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Torque Converter Failure P0894 - Transmission Running Hot 4L85e

Auto Parts Guy

Auto Parts Guy

Full Member
Joined
Dec 3, 2021
Messages
413
Location
Greenville, SC
So we took our camper out for the first time with the Avalanche this weekend. Went to Devil's Fork State Park on Lake Jocassee, great time.

Only problem us the transmission ran quite a bit hotter than it should have and truck pulled the camper like garbage. Felt like it weighed 10k pounds.. I tried towing with T/H on and off, D, 3, and nothing was satisfying. I've always suspected there was a Torque converter issue with this truck, some noise at lockup/ unlock and higher temps on the trans temp gauge than expected, mainly while pulling.

But this trip confirmed it for me. Trans temp rode 195-205 down there (raining) and 210-230 on the way back. And I have the Tru-Cool 40k cooler, 4.88 gears, 180 degree thermostat, new severe duty fan clutch, and filter and 5-6 qts of new fluid installed not too long ago.

Camper is a 2016 Keystone Hideout 185LHS single axle weighing about 3370lbs dry, plus minimal gear. WD and anti-sway hitch installed. Should pull like a dream but it was white knuckle the whole way thinking the trans was going to blow up. I towed between 50-60mph most of the way.

I think I'm just going to have a local shop rebuild the trans and install a new converter. Any tips or upgrades to consider? Kevlar clutches? Also, is the TC supposed to lock up in 3rd gear? I have never seen it lock in 3rd. Locks fine in D but only 4th gear locks. I thought 3 and 4 were supposed to lock??
 

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why do you think it is TC and not tranny?
 
It seems to shift fine. But with the slight noise i hear going into and coming out of TC lock, the excessive heat, not the power i expect from the 8.1L & 4.88 gears while pulling, the P0894 code that wasnt there before this trip, I'm guessing torque converter. I'll get the trans rebuilt either way if it needs to come out. And I'll get the rear main seal replaced.

Just mainly wondering if there's any upgrades I should ask for while they're rebuilding. I'll ask the trans shop as well.
 
I mean could be the friction pack(s) in tranny or a clogged valve body... but I think you are on right path in taking it to a tranny guy and have them check it out.
 
Just got a quote for a remanufactered trans replacement for $4300 plus tax. Ouch!!
May be going with plan B. Not sure what that is yet..
 
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Auto Parts Guy said:
May go with a remanufactured transmission. Maybe ETE or Raman brand and R&R myself. Not sure.
Click to expand...

Check https://www.bestbuytransmission.com/4l80e-transmission
$2395.00 with a new torque converter.
I have used in the past, excellent company and more importantly, the transmission I purchased from them has been flawless for 5 years now. When I installed, it was amazing how much better the truck pulled it was like a new again (1995 Dodge 2500 Cummins horse trailer puller). Their prices are excellent, they remanufacture fixing factory "defects", includes a new torque converter, they warranty for 5 years or 100K miles, they ship you the new one to your installer or house, they pay return shipping for your core, smooth transaction.
 
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That is probably the best deal I've seen so far! I checked ordering one from Advance Auto Parts, looks like they use ETE for theirs, O'Reillys uses Power Torque. Those are both about the same $2400 price, but not as easy transaction and they charge the core plus shipping. Looks like most everyone has about a 4 week lead time though. I think for $2k savings, I'm gonna end up replacing it myself.
 
As a comparison, I was pulling mine at 70 mph and at times with a head wind with an 82 deg ambient temp. Ran 175-180 degrees while moving and spiked to 199 deg in stop and go through a few towns (no cooling from the trans cooler). With no incline or head wind mine will stay in OD (6th).
Good luck with your repair!
 
Thanks for the comparison. I'm guessing a newer AV with 6 gears but either way those are good temps for pulling. I'm expecting 175 max out of mine with this light camper. And i should be able to put her in D, click the T/H button and ride with no issue. I wish i took a picture when the needle was somewhere around 230 and I was barely going 45-50 on a straight road. Embarrassing actually.
 
Can someone with a 2500 see if their transmission torque converter locks up in 3rd gear? I know my 95 Yukon with the 4L60e does but I've never been able to 100% tell if this 4L85e does. Can be regular driving or towing, either are ok. Just wondering if it's actually supposed to or not.
 
