Chevy Impala SS Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
551 Posts
Discussion Starter · #1 · (Edited)
Tranny was rebuilt about 2 years ago with "good" parts. however it appears the Rabestos Z pack has given up 3/4.

Going back in , I'm looking for yeah nay on the following parts.

Remember , the tranny is still working good 1/2 , just 3/4 slipping.

Here we go:


Sonnax .490" boost valve
Red Eagle standard band - heard mixed reviews on the Carbon Fiber Band
Red Eagle Master kit
Molded 3/4 Clutch Piston
Bushing Set
Thrust Bearing kit
Superior/Fairbanks Intermediate and Over Servos - has corvette in it now
High pressure Spring 4L60E high output pump slide spring

this is going together in the next week to 10 days, trying to get to SSH10.

Let me know ASAP.

Thanks,
 

·
Registered
Joined
·
448 Posts
Sonnax .490" boost valve OK.
Red Eagle standard band - heard mixed reviews on the Carbon Fiber Band OK, the factory BW Hi-E Band is better
Red Eagle Master kit NO!!! Just use the factory clutches everywhere and install 8 BW Hi-E clutches in the 3-4 pack. This works very well, will take a lot of abuse.
Molded 3/4 Clutch Piston OK.
Bushing Set OK.
Thrust Bearing kit OK.
Superior/Fairbanks Intermediate and Over Servos - has corvette in it now NO, do not use the Superior for the 2nd apply. If you must go larger go with the Sonnax here and in 4th apply if you make a lot of WOT 3-4 shifts.
High pressure Spring 4L60E high output pump slide spring OK.
I use a "modified" version of the Raybestos Z-Pak, and that does better than the one from Raybestos.
 

·
Super Moderator
Joined
·
8,894 Posts
The two Z-packs I've seen with wear on them (still have them actually, may put a set in my wagon if/when it eats the 3-4 clutchpack) resulted from problems in other parts of the transmission (like line pressure leaks). I would be very sure to air check the input housing for leaks before it gets disassembled any further.

BTW, if your builder hasn't done this before (I've seen builders that haven't), use ALL stamped steel pistons in the input housing, not just the 3-4 piston. You can buy all three, just make sure to also get the modified release springpack for those steel pistons, GM P/N 24206085, as the stock springpack will not work with them.
 

·
Super Moderator
Joined
·
7,841 Posts
Sonnax .490" boost valve



* Be sure and get the one without o rings. You want the factory style .490 boost valve with no o rings.


Red Eagle standard band - heard mixed reviews on the Carbon Fiber Band


* I like the Alto black carbon composite band. I have seen it hold up to more abuse than the Alto red. I disagree with dana here on the borg warner being as good.

Red Eagle Master kit

* Not a problem to use this but its a waste of money. WHy put kolene steels and red eagle clutches everywhere even where they arent needed. I have done it but only when its requested.


Molded 3/4 Clutch Piston

*Use all 3 as sherlock said with the correct spring pack.

Bushing Set
Thrust Bearing kit

Good ideas
Superior/Fairbanks Intermediate and Over Servos - has corvette in it now


* I agree use these two servos, and drill the feed holes to 1/8 inch everywhere transgo says to use .093. Leave the accumulators stock. It will make for a nice shift.

High pressure Spring 4L60E high output pump slide spring

*good


this is going together in the next week to 10 days, trying to get to SSH10.

Let me know ASAP.

Thanks,[/quote]



Make it happen!
 

·
Registered
Joined
·
551 Posts
Discussion Starter · #5 ·
Guys , thanks for the feedback. Exactly what I needed.


You guys are the "drips under pressure" :)


Dustman and Dana - I've followed the discussion on 2 Billet Servos - I thought the answer was NO. But it appears it's still undecided.

Any strong opinion if I just use the Superior on the intermediate and leave the overdrive alone ? Yes i followed the Sonnax issue also, it left me with questions.

Car has transformed to a medium duty race , with moderate street usage, but half the runs are 1/8th , rest are 1/4 mile.

sherlock9c1 - I did not know you could buy all three. Will definitely get the springpack.
Can you help with either a vendor or a part number ?
 

