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80e Pressure Drop During 1-2 Shift = Cooked Clutches

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Old 03-20-2015, 05:45 PM
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The 60e and 80e dipsticks are different, and I'm surprised you could even fit the 60e dipstick because they are really quite a bit different in their bends and whatnot.

The trans was likely cooked therefore due to incorrect fluid volume, and also line pressure should be over 200, 180 sounds suboptimal to me. Ideal fluid volume is at the case/pan interface as Pat mentioned. This correlated to about .75-1" over the "full" line on my 80e dipstick.
Old 03-20-2015, 06:08 PM
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Originally Posted by GMCtrk
The 60e and 80e dipsticks are different, and I'm surprised you could even fit the 60e dipstick because they are really quite a bit different in their bends and whatnot.

The trans was likely cooked therefore due to incorrect fluid volume, and also line pressure should be over 200, 180 sounds suboptimal to me. Ideal fluid volume is at the case/pan interface as Pat mentioned. This correlated to about .75-1" over the "full" line on my 80e dipstick.
The dipstick TUBES are different between the 60 and 80 but the dipstick has the same part number.

Sorry, that was a config for the Flex Fuel Sensor. Try this one out Pat...
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Old 03-20-2015, 06:16 PM
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Yes, the tubes are what I meant (obviously).
Old 03-20-2015, 08:33 PM
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Originally Posted by GMCtrk
Yes, the tubes are what I meant (obviously).
I had an 80 tube on the first one and this one with a 60 dipstick. The first one that cooked was over filled too and it made no difference. Just a little while ago I put in an additional quart in and over filled by about 1/2 to 3/4", test drove and no improvement. Added another quart and still no difference. As much as I was hoping for an easy fix, the fluid doesn't seem to be the issue here or with the first one.
Old 03-20-2015, 08:45 PM
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If everything is mechanically set up correctly then, it sounds like a trans issue. Although FLT has a very good reputation on here. I trust Zippy's tune to be reliable.
Old 03-20-2015, 09:21 PM
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Originally Posted by GMCtrk
If everything is mechanically set up correctly then, it sounds like a trans issue. Although FLT has a very good reputation on here. I trust Zippy's tune to be reliable.
Yeah, I don't care what anyone says, Zippy is the man - he for sure knows these trucks inside and out probably better than anyone else.

Anyway, Chuck's tech did say they would offer me a full refund if I wasn't satisfied. As much as I hate to even think about replacing that trans again, it's looking more and more like that may be the route I'll be forced to take here. I've already spoke to Rossler about building me one and will probably pull the trigger on that early next week unless someone comes up with an easy fix for this.

I will say that FLT has been really good about standing behind their product, I realize **** happens and that's part of the game that goes along with going fast, I just wish it wasn't me all the time...just bad luck I guess.
Old 03-20-2015, 09:32 PM
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I wanted the most badass 80e there was and had the $$$ to spend, it would be Rossler. The name stands for itself. That being said, my Jake's hasn't given me any issues as it should, supposed to be good for over 1000 got everything in it short of a billet main shaft and transbrake.
Old 03-21-2015, 10:49 AM
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Originally Posted by GMCtrk
I wanted the most badass 80e there was and had the $$$ to spend, it would be Rossler. The name stands for itself. That being said, my Jake's hasn't given me any issues as it should, supposed to be good for over 1000 got everything in it short of a billet main shaft and transbrake.
I've never understood this.
People that have never even ran Rossler unit's give him undue credit.
I assure you, your transmission is as well built if not better than a Rossler.
I've been into the Rossler units, FLT units, RPM units, and about every other popular builder on the market.

I've been into them all because at some point in time, they all have issues.
There is no other company in the aftermarket performance transmission industry that builds as many 4L80E's as Jake's. Many other companies use parts from Jake's.

The FLT units I've been into appeared to be well done and with FLT's reputation I assume they know what they are doing. They at least didn't have a worn out pump like I've seen from Rossler.

To answer the OP's question. A pressure drop, ONLY on a WOT 1-2 shift, is a fluid pickup issue. PERIOD.
This isn't a build problem.
If the pressure stays steady under all other conditions but at WOT 1-2 (hardest acceleration) it drops, you either don't have enough fluid, or you have a fluid pickup issue from extremely hard acceleration.

We've seen OEM dipsticks off by 3 qts, and the junky braided steel aftermarkets ones off by more than that.

NO BUILDER can overcome low fluid level or other installation issue. It's beyond their control or responsibility.

If you don't verify your dipstick accuracy during install of the transmission, you can never check the fluid level properly.
This is a required step to proper installation and falls on the installer to check it. It does require removing the pan.
1/4" above the pan to case mating flange is where the warm running, full mark should be for a performance unit.
If you have a gauge on the vehicle, and watch the pressure (as you should on a new install), if it drops on a spirited drive, it doesn't have enough fluid or has a pickup issue. PERIOD.

Clutch type, pack clearance, steel type, use of a wavy plate, all has very little effect. These are just steps a good builder uses to have consistent results.
Old 03-21-2015, 10:56 AM
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A few more thoughts. 180 psi is adequate to hold 1000 RWHP if the hydraulics are setup properly.
The intermediate clutches are not the weak link in a 4L80E. Stock clutch pack will handle 1500+ RWHP with no changes.
The center support bolt isn't brass.
Old 03-21-2015, 11:15 AM
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What filter and pan are on this setup?


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