Wow, that is much lower than I would expect; no wonder these things would eat 3-4 clutches.

I'm expecting to get 200+ psi when all is said and done. The valvebody and pump half had GREAT vacuum numbers when I got done with them; I'll post them up tomorrow.

 

Yes 170 180 i have found is typical with stock set up depending on vehicle with harness unplugged , Some times higher with vettes, camaros and some trucks. But also bear in mind at least with all i have looked at the stock tune is set to 95 percent of max. So actual running numbers can be even lower, and note that in the tune part throttle you may notice an actual pull back on pressure during the 2-3 and 3-2 shift, I think to try and avoid the clunky feel of the band / 3-4 clutch overlap.

 

Last night I was assembling the clutch packs, and I was kind of surprised when I got to the 3-4s: my clearance is .022"- .025". This is the opposite problem I usually have.

Will this be too tight?
I'm using .106" kolene steels, and the clutches have been soaked overnight.

Aren't you supposed to run a tighter clearance with those?
I've read some builds where guys set up pretty tight 3-4 clearance on the grounds that it will open up about .010" shortly after first operation.

What do you guys think?

I have some thinner (.076") steels, and I could substitute one in the pack, but then that would put me at .050+ clearance.

 

That will be fine, apply them a few times at high air preseure and check with relief springs installed you will find you have plenty.

 

Frank, I did that and re-checked, and still had .025".

So I decided to try a different setup: 6 .076" steels (conventional), and 7 .081" frictions, and I ended up with .030.

I'm going to run it; this will be my first time trying a seven-friction setup. I haven't done it in the past because I always wanted to run the thickest steels possible for heat distribution.
I'll be trying your band-lube mod tomorrow, I'll let y'all know how it goes.

 

.020 to .040 is fine and I am assuming a dry pack. On the band cooling mod. No larger than 1/16. I like smaller when possible like right now found warrior has a set with .030 and .025 bits I am using. Though sadly and they are a cheap brand they work for only 1-2 cases then are dull. But cheap enough. You do not want to go larger than 1/16 as you are remember creating a leak in the FWD clutch circuit and always enlarge the FWD clutch feed .092 . Some plates you will find they are already that large but others I have found are quiet small . I guess depends on application. The 60E pump is a monster compared to many trans pumps and can easily make up for the additional flow as long as the feeds large enough.

 

All my units are 7 - 8 or 9 depending on my goals, Performance/ HD units like trucks used for dual purpose racing/ towing get 8 , HD mostly towing daily get 7 with .090 steels and sometimes 1 .076 in the middle as heat dissipation is the primary concern. and extreme performance high hp high rpm shifting units get the .076 steels with 9 sometimes a thinner in middle as hold is the most important, All with custom cut apply and backing plates and hydraulics set up to best suit each application.

The band cooling mod is not so much to save the band but to cool the drum and a cooler drum does not concave or flair as easily as a hot one does and tearing down units you can see that even with the band still looking pretty good the drum does get very hot and must absorb lots of heat.

 

I once built a 4L80E and the VB damn gasket walked on me even though I was using the guide bolts. Just 1mm off was all it took to cover an important orifice in the sep plate resulting in a delayed 2-3 shift. Pulled the VB off, saw the oblong gasket bolt holes.
I felt pretty dumb lol. Now I shine a light into every single VB bolt hole and make sure it's perfectly center and check every hole as I'm tightening it down.... learning pains lol.

 

I got the band-hole mod done today. I did a rough measurement of the area I was going to drill through, and it was approximately .5".

I have some really tiny drill bits, and I decided on a .030" size. I remember Frank mentioning that there was a risk of breaking such a tiny bit. So I drilled a pilot hole with a larger .076" bit about .4" deep, then went the rest of the way with the tiny bit.

The bit was so small it wouldn't even fit my drill; I had to wrap it with foil to get it to hold.







In other news, I assembled the case/ gear train, and the input shaft endplay is .013" (good), but output shaft endplay is .045" (bad).

How/ where would you guys tighten this up?

 

Using the little red straw that comes on brake clean cans, cutting a little piece off and using that in the drill bit works well also

Regarding your end play, you can put a shim between the bearing on the bottom of the input carrier and reaction shaft to make up your end play for your snap ring

 

YES I like the smaller holes as I was messing around with it and found with the smaller hole you get more of a spray than a stream which covered more of the band area. Yes pilot hole works but That is how I also learned different cases are different thickness in this area and drilled through lol. But solution was simple, Borrowed one of the tiny orifices from an old pump back and used that in the hole instead.

 

Okay, boys, I just wnted to add some instruction for this build, since it's an early '90s transmission.

When blocking the 3-2 downshift valve, you will need a longer "plug/ spacer."




This is the '99-up spacer (top) next to the early '90s spacer.




Last of all, these are the orifice sizes I've drilled. I'm going to do Frank's reversible Overrun-mod on this thing tomorrow.



Best wishes to all of you guys.

 

I feel very uncomfortable Posting this as I am Not a Builder, and I have No place here to be Correcting anyone.
I'm sorry and I am Not trying to step on any toes.

The THM700-R4 and Early 4L60E 3-2 Control Valve needs to be blocked from the Inboard End of the Valve-Train Bore, Not the Outboard End.


Use a Cup-Plug as in the Image Above on the Inboard End, or use the Spring from under the Pivot-Pin of the Pump Slide.


-Marcello III

 

I actually do not block it at all, As with My overunmod it is useful to allow the PCM to mediate the 3-2 coast downshift to make it less pronounced.

 

It is not easy to get any answers from My Father now, so I refer to His Notes; which are like a giant Encyclopedia of His Transmission Building Information and Images.

He says that he favors the significant change in making the 2-3 Up-Shift much more Positive and Firm by Blocking the 3-2 Control-Valve and Blocking the #2 Check-Ball Hole (Omitting the Check-Ball).

And will accept the slightly more harsh 3-2 Down-Shift that the Full-Time Overrun Apply Modification compounds.


-Marcello III

 

I think of your father often and miss him commenting in the forum. You and your dad are in our thoughts.

 

Come to think of it, your dad had me to this on my TH700.

I don't want this guy complaining about shifts, so I'm just going to put the springs back in.

 

I adjusted the band clearance today, and I had to add material to the servo pin. This was by far the most I've ever had to add, which is surprising, because I'm using a new band. I've got .050" clearance. That sound good to everyone, or should I go tighter?

This wasn't the final length/ shape, but it's what I started out with.

 

WOW that is a lot, is the drum a reman? turned? Check the gap of band with the band applied. No way should be that much longer than stock. I have however seen reman drums machined/ turned way to much . As for band clearance when i have the pump out I go for as close as I can get while still not getting drag. , If pump installed I go with he no more travel than the thickness of the snap ring. But that's only when trans in car.

 

No idea about the drum, all I know is that it passed the flatness check, so I ran it.
That .050" was checked on the stand, with the pump installed.

This is what the pin looked like in the end:




In other news, I made some plugs out of an aluminum rod today. Just so everyone knows, you may have to trim the gaskets to fit around the plugs. I go the rest of the trans assembled today, so I'll let y'all know how the overrun mod turns out.