IH 434 tranny

[550Doug]

A fairly new-to-me 434 has started to give me problems with shifting. I can now only shift into 1st gear and Reverse in both H & L ranges. Also, about the same time I notice that I cannot engage the pto with tractor running. Can these two issues be connected? I know nothing about transmissions but it seems to me that maybe the actual shifter is not connecting properly. I've heard that sometimes forks get out of place, whatever that means. Do I need to remove the whole top plate?

 

[Fritz Maurer]

Clutch is dragging.

 

[used red MN]

That is a short response, but a very likely cause of
your problem. A better explanation would be that the
clutch is not fully releasing. First thing to check is how
much free play the clutch pedal has. I do not know that
specific tractor but in general when you first start
pushing the clutch down you are just pushing against
the pedal return spring and the resistance is minimal.
Then the release bearing hits the clutch pressure plate
fingers and then the resistance is much greater
because of the heavy springs in the press plate. So the
distance it moves easily is the free play. Just shooting
off the cuff it should be about 1 to 1 1/2 inches of travel
at the face of the pedal your foot goes on. If it is way
more than that adjusting it to the within the spec I gave
may help your problem because then you will be
depressing the clutch pressure plate fingers farther to
hopefully help the clutch to fully release. If you have a
two stage clutch that the bottom part of the travel is
used to release the live PTO that may complicate
things a little. Please report back with your assessment
of this information as it applies to your tractor.

 

[550Doug]

It seems to me that if the clutch was the problem, then I should be hearing some grinding when trying to shift to other gears. But I cannot even move the shifter along the Neutral path let alone trying to get into other gears. Because Neutral is locked out it seems to be something with the forks.

 

[used red MN]

Yes, that was a bad answer I gave in the first reply. I
am not familiar with utilities at all. If the cover the
shifter is in is out in the open and not a lot of things
are in the way of pulling it off that is what I would
suggest. Just beware that things will have to be
aligned correctly when it goes back on. What is the
condition of the fluid in the rear end. Is it milky? If so
have you ever tried to crack the drain plug slightly to
see if water come out? I am thinking you may be having troubles with rust in there. I will attach the CNHI parts
diagrams for your tractor. You should be able to see a
bit of what you are getting into. I have a couple of web
pages that have links to Utility repair manuals. I know
often a lot of the models are the same with only minor
differences, maybe those would be helpful to you. I will
email them to you.
CNHI IH 434 parts diagrams

 

[JimB2]

Hi, shifter rails probably out of position, I have attached a couple pages from my service manual. It does not mention the 434 as it was not marketed in the USA only in Canada, UK and other countries.
434 is just the next newer model of the B414.

It is a PITA to lift the top cover of the transmission on a B414/434 but possibly remove the gear shift lever and work through the hole to align the shift rails.
The knob on the end of the gear shift lever that fits into the slot in the shift rails could be worn down and requires building up.

See photos of pages from Service Manual below.

 

[JimB2]

For your PTO engagement problems, see the link below as the one in the link is the same design just a newer model number.
Make sure foot rest is not bent up, clutch pedal adjustment.

See photo below:

PTO Engagement Problems

 

[550Doug]

(quoted from post at 09:03:48 07/22/22) For your PTO engagement problems, see the link below as the one in the link is the same design just a newer model number.
Make sure foot rest is not bent up, clutch pedal adjustment.

See photo below:

<img src=https://www.yesterdaystractors.com/cvphotos/cvphoto131129.jpg>
PTO Engagement Problems

Thank you for all the info and diagrams. I'll get back with what I find.

 

[used red MN]

What is shown as 6 in JimB2s diagram is an expansion plug. They are are on both sides of the shift tower ..volcano shaped.. part the gearshift goes in. They contain pin 19 that passes through the shifter and acts as a pivot. To remove the shifter as he proposed you will need to drill a hole in one of them and then insert a metal screw to pop it out with something like a vise grip, claw hammer or crow bar. When you get that one out drive the pin over to push out the other one and remove the shifter. You seem to be a user and not a restorer so when you put it back in just put a dab of RTV on the hole you drilled to seal it will be fine. New ones can be found at auto parts stores.

 

[550Doug]

(quoted from post at 22:17:17 07/21/22) Hi, shifter rails probably out of position, I have attached a couple pages from my service manual. It does not mention the 434 as it was not marketed in the USA only in Canada, UK and other countries.
434 is just the next newer model of the B414.

It is a PITA to lift the top cover of the transmission on a B414/434 but possibly remove the gear shift lever and work through the hole to align the shift rails.
The knob on the end of the gear shift lever that fits into the slot in the shift rails could be worn down and requires building up.

See photos of pages from Service Manual below.


<img src=https://www.yesterdaystractors.com/cvphotos/cvphoto131111.jpg>

As suggested by 'used red MN' I checked the pin that holds the shifter in place and found that the expansion plugs had been removed by the previous owner and never replaced, so it was easy to move take that pin out. It was obvious that some water had entered there so I cleaned what I could and then sprayed WD40 all around. I put the pin and shifter back in and I now have Neutral unlocked.
.........TOP....R....2....4
...Neutral---------------
BOTTOM....1....3

Moreover, I now can shift into R, 1, 2, 3 but NOT 4.

From the given diagram it must be rail #23 that is the problem. Should it move forward or sideways? Dare I try poking at it through the top hole where I remove the shifter? I am quite happy to leave it as is since I rarely used 4th gear.

 

[550Doug]

OK, the swivel shaft, #19 in the diagram above, goes through a collar in the gearshift lever #8, and this collar is meant to swivel. It was seized. So with a little heat and some hammer persuasion, it now swivels and I now can shift into 4th gear. Now to seal that shaft either with the right plugs or silicone
Thanks for your help.