Gilbert@Ace Racing

We recently disassembled a 2001 F-Body 4L60E that had been brought to us with the intent of taking advantage of our Stage 2 / SS Converter sale. One complaint of rpm fluctuations at highway speeds was mentioned as a side note. The fluid looked good. There was no pungeant odor. There were no trouble codes. The unit had been well maintained.

Because this unit was sooo clean otherwise, I thought it could easily serve as a demonstration of how these units can have seemingly minor symptoms but actually be hurt and in need of internal repair.

This unit is not representative of what we ordinarilly see when we open them up. But boy, can we learn from it! It would not have been long before this customer lost his 3/4 clutches entirely.

Here are a few pics of the unit immediately after teardown. It is now ready for a detailed inspection.




We have not opened this filter, and probably will not. It looks very good. Again, well maintained.


This is what was in the pan. Some clutch debris. No metal debris at all.




Examples of how clean it is otherwise...

The 4-pin input planet assy.


The 4-pin output planet assy.


Here is the valve body plate with the 2 filter/screens as they looked upon disassembly.








Here are all of the clutch packs... the top left clutch stack is the 3/4 stack. Ordinarilly it is a dark color as they are a different material than the other clutches. But these are defiantely hurt.


The following oics are of a "blistered" 3/4 steel. This is what happens when the clutches slip on acceleration.





So, for now you can clearly see how the fluid would appear to look good and smell good. But indeed there is clear evidence of the 3/4 clutch slipping. In this case it was caught well before excessive damage occured to other components. This could be considered to be a transmission that would live for some time in a non performance environment. However, when it sees a WOT 2/3 upshift there is no doubt it would slip and subsequently fail prematurely.

I hope this thread help some of you guys understand what we are talking about when we talk about slipping 3/4 clutches when everything else is apparently just fine! Unfortunately in these 4L60E's it is not an uncommon occurance at all.

I'll post more of this unit and some good comparators as I have the time.

g

Arc00TA

iTrader: (17)

That looks just like mine, I was driving home normally and the 3/4 went out, took it apart and it was all clean inside, fluid red etc. My question is, will just a flush of the TC be ok and good to go when I get a new trans?

Gilbert@Ace Racing

I would think so. But it is always best to have it opened up for inspection. A local converter shop could do that for a nominal fee. I think it falls under "better safe than sorry".

I would not really be converned about excessive debris as much as I would the converter clutch itself being damaged. Most likely the clutch was engaged when the 3/4 clutches were slipping and therefore it could have been compromised.

g

cablebandit

iTrader: (37)

i'd **** if my fluid looked like that in my 4l80e.
Nice to see one JUST before it gives up so you can see what/how stuff is wearing.

(i didnt forget about you on the converter..just had many more important things come up than my car)

donkey mule

Good pics and educational, thanks for posting that.