MF30 Instant reverse tractor Sudden failed to move

[jkk04]

A couple weeks ago, my beloved 1970 MF30 industrial tractor suddenly failed to move forward or backward while scraping on the ground.

The tractor has Perkin AD204 4 cylinders diesel engine.

The tractor has no indication of any noises nor wrong movement before it happens.

Only I suspect there was no fluid circulation in the transmission internally causing no pump and no supply of the fluid to the torque converter.

I replaced the transmission oil pump because of the seal failure and fluid and sump filter 7 years ago.

Ever since the tractor works without any problem.

Again, I removed the sump pan and cleaned some sludge and filter then added new fluid.

I thought the sludge was to block the fluid circulation through the sucking pipe to the oil pump.

But it did not help.

So, I removed the 1/8" pipe plug at the top of the transmission then connected a PSI gauge for PSI testing according to the service manual.

The pressure gauge shows only 40 PSI.

It should be between 150 to 160 PSI.

Is the pump failing?

I replaced the OEM oil pump about 7 years ago and it has served me for the last 35 years that I couldn't give up this lovely tractor.

Any suggestion from savvy members in here will be much appreciated

Jkk

 

[MKinON]

It maybe that you broke the safety coupling that connects the transmission to the final drive, or that it just slipped back and became disconnected. You can check it through the PTO cover on the side of the case. It should have a cotter pin through one end holding it in place, forward and back. It's meant for easy removal and replacement. If you have a PTO and it still turns when you engage forward or reverse, that may indicate the coupling is disconnected or broken.

 

[jkk04]

It maybe that you broke the safety coupling that connects the transmission to the final drive, or that it just slipped back and became disconnected. You can check it through the PTO cover on the side of the case. It should have a cotter pin through one end holding it in place, forward and back. It's meant for easy removal and replacement. If you have a PTO and it still turns when you engage forward or reverse, that may indicate the coupling is disconnected or broken.

Thank you for responding.

Unfortunately, the PTO is not working either.

Thanks
jkk

 

[jkk04]

The transmission normal pressures range is 150-160PSI.

But the current pressure on the transmission is only 40PSI.

Does it indicate the oil pump failure?

Thanks again

 

[MKinON]

The transmission normal pressures range is 150-160PSI.

But the current pressure on the transmission is only 40PSI.

Does it indicate the oil pump failure?

Thanks again
View attachment 63813View attachment 63814

Since you have a manual, it should state what the possible problems could be and the next steps to repair it. At least most of mine do.

 

[jkk04]

Since you have a manual, it should state what the possible problems could be and the next steps to repair it. At least most of mine do.

The problem is that the service manual does not clearly describe what lower pressure means and what parts need to be replaced.

Splitting the tractor is quite a big job for an especially retired old guy.

That is the reason I need to pinpoint what needs to be done before splitting the tractorand need to be advised by savvy people like you.

Thanks again.

John

 

[jkk04]

Updating...
Split the tractor then discovered the torque converter main back plate for engine flywheel attached.
It is complete broken middle of section.
Unbelievable
Finding and waiting the answer for the plate through the local MF dealer.

 

[hymie2lt]

Looks like the plate is still available

 

[MKinON]

Odd that you didn't hear any kind of strange sounds coming from the engine area when it went. One would think there'd be a least some kind of grinding or rattle.

 

[JLMac]

Wonder if it had something to do with the dirty oil that was in it? By the way, nice tractor!

 

[Jim.ME]

Wonder if it had something to do with the dirty oil that was in it? By the way, nice tractor!

Back plate or flex plates the convertors mount to flex, fatigue, and sometimes break, happens across all brands (cars, trucks, and equipment) from what I have seen over the years.

 

[jkk04]

Yesterday was the day that I had the backplate from a local master mechanic at a tractor repair shop for free and installed immediately.

I contacted him for the problems then responded immediately that he has an extra set of plates and is ready to pick up.

I am waiting for a pump rubber gasket to be repaired completely.

 

[cdhunter]

I am following your post with interest, since I have a MF50E Powershuttle tractor I am going to have to split to replace a leaking seal on the input shaft of the transmission and I am an old goy too. Best of luck with the repair on your MF30! I used to own a MF30B and it was a sweet tractor.

 

[jkk04]

I am following your post with interest, since I have a MF50E Powershuttle tractor I am going to have to split to replace a leaking seal on the input shaft of the transmission and I am an old goy too. Best of luck with the repair on your MF30! I used to own a MF30B and it was a sweet tractor.

Getting old means nothing but losing some strength.

We still have the most life experience and knowledge than young people that we are proud of.

I have had my tractor for 35 years which is exactly half of my life.

I have taken care of her well and she has as well.

She is the best friend in my life.

I can't give her up or let her go,

That is the reason I am repairing her again to finish our life together....

Will update once completed.

Thanks for your input.

 

[jkk04]

I am following your post with interest, since I have a MF50E Powershuttle tractor I am going to have to split to replace a leaking seal on the input shaft of the transmission and I am an old goy too. Best of luck with the repair on your MF30! I used to own a MF30B and it was a sweet tractor.

Finally the tractor has been repaired and runs like a champion.

Actually, I couldn't align the engine and torque converter with the oil pump because of my carport floor wasn't leveled

So, I had to split the center housing and rearend again.

After that, I put the dolly with a hydraulic jack moving the transmission easily.

It was so easy to align and put together in a couple tries.

That was the only way to do it.

Now, I had to reassemble the center housing and rearend.

But still, I couldn't align them easily.

Finally, I found the right-side rear tractor needed to lift about 2" so I put the board under the tire then was available to assemble them.
It took almost 3 days to figure out.

It takes about 1 month to repair completely including 2 weeks waiting for parts.

and repaired the tractor myself 2-3 hours per day to assemble due to the age.

Probably and possibly, this is the last time I split the tractor in my life.