Replacing the 3-4 clutch 700r4/4l60e

[AlienTranz]

This is just some steps to replace the 3-4 clutch pack. You have to realize that this isn't always the best way to go about reparing your transmission, and usually there is reasons why the 3-4 clutch is burned up that need to be addressed, and it is best to do a full rebuild, but if you are just looking to upgrade the 3-4 clutch hopefully this will help, and we can go into more detail about more upgrades like shift kits and the tear down of the pump, as I get more time. Oh yeah and the Sun Shell replacement will defiently be added.

These are the special tools I use when rebuilding the unit. The H gauge pictured is for measuring the end play you can do it by feel, or with this gauge it doesn't matter either way. The black plastic tool is for installing the input shaft teflon rings and the white plastic tool is to size the rings. The big cirle band is to center the pump, the three finger attachment is used for pressing the return springs in the drum, and the black threaded thing is for removing the spring in the back on the low reverse piston in the very back of the case.

now we are getting somewhere for some reason the picture is small but if you click on it you can really see it
So this is a 96 and newer 4l60E i'm showing, but it's going to pretty much be the same with a 700. You should remove the 2-4 servo on the side of the case, or at least take the clip off and allow the servo to back off so it's not pressed up against the band. You'll see the filter already removed and you'll need to take the modulated lock up solonoid off so you can get to the two ten mm bolts that bolt the lock up solonoid on then remove the lockup solonoid out of the bore.

pictures of the two solonoids removed. with the 700r4 you'll just have the lockup solonoid to remove and also with the early 4l60E

This is after the pump is removed. The easiest way to get the pump out without a pump puller is to take a long flat head screwdriver and stick it down the access hole right in front of the filter hole and valve body and give it a quick pop against the pump to force it out. Try to hold in on the input shaft while you are doing this so the drum doesn't come out with it. Now hopefully the drums stayed in place once you've removed the pump and it looks like this picture. You'll now need to take a flat head screwdriver and pop the band off the anchor pin. It's in the middle of the case it looks like a little bullet.

Ones you got the band unhooked from the anchor pin you can pull both drums out together and remove the 2-4 band. Sometimes the input sun gear will stay in the trans, on this paticular one it is pressed into the input sprag, so don't worry if you see the sun gear inside the front planet. The top drum (shiny one) That is the reverse input drum. The 2-4 band grabs on that band and the clutch inside is for reverse. Make sure the drum is smooth and not gooved, It can be a little dark as long as it's not worn down. You can sand it if you want, I use really fine sandpaper to make it real smooth like 500 grit. Just leave it alone if your band is in good shape. The one with the shaft is the input drum or 3-4 drum. The reverse drum just splines to the input drum, so just pull it off and set it aside or go bowling with it if it looks like crap.

the two drums seperated. The reverse input on the left with the band. You can see it's kind of black, but I think it felt smooth, so it can be reused since it's still smooth, or you can replace it if you want a fresh surface for a new band. I've noticed that kevlar bands like the drum surface real smooth I used to sand them with 1500 grit, but it got tiring and overkill so I just leave them alone.
On the right you will see our warped 3-4 drum just messing with you guys. This paticular tranmission didn't have a smoked 3-4 clutch. It blew the sprag apart, but I don't have that pictured.

Here's a picture with the 3-4clutch removed. You'll notice the sprag is there and intact without the sun gear sitting in it. You may see a sun gear there or you may not. I put a good sprag in there cuz hopefully that's what you will see. Anyway you'll notice a little bit of varnish on the inside of the housing, you'll most likely see a lot more than that. The clutch that is still in there is the forward clutch and it splines to the input sprag. You can leave that stuff in if you are just going to slap 3-4 clutches in or you can take it all apart.

I realize there is some steps missing here, but i'll have to take some more pictures sometimes next week. This is a picture of one of the tools you will need if you decide to take the input drum apart. You'll have to remove the other thick snap ring and remove all the rest of the clutches and the sprag to remove the return spring. I just have a three finger attachment sitting on top of the return spring and i'm pressing it down to remove the tension so I can remove the snap ring. You'll need some good snap ring pliers to get that guy off he's kinda strong. It will take very little pressure to push the return spring down.

Pictured here is the different piston set ups you will find inside the input drum. They install in the order shown. The pistons are the bottom are bonded steel, and you can upgrade the aluminum ones to this for durabilty as well as ease for installation, you'll notice the difference in return springs, you will have to use the closed cage return spring when using the bonded steel pistons.

