allison experts!! pull in high1st or 3rd low to help the c1 clutch

[Dragbear]

Hi everyone I am trying to get my brain around this C1 clutch and how to not tear it up again. I have allways pulled in 1st gear high range because we can not get a 3rd gear start to work on my 2009 lmm. I have the A50 controller so I had an A40 TCM programed for a 3rd gear start that I would swap for the A50 at the trac but I have one of the lmm os that will not accept the A40 TCM and goes crazy every time I plug it in. So I am stuck with 1st high range.

So I need so help to see if I am looking at the power flow through the Allison right.
C1 is 1st gear and also acts as a forward clutch to the other foward gears. C1 is applied in all forward gears.
So let's say I have my truck hooked to an object, my gear selection is high range first gear and it took 500hp to get the truck to move. OK the C1 clutch had to hold 500hp all by itself.

OK now I am not to sure about this next part.
I hook onto the same object but geared in low range 3rd. Now by doing this the affective gearing from the input shaft to the driveshaft is almost the same as 1st high range and will still take 500hp to get the truck to move. So the C1 clutch is still going to have to handle the same amount of power either way.

So I guess the million dollar question is how going to a 3rd gear start going to protect my C1 clutch.

Rick Abare

 

[MACKIN]

C1 is applied through all forward gears except 5th?

 

[JoshH]

C1 is applied through all forward gears except 5th?

It is off in both 5th and 6th.

 

[Dragbear]

The main issue is saving the C1
Is going to a 3rd gear start going to help
To me it looks like the same load either way
Rick

 

[mike diesel]

I would imagine your going to put alot more load on the c1's and c3's starting in 3rd gear compared to the load the c1's and c5's would see starting in 1st.

 

[JoshH]

3rd low is a lower overall gear ratio than 1st high.

 

[1pieceatatime]

3rd low is a lower overall gear ratio than 1st high.

By lower I assume you mean slower?


The "basic" answer to what I think the OP is asking would be "protecting" C1 with a 2.72:1 reduction ratio. Or am I lost?


And the next question for the OP, since I know roughly where you are from. Who built the trans and with whos parts?

 

[Sledheadxp800r]

Did you pull at the goshen stampede last week?

 

[durallymax]

If your trans is built and you do not do burnouts, you should make it through a season fine. Low range is generally easier on things. I pulled without a 3rd gear start and S472 with no issues.

 

[Dragbear]

I built the trany with the Raybestos power packs. I ran it all last year with no issues. I just installed 60% over injectors and the Goshen stampede was my first pull. It ran great with 2 first place finish and one 3rd in work stock. I always run 1st high range and do not lock the converter.
On my last pull of the weekend I decided to try it with the converter locked. On the pull I foot braked the rpms up a little higher before stating the pull and about 70' out I locked the converter. As soon as I hit the switch the motor dropped rpms then reved up and stopped and I had no forward gears only reverse.

Rick

 

[Harbin_22]

Didn't the latest EFI release give A50 tuning capabilities?

 

[dracing70]

You should " can" the 1st high range idea and stick with 3rd 4 low. You might get away with it a few times but high range is much more abusive on that tranny. I have pulled trucks with stock trannies for years in low range with no issues, not to mention the fact that yours is built it should work flawlessly in low range on the pulling track. However in high range you are doubling the force on your transmission. Figure out the third gear start and stick with low range

 

[1pieceatatime]

I built the trany with the Raybestos power packs. I ran it all last year with no issues. I just installed 60% over injectors and the Goshen stampede was my first pull. It ran great with 2 first place finish and one 3rd in work stock. I always run 1st high range and do not lock the converter.
On my last pull of the weekend I decided to try it with the converter locked. On the pull I foot braked the rpms up a little higher before stating the pull and about 70' out I locked the converter. As soon as I hit the switch the motor dropped rpms then reved up and stopped and I had no forward gears only reverse.

Rick

You had a stock charger/stock trans truck less than an inch off your pull. I'd say you have some dialing in to do with that Cheetah and those 60 overs. What kind of pump are you running?

Sent from my DROID RAZR HD using Tapatalk

 

[Sledheadxp800r]

Exergy stroker cp3 time :woott:

 

[DIESELMAFIAPER.LB7]

If your trans is built and you do not do burnouts, you should make it through a season fine. Low range is generally easier on things. I pulled without a 3rd gear start and S472 with no issues.

what do burnouts have to do with it? I've never hurt my c1s and done plenty of burnouts sled pulls , at least 100 1/4 mile passes and when I freshened up the trans they looked great just put them back in

 

[Sledheadxp800r]

I have close to 100 hooks on my street truck since the trans has been built and 35-40 on my puller both with 0 issues. Always run 4lo. Snapped 1 output shaft in my driveway trying to light the new charger one time though lol

 

[JakeBrakeIH]

I know of a friend 1st hand that pulled in 4 hi and ended up smoking his big dipper trans.

And in my LMM puller I used to start in 3rd gear 4 lo FWIW.

 

[Dragbear]

I am going to try and wire the trany to be able to lock into 3rd with a switch. We do it for the lockup on the converter with no issue so why not this. I can't find were any body has tried this but from what I see all I need to to do is supply a ground to the C solenoid.

 

[mike diesel]

Couldn't you just go into efi live and use the DVT function to hold it in 3rd gear? Or what ever gear you wanted..? Or does it not work that way? I've only messed with it a few times but it seems like it starts in and holds whatever gear you select.

 

[Dragbear]

We still have no control over the A50 tcm