·
Super Moderator
Joined
·
7,841 Posts
Guys , thanks for the feedback. Exactly what I needed.


You guys are the "drips under pressure" :)


Dustman and Dana - I've followed the discussion on 2 Billet Servos - I thought the answer was NO. But it appears it's still undecided.

Any strong opinion if I just use the Superior on the intermediate and leave the overdrive alone ? Yes i followed the Sonnax issue also, it left me with questions.

Car has transformed to a medium duty race , with moderate street usage, but half the runs are 1/8th , rest are 1/4 mile.

sherlock9c1 - I did not know you could buy all three. Will definitely get the springpack.
Can you help with either a vendor or a part number ?


If you want the transmission to have good holding power and a nice third shift, use both billet servos.
End of story.
 

·
Registered
Joined
·
551 Posts
Discussion Starter · #7 ·
Ok , sounds good.


What exactly is the problem with the 3/4 shift causing all this trouble ? or is it a complication of several things just adding up ?
 

·
Registered
Joined
·
86 Posts
Any strong opinion if I just use the Superior on the intermediate and leave the overdrive alone ? Yes i followed the Sonnax issue also, it left me with questions.

VF1000R
What questions do you still have about the servos? The differences between the Superior/TCI style servo and the Sonnax/factory style servo are very significant. The biggest issues are (1) the Superior/TCI style servos eliminate the cushion spring. There is no benefit to eliminating the cushion spring and the result is excessive harshness that leads to broken parts (a very real problem with these units) when power and traction are combined. The more power you have the more relevant this difference is. (2) The Superior/TCI style servo also changes the way the servo releases on the 2-3 shift. At the highest pressures the Superior/TCI style servo may not fully release because of the changes. The differences require detailed understanding of the way the servos work, but the main point is the Sonnax 2nd servo functions the same as the factory servos but has more apply area than the Corvette servo.

Regards,
Gregg Nader
Sonnax Tech
847-543-8900
 

·
Registered
Joined
·
551 Posts
Discussion Starter · #9 ·
Question is ,

Is it OK to use the Sonnax and Superior together, if so , in what order ?

If not, then Sonnax and what ?


thanks for the reply. the pin length discussion was interesting to say the least !
 

·
Registered
Joined
·
86 Posts
Sonnax 2nd, Sonnax 4th:: 2nd 17% more apply, has cushion, works like factory. 4th 40% more apply.

Sonnax 2nd, Factory 4th:: OK
Sonnax 2nd, Superior 4th:: OK

Superior/TCI 2nd, Sonnax 4th:: NOT OK, Requires 2nd piston to be machined or other modification to provide clearance for Sonnax 4th washer.

Regardless of what set up, set servo pin travel to .075” - .125”
 

·
Registered
Joined
·
551 Posts
Discussion Starter · #11 ·
Ok, thanks,

Edge Racing sells the servos cheaper than i have found anywhere else.


there are no dumb question, so i'm asking one :)


Running 1/4mile track, The selector set to "D" not "OD". Go thru the traps at about 112 :0 , question is, did the transmission ever see 4th gear ?

My gut says no.

If that's the case, is there any argument for beefing up OD ?
 

·
Super Moderator
Joined
·
8,894 Posts
The 2-3 shift gets more line pressure if you race in OD vs. D. I can't find the thread on it at the moment but it's been documented by a number of folks on this forum. I personally have seen it happen on my cars via a line pressure gauge and a seat of the pants feeling to boot.
 

·
Super Moderator
Joined
·
7,841 Posts
Theres too many cooks in this kitchen. If someone is telling you to race in D the rest of their advice might not be so good.

Race in OD. Also, use the fairbanks servos, the sonnax stuff sucks. BTW i dont work for sonnax like the guy above me pushing the stuff does.


Racing in OD does the following, Disengages the overrun clutches and increases fluid to the third clutch making for more line and better shift feel, also using the fairbanks 2nd servo eliminates the built in cushioning for the third shift. Third gear dosent need a shock absorber in these transmissions. So if you want a performance transmission dont use the sonnax one, because the vette, and sonnax ones work, but not as well as the fairbanks.
 
1 - 15 of 15 Posts
Top