310SJ Delayed Transmission Engagement

[Ricardo Cotte]

Good morning all and Happy Holidays!

My 310SJ every once in a while doesn't move forward or reverse when initially started. Even after a few minutes.

If I let it warm up around 10 minutes at a slightly higher rpm than idle (1200 rpm) it resumes normal operation during the day. Also, if it coasts down in gear it will engage a bit sooner.

My weather here is warm all year long, I have changed the filter and top off oil in the ZF transmission and it improved for some time.

The question is: Is there a possibility of the pump draining and needing to prime up somehow? Could it be hardened seals and other stuff that needs to warm up to operate and seal pressure somewhere? And the most dreadful...is it a sign of impending teardown and overhaul?

This TLB has 3400 hrs and it is a 2012.

Other than that everything else tranny related works as advertised.

Thanks much for your comments .

 

[Diesel Dave]

Is the park brake slow to come off as well ?

 

[Ricardo Cotte]

Hello Dave an thanks for your reply.

No, the parking brake releases normally. No hiccups there. Only time I had an issue with parking brake was on an incline, oil level got low and it automatically engaged . It was a bit of a pain to get out of that situation having to level the machine with the outriggers. I put additional oil in the transmission and has not done it again in the same spot.

I don't have any leaks at least on the exterior.

 

[mg2361]

How about a machine serial number?

Any codes, active or stored?

When issue is happening, press and hold the menu button until you are in the "SERVICE MENU". Scroll to diagnostics/diagnostic trans/auto test solenoids. Press select and run the auto diagnostics. Does it pass?

If not, what failed? What code/s did it generate? If it passed, then:

If you raise the wheels off the ground, do they even try to move when transmission is engaged?

Does the transmission have plenty of pushing power when it is working (able to walk through the brakes in 1st gear)?

If you overfill the transmission by a gallon or two, does the issue go away?

If you have an extra transmission filter, remove yours and cut it open. Any debris in there? Broken bypass in the bottom? Might want to drain the oil and then look into the drain hole at the pump pickup tube. Any debris collected around it? Reach in with a screw driver and see if you can move it indicating loose hardware on the pickup.

 

[Ricardo Cotte]

Hello mg,

First, I must say I am very appreciative of your sure and informed responses to all forum members here. It is of huge help.

Serial is T0310SJABD212414

I will look up any stored codes. However, right now the little yellow booklet alarm light is not lit nor it comes on during the issue. I guess no active codes?

Yes, if I lift up the rear wheels off the ground, they spin very little at first until they eventually catch up with whatever ratio the transmission is in. Front or reverse. I have quit doing this out of fear of causing more damage by accelerating the engine/transmission without possibly having any clutches engaged but slipping and causing undue friction.

Transmission seems to have normal power after warming up. I have hilly terrain and fairly steep dirt roads and to my appreciation it climbs these OK considering the weight of this machine. I mean, when you shuttle between F and R engagement feels right and immediate.

I might try "overfilling" the oil if that is not a concern. Last time I had to add about 1/2 gallon. Don't have any visible leaks. But last time I changed the oil (it was kind of dark) and put an original new filter it corrected the issue. I might go the extra mile and perform your suggestion of peeking inside. I have a small borescope that could come handy.

Again, I must stress my gratitude to you and all other members that lend a hand helping to diagnose from afar. I guess this is kind of a sleuth work for you guys.

 

[Ricardo Cotte]

Forgot to add that oil and filter change was about 30-40 hrs ago. This machine is used occasionally and not doing any hard jobs.

Will also do the SERVICE MENU auto diagnostics. Didn't know about it. Thanks

Need to bite the bullet and buy the Test, Operation and Diagnostics Manual. The one I have on repairs is mostly useless. Just a bunch of pictures and non detailed procedures.

 

[Ricardo Cotte]

Hello mg,

See attached photos. I have a video of the stored codes but it was too long. So I wrote them down for your reference.

Solenoid diagnostics passed.

No active codes

 

[mg2361]

The solenoid test was performed while the machine was inoperable, correct?

That's a lot of codes. When in the "SERVICE MENU", you will have to ability to clear the codes. Clear them and lets see if anything comes back.

 

[Ricardo Cotte]

Okay, will go back and do it. Read somewhere else here in HEF your procedure to clear the stored codes. Thanks.

 

[Ricardo Cotte]

Did as you said. Cleared up the codes. Started up the engine and the transmission engaged in fwd. But immediately started to "slip?" and no movement. If you accelerate the engine it tries to move but there's no positive motion. NO CODES (active or stored)

Should I check oil level at warm idle, in Neutral? Or at shutdown?

 

[Steve Austin]

Warn at idle park brake on in neutral. Check both sides of dip stick sometimes these dipsticks will wipe on side of filler tube and give you a false reading appearing to be full.

 

[Ricardo Cotte]

Good morning Steve,

Thanks for your input. I have noticed this kind of thing with my Subaru engine oil dipstick too. You can measure oil level on one side and the other comes out clean!

As I went back to the 310 yesterday to erase codes (per mg2361 advice) I also checked the oil level. It is halfway on the arrow indicating full level. I will add some more oil (again) today and see if that does the trick. No visible leaks anywhere.

Not sure if overfilling it a bit will cause harm. Maybe an info request to ZF could be best?

When this happens no DTC shows on the monitor.

 

[Ricardo Cotte]

Related information I found on the ZF 4WG 94 Manual

 

[Steve Austin]

The cooling system for this transmission is designed for a certain volume of oil.
I have seem many of these units run a couple quarts overfill with no problem.
Your unit has a torque converter temperature sensor also. Just keep the cooler clean in front of radiator Always check between radiator and cooler for debris this is often missed.Check with engine at idle in neutral park brake on.

 

[mg2361]

When I suggested to overfill the transmission, I meant to overfill it only long enough to see if the shifting issue goes away. Then I would drain it back to dipstick level immediately after testing.

 

[Steve Austin]

MG2361 do you remember if the suction tube has a screen attached to it?

 

[Steve Austin]

Might want to consider poaching an oil sample kit and sending it off for analysts.

 

[mg2361]

MG2361 do you remember if the suction tube has a screen attached to it?

Yes, there is a non-removable screen attached to the pickup that can be seen through the drain plug hole. Maybe @JL Sargent can post the picture of his so ricardo can see.

 

[Steve Austin]

Checking the screen would be next step if haven't done so already.
If you have changed the transmission fluid than oil scan may not be accurate.

 

[mg2361]

I think I found it. It may not be the exact same trans but the pickup is similar. Here is the thread.