PBA

"At the top of the separator plate circled in red is the band release hole" My mistake, it should have said,"circled in black".

axekick

iTrader: (18)

Oh well, I have bigger problems now. It slipped right out of gear between 3rd and 4th this morning and now it doesn't go easily into second. I have to let off of it, then it goes into gear and feels alright. I am going to try to get it home from work. I'll know more about what it's doing after that. I checked the fluid this morning when it first did it and it looked like it wasn't registering on the dipstick but I took it for a drive at lunch (a short drive since it was acting up) and checked it again and it looked to be right at the full line. Looks like I'll be tearing farther into it than I originally anticipated.

mrvedit

With luck it might just be a problem in the servo area.
Keep us posted.

axekick

iTrader: (18)

If it was, it's more now. I pretty much had 1 gear left by the time I got home today. 2nd worked best but slipped. 1st slipped. 3rd and 4th were totally gone. I'm glad I got it home. One more red light and I might not have made it. I'm not discouraged. I'll figure out what went wrong. I have a guess. I think it failed due to leakage around the input shaft where it is pressed into the drum. I put a lot of good stuff in this build but nothing for the input drum. I'll figure it out and my next build will be better.

Here's my plan now. I have the stock trans that was working fine when I took it out. I haven't done anything to it. I am going to find a deal on a 5.3 and demod the tahoe and sell it. I want to put my hot 6.0 and fresh trans (after I freshen it) in something better. i am in the middle of some intense house projects so I need to get this done quick and cheap. Then I'll have my good stuff for when I can concentrate on something worthy for it.

axekick

iTrader: (18)

Bringing back my old thread. I haven't gone back through my failed transmission yet but its on the list and in fact on the table. I did, however, put the servo assembly from it in my stock rcsb 2wd last night and guess what... 2-3 feels just like it did in the other transmission. I think that the pin must be too long. I'll check it tonight and most likely grind it a little. I think it's going to be difficult to get a dial indicator on it since the trans is in the truck but I'll do the best I can. If the shifting still feels wrong then I'll ditch the 4th servo.

mrvedit

These Sonnax instructions might help you:
https://s3.amazonaws.com/sonnax-dev/...911-03K-IN.pdf

They say that the end play spec is .075 to .125. I need to check my posts, but I may have posted it as little as .050. I definitely have said 1/16" which is .063 and a little less than spec.

Good luck; sounds like you are learning a lot and figuring it out.

axekick

iTrader: (18)

I finally got the chance to take this thing apart to see exactly what went wrong. I didn't think it would be so obvious and it turns out that it may not have been any mistake of mine. The snap ring blew out the input drum. So far it looks like all I'll have to replace is the input drum abs 3-4 clutches. I'll probably be less aggressive on the separator plate setup this time around.

mrvedit

A blown out snap ring likely damaged the input drum. I would suggest getting a trans pressure gauge ($45 on ebay) and hooking it up when you have it re-installed. Make sure max pressure doesn't go above 225 psi.
If you budget allows $550, you might consider the Sonnax Smart Tech input drum which replaces the snap ring with a bolted-in plate. This also eliminates cones. It also support one extra friction. It also includes their input shaft reinforcement ring. Drum is about $400 plus $150 for an input shaft.

bbond105

Also remove that Sonnax servo check valve.

axekick

iTrader: (18)

Oh yeah. It blew all the tabs on the drum right off. Of course the 3-4 clutches are all burned up but all others, even the band look brand new. I have a spare input drum. I wish I could spring for the sonnax but I don't think I can do that. I will definitely monitor pressure when I get it going. I probably had it too high and I can turn it down in my tune. I never measured it. I just have to tear it all down to convert to 2wd. Its going behind the same motor as before but in a rcsb this time. I'll definitely lose the check valve and I was thinking about using a transgo separator plate the way it comes. My truck wants to loose traction during shifts in turns now with a stock 4.8 and just a billet 2nd servo. I'll ditch that too in favor of a Corvette servo.

mrvedit

The transgo separator plate comes drilled for a V6; the directions have you drill it even for a stock V8.
Do you remember what the 3/4 clutch clearance was on that build?
Do you remember what the size of the 3rd feed hole was on that build?
Clearances over .050 (including with wear) combined with high line pressure and a large 3rd apply feed hole can cause a hammering effect.
I hope I didn't mislead you in my posts during that build.

axekick

iTrader: (18)

The clearance came out to around .030. A little tighter if i remember right. They were alto clutches. I'll be getting one of Dana's heavy duty 3-4 setups next. All Borg Warner high energy. That's very good to know about the separator. I may just reuse mine, then since I just followed instructions. I'll use the tune to dial in pressures after that based on measured data.