Thank you for the input. I have learned a lot just from reading your past posts. I originally started out with the 7 .080 GPZ frictions and the 6 .076 steels, but the clearance with the Sonnax kit was huge! I then swapped in a .106 plate then another and now have .030 clearance with soaked plates and the pack cycled with air a few times. I think I could swap the 2 .106 plates and one more .076 for 3 .095 plates and be about the same height on paper, but I am not sure if it's worth it, as I will have to order those. My plan is to stick the thicker steels in the center of the pack as someone else posted that area runs the warmest.

Since the pack is tight and it's used for towing, never racing, I think I will reinstall the release springs, but with shortened retainers so it doesn't bind as the clutches wear. I found this video on youtube and it almost convinced me to leave them out, but I figure with the shorter retainers it might be better.

 

Too bad he did not solve anything here. He left the centrifugal apply problem to solve itself. Maybe in his shop nothing goes over 5,000 rpm! For the rest of us who go over 5,000 rpm, then the fix is to use the TransGo 7-CS spring pack. This way you can use any clutch count, with any type or thickness pressure plates. I have been doing this since the early 1990's in all of my transmissions and in all of my rebuild kits. I install all the springs and have never had or heard of a problem with using these springs. This spring setup takes the place of the outer oem springs and does not allow centrifuge to happen at anything below 8,000 rpm. They are a little hard to install sometimes, but worth it in the long run. If you are building a motor that will go over 8,000 rpm, let me know and I will tell what is needed to do this successfully.

 

Dana, while your comments and wisdom are always greatly appreciated, the OP's vehicle is a van for towing, I doubt he will regularly rev much past 5000.

Like some, but not all, I think the release springs do reduce friction wear in 1st and 2nd gears, especially with a tight pack. I had heard of concerns over the retainers and benefits of shortening them.

 

Yes if I ever have a need to run a 4l60e past 5000 rpm, I would definitely pm PBA. I think his last post was directed at the author of the video.

This is my first 4 speed auto rebuild so it's a slow learning process, and I do realize that by doing it myself the likelihood of having to R&R the trans more than once is pretty good. The information here though is very valuable, even for someone who is just doing a low rpm build. Also I can post things I am unsure of and if no one replies or stops me, I figure it's pretty safe to proceed as planned. That helps a lot too. Thank you all for the help!

 

I was directing my thoughts on the video. There are other reasons to use the 7-CS spring kit here. Quicker and cleaner 3-2 downshifts. Pretty much guarantees the 3-4 clutches will not come on due to cross leaks in first or second gears or accidently going over 5,000 rpm. Well, I have torn down many hundreds of cores and almost without exception I have never seen the 3-4 clutches still doing ok with the outer oem springs in the 3-4 clutch pack missing. This is on 1987 and up units. Not worth the saving of apx. $25.00 here in my opinion.

 

The Clevite rear reaction shaft bushing showed up today, after pressing it in... its tight too. I had to tap it on to the output shaft with a deadblow hammer, then tried the side tapping PBA sugested. I did more than tap trying to get that to turn smoothly. It still was too tight, so I polished the inside of the bushing with oil and fine wet dry paper. Its still a little tight but at least I can turn it by hand now.

 

"Its still a little tight but at least I can turn it by hand now."
It must turn freely, no dragging or resistance.

 

Thank you for the advise again. I think I got it opened up enough, I don't want any problems though. I am going to trash the original reaction shaft and its problem and upgrade to the newer style.

 

The updated reaction shaft and bearing fit with no problems. I was able to get a lot assembled yesterday. I saw some air test plates on ebay and made a smaller version out of scrap. My big concern is leaks or cut seals. So I did this to double check. Every thing still makes the solid clunk with no excessive leaks that I can hear from inside the case. I am unsure of one thing though when I pressurize the forward clutch hole the 3-4 hole lets out a small amount of air, when I pressurize the 3-4 hole the forward clutch lets a small amount of air escape too. The amount of air is small and is not applying the other clutches with the air pressure set to 50 lbs, but is enough to feel with your hand out over the other hole. I am not sure if this is normal or not? I just pulled the pump again to look and the input shaft rings are in one piece and spin smoothly. I am thinking that maybe the Teflon rings haven't fully seated yet and are leaking a little? I used the kent more tools to install and resize them, no tape or hose clamps. I know I am using the wrong case gasket, but for just pressure testing. I don't think it matters. I did not want to trash the correct one and the area underneath the plate is the same as the early version.


My home made plate.

 

I ended up taking it all apart again to recheck everything with air. The Teflon rings are uncut. The input drum checks fine with air to the individual holes, with no air leaks between the forward and 3-4. So I am thinking the small amount of air between the forward and 3-4 holes when assembled is the Teflon rings not sealing completely. Its a good thing I did though. I somehow damaged the last friction plate in the 3-4 clutch. Turning it into a wavy plate and cutting my clearance to way under what its suppose to be. I will order a friction, some spare Teflon rings and try again in a few days.

 

The trans never grenaded and the fluid was clean. The old converter was doing its job, but had about an .001 step in the hub from wear. I thought I would get a reman converter just to start fresh. Anyway the hub on the reman looks like it was just sanded with crocus cloth and is .002 undersized (1.745 inch), when compared to the unworn part of the original converter. I am having a hard time finding real size specs for the hub. I was hoping for someone to give a little feedback?

 

From what I can find on the internet, the 4l60e hub journal size is listed at 1.748" so .003 undersized seems like a lot to me. The shop where I got it said they will reuse hubs up to .005 undersized, but they are rebuilding another core with a larger hub.

