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I wired in the 2 relay version and tested it out, the first test went 2500 and made 130kpa, the second test the car started creeping forward. I have lowered the 2 step to 2500 and haven't tried it again. Is there anything in the tune that needs changed, line pressure or something to hold it? Here is the tune, which probably has other issues but it seems to drive ok, I don't think the guy who tuned it did anything with the trans, its a Roush base with some tweaks here and there. Thanks
20 bar line presurre? :confused:
Is that too much? what should it be?
20 bar is twice over stock
You can probably say bye bye to your seals - clutches are slipping because you are not holding pressure, some seals are blown probably.
Full line pressure the trans can only make as much as the line pressure solenoid at zero duty cycle will allow, which happens to be the same thing as being in limp mode unless it was somehow modified to make more. I don't think it will blow out the seals. Mines at 265psi knock on wood.
You don't really need that much of line pressure - 15-16 bar is the max that you will ever need.
I had one 6R80 to repair recently in my shop - had blown bushings and seals due the high "tuned" line pressure. I found few shot end plugs in valve body as well.
Something is leaking internally in his trans already.
That 300 psi was max, the scheduled pressure was not over 220
And it seems to hold when the trans temp is lower
Clear and classic indication of internal leakage - fluid is much thinner at higher temps thus it holds better when fluid is colder/thicker.Quote:
Originally Posted by lencomatt
I rebuild this transmissions quite often - bushings, seals usually. Center support has a design flow which we were able to solve.
I have a few questions. I recently installed a Tbrake on a customers car. Car is daily driven very short miles (about 10 a day is what he said) and its city driving. Not driven hard or raced very often. He also opted for a minorly agressive trans tune. After getting a base tune on the car (important to note that I had NOT touched the trans at all) I noticed that same as lencomatt. The Tbrake held fine at lower temps but after about 20 minutes of cruising down the road to fill out some tables I noticed the Tbrake started to slip. Any reason why this would happen on a stock tune (trans portion stock; obviously not the whole thing)? The car was previously tuned by Lund before it came to me and the car was flashed to stock before I got to it.Quote:
Originally Posted by veeefour
Those stock seals and bushings(especially bushings) are so bad they can leak excessively form factory. Lund tunes are very aggressive on trans so this can progress rapidly.
Don't get me wrong - automatic transmission are designed to leak but only at specific rate. ZF likes to seal everything directly on bushings which is fundamentally flawed.
So, is this considered 'normal' for a stock tranny? All the V6 cars I have done don't slip at all.Quote:
Originally Posted by veeefour
6R80 for V6 has different converter and different clutches.
I see, let me rephrase and ask a different question then.Quote:
Originally Posted by veeefour
Is this normal for the 5.0 and is there a way to get around it, without pulling apart the trans?
Yes with Line Pressure, TCC Release and Capacity Intercept parameters.
Awesome, Thank you.Quote:
Originally Posted by veeefour