dajbbsf07

I gotta go check it out the more I think about it that may be the issue

Jake's Performance

iTrader: (2)

I would not recommend .040 clearance in the direct clutch of a 4L80E. .010-.012" is acceptable and with a 6 clutch setup that is a minimum of. 060".
This pack is driven through in low and 2nd. Too tight of tolerance causes frictional losses and glazes the clutches.

dajbbsf07

I started to assemble tranny and book is saying install spacer ring I think for the center support ,, of course I didn't mark it,,book has no measurement on thickness like it does on some other snap rings,,how do I know which is the spacer ring

Vince B

iTrader: (1)

Pretty sure they are talking about the thin snap ring that goes into the case before the center support. Then you will install the center support followed by the tapered snap ring. Tapered up!

I get what your saying however if you re-read my post I gave the clearance with 5 frictions not six. On a six pack I normally set it at .050. I know you have a dyno now so you can appreciate this. After break in of new clutches you will see the clearances you have listed. It has been my experience to see a couple thousands if not more depending on the frictions being used when building any transmission. Keep in mind I know how to build dozens of transmissions.

I find that new friction material will compress once it sees a few heat cycles. I have actually tested this when doing RND with 4L60E units using an 8 friction pack. After three to four or more good heat cycles running a unit for a half hour or more. Cycling the various gears back and forth, take the trans apart and remeasure. If you have not done this already you will be surprised to see what you find.

I know your getting ready to start building 4L60E units. With the spec's you are giving you are going to have a serious issue trying to keep that pack alive. Keep in mind what the reaction shaft and 3-4 clutch hub will be doing in first and second gear. It is very much like the TH400/80E we are talking about here. Its been my experience that high energy frictions will take more heat than a regular old paper friction and running them a little tighter is not an issue. Just a thought. Vince

Jake's Performance

iTrader: (2)

Vince,
I know your experience level. I'll also say you don't have the experience I do with a 4L80E.
Over 150 units this year alone.
It sounded to me like you are recommending .040" with a 5 or 6 pack clutch in your previous quote.

What you have to keep in mind is that the clutch pack clearance on the 4L80E is not critical to the timing of the 2-3 shift like a 4L60 unit.
It's a simple "on" engagement, not a timed band release/clutch engagement.
You could leave it at .100" and it wouldn't affect the engagement time.

There is no reason to make it overly tight and build any heat in that pack with it already being prone to centrifugal apply and in the case of most of the units I build, needing a clean transbrake release.

Vince B

iTrader: (1)

LOL at the experience comment. No big deal. I would think installing some stiffer springs in the direct clutch pack would help with any release issues or premature apply issues. But hey you already know this. If your methods are working for you keep on rolling with it. I've built more than my share of 80's and as you know I'm pretty much in other markets these days. Best of luck to you. Vince

Jake's Performance

iTrader: (2)

Vince,
I have the utmost respect for your work and experience but you know very well that I've spent the time studying the hydraulics on these units to design the transbrake, spragless, etc. We make quite a few of our own parts for them now with more on the way.

We don't just build/upgrade them but we're at the forefront of the 4L80E development.

My opinion is that even though that tight of a stack may work, there is no reason to create any drag or heat in a clutch pack that the tolerance isn't critical for shift timing.

Griner recommends .070" clearance on a 5 clutch pack in a Th400 (same drum/same rotational effects) with his transbrake. the guy has more experience that both of us combined in that respect.

We also are not seeing the clutch pack compressing after a few dyno runs or even a few months in a vehicle.

transtech1968

Clearance less than .050 in direct is not a good Ideai in any gearbox . min .050 for stock motors. Performance engine that spins over 6500 RPM with high torque Transbrake ect. need .070 to .090 at least. You can get away with murder with stock and Low RPM engines. Just Use common sense. Someone who says shift feel and overlap is not effected by clutch clearance is wrong even on E units that calculate and adjust for fill rates which is most of them

Automatic Transmission in cars or trucks weighing over 3500 lbs making over 900 honest HP will not live at the race track that long. Doesn't matter who builds it, the Convertor will just not take the weight/HP anyone who says they can make it work is a liar. Been into them all, built by all these so called High Dollar Builders Units and most of them are selling a bill of goods nothing Magic inside.

Good Luck all