 

I asked Sonnax for a little more information about their air testing instructions on the last page here.http://d2q1ebiag300ih.cloudfront.net...f?v=1498576047

I had some very small puffs of air going from the reverse hole to the hole they mark as torque signal. I also have some air cross leaking between the pump holes on the forward and 3-4 clutches when both drums and the pump are tested as a unit, but not when pressure is directly applied to the input shaft holes. Its not enough to cause the wrong clutches to apply but it was enough that it worried me so I wanted more advise. This was their reply hopfully it helps others too.

 

Fingers crossed, but I just got it in and running. I think its working like it should. I drove it four miles and I have all four gears and reverse. I parked it for tonight. I will check it out better tomorrow with a pressure gauge, before I venture too far from home.

 

OK I hooked a pressure gauge to the transmission and have some more questions. Reading is PSI. I have a Sonnax .490 boost valve in the pump along with Trans go unbreakable pump rings (the under 5000 rpm kit). Pump clearance was .002 with a feeler gauge.

Park Idle -70 WOT -230
Reverse Idle -100 WOT 260 Not moving WOT is Power braked
Drive (No movement - WOT readings are power braked) Idle -70 WOT -240. I do it pretty fast though only a second or two, so the gauge rises up fast, not sure if that a stable reading.

When in drive, actually driving and manually holding gears the pressure readings are 170 -190 in all forward gears at WOT these readings are held for a long time and there is no gauge bounce. This is the part I am unsure about as I keep seeing pressures listed that are higher on forums but they don't state how they were obtained. Since the transmission had just over 100k and never exploded I kept the electronics that were there, just cleaning and changing O-rings and seals. The pressure switch was a bear to change the seals on, but I got it. I read though that a worn EPC solenoid could cause problems. I am not sure if this is something I should look at or not if my line pressures of 170-190 in forward gears are not OK.

On a side note the transmission acts and shifts almost exactly how it did before. I think that's a good thing since the shift kit was done before the refresh. I now have the Sonnax HD 2-3 Shift valve with the hole drilled in the valve body. What a mess that was to clean up! I did the servo cover modification that PBA recommended when doing the valve. I cant feel any clunk on down shift, its a big old van though. It now has the corvette servo set to .070 band clearance. The valve body hole sizes are 2-.082 3-.097 4-.097 Band release - .093 Reverse -.093 I went back to the stock springs in the forward accumulator and the 2nd accumulator as I didn't like the banging in to gear and the 1-2 shift was just slightly too firm at light throttle with the Superior shift kit instructions. Now even with the new corvette servo, the 1-2 shift is solid but not harsh when cold. When warmed up the shift seems to soften a little, so I may play with more springs when I pull the pan to check things in a few hundred miles.

I put the case spacer in place of the anti-clunk spring because I saw it recommended a few times here by pro builders and do hear a very small clank at times. I think that just comes with the product.

 

Sonnax Tech line comes to the rescue again! It looks like the transmission is operating in the normal pressure ranges. Here is their reply, so others have a reference too. The pressures were also given a pass by a very nice transmission person on Gearhead-EFI. Also a big thank you to all who helped out here, I learned a lot.

 

I did my second pan check at about 1200 miles today. Most of that had a 5000 lb trailer attached. It looks good to me. Thank you to all that helped! The first check at about two hundred miles was a little more dirty and had a small piece of very coarse friction material, not like anything I put in the transmission. I was just guessing that it was from the reman converter. This time though no more pieces.

 

The transmission is still going strong. I have noticed the fluid getting a little hot in the summer time, not bad but I would like to keep it down next summer when pulling. It has the factory stacked plate trans cooler option. I upgraded to the deep pan too a few months ago, but its winter so no telling if that helped temps or not. The messed up part is the factory lines look like 5/16 and when GM did its add on cooler they necked the snap in line down smaller than 5/16 to snap in to the original line after running it through the radiator. Is there a big advantage to switching to larger cooler lines when installing a bigger cooler?

 

Thanks for the update and glad to hear that your trans build is holding up well. Given your concern over every detail, your success is no surprise.

 

I finished a 200 mile trip, towing the chassis dyno to a car show. It was old volcano country in eastern Oregon, with 7% grades up and down. As long as I did not push it too hard and unlock the converter the trans temps still stayed good. On the steep parts, one was 13 miles long I had to back off as I was going to cook the trans. I did see 220 on the trans gauge once compared to 170ish when the converter stayed locked. Backing off and creeping up the grades like an old man kept it in the 200 range and that was an off an on thing through the entire trip. It has the factory tow package trans cooler after the standard radiator cooler. Like I mentioned before, it has 5/16 lines, but gm made a hokey add on for the towing trans cooler. At the quick connect they took a 5/16 line and necked it down to slide into the other 5/16 line. That part is definitely going away along with a new, larger cooler. My question is the rest of the system is 5/16 and I think the newer 4l60e has 3/8 line probably for good reason. If I upgrade to 3/8 line for flow I would also have to bypass the radiator trans cooler as its threaded for 5/16 line too. I mean it could be adapted and kept in the system but the point in going to 3/8 is flow. No use running 3/8 into the 5/16 rad cooler. I stopped in to the scales on the way home, the van, support gear and dyno in the enclosed trailer weighed 9860 lbs. Not horrible but its not an easy job for the van on steep grades with a 4l60e. I do have TunerproRT and have the chip keeping the converter locked more than factory, but I think it really needs an upgraded trans cooler and maybe lines. Anyone have any insight on the line size and cooler configuration?