4L80E & TH400 Tech.

[softballnrd27]

I am hoping for the best but planning for the worst:
98 4l80e just under 100k, very little metallic "dust" in the pan and the fluid seemed ok when I drained it. It is currently installed in my 73 with an 04 5.3 in front of it to replace the tired th350 that was in it. I want it to work just fine but in case it doesn't is this a transmission that I can rebuild without any prior experience rebuilding transmissions? I would rather do it myself to save the extra money for a good converter.

[clinebarger]

Originally Posted by softballnrd27

I am hoping for the best but planning for the worst:
98 4l80e just under 100k, very little metallic "dust" in the pan and the fluid seemed ok when I drained it. It is currently installed in my 73 with an 04 5.3 in front of it to replace the tired th350 that was in it. I want it to work just fine but in case it doesn't is this a transmission that I can rebuild without any prior experience rebuilding transmissions? I would rather do it myself to save the extra money for a good converter.

In my opinion they are easier than 700R4/4L60E units, Think of it as a TH400 with a few more parts. I have a few tricks to make it easier on you if the time comes.

[Mrturner1]

So I have a th400 in my 70' c10 and I have the engine out for rebuild, and I want to do a couple things to the transmission before it all goes together. The truck is driven for fun, and should be around 400hp when I'm done with a 2600rpm stall ) gonna be fun. I got a new adjustable modulator, a new filter, and a stall converter for the trans. I also got a deeper pan and autometer temp gauge.

I want to make the 1-2 shift as hard as possible (love it when the tires chirp and screach when it hits 2nd) and I'm wondering how to accomplish this without a shift kit. It would bark 2nd now and then before the tear down, but I want it to be consistent and much more firm.

I'm keeping the old fluid for the re-installation, and topping off with new if need be

Thanks guys
Matt

[clinebarger]

Block the 2nd Accumulator....The Inner bore is where the 2nd Accumulator piston rides, There is a feed hole at the bottom of this bore. Using a punch, Drive a .250" checkball into the feed hole below flush.
The arrow is pointing to the hole, I don't have a clear photo of the actual hole because I never thought I would have to tell someone how to do this... If you need a better picture? I'm in the middle of a 4L80E build & can snap a pic.


Block the 3rd Accumulator like I already covered in this thread.


Drill out the 2nd (Red circle) feed orifice out to .200"
Drill out the 3rd (Yellow circle) feed orifice out to .200"



********I DO NOT recommend doing this! You are getting the advise you want, Not so much what you need, When this trans breaks it's solely on you*********