4L70E Build for TBSS
Sort of looks like this:
Last edited by mOtOrHeAd MiKe; Oct 23, 2017 at 07:03 PM.
One thing that has me perplexed is that this transmission was ordered from RPM for a 2007 Trailblazer, yet they installed a Trans Go 46-PLT-96 separator plate ('96-06 4L60Es) and it has a 2005 MY valvebody. As I understand it the 2007/2008 4L70E has a more bespoke plate and valve body.
The shop obtained a 46-PLT-07 separator plate to have a fresh unit to work with as we are replacing the Trans Go shift kit for the Sonnax Performance Pack - at this point I am wondering if it is worth getting an '07 valve body too? Or is there a benefit to backdating these parts?
Obviously clinebarger has given you excellent advise, as always.
My only difference would be to suggest a billet 13 vane pump; Chuck (owner) at Finish Line Transmission can hook you up with one; less than $100.
And I also think that the GPZ frictions are equal to the BW HD ones; I have used them successfully and I know a bunch of members here have used them too.
Good luck and keep us posted.
One thing that has me perplexed is that this transmission was ordered from RPM for a 2007 Trailblazer, yet they installed a Trans Go 46-PLT-96 separator plate ('96-06 4L60Es) and it has a 2005 MY valvebody. As I understand it the 2007/2008 4L70E has a more bespoke plate and valve body.
The shop obtained a 46-PLT-07 separator plate to have a fresh unit to work with as we are replacing the Trans Go shift kit for the Sonnax Performance Pack - at this point I am wondering if it is worth getting an '07 valve body too? Or is there a benefit to backdating these parts?
The only difference in the spacer plate is a extra Actuator Feed Limit slot to feed the EPC Solenoid. I have mixed & matched the 2 style spacer plates with each other....Not a functional difference that I have detected!
**2007 Plate Detail (Includes M33 Hybrid) Doesn't show the extra AFL hole.

2009 Plate detail...Shows the extra AFL hole.

2004 GM Corvette replacement spacer plate....Has the extra hole (yellow)
Obviously clinebarger has given you excellent advise, as always.
My only difference would be to suggest a billet 13 vane pump; Chuck (owner) at Finish Line Transmission can hook you up with one; less than $100.
And I also think that the GPZ frictions are equal to the BW HD ones; I have used them successfully and I know a bunch of members here have used them too.
Good luck and keep us posted.
We definitely planned on putting a 13 vane unit back in, just not sure if it was billet or not? I know the builder deals with TCS out of BC, Canada - so I may ask him to order one of these: http://www.tcsproducts.com/products/...ne-pump-rotor/ Because shipping, customs, duty, taxes, exchange rate, etc are all killers for us up here. Otherwise I'll touch base with FLT.
Thanks! This is a very exciting process - I know the builder has been fairly open to the information/suggestions I have provided from the folks here and by my own research. I think it is unusual for this shop to have a customer so engaged in the process.
The only difference in the spacer plate is a extra Actuator Feed Limit slot to feed the EPC Solenoid. I have mixed & matched the 2 style spacer plates with each other....Not a functional difference that I have detected!
**2007 Plate Detail (Includes M33 Hybrid) Doesn't show the extra AFL hole.
2009 Plate detail...Shows the extra AFL hole.
2004 GM Corvette replacement spacer plate....Has the extra hole (yellow)
Fantastic! I will pass this along too. It is a relief to know that there is little consequence in alternating the parts.
The Best V8 Stories One Small Block at Time
I didn't install it in my billet input shaft and I know some mechanics even remove it from the stock shaft.
Oh....And the Accumulator Valve Spring Shim, Throw that thing away!!
The RPM Valve Body probably has the 3-2 valve blocked inboard, I already stated that but I will again because it's important to a performance 4L60E build no matter what Sonnax thinks.
It probably also had a High Rev spring kit in the Input Drum.....Did they get reinstalled?
I understand that RPM treated you poorly, But your converter caused this issue NOT how the trans was built......Or at least I haven't seen anything yet?
Good luck!
Oh....And the Accumulator Valve Spring Shim, Throw that thing away!!
The RPM Valve Body probably has the 3-2 valve blocked inboard, I already stated that but I will again because it's important to a performance 4L60E build no matter what Sonnax thinks.
It probably also had a High Rev spring kit in the Input Drum.....Did they get reinstalled?
I understand that RPM treated you poorly, But your converter caused this issue NOT how the trans was built......Or at least I haven't seen anything yet?
Good luck!
I firmly believe that the builder just wants to feel confident in knowing what he has vs. what another shop may, or may not, have done. And since I am not made of money - buying another VB vs. using the one I have makes sense to me. To this same end I can transfer all of the left over parts from the RPM trans (VB, shift kit, servos, accumulators, etc) into the other unit and sell it as-is (still recommending that it get a soft rebuild). Yes, it seems like an extra step - but it is what it is.
I do believe that the High Rev springs were supposed to be carried over. But, will confirm. I know the hardened pump rings were transferred to the new pump.
I am done poo-pooing on RPM Transmissions - they handled it poorly and I am leaving it at that. I spoke with Dave at Yank about this earlier this week and we had a very civilized conversation. You could tell he was expecting it to degrade into an accusational yelling match; which it didn't. I assured him that I was only offering information and an opportunity to get answers on what let go in the TC. He generously offered me a significant discount if we found that it was an internal failure in the TC locally (granted shipping it back to them from Canada was a nonstarter for me). I appreciated the sentiment and made it clear I wasn't looking for compensation.
Just out of curiousity is this not essentially the same thing? https://www.sonnax.com/parts/2460-fo...buse-bore-plug
That being said, I bought a low mileage 4L80E immediately after the Yank/RPM combo was damaged - before accepting I really wanted AWD.
The 4L80E can go in the station wagon.








