John Deere 4450

4450deere

New User
Hello everyone

I am new here and hope someone can help me. I have a '88 JD 4450 with powershift transmission.
Today I made some repairs on the front axle and steering transmission. (Replaced the sealing ring and O-ring and replaced the bushings form the axle )
After mounting all parts back to the tractor, the steering didn't work correctly, I can turn 1/4 and the wheel go from full left to full right...
I think there's air in the steering system, but I don't know how to bleed the system correctly?
We had a pressure gauge on the valve (where's the electrical switch is) right under the hood on top of the engine and after shutting off the engine the pressure getting down to 0 bar very fast. This means in the service book there's a leak...?
I hope someone has an idea for that?:?:

Next project will be the removing of the cast wheels and mount of 8 hole wheel hub...
If someone has tips for the removing, i would be very thankful to get them :)

Thanks in advance for an answer

Greetings from switzerland :wink:
Stefan
 
Hello

Today I have a small update from the tractor works.
I tried to bleed the steering system by loosing the oil lines, once directly after the valve and once under the fuel tank. It didn't help... :?:
I am pretty confused, because the steering worked perfectly before the repair.
I hope someone has an idea, what I can do?

A good news of the day is, that I was able to loosen the rear wheel from the wedges :p

I hope my english is understandable

Thanks in advance

Stefan
 
Hello Donmyeil

Thanks for your reply. Which O-Rings are you talking about?
RP3981_________UN01JAN94.gif


I replaced Position 36 and 37.
Are you talking about position 23?

The courios thing is, that it worked as it should before the repair work... :roll:


Thanks in advance
Stefan
 
If I am understanding correctly you removed the steering arm/gear from the bottom to replace that o-ring? If so that gear needs to be timed. No bleeding is needed on that system so Im thinking gear timing is your issue.
 
Hello

Yes you are right. I removed the spindle (part 33) from the steering motor and replaced the O-Ring (Part 36) and the Sealing (Part 37).
Yesterday I bought a TM 1353 and seen there, that the steering motor needs to be filled up with oil?
I removed the spindle while the steering was still mounted to the tractor...
So should I remove the whole steering motor from the tractor to fill it up with oil?
I was thinking it will be filled automatic while the tractor is running :oops:

Hope you understand my english :? :oops:

Thanks
Stefan
 
Hello

I want to grab out this older topic, because the problem with the steering still exists.
I like to know, if someone has an idea what I can do or try on the tractor? (the reason for that long "standing still time" is, that it is my hobby and I was a long time away...)

I tried to bleed the system by turning from one side to the other...(done this 15-20 times) But if I do about 1/4 turn of the steering wheel, the front wheels goes from full left to full right and then I can turn the rest "free". It needs very less turning of the steering wheel to turn the front wheels...

I really don't know why this happend, we had opened the lines from the feedback piston when we mount the spindle back to the steering motor, because we were not able to turn the piston in position to fit the spindle back in.
I tried to lose these lines and turned the steering wheel (to bleed the feedback piston) but this also did not help.

I hope anyone has an idea what the problem could be? Or what I can try?

Thanks in advance !

Best Regards
Stefan
 

As my old tech lab instructor said " no feedback, no control". The smart old cuss was correct too.
Unless a govener, voltage regulator, amplifier or hydrostatic system is feeding back position to the controller. The controller is going to keep increasing output up to 100% or decreasing down to 0.0%. if there is no feed back signal to indicate to the controller that the desired position has been reached. to stop flow or motion at the desired point .
 

Stefan
I think when you originally replaced o-ring & seal you must have let pin(part key 25) come out of position in piston(parts key 33) by letting piston rotate in housing?(parts key 9) therefore loosing control of feedback of feedback piston(parts key 11).

I agree I think your English is better than a lot of Americans including me.
Jim
 
Hello

Thanks alot for your answers. So you mean, that I have to check the feedback piston? This will mean I have to remove the fuel tank and the whole steering motor, if I understood right from the Tech manual.
I think this wont be a problem, it only means a few work :wink:

But I have another question, the oil thats in the spindle, where does it come from? Do I really need to fill it up before mount back on the tractor?

Thanks for all your help :!:

Best Regards
Stefan
 
Hello

Thanks everyone for the nice help.
We worked again on the 4450 and we opened the steering motor again and saw that the feedback piston pin was out of position. We assembled all back to the tractor and it worked as it should. :D

Now there are only a few small things and the new cab upholstery to do and then I can go for the vehicle testing to get a license plate.
:wink:
Have a great weekend

Best Regards
Stefan
 
Hello
I have another two question about the serial number plate. The first one is, where is the serial number written in the frame?
And on the serial number plate on the right side of the front end (near the wheel) is a "coef abs" value (0,64).
What does this mean? Should it be the emission values?

There should be a picture about the plate, I am talking about
:wink:
38784.jpg



Thanks
Stefan
 
Hello
I have another question about the JD 4450. How would I notice that the hydraulic accumulator is less charged?
To check the accumulators, how much pressure should they have?
I think there are two of them, one for the seat and one for the Powershift? The seat lowers pretty fast, when I turn off the tractor- so I think this one doesn't have the right pressure?

Thanks in advance for all answers and tips :wink:

Stefan
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top