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



## mkwl (Jan 21, 2005)

With a major storm on the horizon (hopefully ) 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


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## chcav1218 (Jul 31, 2008)

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


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## B&B (Nov 4, 2006)

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.


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## mkwl (Jan 21, 2005)

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?


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## B&B (Nov 4, 2006)

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.


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## Detroitdan (Aug 15, 2005)

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.


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## B&B (Nov 4, 2006)

Detroitdan;992943 said:


> 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.


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.


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## mkwl (Jan 21, 2005)

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


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## 2COR517 (Oct 23, 2008)

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.


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## stacks04 (Jan 22, 2008)

so glad i have an allison


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## mkwl (Jan 21, 2005)

stacks04;993325 said:


> so glad i have an allison


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.


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## 2COR517 (Oct 23, 2008)

stacks04;993325 said:


> so glad i have an allison


That's a helpful post.......


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## stacks04 (Jan 22, 2008)

2COR517;993383 said:


> That's a helpful post.......


his question was answered properly already.


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## stacks04 (Jan 22, 2008)

mkwl;993360 said:


> 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.


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.


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## tuna (Nov 2, 2002)

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


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## t.i.b (Jan 17, 2009)

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.


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## Evanbrendel (Jan 2, 2010)

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?


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## B&B (Nov 4, 2006)

t.i.b;993563 said:


> 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.


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.


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## B&B (Nov 4, 2006)

Evanbrendel;993650 said:


> 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?


No adjustments, just annual fluid and filter changes and proper driving techniques are all that's needed to keep it alive.


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## t.i.b (Jan 17, 2009)

good to know, thanks.


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## Kris_Kris (Feb 7, 2010)

I was very careful with my 4L85E. Always waited feel it go into gear before I gave it any power. Plowing or not. Only screwed up a couple of times. But I never plowed with the T/H on. At 120K I learned that the E is for expensive. I had a shift kit installed during the rebuild. It shifts fast and firm now.


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## papa (Dec 12, 2007)

I have an 01' with a 6.0 so do I have this trans we're talking about?

if so. is it best for me to use the T/H mode while plowing. the truck has a 3.73 rear


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## Detroitdan (Aug 15, 2005)

stacks04;993325 said:


> so glad i have an allison


I've heard bad things about Allisons. Such as, if you bump up the horsepower a significant amount, the Allison will fall out of the truck and run home crying. I've also heard they are annoying as hell to plow with because they won't back up fast. I like to back up way faster than is prudent.

When I was towing my company was a vendor for Ryder and Budget rental, I used to tow 24 ft International 4700s with broken Allison 1000s all the time. They were absolutely fine up to their GVWR, but if you overloaded the truck to any degree the tranny would fail just like a fuse.

So, I'm sure the Allison is nice, what with all those forward gears and everything, but they are not the strongest tranny in the world. I think I'll stick with my old reliable 4180e for now. Been pounding it for years and it still works perfectly.


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## Kris_Kris (Feb 7, 2010)

papa;994333 said:


> I have an 01' with a 6.0 so do I have this trans we're talking about?
> 
> if so. is it best for me to use the T/H mode while plowing. the truck has a 3.73 rear


Yes, you do and you should use the T/H when plowing. It increases the clutch pressure and changes the shift points.


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## mkwl (Jan 21, 2005)

I've been using the R-1-1-R shifting for this storm, and so far, my trans temp has stayed lower overall- I'll be using that shift pattern from now on!


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## B&B (Nov 4, 2006)

Detroitdan;994348 said:


> I've heard bad things about Allisons. Such as, if you bump up the horsepower a significant amount, the Allison will fall out of the truck and run home crying. I've also heard they are annoying as hell to plow with because they won't back up fast. I like to back up way faster than is prudent.
> 
> When I was towing my company was a vendor for Ryder and Budget rental, I used to tow 24 ft International 4700s with broken Allison 1000s all the time. They were absolutely fine up to their GVWR, but if you overloaded the truck to any degree the tranny would fail just like a fuse.
> 
> So, I'm sure the Allison is nice, what with all those forward gears and everything, but they are not the strongest tranny in the world. I think I'll stick with my old reliable 4180e for now. Been pounding it for years and it still works perfectly.


Think I detect a little jealousy there. What does an overloaded 24' Ryder truck have to do with a 2500/3500 pickup? Is that what it takes to downgrade a guy plowing snow with a pickup truck that just happens to be equipped with an Allison? Doesn't matter anyway as a 4700 IH would use an AT545 or A2400. Neither of which has anything to do with an A1000 in a pickup truck.

An A1000 in a 10K GVWR truck is plenty. Far more robust than any stock 4L80E. Wonder why an 80E was never available behind a Dmax? Because in stock form they won't hold up. Couldn't even get one behind an 8.1 in anything but a Sub or Avalanche. 8.1 pickup's and C+C used the Allison.

I'll assume stacks original comment was geared toward the fact that there's much less to be concerned about to keep an Allison alive. They run cool when plowing, don't need to be babied with their backup redundancy and failsafe controls and there's no worries about keeping the bands alive.... because there isn't any.


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## B&B (Nov 4, 2006)

Kris_Kris;994424 said:


> Yes, you do and you should use the T/H when plowing.


Not always, depends on the situation. I've covered that several times in past threads if you dig around a little.