This also goes to the input drum this paticular assembly will install into the drum as a unit, after you get the 3rd piston installed(the third piston is the first piston on the left in the picture with all the pistons. This picture is with the pistons not arranged in the order that you will drop it in the drum yet.

This is the pistons assembled in the shape that you will drop it into the 3-4 drum once you have the 3rd piston already in. You will just hold the tangs on the big piece and slowly lower it in till you get it down far enough when the inner lip seal on the top piston bottoms out on the inside of the drum, you will then work it down till it drops all the way down. It will be down when you can push on it and it springs up when you push it down. Next you will install the last piston, then the return spring. In this picture I'm showing the bonded steel piston, if you are using the aluminum pistons you will have to use a lip seal tool to work the lips around the edge of the sealing surface. I use a .012 feeler gauge for this task.

This is how I set it up for reasembly I've removed the output housing so it will sit flat and you will need to find something with a hole in to allow the output shaft to go through. You can see the empty servo bore, which I find easier when trying to get the band back in.

again I know there is some steps missing, but once you got the 3-4 drum back together and your new 3-4 clutch installed. You need to spin the reverse drum onto the 3-4 drum just keep spinning it till all the clutches spline on to the teeth on the input drum. Once you got the two drums together you are going to install them as one unit. Make sure you put the sun gear back in first if it's not attached to your input sprag in the drum. To install you will just keep spinning it back and forth and shaking it side to side, or any way you can to get it down. You'll know it's down when you can pull up on the shaft and it pulls up a little without touching the other drum, cuz the other drum will now be resting on the sunshell. Then install the band, you'll have to fandangle it in there, once you get it in place make sure you get the circular hole on the band over the anchor pin. Then reach in the servo bore with a screwdriver and push it through the hole where the servo pin goes and make sure you are going to hit the end of the band to apply it.
The picture is me showing how I get the pump back on. Just take a screwdriver and stick it through a bolt hole and down through the coresponding bolt hole in the case, then you'll have to force it down. Make sure you change the o ring on the pump and the pump gasket. Lube the pump ring up real good, and just tap the pump in with a mallet. It shouldn't take that much force. Once you got it down and you have the pump tightened make sure you can turn the shaft both directions. If you can't turn the shaft you either don't have the drums down all the way or you don't have enough end play. You won't have to worry about end play since you aren't changing any hard parts, so you don't have the drums all the way down. Also we didn't take the pump apart, but if you do you need to align the pump halves with a special tool, or you can take the oring off the pump and install it in the case upside down then tighten the bolts

Here is the classic broken sun shell syndrome. This is what happens when you lose reverse second gear and 4th gear. The one pictured to the Right is "the beast" it's an upgraded sunshell that they claim is unbreakable. This is what I upgrade all of my sunshells with. You may want to look into replacing this part if you are in there.

[90'rado]

if only i didn't live in oklahoma

[doublelow49]

Com'on guys. There's got to be somebody in Sacremento with a digital camera who can help AlienTranz get this worthwhile project going.

[AlienTranz]

Okay I got it in the works now. I posted it in the technical section under transmission pictures. I'm still gonna put more pictures up, so keep checking back.

[90'rado]

[doublelow49]

AlienTranz,

You indicated a while back that you could recommend some sources for good, reasonably priced replacement parts on this repair. Also, a rundown of what parts would be needed would be great. I want to use some good, heavy duty parts for the repair. Have been looking at kits from PATC but they are pretty pricey.

Haven't torn the trans apart yet but am sure the 3-4 clutch pack is blasted. Don't know what else may be bad yet. I am about ready to nut up and make the repairs on my 87, 350, 700r4 since the used trans I put in is leaking at the front seal. Might as well fix my old unit since am going to have to pull the trans again.

Thanks,
Buddy

[chevy_ss_383]

Dont Forget To Remove The Aux. Valve Body Tube On The 700/4l60 (non-e). If You Dont, Youll Break The Tube And Possibly Damage The Input Shaft.

[chriskg]

I've got a 700-R4 that's out of a 91 4x4 chevy, a friend is rebuilding it with a master rebuild kit, but he's stuck on getting the sun gear out, how does it come out?

Thanks

[xx_ED_xx]

a clip retain its