700R4 Rebuild PT5: Forward Drum Assembly and Clearance Checks 

Thank you and will do, HMG!

You're welcome, Alan! Thank you for watching.

Great idea, James - will definitely look into it. Thank you for watching!

Hi Jerome, thank you for watching...If you're shopping at a local transmission parts supply, simply ask for an apply plate for the 700R4 and specify the thickness you're looking for...If shopping on-line, search for the same but ask the seller (individual or company) for the thickness as they are selective.

Sounds like a mess, aka what I typically see on tear down...The third and forth sealing ring on the input shaft are for the 3-4 clutch pack so if those sealing rings were buggered, that would explain the delayed engagement/flare shifting you observed and burnt 3-4 frictions/steels. The band sounds like it's worn in the typical manner...Sometimes I see the bands broken at the anchor points (too much clearance and too large a 1-2 feed orifice. You must have a non-aux valve body (82-86), so no feed pipe and no aux valve body (you should have a large hold down plate at the rear of the case where the valve body was located). Look at the passenger side rear of the case, just above the pan rail - there should be an alpha-numeric code that starts with an integer...If that integer is 2,3,4,5 or 6 and there is no 'dam' at the low-reverse worm tracks and no cut-out in the case at the pump for the feed pipe then you have an early 700R4. If your transmission IS an aux-valve body style unit (87+) and didn't have a feed pipe installed when it should have then you'd likely have no forward movement as that pipe routes fluid to the forward clutch pack...You can air test the forwards when the transmission is assembled but pipe left out - just put your air gun there and shoot compressed air...You will hear the forward clutch apply and release (at least you should).

Hi Sirens, thank you for watching...The use of the load release springs (what you are calling the 'relief springs') depends on application and clutch pack clearance...I will typically install the load release springs back in when running the Alto power pack as I aim for a clearance between .025-.035 as measured on the bench. If you have a clearance in excess of .045, I'd leave them out, especially if you also happen to be using Transgo's high rate return spring kit in the drum.

First of all i should appreciate you to share your knowledge with us and i really enjoying and learning a lot of you. You know i live out of usa and i bought this package *Rebuild Kit Heavy Duty HEG Master Kit Stage 4 w/3-4 Power Pack 1987-1993* from ebay to rebuild 1992 transmission and i am doing step by step from your video, about load springs the clearance of these nine frictions is about. 0.055 - 0.060. In the other hand if i put its stock load springs it will be short for nine because the stock has 6 frictions. So i i figured out with this clearance that i mentioned above i can eliminate these load springs.

I think I will do a video on use of the load release springs as I'm getting quite a lot of questions and there isn't super clear direction out there on exactly when those springs should be installed and what to consider when deciding whether or not to install them...Subscribe if you haven't already so you know when that video becomes available...I'll likely film it this week or early next.

Do you use two feeler's gauges when air checking 3/4 clutch clearance at the snap ring? Thank You for the knowledge!!!!

Hi Sean, not sure if you're asking me or @Sirenswhispering but I don't use feeler gauges at all to check clearance; I use dial indicators as I feel they are more accurate...If you want to use them and be comprehensive, take two readings on opposite sides of the backing plate when air checking.

Hi Kevin, the larger clearance figure is more accurate. I do the same as far as positioning the dial indicator plunger. There's a bit of "compression" in that clutch as you've seen so will run it on the tight side knowing it's a bit looser than it appears sitting in the drum. Hope that helps...

So the more accurate reading comes from using the feeler gauge. Do you think I should tighten up that .053 reading a little bit?

Generally, yes as you're able to push down a bit on the clutch pack and as you've seen, it does move a little when downward force is applied. The reason is slight 'springiness' between the apply ring and apply plate's engagement lugs - at least that's my theory based on trying to figure out why there's a bit of vertical play in that pack...

So, with the high rate return spring kit installed, what would be your minimum and maximum clearances be on a performance build using a feeler gauge? Thanks for all the great videos and all your help along the way, much appreciated!

I typically like to be .035-.040 for any performance build unless there's an 8 or 9 clutch stack then .040-.045 is my target (if im tighter ill reinstall the load release springs in addition to the high rate return springs). Both sets of springs require only about 20-25 more PSI to fully compress and an upgraded boost valve and PR spring should deliver that at higher throttle angles without any issue.

