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09-28-2009, 08:39 PM #1
OT- Drilling a 4L60e Torque Converter
I have recently purchased a used 1995 Suburban and I'm looking to drain ALL of the fluid if for no other reason so I don't have to pump more or less $30 of Dexron 6 into a bucket to sort of purge the converter. I intend to use a 1/16 pipe plug so that hopefully I can complete the drilling and tapping while it drains to carry out the chips. Any good info on this procedure would be appreciated.
09-29-2009, 05:53 AM #2
What you want to do really isn't necessary when doing a fluid/filter change. If the fluid is that bad there are going to be other problems.
If you feel you must drill the converter make sure you don't drill anywhere where the lockup clutches are or the converter will fail.
One trick to keep the chips from falling in is to pack the tap in grease.
09-29-2009, 07:12 AM #3
I know it can be done.......but when my friend tried it It always leaked..... the metal it is made of seems too thin.... only 1 1/2 threads in the converter..... I don't see any need to change all the fluid. If the fluid is that bad It probably needs a rebuild anyway. The main thing is to change the filter, and the "fluid change" is you replacing the the fluid you lose when you drop the pan. I have herd of some trans shops that can disconnect the cooler and pump out and refill with the engine running but have never seen it done myself.
09-29-2009, 07:13 AM #4
I haven't ever drilled out a 4L converter, but we usta doo it all the time on the non-lockups. Usually a lock-up converter was the reason the tranny was in the shop to begin with.
But common practice for us back then was to drill near the stud area where the core steps out a bit and offers more material/clearance to the internals.
Also - we always used 1/8" pipe, but the 1/16" would prolly be better if you have access.
FWIW - I have been VERY impressed with the 4L tranny. Not much diff from the 700, ut OH MY what a diff in lifetime! (As long as you git that one valve back in the right direction.... )
Think Snow Eh!
09-29-2009, 09:03 AM #5
09-29-2009, 09:50 AM #6
Yeah - I believe that is a standard upgrade at rebuild time, but ours went to 225K before I had'ta tear it down.
Then I couldn't git it figgered out. Seems I turned a valve around when dooing the valve body. My manual didn't have a pic of that particular valve (diff yr?) and it really was almost indistinguishable one way or the other. Had'ta take it to a guy that did them everyday... It took him a cpl times to figger it out. (And he's the one that replaced the shell.)
...Only to have a thrust go out a yr later. Complete train wreck inside! (So much for the new shell. LOL!)
Bought a junk 700 and swapped in the guts and drove down the rd. That last time musta been maybe 90K ago?
WEhen I first tore into the 4L I figgered on seeing a hand full of selenoids and a cpl valves for line press and such and that's it. I mean - how much should you need if it's "Computer Controlled"? Boy - I koodn't'a been eny further from reality!
I still hafta question the need for all that complexity? I guess GM had more confidence in Hydromatics (ratt'cheer in Toledo - thank you very much!) ability to build good valving as Delphi's ability to map a good computer?
Think Snow Eh!
09-29-2009, 10:00 AM #7
just suck it out with a vac oil slurp?
09-29-2009, 10:27 AM #8
When the converter is not locked there is slippage from the motor to the wheel thus, not as many mpg. I believe they're trying to lock the converter as much as possible given the demand of the motor. Now they're puttin in 2 ecm's on some vehicles, 1 engine management, 1 transmission management.
When you look at the maze of vacuum hoses and wires it's a wonder it doesn't die sooner
09-29-2009, 11:56 AM #9
Thanks for the feedback, I probably am just making extra work for myself. I have pulled the cooler line to purge a few converters in the past, I just don't consider that very thorough unless I care to waste a lot of fluid and I'm not inclined to waste much Dexron 6 due to the cost. I'm also motivated by the fact that the mechanic for the previous owner did some incredibly stupid things like installing brake lines upside down such that in a turn the hose ran into the end of the sway bar, reusing old grease seals in the front hubs and adding dirty grease to what was already in there. This only a few of the things I've discovered, who knows what he may have poured into the tranny (it's red). Since Dexron 3 has become a multipurpose fluid I'm also not convinced it's ideal for GM trannys. GM now recommends Dexron 6 as replacement for all of their vehicles old and new and from what I've read Dexron 6 is a much improved fluid. I found an interesting website with pretty good photos of the 4L60/700
It looks like I can drill about 5/8 or so forward of the weld to be in the clear.