Building a 48re

[Srt10650]

Hello, I’m rebuilding my 48re and wanted some input from the 48re gurus. I’ve been looking a the diesel guys forums for a while and they know what works for the diesel application. I’d say they have us covered about 75%, basically what I’ve read the difference between the diesels and the srt10 48re is the valve body calibrations and the pump.

Little info on my truck, 05 quad cab currently has bolt ons. Truck will be getting a Roe Whipple, I’d say maybe about 600whp. Truck will not be daily driven, weekends mostly with some track use. Just want to see what works for us, thanks.

For this application what would the recommendations be?

Sonnax input?
Sonnax output?
Sonnax billet servos?
Sonnax intermediate shaft?
2800 or 3200 convertor?
Triple disc or single disc converter?
Billet flex plate?
727 front band?
Transgo shift kit or built valve body?
DNJ GM solenoid or Borg Warner solenoid?
Rostra HD transducer or Gold transducer from the 47RE?
5 or 7 clutches?
What ratio lever?
What fluid to use after rebuild?

What I know for sure is
Deep transmission pan
Sonnax strut
Billet anchor
727 filter

 

[rottenronnie]

I have a "1500 Horsepower Diesel Build" with no special treatment just because it is behind the 8.3L. They are the same transmission.

The Valve Body & Front Pump are identical between the diesel and SRT-10 48RE.
RPM Shift control & O/D lockup is through ECU programming.
I upgraded to a Billet Input Shaft.
The Output Shafts are tough and it doesn't need to be changed.
The Intermediate Shaft doesn't need to be changed either.
A 2800 stall convertor (good quality) is a great choice.
727 Front Band is a good choice as they are meaty.
GM Solenoid is a required mod in my opinion. (Have the Mechanic watch the attachment surface, it may need a bit of filing to fit/seal properly to the Valve Body).

I went with the 47RE Gold transducer.
Don't use race clutches as they are for full-throttle application only.
You can use 5 or 7 clutches (your choice), it depends on how loose/tight they are installed.
Stock ratio activiation lever is fine.

I use Dex 6 (GM Fluid) that doesn't use friction modifiers the mopar fluid uses (primarily for their Mini-Vans). And it doesn't stink like Mopar Fluid!

Shift kit (your choice); My Valve-Body was modifed by the Builder so I don't have an aftermarket shift kit.
As an additional safety measure, my planetaries were pinned. Not necessary, but I did it anyway.
I'm using a stock flex plate.

Have the valve body modifed to prevent drainback when sitting for a while. It MAY be part of the shift-kit. Your tranny guy should know.

I'd also change out the cooler hose that has a check valve in it as they have been known to fall apart inside. I had a hose made without a check-valve, instead of installing another OEM hose that could cause an issue down the road. It is the hose behind and below the washer bottle. Again, check with your tranny guy.

It might sound counter-intuitive but a deep pan WITHOUT the filter extension is the way to go. That will keep any particulates away from the Solenoids and help keep them at the bottom of the pan where they belong and further away from the Filter Inlet.

Plugging up the TINY screens on the O.E.M. Solenoids with particulates prevents the Valve Body from producing full line-pressure for Bands/Clutch application and is the 48REs main weakness. So...the larger screens on the GM Solenoids can help the 48RE live considerably longer.

Make sure the initial Band Adjustments are per the 48RE shop manual as they differ slightly between the SRT-10 and Diesel. Tighten to 72 inch pounds, back the screw off 1-1/2 turns then tighten the locknut.

Your ECU will look after shift-point rpm. By the way, have your Tuner extend the 3-4 (Overdrive) shift-point. I have mine set for 120 mph. It makes a LARGE difference and prevents the tranny from short-shifting and potential engine detonation when you are up there in vehicle speed and pushing a lot of air.

As simple as the 48RE appears to be, there seems to be a real shortage of guys that know how to build them properly, (at least around here).

I'd also suggest having a good look at your warranty.

Good Luck.

 

[Adam Craig]

I have a "1500 Horsepower Diesel Build" with no special treatment just because it is behind the 8.3L. They are the same transmission.

The Valve Body & Front Pump are identical between the diesel and SRT-10 48RE.
RPM Shift control & O/D lockup is through ECU programming.
I upgraded to a Billet Input Shaft.
The Output Shafts are tough and it doesn't need to be changed after checking all https://epicvin.com/license-plate-lookup/california.
The Intermediate Shaft doesn't need to be changed either.
A 2800 stall convertor (good quality) is a great choice.
727 Front Band is a good choice as they are meaty.
GM Solenoid is a required mod in my opinion. (Have the Mechanic watch the attachment surface, it may need a bit of filing to fit/seal properly to the Valve Body).

I went with the 47RE Gold transducer.
Don't use race clutches as they are for full-throttle application only.
You can use 5 or 7 clutches (your choice), it depends on how loose/tight they are installed.
Stock ratio activiation lever is fine.

I use Dex 6 (GM Fluid) that doesn't use friction modifiers the mopar fluid uses (primarily for their Mini-Vans). And it doesn't stink like Mopar Fluid!

Shift kit (your choice); My Valve-Body was modifed by the Builder so I don't have an aftermarket shift kit.
As an additional safety measure, my planetaries were pinned. Not necessary, but I did it anyway.
I'm using a stock flex plate.

Have the valve body modifed to prevent drainback when sitting for a while. It MAY be part of the shift-kit. Your tranny guy should know.