You need an 88+ complete sprag gear assembly.

Awesome, man...What year 700R4? If not known, you can look at the rear passenger side of the case right above the pan for an alpha-numeric code. The first character is a number, which represents the year...The other physical indicator is on the pass side of the case...All units with an aux valve body made in 1988+ have a large upside down U-shaped crease. For example, if you have a case with a '2' as the first number and that crease, that would indicate a 1992 unit. Your response here will determine what tips/points I give for your build.

@@nickstransmissions 9THM119H is the code, I never paid attention to if there was a U shaped crease. I'll take another look tomorrow if I need to. Thanks

Sounds good but you should have a 1989 case as 1979 is too early and 1999 is too late. Do the following: - purchase 4L60E late model bonded steel/rubber forward drum pistons and corresponding return spring and use those in lieu of the aluminum pistons in there now - install a .472 or .500 boost valve (Sonnax) and Sonnax TV sleeve and plunger kit - use Alto's high energy kevlar lined clutches (you can find them as part of a complete kit on Ebay) and an Alto wide 2-4 band - remachine your pump and rev input drum - install a corvette second gear servo - install Transgo's SK700Jr shift kit (you can use either the Sonnax or Transgo TV spring) - leave out the MTV upshift spring (dont install Transgo's) - block the 3-2 downshift valve for crisper 3-2 shifts - block the 4th accumulator and leave the piston, pin and spring out of the bore if your TC stall is 2800+ There's more I can suggest but ill let you marinate on that for now...Let me know if you have any questions...

If you run the factory deep pans from the 97+ units then install the deep pan filter (black). If going with an aftermarket deep pan, confirm whether or not the pan needs a filter extension tube/adaptor and that the pan comes with one. The filter must maintain a slight interference fit with the pan to hold it in place.

Thank you for the reply! Do you have a Patreon? Or merch to buy?

@Bonnachill865 You're welcome, man. I have a "Buy Me a Coffee" link in my channel's "About" section but no Patreon or Merch (yet). Merch is in the works, hope to have something to share in Oct or Nov.

Hey Steve, thank you for watching! Re you questions: 1) Transgo springs: I always install all the springs, never did a partial or mix of factory and Transgo. Between that and the bleeder orifice for the 3-4 addresses centrifugal apply risk for anything under 5500 RPMs. If going over 5500 rpms, I also install the load release springs and run the clearance down to .030-.035 max. Re cushion springs - which springs are you referring to? The load release springs that were added to the 3-4 clutch pack starting in '88? If so, I don't recall installing them in this build but I do occasionally use them, esp if RPMS are expected to regularly exceed 5500 and clearance is at or below .040 (or I'm installing a super drum from Sonnax). 2) Non-Lock up: Are you installing Transgo's non-lock up conversion kit? If not, you'll need to otherwise the converter and trans will way overheat and burn...Also ensure he installs a very large aftermarket transmission cooler and that he runs the supply line through the internal cooler and the external cooler, assuming that's not already part of his set up..Also, make sure he flushes the lines and cooler(s) before installation (even if it/they are new). Remove the check ball capsule in the snout of the input shaft and leave the black o-ring off. 3) Also, valve body mods (in case you weren't already doing them): block the line bias valve from moving, remove the spring from the MTV upshift valve, install whichever 1-2 accumulator valve spring came in your shift kit, shim the 1-2 accumulator (or install Sonnax pinless kit) and block off the 4th accumulator completely - leave the piston, pin and spring out. Are you running super hold servos for 2nd and 4th plus a wide kevlar 2-4 band on a new reverse input drum? What sizes will you go with when drilling the plate feed holes? Reaction shaft - if possible, locate a 4L70E reaction shaft - it's induction hardened where as the 03+ 4L60E isn't... Sun Gears: Cut shallow lube grooves into both ends of the rear sun gear and planet-facing side of the front sun gear - I go 3,6,9,12 o'clock position. Gives more lube oil to bearing and pinion gears.

