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No experience with the Transgo plate. I understand the Transgo plate is thicker and heat treated to resist peening by the steel check *****. Might be a good upgrade. I've seen a plate where the accumulator spring was on it's way through the plate.
You might also consider is replacing the steel ***** with Torlon.
I use this plate all the time. You have to set it up for the Torlon check *****. I add a hardened corner plate to eliminate the accumulator spring from eating through the separator plate.
I hear somewhere that holes must be drilled for the omitting of the 3-4 load release springs. My drum did not have these springs when I tore it down. I guess that these dampen the centrifugal force of the 3-4 clutches and were found on 4L60E’s
1. The recommendation above is to leave them in if you're running the stock clutch count.
2. Your ATSG manual recommends leaving the springs out (regardless of clutch count) in addition to making or enlarging Hole #44 in the separator plate to 0.093" (~3/32") dia.
If you're using the stock clutch count, you have the two choices above.
The missing booster springs - from ATSG Update Handbook:
"Beginning on July 23, (Julian Date 204) 1988, there were five 3-4 clutch boost springs added between the backing plate and the apply plate in the 3-4 clutch pack, as shown in Figure 55. These "load release" springs were added only on the following models, YDM, TMM, YWM, and YZM for the 1988 model year. Beginning in 1989 they were implemented on all models."
As far as I know, the transgo plate is the only replacement available for a worn out factory plate. Heads up: if your trans has steel check *****, don't reuse them. Install derlin(plastic) ***** instead. The steel ***** won't just tear up your Sep plate but also your case in a hard shifting.modded trans. Be sure to prep the holes for the derlin ***** using a 5/16 steel ball and a brass hammer.
The load release springs are intended to prevent centrifugal apply of the 3-4 clutch and I recommend you use them. The later 3-4 apply plate was designed to have those springs installed. Without them, you will likely have issues with 3-4 clutch failure. The Sonnax Smart Tech input housing comes with long springs for the housings increased 3-4 capacity. You must use the springs with this housing.
When using the Transgo 2-3 shift kit, or otherwise modifying the trans with removal of the 4th accumulator, the 2nd accumulator spring will cause the Sep plate to deform with nothing supporting the plate from the other side. Especially with big servo and boost valves. I use left over accumulator pistons and washers to replace the 4th accumulator piston and fill the 4th accumulator bore flush with the case surface to support the Sep plate. Be sure to drill a bleed hole in the pistons you use for this. There is a bleed hole in the top of the 4th accumulator bore that purges air from the valvetrain. Install the correct seals on the pistons to prevent bore wear and adding unnecessary metal to you trans fluid.
I also use that TransGo separator-plate all the time.
It is slightly thicker and of slightly better material than OEM plates.
I make a lot of changes to the THM700-R4 separator plates... and it is always nice to start with a new plate.
Using the Imidized-plastic/ Torlon check-***** will definitely prevent the normal separator-plate wear/ damage that occurs from OEM Steel check-*****.
I prefer these as well.
Creating a proper seat/ sealing surface in a new separator plate is crucial!
The separator plate orifice (#44/ G) mentioned in posts above is also a crucial addition to any 700-R4 that did not originally have this orifice.
Sizing is also important, and becomes more important with the 3-2 Control valve blocked in the closed position.
I recommend blocking this valve in all performance builds.
Here is a simplified diagram of the circuits for the 2-3 shift including orifice #44/ G:
I have built hundreds upon hundreds of these THM700-R4s and 4L60Es...
I have seen NO difference in using the springs vs not using them.
The way I have been setting up the 3-4 clutch assembly...
I never have issues with these burning-up or wearing-out prematurely.
Once the hydraulics have been corrected throughout the transmission...
Failed 3-4 clutch assemblies will be a thing of the past.
When getting up in power (800 - 1,200 HP) I normally will add the 4L79 input-drum.
This is nearly the ONLY time that I do not use the Borg-Warner High-Energy frictions for the 3-4 clutch.
With the 4L79 input-drum, I will use Raybestos GPZ (THM350 Direct) frictions or Raybestos Stage-1 (THM350 Direct) frictions depending on the intended use for the transmission.
Also if I can not get the Borg-Warner High-Energy frictions for the OEM or Sonnax input-drum... the Raybestos GPZ frictions for the 3-4 clutch do also work very well in comparison to the Borg-Warner High-Energy frictions.
