), Sealing rings on fwd clutch(parts keys 2A or 2B) depending on tractor serial number.

 

[jdm0125]

Ok which means I have to break the tractor back in half again. Not what I was hoping for but.....

Since you said reverser before, I went ahead and pulled it off. Found a valve stuck with metel shavings in the port. And another valve has a good size burr on it. I ordered new rebuild kit which will be here tomorrow. Someone had told me to put air hose on lines to clutches and if I heard a "thud" that was clutch pack engaging. Which means there is not anything wrong with them. Is there anything to that?

 

[Cpjlube]

Yes. There is something to that. If you remove the clutch control valve you will reveal some tubes. If you hit the correct tube w air you can engage the clutch pack. Check forward and reverse. Basically it's a simple design. Auto transmissions are test w air all the time. I'm assuming you have not split it again but just removed control valve off the side of it. BE CAREFUL! Those tubes can dislodge if you take the mount plate off. Some of them are darn near impossible to reinstall with reverser in the machine. Try the control valve clean up first. Hopefully that will work.

 

[jdm0125]

Cpjlube
Yes I found that out the hard way. I tried to remove the reverser without the back plate but it was stuck and 2 of the tubes fell out. Also when I put the air to the oil line to the forward and reverse I did hear a "thud" but I also hear air that sounds like it's coming out from the o rings where the tubes go in. I say that because I was getting a fine mist of oil back at me. I'm heading to JD now and Amy going to try and replace all the o rings in the tubes and rebuild reverser. I'm praying I can write back saying "IT WORKED"!