So after excessive research, I finally pulled the trigger today. I called my local Advance Auto Parts and the guy said they use a company out of FL with great success. So for $2000 plus tax, I get the same thing everyone else offered only with an 18mo/18k mile warranty. The warranty wasn't too big of a deal for me since I'm the one doing the work anyway, and if it makes it 18 months, it will likely be good for longer.

Everywhere I looked I could find all sorts of bad reviews mixed with good reviews, so hard to know what to believe and made the choice pretty difficult. I think it just comes down to the dude actually doing the work on the trans you receive and the quality of parts used. Simple as that.

My close second was Best Buy Transmission. They were $400 more plus $75 residential shipping (couldn't pick up at Estes/DHL/etc). AAP offerred a 36mo/100k mile warranty for an extra $400 too. Everyone was also out 4-6 weeks and in some cases 10-12 weeks. And basically you get what you get as far as parts availability. Crazy.

They're supposed to ship in 3 weeks. So hopefully in that time, i can get everything out and ready for the new one to go in. Thats the plan anyway. Stay tuned. Plan is to do a few other things while i have her apart. I also need a rear main seal tool for the 8.1L if anyone has one I can borrow. $100 for the removal tool and $300 for the install tool. Ouch! May also do the T-Case repair where the chain rubs a hole in the case before i have that problem. Maybe trans lines, mount, who knows.

Still need to know about 3rd gear TC lockup if anyone can check for me that has a 2500.
 

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Auto Parts Guy said:
So after excessive research, I finally pulled the trigger today. I called my local Advance Auto Parts and the guy said they use a company out of FL with great success. So for $2000 plus tax, I get the same thing everyone else offered only with an 18mo/18k mile warranty. The warranty wasn't too big of a deal for me since I'm the one doing the work anyway, and if it makes it 18 months, it will likely be good for longer.

Everywhere I looked I could find all sorts of bad reviews mixed with good reviews, so hard to know what to believe and made the choice pretty difficult. I think it just comes down to the dude actually doing the work on the trans you receive and the quality of parts used. Simple as that.

My close second was Best Buy Transmission. They were $400 more plus $75 residential shipping (couldn't pick up at Estes/DHL/etc). AAP offerred a 36mo/100k mile warranty for an extra $400 too. Everyone was also out 4-6 weeks and in some cases 10-12 weeks. And basically you get what you get as far as parts availability. Crazy.

They're supposed to ship in 3 weeks. So hopefully in that time, i can get everything out and ready for the new one to go in. Thats the plan anyway. Stay tuned. Plan is to do a few other things while i have her apart. I also need a rear main seal tool for the 8.1L if anyone has one I can borrow. $100 for the removal tool and $300 for the install tool. Ouch! May also do the T-Case repair where the chain rubs a hole in the case before i have that problem. Maybe trans lines, mount, who knows.

Still need to know about 3rd gear TC lockup if anyone can check for me that has a 2500.
Click to expand...

BBT is in Boca Raton FL, wonder if that is who Advanced uses as supplier. Does it come with new TC as BBT does?

Re the rear main seal installer tool, can you get a loaner from Advanced Auto or Auto Zone (they have tool loaner programs). I did a quick search and I think you can get a way a lot cheaper than what you found.
 
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I think they use American Transmission out of Jacksonville. Comes with a new torque converter. I asked them about the tool and they don't have one for the 8.1L. It's different than the other engines. If you find one please share!
 
I started the tear down today..
Spent about 1.5hrs getting the truck on the lift and getting the rear driveshaft and driver side exhaust off pretty much. So much detail, even the oxygen sensors were a pain bc of the heat shield wrap. And i had to remove the PITA exhaust bracket in order to get the exhaust out. Had to use a breaker bar for the exhaust bolts.. Enough for today. I'll try and get the transfer case out next. But looks like there's nothing supporting the trans once i remove that t-case crossmember so I need to think what order to remove everything.


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Auto Parts Guy said:
I think they use American Transmission out of Jacksonville. Comes with a new torque converter. I asked them about the tool and they don't have one for the 8.1L. It's different than the other engines. If you find one please share!
Click to expand...

Sorry about the seal kit, previously just did a search and showed results but when I actually clicked into the links today, they are for other motors (bait and switch!). I did find this but I don't know the diameter of your seals, you can check, maybe it will work.

BTW, I think I'm in love with your truck! I could use a nice 2500 like that, sometimes the 1500 is a little lacking (of course once fuel gets back to "reasonable" cost...in two years).

