Another tranny slipping post...

[wildmanscout]

I'm stumped! Transmission begins to slip after a few minutes operation until it won't go at all. After a short wait, all is well again (for a few more minutes). At first, I thought something was cooling down during the wait, but I now know that 30 seconds with the engine off and the transmission works again, flawlessly (for a few more minutes).

Particulars:

-1997 FZJ80 with 140K mi
-Submerged the truck a year or so ago and had the ATF flushed at Jiffy Lube (Pink on stick, but water did not raise the fluid level above the "add" mark).
- No problems until a few days ago. Using DIY method from MUD, I replaced 46 qts of ATF tomato soup until almost clear red.
- Added a quart of Rislone Transmission tune up. Same symptoms.
- Adjusted throttle cable in and out a few turns, but only made it worse (longer delay time before engagement).
- Edit: No difference with PWR switch on/off, OD on/off, 2nd Start on/off Xfer in Hi/Lo range, CDL on/off
- Edit: Sat in driveway shifting though the gears as the engine warmed up. Noted between 1 and 2 seconds delay before engaging N-D or N-R (as observed by drop in rpm) until water temp on scangauge2 reached 170 degrees and then steadily increased to 5 seconds at 185 degrees. Shut off engine for 30 seconds and the 1-2 second delay is restored for about 3 minutes when it goes back to 5 seconds delay N-D or N-R.
- Edit: Tried connecting shopvac to the trans filler tube in attempt to clear possible blockage in transmission breather/tube, but only sucked out some ATF. No change in symptoms.

The only post I could find with on again, off again symptoms was, https://forum.ih8mud.com/80-series-tech/134226-tranny-woes.html , but he ended up getting a new transmission and doesn't respond to PM. I'd like to think that if the transmission works intermittently, it's not a catastrophic failure. (Optimist, I know)


Any theories?


Could suspended water boil forming an air bubble that circulates until it vapor locks the pump, then with engine stopped, bubble rises past the pump and it runs until the bubble circulates around the system and arrives again at the pump?

 

[97 4runner]

Check the linkage to the throttle body just to rule things out. mine was slipping badly and my cable had all but broken off.

 

[wildmanscout]

Check the linkage to the throttle body just to rule things out. mine was slipping badly and my cable had all but broken off.

Thanks -- I just double-checked. The cable is not frayed and moves in and out when the cruise control cable is manipulated.

 

[CJF]

Does it do it no matter what gear/position the shifter's in? Does it do it with the center diff locked?

 

[wildmanscout]

Does it do it no matter what gear/position the shifter's in? Does it do it with the center diff locked?

It makes no difference whether Xfer is Hi or Low, CDL locked or not, PWR switch on/off, OD on or off. I tried all those before walking/ hitch-hiking home to come back with another truck and snatch strap. After hooking up the strap, I started the motor to have brakes and steering only to find that the tranny was working. It wasn't until much later that I discovered that only 30 seconds with the motor off was enough to make it go again.

 

[jonheld]

I replaced 46 qts of ATF of tomato soup until almost clear red.

What does this mean?

 

[wildmanscout]

What does this mean?

Tomato soup = pinkish opaque fluid vs. clear red

The water in the transmission from being submerged did not raise the level on the dipstick past the fill mark, but one flush evidently did not eliminate that water. The color of ATF on the dipstick after the first flush didn't hint at the milky tomato soup fluid that filled the bucket until nearly through the fourth flush at 12 quarts each after the slipping began.

Each quart you add mixes with the other 11 via the torque converter as a quart is pumped into the bucket. So, after multiple flushes, the fluid is now red (not pink) but is still not perfectly clear.

 

[dosruedas]

I'm interested in this too. My truck is driving great- gets me from Salt Lake up to Park City a couple times a week and running strong. But... every once in a while (3 times now in the several months I've owned it), and every time when I stop hard, it revs pretty high when I accelerate again like it's stuck in 3rd and just crawls- if I let off the pedal for a few seconds or wait then it drives normally again. Fluids have been checked and topped when needed and the local shop said it looked fine to them. I'd rather fix the problem before I get stuck somewhere- but I'd also love to find out it's something minor so I can commit the $$ to getting a lift and some new shoes on her!

 

[wildmanscout]

Updated to mention that there is no CEL or trouble codes on my Scan Gauge-2.

Also, I'm puzzling on the best way to apply suction to the tranny breather tube (which I can't reach with my big hands) to verify that the breather is clear.

Edit 6/12: I haven't isolated the tranny breather, but I did apply suction with a shop vac to the transmission filler tube, which ought to suck on the tranny and transfer breathers. All I did was suck up some ATF -- no changes in symptoms.

 

[Livin_Loud]

I'm interested in this too. My truck is driving great- gets me from Salt Lake up to Park City a couple times a week and running strong. But... every once in a while (3 times now in the several months I've owned it), and every time when I stop hard, it revs pretty high when I accelerate again like it's stuck in 3rd and just crawls- if I let off the pedal for a few seconds or wait then it drives normally again. Fluids have been checked and topped when needed and the local shop said it looked fine to them. I'd rather fix the problem before I get stuck somewhere- but I'd also love to find out it's something minor so I can commit the $$ to getting a lift and some new shoes on her!

got this problem with my 93 fzj80. From all the research I have done, it points to the shift solenoids. FSM says that it will start in third if No 1 shift solenoid is dying.

when this happens, the OD light in mine is blinking but I haven't been able to count how many flashes yet.

