mrvedit

Do you need the Sonnax 2nd and 4th servos to run a Kevlar band, or are the Vette 2nd and stock 4th servos enough?
Any hints on what "set everything up correctly"" might entail?

thunderstruck507

iTrader: (18)

I've read that the Kevlar band is "jerky". I had no issues with the band I was using but what little reading I can find suggests the carbon band is better without being as harsh as the kevlar. I was very happy with the shifts the way we had it all set up but 2nd gear definitely doesn't need any more help in the grabbing department. If anything it could stand to be turned down a hair.

There isn't much reading on bands online that I could find with google.

Just trying to source a good place to order the clutches/steels from now. Was trying to wait in case they also had a band but if I have to I will just have to order the pump, band, and 3-4 pack separate from different vendors.

carlsonauto

That all depands on the application. The 4th servo doesnt really matter as far as shift feel goes as it's pretty hard to accidentally get a real firm shift under normal driving into 4th regardless of what servo and band you use unless the converter is locked. (I cant see a reason to shift into 4th with converter locked so thats not really an issue) You could go hog wild with a drill and block the accumulator if you really wanted to chirp the tires into 4th but again not sure why you would want to. The 1-2 shift is the shift that can be really tricky to get just perfect.

Another thing that plays a HUGE part in shift feel is how tight the converter is. On a transmission with a stock converter you can have shifts that chirp the tires in every gear. Put a loose converter in it and all of a sudden the exact same trans feels like a slush box.

This may sound backwards but for light throttle driving and a kevlar band its easier to get 1-2 shift feel correct with larger apply areas. (super servo of whatever flavor you chose) The reason is at lower line pressures (cruise speeds) with a larger apply area if you change the 2nd feed hole diameter by say .005 it makes a pretty big difference in apply speed at that lower line pressure. Raise the line pressure to say 220 and that .005" doesnt really affect the shift speed all that much.

Now take a stock servo, the surface area is so small that the apply hole has to be so tiny in order to get good shift feel at cruising speed that when you make a wot pass it shifts sloppy because it just plain cant get enough apply oil fast enough. When it does get enough apply oil the surface area of the servo applying the band is so small it cant hold properly and you get a bad slide shift or even a slip condition.

Its a balancing act and the biggest thing that changes what the shifts feel like is the converter. There is no one size fits all combination in my opinion.

The loser the converter the stiffer the accumulator springs can be and the easier it is to get it to feel acceptable at light throttle and full throttle.

With a really tight converter you might want to soften up the accumulators a tad. With a tight converter it can be pretty tough to get shift feel right at cruising speed then also have it shift good at wide open as well.

I am extremely picky about shift feel and it is not an uncommon sight to see me pulling a valve body after a road test because its not exactly how I want it. I have test driven many times with customers in their own vehicles and they are extremely pleased with how it works and I am not. They think I am nutts when I tell them I want to pull the pan off and change this or that...

On a 700R4 its tougher to get everything "perfect" than on a 4L60E as well. If a 4L60E is not just exactly perfect a good tuner can change shift feel with a laptop in no time flat. I am not saying that if your trans shifts completely wrong to just say good enough and mask a problem with the tune. I am saying that once the trans shifts about as good as one can make it mechanically, a good tuner can fine tune it to be just perfect in every possible scenario..

thunderstruck507

iTrader: (18)

Mine is firm but not harsh at part throttle, at higher throttle if you can get first to stay planted on street tires it will bark 2nd pretty hard at 3/4 throttle or more but it doesn't feel harsh when it does this like my old 700r4 did....that thing was a neck snapper at all speeds or throttle levels.

On drag radials 2nd comes on with a firm lunge unless the road surface is particularly slick in which case it will get a light "chirp". At the track it usually gets a sharp "chirp" just like a well driven (but not powershifted) manual car.

On a tight budget so we are trying to rebuild what is already there and know works well so I don't want to alter things much that would send my valvebody back to the drawing board or require a bunch of new upgrade parts that weren't already present.

thunderstruck507

iTrader: (18)

And as far as budget...it almost sounds like more people recommend the stock size band than the wide one.

I could do the Alto Carbon regular size band for half the cost of the wide one...

mrvedit

Wow! That is a very informative and detailed explanation.
That really helps me understand why various shift kits and builders adjust the size of the 2nd feed hole according to the servo (stock, Vette or Super) and the stall of the converter.

I fully agree that getting the 1-2 shift right under all conditions with a low-stall converter is almost impossible; a higher stall converter masks fast 1-2 shifts that would otherwise be annoying.

Thank you for sharing your hard-learned "secrets".
You can remove my valve body any time you want.

thunderstruck507

iTrader: (18)

Anyone here ever handled an Alto Carbon band? My dad said that it arrived and he inspected it but it feels kinda tacky even though it's dry. Maybe just the nature of the material?

Also got a 3-4 clutch pack with BW HE .062" discs and ordered 2 extra .080" discs to tighten it up a little.

Pump should arrive Weds and we are hoping to put it together this weekend. Then I will just be waiting on the converter for it to go back together.

mrvedit

I cannot answer your question about the Alto Carbon band; I have a few extra bands, no longer know which is which, but none feel tacky.
Perhaps Carlsonauto will chime in again.