Last edited by vorteciroc; 09-19-2020 at 09:13 PM.
The 4L79 drum looks very interesting. The first real alternative I've seen to the Sonnax. Sounds like the price is good also. I already have the Sonnax but for anyone building a 4L60 for performance should look at 4L79.
The problem with not using the springs with the Sonnax drum is the Sonnax apply plate. The lugsthat engage the apply plate are very shallow. After the first 3-4 failure I had using the Sonnax drum, I could see where the legs of the apply ring were walking climbing up the lugs of the apply plate. I set clearance on the 3-4 at about .050 - .052. That leaves a little more for the apply ring and plate to move around. The springs hold the apply plate firmly in place against the apply ring legs. I don't have the experience of building hundreds of these guys but I try to learn from my failures. My 3-4 shift since this last build feels very good and solid. So far, through several hard runs there is no sign of damage.
I'll be giving my 700 a freshen soon and will be putting in some new hard parts. Some of these look very promising for my level of stupidity I put them through
The 4L79 drum looks very interesting. The first real alternative I've seen to the Sonnax. Sounds like the price is good also. I already have the Sonnax but for anyone building a 4L60 for performance should look at 4L79.
The problem with not using the springs with the Sonnax drum is the Sonnax apply plate. The lugsthat engage the apply plate are very shallow. After the first 3-4 failure I had using the Sonnax drum, I could see where the legs of the apply ring were walking climbing up the lugs of the apply plate. I set clearance on the 3-4 at about .050 - .052. That leaves a little more for the apply ring and plate to move around. The springs hold the apply plate firmly in place against the apply ring legs. I don't have the experience of building hundreds of these guys but I try to learn from my failures. My 3-4 shift since this last build feels very good and solid. So far, through several hard runs there is no sign of damage.
BTW, 4L80M 5-speed? That sounds very interesting.
Nice!
For your next THM700-R4 or even 4L60E; try and tighten up the 3-4 clutch clearance to about 0.030" - 0.035".
I find this clearance to be optimal for the 2-3 shift and 3-4 clutch longevity...
2-4 servo clearance should be set to 0.060" for proper timing on the 2-3 shift.
Block the 3-2 control valve closed; and drill separator plate hole #44 if not originally in the plate.
The separator plate orifices for 3rd feed, 3rd exhaust, and band release (#44) all need to be drilled/ sized in a relationship to one another for 2-3 shift timing and 3-4 clutch life.
HP/ vehicle combination will dictate different hole sizes.
Yes lol a 5-speed 4L80E... If I changed the gear set ratio, it could have been a 6-speed like a TCI or PCS unit.
I used to be on the GM engineering team for the 4L80E... I absolutely love the transmission!
For your next THM700-R4 or even 4L60E; try and tighten up the 3-4 clutch clearance to about 0.030" - 0.035".
I find this clearance to be optimal for the 2-3 shift and 3-4 clutch longevity...
2-4 servo clearance should be set to 0.060" for proper timing on the 2-3 shift.
Block the 3-2 control valve closed; and drill separator plate hole #44 if not originally in the plate.
The separator plate orifices for 3rd feed, 3rd exhaust, and band release (#44) all need to be drilled/ sized in a relationship to one another for 2-3 shift timing and 3-4 clutch life.
HP/ vehicle combination will dictate different hole sizes.
Yes lol a 5-speed 4L80E... If I changed the gear set ratio, it could have been a 6-speed like a TCI or PCS unit.
I used to be on the GM engineering team for the 4L80E... I absolutely love the transmission!
Outstanding
I have a 4l80e gm reman still in the crate for traditional sbc/bbc bolt pattern. Anything I need to look at parts wise to help it hold 1000-1500hp or what are the "stock" limits?
Most of the 4L80E stock components are good for 1,000 HP.
The direct-clutch needs to be "dual-fed", the input-shaft needs to be upgraded, along with a PR boost-valve/ valve-body recalibration kit...
Will get the transmission to be good for 700 - 800 HP, unless the vehicle is very heavy/ a truck.
The forward clutch hub should start to be upgraded at this point...
High revving engines also should have an intermediate sprag upgrade at this power level to a 36-element version...
Otherwise the transmission is good for 1,000 HP.
From there upwards in power, more modifications are needed.
These transmissions can support a good 1,800 HP when upgraded accordingly...
Past that, a THM400 should be considered instead... up to about 3,500 HP.
04-23-2020, 09:01 PM