 

[LUV24BY]

got this problem with my 93 fzj80. From all the research I have done, it points to the shift solenoids. FSM says that it will start in third if No 1 shift solenoid is dying.

when this happens, the OD light in mine is blinking but I haven't been able to count how many flashes yet.

x2 on this. My 93 A442 does the 2nd/3rd gear start every once in a while, I just drop the gearshift into L and it kicks 1st in, leave it there until it shift to 2nd and then I up-shift to D. This fixes it. I don't have the $$ to drop into new shift solenoids yet.

Did you try all positions on the gear shift and have the same result?


From my understanding, if you had water in the tranny and the the clutch packs absorbed the water, then filling/flushing with new ATF my be harder on the clutch packs if they were weak with all the new detergent in the new fluid. Just an opinion, could or couldn't be the case....

John

 

[Livin_Loud]

shifting into L and then manually shifting to D works for me. i've got the A442f as well. mine does it when it has been working hard in slow traffic. it's perfectly fine on the highways.

 

[wildmanscout]

From my understanding, if you had water in the tranny and the the clutch packs absorbed the water, then filling/flushing with new ATF my be harder on the clutch packs if they were weak with all the new detergent in the new fluid. Just an opinion, could or couldn't be the case....

John

Hi John -- Sorry I didn't see this note to me in your reply to Livin_Loud. The thing that has me stumped is that the truck drives perfectly for a few blocks after waiting 30 seconds with the engine off. Doesn't this eliminate clutch packs? Thanks, Paul

 

[Kernal]

Could a blocked filter/cooler/cooler lines cause these symptoms?? If you drop the pan and pull the filter take some photos; curious what they might look like.

 

[wildmanscout]

Could a blocked filter/cooler/cooler lines cause these symptoms?? If you drop the pan and pull the filter take some photos; curious what they might look like.

The truck is still just sitting until I can figure a plan of action that doesn't include taking it to the shop. I'll take some pix when I pull the pan, but I can say that the ATF was pumped into the 5-gallon bucket with no signs of being impeded. In the time it took to cycle the gears (20 seconds?) there would have been two quarts of ATF pumped out. This is with both hoses disconnected from the cooler, though, so not the same condition as with the hoses connected.

Edit: When the hoses are reconnected and it's a closed system, again, could there be a soft hose (somewhere) collapsing under suction and starving the pump? It sure would be nice to watch the pressure while this was going on! Does anyone know how to set this up on the Scan Gauge-2? It was my impression that the ATF is being "pushed" through the cooler and neither hose is under suction. Suction would have to occur on the low-pressure side of the pump, right?

 

[thestunts]

I've got this going on in my 94 a bit sometimes ... Will start using everyones suggestions.. not to hijack though, are the clutch packs replaceable ?

 

[wildmanscout]

Post Mortem

Well, I finally took it in for repair. To no surprise, the cause of death was water in the ATF, which dissolved the water-soluble glue that sticks the clutches. Apparently, this glue is and has been a standard of the industry. The single ATF flush after drowning was NOT sufficient! Clutch particles clogged the filter, losing pump pressure. Shutting off the engine allowed the particles to fall, until the engine is started, again, when the filter is again blocked.

While the transmission was removed, I had the PHH replaced and the XFER and diffs serviced. The XFER also had water, evidently sucked through the transmission filler tube? The whole repair was $2300 with a 1-yr guarantee.

Thanks for all the help I have received from this board. It sure is great to have my truck back!

 

[Tools R Us]

Well, I finally took it in for repair. To no surprise, the cause of death was water in the ATF, which dissolved the water-soluble glue that sticks the clutches. Apparently, this glue is and has been a standard of the industry. The single ATF flush after drowning was NOT sufficient! Clutch particles clogged the filter, losing pump pressure. Shutting off the engine allowed the particles to fall, until the engine is started, again, when the filter is again blocked.

A single flush can be enough. The keys are, doing it ASAP and thoroughly. IIRC it took 22 quarts to get all of the water out of mine. That was ~100K miles ago, recently had the pan off, for the first time from the factory and it is immaculately clean, nothing in the screen, etc.

While the transmission was removed, I had the PHH replaced and the XFER and diffs serviced. The XFER also had water, evidently sucked through the transmission filler tube? The whole repair was $2300 with a 1-yr guarantee.

Thanks for all the help I have received from this board. It sure is great to have my truck back!

The stock breather setup vents the trans, transfer and CDL actuator on the same vent tube. So, even if water only gets into the trans, the heat from driving evaporates some of the moisture and that vapor condenses in the other units. Watch the CDL actuator operation, it is likely that some moisture got into it. This may cause the grease to be degraded, rust to form, binding the unit. If it shows any sign of slow operation, etc, I would remove it, clean and relube, it's not a cheap unit, so not worth risking. I disagree with venting units together, prefer to have separate vent lines for each.