700R4 & 4L60E: Reverse Input Drum Deep Dive

I take you on a deep dive into the reverse input drum for 700R4s and 4L60Es including a review of the different designs over the years, changes to the contents, interchange rules and go through a couple of stack ups.
This video will be helpful for anyone getting into these transmissions for the first time, those having to swap drums on an early 700R4 or who is simply interested to learn more about them in general.

[@jchaire3622]

Another great informational video. Keep them coming. Job well done sir.

[@nickstransmissions]

Thanks, JChaire! Will do...

[@josecarreira8934]

Nicely done NICK great bit of knowledge tips and tricks on the reverse input drums.

[@nickstransmissions]

Thank you, Jose! Appreciate the viewership.

[@hybridmusclegarage4590]

Awesome info as always!!!

[@nickstransmissions]

Thanks again, HMG!

[@jraydelatorre]

Excellent information I’ve always been told to be careful not to use a square hole drum where the round hole once existed. And my question was to those that told me this was what changes do I need to make in order to use the square hole drum in place of a round hole but no one can answer that they just said don’t do it and said do not use a transmission that had the small round hole, those were not desirable units now I’m extremely confused. Maybe I should ignore those people regardless of their experience. I’m starting to think now the issue is in the selective plate and the piston bore size.

[@nickstransmissions]

Thanks for watching Jray. When you say you're confused about what drum to use or not use, I'm not sure what you mean... the video explains why the ATSG manual tells you not to use the round hole 2nd design drums when the unit came with early square hole...Perhaps re-watch starting at 21:20 where I cover this specific issue in detail. Has nothing to do with the piston and bore size, unless you're meaning to say folks were telling you not to use the aluminum piston with the early square hole drum - if so, they're correct as the aluminum pistons simply won't fit into those early drums.

[@royatthestar3279]

The square hole drum can be used in any transmission any year with no side effects whatsoever. You can use the late drum in anything as long as you enlarge the hole as to take away the orifice. This information can of course cause a bit of a harsh reverse, But for simplicity's sake it is good information.

[@jraydelatorre]

@@nickstransmissions yes pretty much what you’re saying and I think the other issue was the selective plate or trying to use the Belleville plate where the wave plate used to live. I’ve never tried it. I was just warned about using or reusing the drum with small round hole. and to replace it always no matter what and never to use it in any other model or years even if it is a good one if it has the small round hole, avoid it that’s what I was told. Then I have four or five of these transmissions that I’m planning on rebuilding and putting back together someday soon and I think two of them are pre-87,84 through 86 maybe one of them had the both of them had the small round hole and when I was wanting to buy the drums, I could not get them and the guy told me that if I use the drum, I’m gonna get myself in trouble and have issues with reverse. But that’s OK man I’m watching all the videos and taking notes and when I get ready even though I have all this experience it’s easy to make mistakes because I don’t do it but just once in a while I wanna do it so I’m gonna be watching taking notes as I said, when the time comes to buy the parts, I’ll get what I need and do it right

[@nickstransmissions]

Gotcha...The main takeaway when it comes to using the different drums are is that the latest design, part number 24245624 is what you want to purchase for any 700R4 or 4L60/65/70E regardless of year. So, when you rebuild all of your 700R4 and/or 4L60E transmissions, purchase 24245624 (Reverse Input Clutch Housing). To your other point, if someone were to mix/match cushion plates (waved or belleville) with the incorrect version of the clutch discs then they will likely end up with either too much clearance or not enough. Hope that clears things up for you - let me know if you have any more questions.

[@fluffnstuff15]

the blue plates are from a factory performance 4l65e they also came with 5 pinion planets.

[@nickstransmissions]

Are you saying blue plates are found in the production 4L65Es or their off the shelf 4L65s, 70s and 75E Supermatics?

[@fluffnstuff15]

as far as I know like the factory performance ones like in a chevy ssr. As far I as know/seen even the steels in the reverse drum are rhe blueish colored one which there is no benefit to this because most people ain't putting power down in reverse. Only thing I can think or is maybe forr towing like reversing a heavy trailer. BTW I also have a hoard of factory steels drums etc laying around and when I find something I that is kind of unusual I keep it as well. keep up the good work there's nobody that goes in depth like you do for this particular trans and many people put these together not knowing these things like differences in pump reverse drums ect and end up in trouble and that's what gives this trans a bad name for some people. when they are great transmissions and super reliable had then been built correctly. have s good one though.

[@nickstransmissions]

Interesting, I have never seen any Raybestos blue plate frictions in any 4L60/65/70s but will keep an eye out for them...All the 4L65s and 70s I've done had the usual 7-clutch BW HE frictions; I do like the Blue Plates for racing or serious street strip - prefer them over the Alto Reds. Thanks for the kind words, man....I learn something new just about every time I rebuild one of these...

[@fluffnstuff15]

precision transmissions has a video as well of a 4l65e from a ssr that has the blue plate throughout as well. interesting though the changes

[@nickstransmissions]

I'll be on the lookout for a 4L65 from an SSR or similar...I'll see one of those trucks on the road every once in a while...Thanks for the heads up on that stuff.

[@taylorh3930]

Whats your thoughts on the constant pressure valve body for the 700r4 ?

[@nickstransmissions]

I don't like them for the street w/factory or otherwise tight converters...I do think they have a place in applications w/loose converters, street/strip and/or full race.