Glad you ordered a few of the .080 frictions too; this will let you set the desired clearance.

thunderstruck507

iTrader: (18)

That was my thought and they were only $9 shipped.

My backing plate and the one that comes with my kit are thinner than the one you listed above. We are going to search through the stock pile for a thicker one but if not will it be fine to use one of those along with the thicker clutches rather than trying to source a thick backing plate? I do have the thick apply plate.

mrvedit

IMO it is important to use the thickest apply plate; and you already have that. You should be fine. Otherwise, try your local dealer; I may be listed the part # or I might have it at home. My dealer gets such parts for me same day, but that might be because we are so close to Detroit.

thunderstruck507

iTrader: (18)

Glad I ordered some thicker frictions...the steels from the vendor on ebay were thinner than advertised which led to the pack setting up loose. Even with the 2 .080" frictions it only tightened to .045" wet.

We dug through my dads stuff and found a couple thicker steels and got it to set up at .030" wet which should be pretty good.

Also had to adjust pump shim clearance for the new pump. Everything else went back together well. Just waiting on to hear and update on the converter.



Upon further inspection the metal plate of the reverse spring/retainer was severely worn in the middle so it was replaced with a spare. Can't say I've seen that happen before...

mrvedit

Frictions advertised as .067 are often .065 dry. As you discovered, it helps to have a few frictions (and or steels) of different thicknesses available to reach the desired clearance.
Probably insignificant, but I put the thicker frictions/steels in the middle of the pack where the heat might be a bit higher.

Among the builders and experts I have spoken to, I cannot get a consensus on whether thicker frictions (.080 frictions with .080 steels) or thicker steels (.067 frictions with .097 steels) is better; each camp insists they are right. My conclusion is that either works well as long as quality parts are used and the shift is shortened (to reduce friction) by increasing line pressure, increasing volume by drilling the separator plate and a tighter than .050 clearance. And of course careful assembly to eliminate leaks.

Good luck and keep us posted.

thunderstruck507

iTrader: (18)

Just spoke to Dave at Yank, converter is heading back to me today.

Ready to get this thing back on the ground. Being a jackstand jockey during the perfect fall weather is no fun.

thunderstruck507

iTrader: (18)

Spent all evening after work last night getting it back in the car. Dave at Yank was awesome and answered all of my questions and got the converter back to me the same day he had time to cut it.

Car is making all gears with no apparent issues. Second gear feels a little bit softer but that could be me going so long without driving a stalled vehicle, converter might be a tad looser since it was built for my car this time, or the band might just need to burn in to the drum. Only has 6 miles on it so far (babying it) to get some heat in it and check fluid levels.



194 miles to go to break in the converter.

mrvedit

Congrats on rebuilding your trans!

thunderstruck507

iTrader: (18)

Yesterday the car stopped going into park. Went home and fought the B&M shifter cable for 3 hours...could either get it to reliably hit "park" or the drive gears, but never both at the same time.

Pulled the top off the console and it looks like I bent the shifter cable at a weird angle and sandwiched it between the trans case and floor, it must have stretched it a fraction of an inch.

So car is parked again until I get a new one...don't want to risk it breaking when I'm somewhere away from home.

*BANGS HEAD ON WALL* that's what I get for putting the trans in by myself instead of waiting for help

thunderstruck507

iTrader: (18)

UPDATE:

Car is approaching 200 miles and everything seems to have settled in rather well. Feels just like it did before except 3rd is not quite as soggy (very small difference, could even be in my head).

I notice no difference driving between the Alto Red Eagle wide band and the Alto carbon fiber wide band so far. It might become apparent under heavier throttle driving now that the converter is broken in.

I slightly overfilled the fluid (less than a quart at a temp between cold and hot) which I am guessing is why I occasionally smell fluid, guess it is venting some. No drips or leaks anywhere I can find.

All shifts and downshifts I can achieve at mid throttle or less are perfect though. The downshifts to 2nd feel a little more crisp but I can't tell if it's from the band or my imagination.

mrvedit

Excellent news!
You are now a trans guru and great to see you helping others on their threads.

thunderstruck507

iTrader: (18)

I like to give feedback on parts whenever I can. For instance, when searching I could not find any good reviews of the carbon band versus the red eagle band.

I will update this thread again once I get the good tires on so I can really feel what it is doing when hitting 2nd at heavy throttle to try to better compare them.

Auto transmissions are definitely one of the more complex pieces in the car IMO and it seems a lot of people don't like to share their secrets and it can cost a LOT of money to guess wrong.

I want to thank you again for all the help you've posted...while my dad is a very experienced GM trans builder there are things that need to be done differently and better parts to buy when building one to live behind higher HP cars.

thunderstruck507

iTrader: (18)

Update:

I hit the track over the weekend and the new trans feels great there.

Third gear is noticeably firmer at WOT for sure. Very positive and snappy going into 3rd. Second gear feels about the same as before (which was fine).

No changes in ET or MPH (slower than previous bests in fact in better air) which I believe is caused from my lower shift points I tried when it was hitting the rev limiter last time out. Was short shifting by around 300-400rpm.

Best of the day was a 1.70 60ft, 7.48@92.5mph, 11.78@114mph (360 ft DA)
Previous best was 1.68 60ft, 7.42@93mph, 11.67@114.5mph (800 ft DA)

Previous best MPH was 94 1/8 and 116 1/4 on a different pass