LML trans tuning here!

[bluessmax]

I would not check pressures with a transducer as they can be way off. A liquid filled gauge is preferred. I have never seen pressure any higher than 250 psi on an LML with the main mod disconnected. I tested a A50 TCM 5 years ago on my truck and saw 250 psi. I also saw higher temps with both these mods. Higher pressure will keep the trans alive longer no doubt; but you have shit clutches to begin with and converter clutch does not like anything above 800 ft lb of tq before the lining begins to break off.
I'll just keep doing things my way with building the trans.

Yea, when Brad checked with his liquid gauge he said hit and miss on some trucks, but he did see 280 as well... He stated same thing you did though- that some will hit relief and not make more than 250, while others will.

Regardless, we can run it to its max setpoint with a simple calibration. As you know (and I have stated a few times) this is NOT A REPLACEMENT for built trans.... but longevity will for sure go up with the pressure added. If someone is spending the money to get big power - plan on spending it on a built trans over time as well... but until then, I see no reason to not run a calibration that allows for higher line.

Thanks for your feedback, Mike. Always appreciated!:hug:

 

[bluessmax]

At what torque level do the stock trans clutches start to wear abnormally?

Also is the converter clutch applied with main line pressure?

Mine line stays constant locked/unlocked... So either way, all good.

Stock clutches im sure will start to wear at the 1000tq mark, but we have been making 1000ftlbs on LMLs for a few years and those trucks still going. So- even though they do get some wear, they seem to click along quite well. With that info, i feel pretty confident saying one could live a VERY long time in the 1000-1200ftlbs mark with higher line (At least our trucks and some of Brayden's still are).... but it is always wise to prepare for when power goes up, the wallet size to go down! :spit:

 

[Mike L.]

At what torque level do the stock trans clutches start to wear abnormally?

Also is the converter clutch applied with main line pressure?

The stock LML Allison runs at 80 psi ( main line ) constant and spikes to 220 psi on every up shift and downshift then drops back down to 80. Converter clutch applies at 220 psi also then drops to 80. At wide open throttle the trans will spike to 250 psi for about 5 seconds and drop back to 80 ( while still at WOT )
The clutches inside the trans and converter clutch are designed to work at a max of 250 psi. They do not like anything higher before they start breaking off.
The TCM will rarely cause limp as it will continue pulling power back til it is satisfied. I've seen it pull back 50 hp or better. The truck subtly just starts getting a little slower.
If by chance you are seeing 300 psi ( which I have never seen ); I would be worried about the pressure regulator valve being off ballance and restricting converter out passage in the stator. Simple fix is opening the hole in the bell housing plate. But then the trans has to come out.

 

[bluessmax]

The stock LML Allison runs at 80 psi ( main line ) constant and spikes to 220 psi on every up shift and downshift then drops back down to 80. Converter clutch applies at 220 psi also then drops to 80. At wide open throttle the trans will spike to 250 psi for about 5 seconds and drop back to 80 ( while still at WOT )
The clutches inside the trans and converter clutch are designed to work at a max of 250 psi. They do not like anything higher before they start breaking off.
The TCM will rarely cause limp as it will continue pulling power back til it is satisfied. I've seen it pull back 50 hp or better. The truck subtly just starts getting a little slower.
If by chance you are seeing 300 psi ( which I have never seen ); I would be worried about the pressure regulator valve being off ballance and restricting converter out passage in the stator. Simple fix is opening the hole in the bell housing plate. But then the trans has to come out.

Thanks for the info! Perhaps that was part of why we seen 300 spikes... Its nuts how low of pressure they run these things. I'm sure in hopes of mileage/heat. We haven't really seen any mileage changes with the higher pressure, roughly 10* higher temps, and shifts actually feel the same once it learns.

So its safe to say going from 80 to 250+ line is quite the upgrade and worth 300.00 in your eyes? This is why I like this forum, feedback from knowledgeable folks!

We actually have the ability to shut off the tables that pull power due to slip... but im sure they wouldnt last long for those that do not realize its slipping...

 

[ChargedTTq]

We actually have the ability to shut off the tables that pull power due to slip... but im sure they wouldnt last long for those that do not realize its slipping...

I have a feeling this is why the LML seems to "hold" more power... It just reduces wear at the times it happens to slip.

The clutches inside the trans and converter clutch are designed to work at a max of 250 psi. They do not like anything higher before they start breaking off.

So does this mean that the trans clutches have a similar torque capacity?

Trans tuning and a Precision converter to reliably hold 650 HP sounds pretty good... Especially as an incremental upgrade. Of course we all know nothing is for certain.... other than a Mike L built trans of course :thumb:

 

[bluessmax]

I have a feeling this is why the LML seems to "hold" more power... It just reduces wear at the times it happens to slip.



So does this mean that the trans clutches have a similar torque capacity?

