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What's the best practice for a 4L80E/4L85E trans?

Discussion in 'Chevy Trucks' started by mkwl, Feb 8, 2010.

  1. mkwl

    mkwl 2000 Club Member
    Messages: 2,361

    With a major storm on the horizon (hopefully :rolleyes:) I'm wondering, what is the best practice for helping the reverse (the notorious "weak link" on the 4L80E trannies) last longest? I've read on here that its best to shift (always after coming to a complete stop) from D to R, and R to D..... I've also read that its best to shift from R to 1, and 1 to R while plowing (I do driveways)... thoughts?

    I always use T/H when plowing, and did the R to D and D to R shift- is this best, or is the R to 1 best?

    Main reason I ask- I have several drives that I need to "back up" (in reverse) into- they're relatively steep uphill drives.... is backing up steep drives going to damage the trans any more than backing up lesser steep drives?

    What's the best practice to help get the maximum life out of these trannies (with immediate regard to the reverse)?

    Thanks,
    Matt
     
  2. chcav1218

    chcav1218 Senior Member
    Messages: 954

    I've always heard the going from R-1 is the best, and I do it to keep my speed down as well. I get payed by the hour lol
     
  3. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    A couple critical things Matt...

    1) Don't touch the throttle until you physically feel reverse engage. This give it a chance to firmly clamp the reverse band tight on the low/reverse drum but just as importantly also remove any/all slack from the drivetrain before power is applied. Shouldn't take but an extra second to be sure and will add life to the entire drive train.

    2) Avoid breaking and regaining traction repetitiously as much as possible, especially while in reverse. Spinning the tires and then gaining firm traction, losing it, and gaining it again places an immense amount of unnecessary stress on everything from the differentials all the way to the reverse band in the trans and to the torque converter. So avoid doing it as much as humanly possible. Wheel hop is a major no no also for the same reasons. So if you experience wheel hop (and again especially in reverse) GET OFF THE THROTTLE IMMEDIATELY. Nothing is harder on the drive train components then wheel hop, except for neutral drops.

    3) Monitor trans temps. Do what you have to to keep it at and below 200* as much as possible. It's not to say that it will immediately self destruct if it get to 210* by any means but the cooler it is the longer it will last.

    4) And of course as you know, be sure the tires are stopped before reverse is selected.


    When you lose a 4L80E it's either from being cooked or breaking the reverse band. And in most cases both of those are determined by the operator. Most broken/cooked drive train components are from operator inadequacies and throttle jockey's.
     
  4. mkwl

    mkwl 2000 Club Member
    Messages: 2,361

    Thanks for the tips, Mike. I always do my best to stop fully and let he trans engage before giving it throttle- I'd rather take longer than do a trans rebuild!

    So plowing in D or 1 is really okay, so long as its in T/H and I keep the trans temps low?
     
  5. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    You can plow in D and T/H as long as the runs are short enough for it to stay in 1st gear. But if you find it still wants to upshift to 2nd gear (even with T/H) near the end of a run when you'll be stopping shortly anyway, then you're better off to hold it in manual 1ft. This prevents the unneeded upshift, thus less wear. The less unneeded shifts the better off you are.

    Todays transmissions are intelligent but not for plowing and every situation during plowing. They still need knowledgeable driver input to make them most effective and prolong their life expectancy.
     
  6. Detroitdan

    Detroitdan PlowSite.com Addict
    Messages: 1,937

    B&B, I think what he is referring to is the back and forth of plowing, should you go all the way to 1st? I read the same thing he did, someone on one of these forums is saying that if you go from R to D, the reverse gear is still spinning and has to jar to a stop suddenly, but supposedly if you go past D to low 1, the reverse gear is stopped completely, and you can engage forward without wearing unnecessarily on the reverse gear, or band or whatever.
    I've been doing it wrong for many years apparently. Last storm I tried to shift into 1st, but I found it to be a huge PITA and I just couldn't remember to do it most of the time.
    As for shifting before it stops moving, I've only been guilty of that maybe a few hundred thousand times. Just get so tired or impatient that you get sloppy. It's a wonder my tranny still works, 173k miles with oversized tires, a big plow and generally a big load on the back. But it's tight.
     