 
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I'm sure that you will/can muscle through, maybe there's something mentioned here that will ease the pain. If you need/want another section, let me know.


​
Document ID# 825219
2004 Chevrolet Avalanche - 4WD​
​

Transmission Replacement​

Tools Required
J 21366 Converter Holding Strap

  1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical.
  2. Drain the transmission fluid. Refer to Automatic Transmission Fluid/Filter Replacement .
  3. Remove the rear propeller shaft. Refer to Propeller Shaft Replacement - Rear in Propeller Shaft.
  4. Support the transmission with a suitable jack.
  5. Remove the transmission mount nuts.
  6. Remove the transmission support bolts/nuts.1654894298751.png
  7. Remove the transmission support.
  8. Raise the transmission slightly and remove the transmission support from the vehicle.
  9. Remove the exhaust manifold pipe. Refer to Exhaust Manifold Pipe Replacement in Engine Exhaust.
  10. Remove the transfer case, if equipped. Refer to:
  11. Remove the transmission mount bolts and mount.1654894486241.png
  12. Ensure the transmission manual shaft is positioned in mechanical park.
  13. Remove the retainer that secures the cable to the bracket.1654894525862.png
  14. Remove the range selector cable end (2) from the transmission range selector lever ball stud (1).
  15. Depress the tangs and remove the cable from the bracket.1654894548296.png
  16. Disconnect the following electrical connectors:
    • Input speed sensor (1)
    • Output speed sensor (3)
    • Park/neutral position (PNP) switch (5)
    • Transmission (4)
  17. Disconnect the oxygen sensor (HO2S) electrical connector.
  18. Disconnect the wire harness clip (2) from the bracket on the left side of the transmission.
  19. Cut the tie strap to separate the vent hose from the wiring harness.1654894575463.png
  20. Remove the flywheel inspection cover.
  21. Mark the torque converter to flywheel orientation.
  22. Remove the torque converter bolts.1654894601985.png
  23. If equipped with a 6.0L engine, remove the exhaust hanger mounting bracket bolts and bracket.
  24. If equipped with a 6.0L or 8.1L engine, remove the exhaust hanger mounting bracket bolts and bracket.1654894678104.png
  25. Disconnect the transmission oil cooler lines. Refer to Transmission Oil Cooler Line Quick Connect Fitting .
  26. Plug the transmission oil cooler line fittings.1654894696582.png
  27. Remove the stud on the left side of the transmission.1654894883696.png
  28. Remove the remaining transmission studs.
  29. Install the J 21366 onto the transmission bell housing to retain the torque converter.
  30. Pull the transmission straight back.
  31. Remove the transmission from the vehicle.
  32. Flush the transmission oil cooler and lines at this time. Refer to Automatic Transmission Oil Cooler Flushing and Flow Test .

Installation Procedure​

  1. Install the transmission to the vehicle.
  2. Raise the transmission into place and remove the J 21366 from the transmission.
  3. Slide the transmission straight onto the locating pins while lining up the marks on the flywheel and the torque converter. The torque converter must rotate freely by hand.