Trans tuning and a Precision converter to reliably hold 650 HP sounds pretty good... Especially as an incremental upgrade. Of course we all know nothing is for certain.... other than a Mike L built trans of course :thumb:

Potentially... but I dont think so personally... Mine slipped like crazy on the old denali after miles of abuse and i never actually logged it pulling mm3. I have seen Mike say it does this - and I have seen the tables that are supposed to do it... but none of my logs have reflected it yet.. Maybe some trucks do and some dont... These LMLs are finicky.


Trans tuning and the converter is a very wise choice... Should hold for a long time... but be ready for the built trans when the time comes!

 

[Mike L.]

I have a feeling this is why the LML seems to "hold" more power... It just reduces wear at the times it happens to slip.



So does this mean that the trans clutches have a similar torque capacity?

Trans tuning and a Precision converter to reliably hold 650 HP sounds pretty good... Especially as an incremental upgrade. Of course we all know nothing is for certain.... other than a Mike L built trans of course :thumb:

Capacity is the same. If you do this, keep an eye on the sump filter.

 

[Evan@InglewoodTrans]

Results will very greatly depending on the beginning condition of the transmission. However condition aside some just plain hold up better then others. The design of some the LML internals has a lot to with how well they hold power. The c3/c4 apply is much better then older years. If the friction material was better they would be real winner. There will always be fluke stock transmissions also. I know of a few CC/SB LMM's running mid to high 12's with just a converter and transgo Jr and have been for a while but that doesn't mean they all will.

 

[duramaxzak]

How would this compare to Ben's pressure box? or pretty much the same? Is this tuning ability available to all tuners?

 

[bluessmax]

How would this compare to Ben's pressure box? or pretty much the same? Is this tuning ability available to all tuners?

Its pretty well doing the same thing as far as pressure goes... Maybe Ben can chime in, but the biggest thing is us maxing out Main control.... I'm pretty sure Bens box does basically the same manipulating the Amperage to wide open.

 

[bluessmax]

Results will very greatly depending on the beginning condition of the transmission. However condition aside some just plain hold up better then others. The design of some the LML internals has a lot to with how well they hold power. The c3/c4 apply is much better then older years. If the friction material was better they would be real winner. There will always be fluke stock transmissions also. I know of a few CC/SB LMM's running mid to high 12's with just a converter and transgo Jr and have been for a while but that doesn't mean they all will.

Thanks Evan... I look forward to learning more. Also Thanks for the call this morning - The knowledge you guys have is nuts!

 

[ChargedTTq]

How would this compare to Ben's pressure box? or pretty much the same? Is this tuning ability available to all tuners?

From what I know bens box holds 250psi at all times when the box is turned on. And that's all it does. No shift point changes.

Korys tuning varies pressure based on load so it will make the transmission run cooler and saves a little.bit of fuel.

 

[ChargedTTq]

Capacity is the same. If you do this, keep an eye on the sump filter.

So what would a guy be looking for? Flakes? Gunk? What color material?

 

[Ne-max]

hey Mike. How is the torque converter going to like 650 horsepower? is that converter good to use in a built trans under 600 horsepower on the earlier Alison's?

 

[Mike L.]

hey Mike. How is the torque converter going to like 650 horsepower? is that converter good to use in a built trans under 600 horsepower on the earlier Alison's?

It's not going to like it. The LML converter is loose as a goose and you will blow right through it if you have a tune in it.. It was left loose to make sure the LML turbo would spool at high altitudes.

 

[Chevy1925]

So what would a guy be looking for? Flakes? Gunk? What color material?

if you see things at the bottom of the pan besides fluid, you have a problem.

 

[02CCSB]

Hmm that doesn't look like an Allison gear train...

 

[bluessmax]

hey Mike. How is the torque converter going to like 650 horsepower? is that converter good to use in a built trans under 600 horsepower on the earlier Alison's?

I highly recommend a suncoast or one of Mikes converters... Ours are all still hanging in there, but I highly recommend getting a nice converter.

I have some customers with over 50 12 second passes and daily driving/towing though on stock converters (Anthony Piaska, Burt reed, etc.)

 

[duratothemax]

From what I know bens box holds 250psi at all times when the box is turned on. And that's all it does. No shift point changes.

Korys tuning varies pressure based on load so it will make the transmission run cooler and saves a little.bit of fuel.

That is not correct.

My module can be put in two modes...

Mode 1 is max pressure all the time, regardless of throttle % and load. This is if you know you're going racing or something.

Mode 2 is fully automatic and will vary line pressure based on throttle % and load.

Effectively my box is identical to kory's tuning as far as line pressure control goes.

My line pressure box does not change shift points and does not change converter lockup....but you can pair my line pressure box with a lockup controller and do the same thing.

Hope that clears it up.

 

[bluessmax]

That is not correct.

My module can be put in two modes...

Mode 1 is max pressure all the time, regardless of throttle % and load. This is if you know you're going racing or something.

Mode 2 is fully automatic and will vary line pressure based on throttle % and load.

Effectively my box is identical to kory's tuning as far as line pressure control goes.

My line pressure box does not change shift points and does not change converter lockup....but you can pair my line pressure box with a lockup controller and do the same thing.

Hope that clears it up.

El correcto! Your box kicked butt on my old Denali... You were ahead of the curve for sure!!