1969-JD400 Oil leak

[Brokk]

My apologies if this posts twice. I posted 5 hours ago and it hasn't shown up yet.

I have a new oil leak at the bottom of my engine. There is a hole with a bit of metal sticking out. It's been there since I bought the tractor 9 years ago. There is often a dollop of oil hanging there when I look, but I have never seen it actively dripping until this week. It results in a fist sized oil stain on the driveway within 2-3 min.



1) Any idea what that hole and metal bit is? (circled in red)

2) What are the best steps to fix this leak?

I am hoping no one tells me I need to pull the engine out...

 

[Zebrafive]

Hard to tell in your picture, is that the clutch housing?
Metal could be the head of a cotter pin. Put there by JD to keep "mud dobbers" from closing the hole.


Have you determined if engine or hydraulic oil? If it's the clutch housing, and engine oil, I would suspect the rear engine crank seal.

 

[Brokk]

It does resemble a cotter pin.

It is not hydraulic.

So the hole is there as a way to allow condensation to drain out during normal operations? Looking at the manual, it does look to be the clutch housing.

Yeesh... I just looked at what was needed to replace the rear engine crank seal. I have to disassemble a hefty chunk of the tractor, including removing the engine and front end. I'm not even sure how I would support the sections or lift out the engine. That's a big job.

 

[Tx Jim]

Engine doesn't require removal to R&R rear engine crankshaft seal. Tractor would require a split between engine flywheel housing & clutch housing similar to R&R of disconnect clutch.

 

[Brokk]

Engine doesn't require removal to R&R rear engine crankshaft seal. Tractor would require a split between engine flywheel housing & clutch housing similar to R&R of disconnect clutch.

Hmmm... Service manual starts by instructing you to pull off the front end, then pull out the engine. That would give you plenty of room to work on the seal. If you separate the flywheel housing from the clutch housing... Something has to move forwards or backwards. Or are you saying you are basically splitting the tractor (like they were doing for the front end and leaving the engine and clutch housing on the front and the flywheel housing on the back?

 

[Tx Jim]

My knowledge is limited about JD industrial tractors due to I was employed by an Ag only JD dealer. If you have a JD tech manual then that's probably more correct than my memory.

 

[Brokk]

My knowledge is limited about JD industrial tractors due to I was employed by an Ag only JD dealer. If you have a JD tech manual then that's probably more correct than my memory.

I believe the JD400 was built on the body of the Ag2020. So it should have a lot in common with them.

The service manual starts by telling you how to take it apart in chunks. Taking off the front, then the engine, then the clutch housing. They keep working their way back all the way to the PTO. However, it would seem silly if the only way to work on something on the back end, was by starting at the front and removing everything until you reached the back. I'm not sure if this book is just offering you guidance at a high level, then more detail at a lower level, or if it is the Gospel, one true way to do things. I'd rather get the answer from someone who has experience doing it.

 

[Zebrafive]

Tech manual may say to pull the engine verses splitting, due to being an industrial tractor.
The loader mounts maybe much more work to pull than an AG tractor.
Same as Tx Jim, I have only dealt with small AG utility tractors, not the Industrial versions.

I did replace the rear crank seal on my JD 2030, years ago, when I replaced the clutch, since I was almost there. It took a special tool to install the seal, which the Service Manager of the local JD loaned me. Probably would not happen today, they were bought up by huge JD "mega" dealer and he has since retired.

 

[Brokk]

I did replace the rear crank seal on my JD 2030, years ago, when I replaced the clutch, since I was almost there. It took a special tool to install the seal, which the Service Manager of the local JD loaned me. Probably would not happen today, they were bought up by huge JD "mega" dealer and he has since retired.

The manual refers to a JD 251 Driver tool, as well as a JD 251 Plate. Is that the special tool?

I took a closer look at what holds the tractor together. You mention removing the loader. Looks like there are 6 arms that hold it on. I was thinking if I set the bucket up off the ground, there would be enough room to pull the front end forward, but I'm not sure how far apart I need to separate the tractor to do the work. Also it has a backhoe which is really quite large/heavy. Should I plan to remove that first so that I don't have to worry about all that weight pulling down the back?

Of course the service manual makes no mention of the loader or backhoe, as they are officially attachments, although from what I've read the vast majority of these models were sold with both of those attachments as standard.

While I can see good places to hold up the back of the tractor, I don't see obvious solutions for the front, especially as it feels like the back will be standing still and the front will need to be moving/mobile. Also, There is a limit to how far apart I can separate them because of the hydraulic lines which attach under the front of the tractor. I suppose I can disconnect all of them as well though.

Similar to you... Once I have it apart do you think I should plan to replace the clutch? I'm not sure if it's the clutch of the reverser that is giving me some large play in the motion. Sometimes when I have shifted it into gear and let out the clutch, there is a delay before power seems to go to the wheels. This feels more common using the reverser, going back/forth though.

 

[Tx Jim]

Yes JD 251 driver & plate is a special tool usually supplied to JD dealers by OTC.

Back when I served as a JD dealer service manager for 13 long yrs we split JD tractors & rolled the back 1/2 by rotating rear tires. The tech's drove/pushed tractor forward into their stall then when unbolted roll back 1/2 out towards aisle. There's a serial # break at ENGINE SN 36276. Lower serial # seal is T20326 @ $450 & later engine SN seal is RE24959 @ $30. I've read where tech's have replaced flywheel housing with later style or re-machined old flywheel housing to accept later style cheaper seal. I think FEL frt mounting bracket can be unbolted from frt tractor support.

Some hyd reverser have a modulation valve that can be adjusted to decrease/increase harshness of the reverser shifting.