Did some experimentation with the factor pin , A sonnax pin with teflon rings and my pin with o-rings .
I wish I had someone to hold cam but here is what I found, Applying the band vis 4th feed hole , tight seal using sonnax 4th servo
Stock pin with air release band release pretty much immediately (lots of leakage)
Sonnax on released still released pretty quick but not as quick (still good bit of leakage)
My stock pin with Green nytril o-rings, No observable leaks or sound, With air stop but maintaining seal to hole, The band did not release at all for the 5 minutes I held it sealed.

Additionally I did 300 apply and releases in a dry bore then removed to observe rings, Found no obvious signs of wear to the rings
My concern and doing the test was to determine durability and lifespan. Its my determination they are up to long term sealing and no roll issues as pin travel is very limited if clearance correct, In normal situations the rings would be well lubed and in real world even if over time they do wear worse scenario they do stop sealing and return to the condition you would see with just the pin which is how most are built and work fine,
But they do seal superior and I do feel this is a major leak to be addressed,
I have not done same test with an enlarge bore and pin but will at some point with and without o-rings.
But for now I am confident they are a good add on to reduce considerable leakage in the 4th circuit.

 

Note others are still welcome to add to this post with any ideas suggestions , it is open to all to contribute

 

@FranksCustomTrans

On your 2nd and 4th band clearance discussion.

Am I understanding this right, that when done correctly, the 2nd piston is contacting the pin, the spacer ring is contacting the 2nd piston, the 4th piston is contacting both the snap ring and the spacer ring, and the cap is contacting the 4th piston? All this, while the 4th travel (dial indicator on the cover and stroking by hand as to not compress the cushion springs) is set to preferred travel, let's say 70mil new and dry.

Also, I guess the cap is contacting the spacer ring? I don't have a servo in my hot little hands at the moment but I will this evening as my Sonnax pin is waiting for me.

 

sounds right, The idea is you want both the second and 4th servo as close at possible to equally contacting the band in the respective places with servo at rest then set overall clearance from cap , No more than the thickness of the snap ring in travel , Ideally though I set up with pump off and set to min with no drag on band when turning the rev drum by hand , Then once that is done check again with return spring installed it will actually open up a bit . So if it seems like its dragging just a hair ,But close, add the return spring and check again , Will likely be perfect then.

 

by teflon rings...you mean the 200r4 teflons that Vor recommends for the pin ? did you test the seals that come with the sonnax pin...cant remember the material of those

 

The ones that came with the pin .

 

A while back, I picked up a random "warranty return" 4L60E transmission and torque converter from a local junk yard for sixty bucks on a Half Price Sale Day. I knew the transmission would need a rebuild but I wanted to know more about the torque converter - stall speed, mostly. This TC still had its GM identity stickers and they didn't tell me much but I did eventually find the table below that was a big help. My "DCNF GM35CW" torque converter is listed on page 734, top left corner and there's lots of other useful torque converter knowledge therein. And not only about GM products.

This will help you when you find or are offered an unknown torque converter. The actual document is too large to post here but you can grab it at the Transtar link below:

https://www.transtar1.com/transtarin...​​

This site really seems to prefer viewing with viewer other than Chrome. The link works well with Edge. With Chrome, click on the catalogs link and it will take you to their torque converter catalog.


Rick

 

Link no good

 

I am going to pick up a core after work today to play with. Finally....I have been wanting to do this for a couple of years now. It's a 4l60e out of a 4x4 2001 Tahoe. Guy says no reverse or 2nd. $100.

Is there a way to speed up reverse engagement? Although it's a very minor thing compared to everything else to worry about, it annoys me. I come to a complete stop before shifting reverse, so instant would be ideal.

 

Remove the check ball at bottom of case, enlarge the feed for rev input and rev side of low rev clutch.

 

@FranksCustomTrans Thank you. Hopefully I will get to know this thing well enough to picture what you are talking about. I have only a very general idea. But that points me in a good direction. I am going to read / control F the Hydra-matic 4L60-E Technician’s Guide and search the huge well of knowledge on this site. It's really incredible.

Anyways - Here is the thing. I am really excited.

 

Here you go (the Left Side of the Image would be the Bottom-End of the Transmission Case):



-Marcello III

 

Thank you!! @vorteciroc

 

Simple do it yourself shift kit that will improve - functions - durability of any 4L60E that is in decent shape , Even stock . Just buy plate and do mods install.

 

Frank, are there different length 3-4 apply cages? I have a 4l79 drum I’m assembling and it looks like a good .050 travel of the cage before it even contacts the bottom apply plate. I can post a video if you like

 

No , You are actually supposed to use one of these , He used to send them with the drum. Some do use without but you risk the stand splaying out which i have seen happen, You can find them in 700r4 units and if you still need more you can add one of these also from a 700r4
Optionally you can do things with a lathe to accommodate but that is a bit to get into right now.

I have a personal preference for the smarttech drum by sonnax but that is a discussion for another day.

 

Yes the THM700-R4 uses different Height 3-4 Clutch Apply Cages/ Apply Fingers.
They have an Identifier Number/ Letter on them.

The one that we use for the highest amount of Clutch Plates, will have a Number "7" Identifier on it.


-Marcello III

 

Hmm interesting, I did know the very very early 700 had a slightly taller one but everything I have ever seen after 87 was even with the case lugs.
Learn something new every day.

 

thanks!!! I actually forgot about that plate. I’m glad you reminded me. I’ll pick one up from my parts place tomorrow if I can’t find one in my parts.

yes I could make something on the lathe, but I really don’t feel like it. lol. That’s time I could use doing something else. I gotta pick up a pump tomorrow from my parts pls e anyways.

 

I remember that