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## mkwl (Jan 21, 2005)

Alright- Question... I have 1 driveway which is a steep (probably 25% uphill) uphill drive, about 250' long with the garage door at the very top. My question is- am I better off (in terms of keeping the drivetrain happy) to push the snow uphill in 1st gear? Or am I better to back up (with the blade up) the drive to the garage door, then plow the snow downhill.

Reason I ask- am I going to prematurely "wear out" the reverse band by backing up such a steep slope with the plow mounted? Or would I be better off doing this, versus pushing 1,000+ Lbs of snow up a 25% slope?

Up to now, I've been backing up the hill and pushing downhill.


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## mkwl (Jan 21, 2005)

I should also mention- I was thinking about using 4LO for this drive, but am a little leery about popping it into LO, as I've never used 4LO and am worried I'll try to get it in/out of LO and something'll go wrong. Last thing I want to have happen is find out my 4LO doesn't work and be stuck stranded in a snowstorm :crying:

Is there any chance of my trying to use 4LO and the chain in the t-case pops off or something along those lines?


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## 2COR517 (Oct 23, 2008)

mkwl;1011732 said:


> I should also mention- I was thinking about using 4LO for this drive, but am a little leery about popping it into LO, as I've never used 4LO and am worried I'll try to get it in/out of LO and something'll go wrong. Last thing I want to have happen is find out my 4LO doesn't work and be stuck stranded in a snowstorm :crying:
> 
> Is there any chance of my trying to use 4LO and the chain in the t-case pops off or something along those lines?


I use 4LO on some steep drives. No comparison on how much easier it is on the truck. The chain won't pop off in LO unless it EXTREMELY worn. And you would know that by now. Low range is provided by a very simple and durable planetary gearset at the front of the trans. If you've never uses Low Range on your truck, try it near the house sometimes. Trans needs to be in neutral. Truck should be fully stopped, or rolling just slightly. If it's pushbutton, just hit the 4LO button. Doesn't matter if you are in 2HI or 4HI. There should be a little clunk and it will go right in. Sometimes the gears won't mesh unless you are moving a little bit. Shift technique for the floor lever is similar. Trans in neutral, truck barely moving, nice quick and smooth shift from 2HI to 4LO. Do not stop at neutral.


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## Kris_Kris (Feb 7, 2010)

Unless i have to do a lot of backing ( long distance) I always run low range. Aside form the obvious reasons, you get more power from your alternator from the higher motor RPM


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## snowman682 (Aug 8, 2009)

When in 2 hi or 4 hi, the transmission is the spot that all the torque is transfered. When in 4 lo, the t case takes all the torque. I have an 03 2500, 151000 miles, 8 foot v hanging on front in the winter, trailer on back in summer. Never had an issue with t case. If I am going to work the truck pretty hard, i dont hesitate to put it in lo. Deep snow, steep drive, or alot of drives close together. Plus the trans temp stays pretty cool whin in lo. Just my experience>


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## partsguy08 (Sep 1, 2008)

I have done a drive similiar to the one you are describing for years. I back all the way up and push down everytime. I feel it is harder to control the push (this drive has some turns in addition to trees and a drop off) and harder on the drivetrain if I push all the way to the top. jmo.


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## 2COR517 (Oct 23, 2008)

snowman682;1011807 said:


> When in 2 hi or 4 hi, the transmission is the spot that all the torque is transfered. When in 4 lo, the t case takes all the torque. I have an 03 2500, 151000 miles, 8 foot v hanging on front in the winter, trailer on back in summer. Never had an issue with t case. If I am going to work the truck pretty hard, i dont hesitate to put it in lo. Deep snow, steep drive, or alot of drives close together. Plus the trans temp stays pretty cool whin in lo. Just my experience>


Hmmm. I always thought the torque was transferred through the entire driveline, and ultimately the tires.

Guess I better go back and study.


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## mkwl (Jan 21, 2005)

It always does fine in 4HI (knock on wood), so I'd assume the chain isn't worn too badly. I'll probably give 4LO a shot in this next storm because this hill is STEEP and I don't want to create unnessicary wear on the truck...


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## snowman682 (Aug 8, 2009)

yes the entire driveline takes a beating in four lo, it just saves a ton on the trans when you run in low, as long as you time your shifting right. Not much room for off timing in lo! It is a catch 22, either the trans, or the rest of the drive train. Somethings going to take a beating.


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## B&B (Nov 4, 2006)

If the drive is very steep low is a good idea, not so much to reduce band stress (as it's the initial application or wheel hop that takes them out as I've mentioned in the past) but it reduce stress on the low/reverse clutches and especially the torque converter.


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## mkwl (Jan 21, 2005)

Thanks for the info guys- I'm still a little leery about using LO, but I think I'll still give it a shot to see how it does... I just don't want to be stranded :crying: with a broken t-case....


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## mkwl (Jan 21, 2005)

Well, I used 4 LO during this last big storm we got with around 16-18" and...



























It worked GREAT! I can't believe I never used it before- adds torque like no other- feels like the truck could push down a house! I'll definitely be using LO on some of my trickier drives from now on!

Thanks for the advise guys! :waving:


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## Sydenstricker Landscaping (Dec 17, 2006)

I started doing the r-1 1-r thing now when plowing. Works real nice and I can feel a little difference in it. Although I already formed the habit and find myself taking off out of my drive or a parking spot in 1st, lol Didnt really do much for trans temps since I have a big a$$ cooler out front, synthetic fluid and the line pressure/shift points changed with the tune. I only use 4lo when we get wet heavy snow on my bigger places or when I am stacking a big arse pile. Otherwise I have never had an issue in 4hi.


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