Thanks for all the inputs. Here's some answers and more questions: 1. Yes, I was referring to the load release springs; I'll keep them in. 2. Will have to get a Transgo non-lockup kit; didn't know that, glad I asked. 3. How do I keep line bias valve from moving? 4. Shim the 1/2 acc to what? 5. Running Vette servo; need to go to the super servo? 6. Yes have both Kevlar and HD wide bands available; some people shy away from Kevlar? New reverse drum. 7. Drilling feed holes: 2-3 to .155, 3-4 to .125, band release .106. Open for other suggestions/ideas? 8. Already have new 60e reaction shaft.... 9. Ya, saw you ground grooves in rear sun gear; will do that 10. What does removing check ball and seal on input shaft do?

So here's maybe a stupid question, but can steel/frictions sizes be mismatched, i.e, .077 & .095 steels to get clearance?

You're welcome, Steve. What's the converter's stall speed and exactly what vehicle is this going into and what is the final drive ratio? Line bias valves are typically blocked off via rod of some description long enough to prevent the valve from moving - my machinist will supply me a stainless dowel pins that can block but I only do it for street/strip or full race..B&M Transpak shift kit also comes with a block-off rod for it...If you can't block it off, no big deal. Blocking it prevents 'excess' line pressure from bleeding off at part-throttle keeping shifts from being overly harsh in factory/mild performance applications. Run a Sonnax pinless accumulator and corresponding spring in the 1-2 accumulator housing - that should be sufficient but won't know for 100% certainty until you have it out on the road. If shift feels mushy then shimming (i.e. preventing the piston from moving even less will send more oil to the 1-2 servo for band apply, firming it up). The Sonnax piston's larger size already cuts travel by roughly ~30% producing a firmer/stiffer 1-2 shift over stock, all other things equal. Install the Vette servo for now but if it's not holding at 6000+ RPM WOT 1-2, you'll want to run the Sonnax super hold servo in 2nd gear. Won't know until you have the driver make a few passes. Kevlar holds firmer on the drum at the trade-off of increased wear over traditional high-energy or red material - your call here as you're familiar with what the driver's goals, application & preferences are. Hole sizes in the plate look consistent w/a high stall/high performance application so good place to start; drill/modify further after a shakedown cruise and/or passes down the track if necessary. Removing the input shaft check ball capsule and o-ring allows uninterrupted fluid to flow to the converter. The o-ring simply seals off the TCC clutch apply circuit, which isn't needed any more since you're running a non-lock up converter. The check ball capsule regulated flow of apply fluid to the converter clutch piston, which again, isn't necessary in a non-lock up TC. Transgo's instructions will explain the same.

This is going into a 71 Nova, 4.11 gears on 28” street/strip tires. Believe stall is 3000 rpm but not exactly sure. What are your thoughts on kolenes and alto frictions? The kit I bought had 2-3 sets of them.

Snap ring pliers, both made by Snap On. I use those and a set of similarly-sized 90 degree pliers for removing the output shaft-front planet and low-reverse snap ring.

There is always a wave/cushion plate in the forward clutch. The 82-87 units had a thinner wave than the 88+ but you should have one regardless of what year unless someone did something "outside the box" to eliminate it and still keep to the .030-.060 clearance requirement.

@@nickstransmissions ok thanks

You're welcome, man.

Lol its only a few month’s old. I have a drawer full of them as they get worn out pretty quick. Thanks for watching, Kevin!

Also, am I able to check the drum for air leaks around the shaft by just installing the bonded pistons and retaining ring? Just curious as most shops sell "Used" input drums with absolutely no warranty. They are already set up with the pistons and spring with the retainer.

Yep, you can check the drum with no clutch packs - just be careful not to put too much air into each feed port as you could potentially pop the piston out of it's location. I'll test drums on-site at my hard parts supplier...I just pull the drum from the box (it usually has pistons, etc installed but no clutch packs or sprag just like what you're describing) and do the test using their shop air.

You don't need any more than about 50-60 PSI to do air checks.

Excellent info.! Found a Transmission Outlet to get parts. However, it's about an hour and a half to two hours away from me, one way. What you described is exactly what I bought with the box and all. I made sure to get a "716", just no way of checking it on site. I appreciate the information.

You're welcome, man.

I address those springs in the video but in short, i leave them out unless the application is high performance and clearance is .030 or so...