  4. Notice​

    Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  5. Install the transmission studs.
  6. Tighten
    Tighten the studs to 50 N·m (37 lb ft).
    Install the stud on the left side of the transmission.
  7. Tighten
    Tighten the stud to 50 N·m (37 lb ft).
  8. Remove the plugs from the transmission oil cooler line fittings.
  9. Connect the transmission oil cooler lines. Refer to Transmission Oil Cooler Line Quick Connect Fitting .
  10. If equipped with a 6.0L or 8.1L engine, install the exhaust hanger mounting bracket and bolts.
  11. Tighten
    Tighten the bolts to 12 N·m (106 lb in).
  12. If equipped with a 6.0L engine, install the exhaust hanger mounting bracket and bolts.
  13. Tighten
    Tighten the bolts to 12 N·m (106 lb in).
  14. Align the torque converter to the flywheel.
  15. If reusing the torque converter bolts with a 6.0L engine, clean the bolt threads and apply Loctite 242 GM P/N 12345382 (Canadian P/N 10953489), or equivalent to the threads prior to installation.
  16. If reusing the torque converter bolts with a 8.1L engine, clean the bolt threads and apply Loctite 272 GM P/N 12345493 (Canadian P/N 1095348:cool:, or equivalent to the threads prior to installation.
  17. Install the torque converter bolts.
  18. Tighten
    Tighten the bolts to 60 N·m (44 lb ft).
  19. Install the flywheel inspection cover.
  20. Tighten
    Tighten the bolts to 33 N·m (24 lb ft).
  21. Connect the following electrical connectors:
    • Input speed sensor (1)
    • Output speed sensor (3)
    • PNP switch (5)
    • Transmission (4)
  22. Connect the HO2S electrical connector.
  23. Connect the wire harness clip (2) to the bracket on the left side of the transmission.
  24. Depress the tangs and install the cable to the bracket.
  25. Install the range selector cable end (2) to the transmission range selector lever ball stud (1).
  26. Ensure the transmission manual shaft is positioned in mechanical park.
  27. Install the retainer that secures the cable to the bracket.
  28. Install the transmission mount and bolts.
  29. Tighten
    Tighten the bolts to 25 N·m (18 lb ft).
  30. Install the transfer case, if equipped. Refer to:
  31. Install the exhaust manifold pipe. Refer to Exhaust Manifold Pipe Replacement in Engine Exhaust.
  32. Install the transmission support.
  33. Install the transmission support bolts/nuts.
  34. Tighten
    Tighten the bolts to 95 N·m (75 lb ft).
  35. Install the transmission mount nuts.
  36. Tighten
    Tighten the nut to 50 N·m (37 lb ft).
  37. Remove the support from the transmission.
  38. Install the rear propeller shaft. Refer to Propeller Shaft Replacement - Rear in Propeller Shaft.
  39. Fill the transmission fluid. Refer to Automatic Transmission Fluid/Filter Replacement .
  40. Connect the negative battery cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Engine Electrical.
  41. Fill the transmission to the proper level with DEXRON® III transmission fluid. Refer to Transmission Fluid Checking Procedure .
​
Document ID# 825219
2004 Chevrolet Avalanche - 4WD​
​
 
Many thanks for the instructions! I actually had my computer out tonight looking for them but ended up falling asleep so no progress tonight.

Thanks for the kind words! I love this truck and can't wait to get her back on the road working. I'll update what i decide on the rear main seal tool. Guess I'll get a better idea once the trans is out. I'll update this weekend hopefully!
 
Auto Parts Guy said:
Many thanks for the instructions! I actually had my computer out tonight looking for them but ended up falling asleep so no progress tonight.

Thanks for the kind words! I love this truck and can't wait to get her back on the road working. I'll update what i decide on the rear main seal tool. Guess I'll get a better idea once the trans is out. I'll update this weekend hopefully!
Click to expand...
Agree! That truck looks VERY nice, even on a lift :mad:.
 
Auto Parts Guy said:
Many thanks for the instructions! I actually had my computer out tonight looking for them but ended up falling asleep so no progress tonight.

Thanks for the kind words! I love this truck and can't wait to get her back on the road working. I'll update what i decide on the rear main seal tool. Guess I'll get a better idea once the trans is out. I'll update this weekend hopefully!
Click to expand...

Glad to help, just let me know if you need/want other sections or torque values.
 
Transmission is out finally. I worked on it another 3.5 hrs or so, about 5hrs total. Not too terrible. That top center bolt on the bellhousing was kind of a pain. Now to order some parts and wait for the new transmission to come in. Pretty sure rear main is leaking. I'll pull the flywheel off tomorrow. I decided not to use the trans jack for the transfer case. I just pulled it down by hand. Not too fun. I'll probably get some help when I re-install the T-case and trans just to be safe.

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Just took the flexplate off and i think its the oil pan gasket that's leaking. I'll clean it up later. But I hate to take that rear main seal out if it's not leaking. But i hate not to at the same time.. If I do, i would buy those tools, another $400.. Hmmm

Oil pan gasket looks pretty straight forward? Should be easier with the lift kit I think.

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Man, your truck is so clean compared to mine, I'm jealous! Thanks for the photos, I'm sure this will help us in the future.
I'm with you on the rear main seal but you know that you have to do it now. If you don't, it will eat at you everyday until either it holds good for a year or until Murphy's law kicks in about 15 days after you're done (at least that's what would happen to me).

That shifter cable, were you able to just pop it out of the bracket? On my previous truck it was not routed right over the bolts so I never had to get it out of the way to change the trans filter.
 
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