Tractor Repairs

If you have a question you would like to ask the Bob, Ken or Kevin please feel free to send an e-mail to kuhns@antiquetractorsrus.com . Anyone of them will be happy to answer any question you may have. However the guys are busy in the shop so I (Maggie) will be typing for them.

A WORN SHIFTER TURNED INTO A TRANSMISSION IN TROUBLE

Project:
TOP SHAFT SYCHRONIZED TRANSMISSION (TSST) REBUILD

Tractor:
1970 JOHN DEERE 4000

Engine:
D404

Ken wanted to make sure that everyone knew from the beginning that this is a job for a professional. It will take some special tools and since this is a Synchronized Transmission it will be tricky. Ken has been working on tractors all his adult life and said this is the first time he has had to rebuild a Synchronized Transmission on a John Deere 4000. He has rebuilt synchronized transmissions on John Deere 4020’s and John Deere 3020’s as well as on other tractors, so he knows what he is doing. That just goes to show you that the learning process never stops.

THERE ARE MANY SAFTY ISSUES IN THIS PROJECT SO PLEASE BE VERY CAREFUL. IF YOU DECIDE TO ATTEMPT THIS PROJECT.
SAFTEY ALWAYS COMES FIRST IN THE SHOP!

The first thing we did is to remove the rockshaft covers, sheet metal and the floor. Then Ken drove it onto the cement pad for a wash. Washing the tractor is important so the mud or manure do not contaminate the parts and inside of the tractor.

Wash your tractor first

Then he removed the 3-point hitch housing, bucket loader, seat, fenders and any other attachments that were on the tractor that was in the way.

Note: Make sure you keep all your bolts and hardware separate and labeled so they don’t get mixed together. This was there is no guessing when you go to put it back together.

Keep your parts separate with a tuna can

Disconnecting and draining all the hydraulic lines and electrical lines to the back end of the tractor is the next step. Make sure that you label your lines as to where they go and what they are connected to. Green painters tape works great for this.

Label your lines with tape like Kevin is doing

The next is to split the tractor. Split it between the transmission and the clutch housing.

The John Deere 4000 split

NOTE: Remove the shifters and the transmission pump.

When that is done you can remove the top shaft itself. This has to be disassembled in a press.

The next part is the trickiest, removing the Synchronized shaft. This is the cluster at the top shaft. That is why it is called a Top Shaft Synchronized Transmission (TSST)
Things do tend to fly apart if you arre not careful. This is a safety hazard area of this job so PLEASE be careful.
To do this successfully, pull the collar apart VERY SLOWLY!!

Now you can start to look for the problem. Look for things like chipped teeth, a worn synchronize clutch, or broken or worn bearings. Also check the shift forks to see if they are worn, broken or if they missing parts.

NOTE: While the trans. pump is out, it should be disassembled and inspected carefully. This is a problem area on all “new generation” John Deere’s. If it needs to be replaced NOW’S THE TIME!!

Carefully check the shifter cam

Check for worn detents or worn cam grooves.
Check the teeth and shift collars on the bottom shaft.
On this particular tractor they were good so he did not have to pull them out.

Your next step is to make a parts list

On the John Deere 4000 our parts list consisted of

Multiple Gaskets and seals
New spring for shift detent
All new snap rings in top shaft itself
New Reverse shift collar
High Sync drum
Shift lever which was repaired in the shop by building it up with weld to repair and then painting it so no rust accrued

While this tractor was split and torn down the customer also had Ken replace the load control seal and repack the cylinder for the loader.

Back together

What you should do and what Ken did was check the end play when you reassemble it.

SPECIAL TOOLS NEEDED FOR THIS JOB

Tool for holding the detents in shift collar this tool is cone shaped. This tool pushes the detents into the holes inside the shift collar As the collar is installed on the shift hub.

A press to disassemble and reassemble the top shaft.

WHAT TO WATCH OUT FOR ON YOUR TRACTOR

A “Traveling Shifter”. This is when the shifter travels too far and it is partially pulling the tractor back out of gear. Watch the transmission as you move shifter to see it moves into gear or if it actually comes back out part way.

DIAGNOSIS

Worn shifter parts. Causing an over shift and the tractor to jump out of gear. This caused damage to the shift collar and the gears.

PREVENT A VERY NORMAL PROBLEM

To prevent this very normal problem as soon as you notice it seek help.
You will notice jumping and grinding like it is coming out of gear after it is in gear. Correct this problem ASAP or risk and more costly repairs to the transmission itself.
If you suspect you have a worn shifter put your tractor in gear and wiggle the shifter. See if it stays in gear. If it doesn’t stay in gear have it looked at.