I'd also change out the cooler hose that has a check valve in it as they have been known to fall apart inside. I had a hose made without a check-valve, instead of installing another OEM hose that could cause an issue down the road. It is the hose behind and below the washer bottle. Again, check with your tranny guy.

It might sound counter-intuitive but a deep pan WITHOUT the filter extension is the way to go. That will keep any particulates away from the Solenoids and help keep them at the bottom of the pan where they belong and further away from the Filter Inlet.

Plugging up the TINY screens on the O.E.M. Solenoids with particulates prevents the Valve Body from producing full line-pressure for Bands/Clutch application and is the 48REs main weakness. So...the larger screens on the GM Solenoids can help the 48RE live considerably longer.

Make sure the initial Band Adjustments are per the 48RE shop manual as they differ slightly between the SRT-10 and Diesel. Tighten to 72 inch pounds, back the screw off 1-1/2 turns then tighten the locknut.

Your ECU will look after shift-point rpm. By the way, have your Tuner extend the 3-4 (Overdrive) shift-point. I have mine set for 120 mph. It makes a LARGE difference and prevents the tranny from short-shifting and potential engine detonation when you are up there in vehicle speed and pushing a lot of air.

As simple as the 48RE appears to be, there seems to be a real shortage of guys that know how to build them properly, (at least around here).

I'd also suggest having a good look at your warranty.

Good Luck.

Thank you for this useful information!

 

[rottenronnie]

You are welcome.
That's what Forums are for (I think).

 

[Srt10650]

Just wanted to update the thread. Decided to hold off on my rebuild, the only issue I was having was I would have to release the gas pedal to get it to shift into 2nd from 1st. Upgrade a lot of components in the valve body with Sonnax parts, DNJ governor pressure solenoid, 47re transducer, 727 front band, transmission cooler thermostat delete kit and transgo shift kit.

 

[Srt10650]

I installed the transgo HD2 shift kit when I first got the truck but they upgraded some components on the transgo PRO shift kit so decided to install that as well.

 

[VIPR PWR]

I installed the modified Sun Coast valvebody .. made a difference and still after all these years works fine.... chirp chirp !

 

[VIPR PWR]

Talking to order the valvebody from SunCoast ... he told me it makes a difference between the Srt10"'s and the diesels .. Something about deiels torq and the fast reving of the 10's ..
I know years ago there was a thread about that ...@rottenronnie can you enlighten us on this thread

 

[VIPR PWR]

@rottenronnie

 

[Srt10650]

Perfect timing too because I noticed my transmission pan gasket leaking.

 

[Srt10650]

Here’s a few pictures of when I removed the valve body, cleaning and installing the sonnax valves.

 

[Srt10650]

For comparison here are the pictures of the stock governor and the DNJ with the GM governor. And also the stock 48re transducer with the 47re transducer.

 

[rottenronnie]

@rottenronnie

Not sure, as there isn't quite enough info and there isn't a question in there, so...??

The valve bodies for the 48RE are the same part number for the SRT-10 and the diesel.

The shift kits can be tweaked for the application.

The 10s are fast revving in comparison and if the tuner sets the shift points too high, they will bounce off the Rev limiter during w.o.t. adventures and require letting off the throttle to make the shift.

The main advantage to using a shift-kit is to reduce the 1-2 shift overlap which keeps them alive longer by reducing clutch/band debris from entering the oil and clogging the Governor screens.

Hope this helps.

 

[Srt10650]

Here’s the stock accumulator piston and the sonnax billet accumulator piston. And the stock servo with the sonnax billet servo.

 

[rottenronnie]

For comparison here are the pictures of the stock governor and the DNJ with the GM governor. And also the stock 48re transducer with the 47re transducer.

Great pics.
When using different Governors than o.e.m., make sure they are FLAT when mounted as the sometimes the corner of them hits the tranny case and will NOT seal like they should.
(Require a bit of grinding sometimes).

 

[Srt10650]

Here’s the stock anchor and band strut. With the upgrade band strut and anchor.

 

[Srt10650]

Here was my issue, stock band had no material left. So I upgraded to the 727 band. Inspected the drum and had no groves from the band. Looks like I got in there just in time. The band was installed with the transmission inside the truck, just hand to cut the old one out with some pliers. I had to bend the tab a little with a vise and used a wire coat hanger to pull the new band in. Wasn’t too bad of a job.

 

[Srt10650]

All wrapped up, installed the new TCC solenoid, new neutral safety switch, new speed sensor and new 727 filter.

 

[Srt10650]

Band adjustments, connected all the cables(shifter and throttle), fluid and she’s back on the streets.

 

[VIPR PWR]

Not sure, as there isn't quite enough info and there isn't a question in there, so...??

The valve bodies for the 48RE are the same part number for the SRT-10 and the diesel.

The shift kits can be tweaked for the application.

The 10s are fast revving in comparison and if the tuner sets the shift points too high, they will bounce off the Rev limiter during w.o.t. adventures and require letting off the throttle to make the shift.

The main advantage to using a shift-kit is to reduce the 1-2 shift overlap which keeps them alive longer by reducing clutch/band debris from entering the oil and clogging the Governor screens.

Hope this helps.

I can't remember the why in the old thread that was on here or what the suncoast guy said the reason was ...

I think it has something to do with pressures and fluid depriving the bands and or clutches between the diesel and the 10's higher higher faster reving ,when replacing the valve body ...

I did install a transgo shift kit at first ,,, it helped but i wasnt satisfied and replaced the entire valvebody with the suncoast one ....