  7. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Doing the R-1-1-R manually on very very short runs is beneficial to reverse band life due to the reduced cycling. I was the "someone" that you're referring to who posted that in another thread on a similar subject. The band is applied in reverse and M1...but not in D. So if you go from R to M1 instead of D the band will stay virtually applied the entire time between direction changes thus reducing the on/off cycling on the apply servo and band anchor lugs.

    Most guys simply don't like to do it due to the inconvenience. But then again so is a broken band during a snow event. It's all in how willing you are to do preventative actions.
     
  8. mkwl

    mkwl 2000 Club Member
    Messages: 2,361

    If it'll help save my trans, you bet I'll be doing the R-1-1R shift!
     
  9. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    I've gotten so used to the [1] - [R] - [1] shifting it's second nature. Sometimes find myself going from [P] to [1] when I won't be using reverse. Then I get grumpy at me for engaging the Rev/Low band when I didn't need to. But that's another conversation. :dizzy:
     
  10. stacks04

    stacks04 Senior Member
    from ct
    Messages: 119

    so glad i have an allison:)
     
  11. mkwl

    mkwl 2000 Club Member
    Messages: 2,361

    I still think the 4L80E is a good trans from what I've read- it was GM's heavy duty trans for many years until they started putting allisons in the DMax/8.1 trucks.
     
  12. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    That's a helpful post.......
     
  13. stacks04

    stacks04 Senior Member
    from ct
    Messages: 119

    his question was answered properly already.
     
  14. stacks04

    stacks04 Senior Member
    from ct
    Messages: 119

    yeah they are very good trans assm. the ratio of them on the road to the amount that get rebuilt is very low. atleast from what we have seen at the dealer here. the more recent models had a run of bad parts and were burning up pretty frequently, but compared to the amount we have sold in the last 10 yrs, its such a small fraction. every heavy duty up until the dmax had one since the 700 retired. maintenance is crucial to those i have found. keep it fresh and clean they will last. beat it to hell alot then your asking for an expensive rebuild.
     
  15. tuna

    tuna Senior Member
    Messages: 488

    This is good info ,I will be doing r-1 from now on. Thanks.
     
  16. t.i.b

    t.i.b Senior Member
    Messages: 140

    since we're on the subject i've got a ?. i plow roads and have always plowed in drive. my trucks got the 8.1/ally the temps between 200-215. should i plow in a different gear and are these temp acceptable for that tranny? sorry for the hi-jack.
     
  17. Evanbrendel

    Evanbrendel Senior Member
    Messages: 181

    i have a ? is there any matanince besides fluid change thats good for a 4l80 like a band adjustment by a trans shop or is that a set it once thing and it stays?
     
  18. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Plowing roads is slightly different but not too much as far as gear selection goes. The top gear you plow in depends upon the speed you need to travel. You want some RPM's so you're not lugging the drivetrain and in most cases 4th isn't used due to lower speeds, so D isn't usually the right gear position. But the Allison's are a little more intelligent so it may never upshift to a higher gear than whats needed anyway. However, if you're always in at least 2nd gear for any length of time (continuously)) use T/H also. This keeps the TQ fully engaged thus reducing heat buildup.

    200*-215* is about your maximum continuous "safe" working limit and is fine, just refrain from allowing it to climb much higher if your running DEX3 non synthetic fluid. The Allison's will live day in and day out running at 240* with no problem, it's the fluid that is the weak link and the first to fail.

    Every situation is a little different and that's why it's important for the operator to know the right and wrong ways of doing things to prolong trans/drivetrain life.
     
    Last edited: Feb 9, 2010
  19. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    No adjustments, just annual fluid and filter changes and proper driving techniques are all that's needed to keep it alive.
     
  20. t.i.b

    t.i.b Senior Member
    Messages: 140

    good to know, thanks.