FAQ: What transmissions swap into our Rivieras? ('97-99)

Update.

Add valve cover gaskets and oil pan gasket to the list. I found out I had them at another one of my stores so I got em.

I've also decided I'm going to get the compcams OE-R lifters and a set of non-restricted pushrods.

On the rods though, I can either get ZZP 3/8" which would be the strongest possible on my heads or I can get Intense 5/16" rods which are still stronger than stock plus lighter-weight than stock. The downside to those rods is not actually as strong as the ZZP ones since they are the stock thickness.

Right now, I'm leaning towards the Intense rods (even though i'm buying everything else from zzp). They are cheaper too

Any thoughts?

Does any of this have to do with a transmission thread?

deekster_caddy wrote:

Does any of this have to do with a transmission thread?

No, other than I'm doing it at the same time.

Feel free to move it along with the first part when you scroll up Aaron, please and thank you.

i put a 1998 gtp tranny in my 1998 supercharged riviera with a 3" pully and intense stage 3 shift kit and a 3000 stall converter and on the first run it was real strong....so i tried launching it from a dead stop and it tore out the front tranny mount bolts and tore the rear ones out any body have any clue how to keep the torque under control?

I don't recall the exact details, but it seems to me it's been stated that the Riv version of this trans has a different mounting setup than the W body cars. Wonder if this could be part of the issue? Also possible there were stripped threads???

The GTP tranny does not have the extra webbing braces that the Riv's trans has. AA had similiar problems and a thread about it somewhere with photos...

But you also wouldn't think a "performance" car like the GTP would have a weaker? mounting design than the Riv got? It's not like the Riv weighs a TON more than a GTP, and the eng perf is pretty much identical.

Can anyone say "Torque Management"
Need to tune for it after all the broken metal is fixed.

1998 Riv wrote:

But you also wouldn't think a "performance" car like the GTP would have a weaker? mounting design than the Riv got? It's not like the Riv weighs a TON more than a GTP, and the eng perf is pretty much identical.

GTP has a totally different mounting set-up than a riviera....

mrbigwheels2009 wrote:

i put a 1998 gtp tranny in my 1998 supercharged riviera with a 3" pully and intense stage 3 shift kit and a 3000 stall converter and on the first run it was real strong....so i tried launching it from a dead stop and it tore out the front tranny mount bolts and tore the rear ones out any body have any clue how to keep the torque under control?

Your going to need to find a casing outta a 97-99 Park avenue or a riviera.. MAYBE a bonneville i'm not sure if that has the right webbing...

98riviera98 wrote:

1998 Riv wrote:

But you also wouldn't think a "performance" car like the GTP would have a weaker? mounting design than the Riv got? It's not like the Riv weighs a TON more than a GTP, and the eng perf is pretty much identical.

GTP has a totally different mounting set-up than a riviera....

No shit Sherlock... what's that got to do with my post? You must not be reading it right.

98riviera98 wrote:

Your going to need to find a casing outta a 97-99 Park avenue or a riviera.. MAYBE a bonneville i'm not sure if that has the right webbing...

Hey Genius,
How many transmissions have you swapped all the internal parts out of into another case.
Why not leave the difficult questions to the guys who know for sure.
Your just posting for the sake of posting again.

I read that the most effective way to manage torque and adapt HP to the transmission without damaging internals and what not,is to not step on the gas so hard. it sounds simple ..but you try it!

Rickw wrote:

98riviera98 wrote:

Your going to need to find a casing outta a 97-99 Park avenue or a riviera.. MAYBE a bonneville i'm not sure if that has the right webbing...

Hey Genius,
How many transmissions have you swapped all the internal parts out of into another case.
Why not leave the difficult questions to the guys who know for sure.
Your just posting for the sake of posting again.

Woah... dude.. Was anything i said wrong? And i did swap a tranny in a riv before..

1998 Riv wrote:

98riviera98 wrote:

1998 Riv wrote:

But you also wouldn't think a "performance" car like the GTP would have a weaker? mounting design than the Riv got? It's not like the Riv weighs a TON more than a GTP, and the eng perf is pretty much identical.

GTP has a totally different mounting set-up than a riviera....

No shit Sherlock... what's that got to do with my post? You must not be reading it right.

whoops.... sorry.. I basically said what you did...

This is what the back of the tranny case this OP has...


This is what he needs

I think Derek mentioned he did the same thing or something similar a while back. The trans that ended up with the broken case had all the high performance stuff in it.
Then he had all that stuff transferred into the Riv trans case he now has.

Yes, you need a bonneville/PA/Riv casing to have the proper tranny mount webbing. I believe late mode ('01 and later?) GTPs had the reinforced webbing in the rear.

Does anyone know if a '99 PA Ultra transmission will fit and connect correctly into a '98 Riviera? I heard there was a change in '99, they went to the internal mode switch. To make work, you are supposed to repin some plugs on your harness. Can anyone validate this info?

Thx,
AA

PS - what does "internal mode" mean, anyway?

AA wrote:

Does anyone know if a '99 PA Ultra transmission will fit and connect correctly into a '98 Riviera? I heard there was a change in '99, they went to the internal mode switch. To make work, you are supposed to repin some plugs on your harness. Can anyone validate this info?

Thx,
AA

PS - what does "internal mode" mean, anyway?

The '98 Riviera (G body) trans uses a PNP switch which is integral to the trans. It's powered by Ignition voltage directly, goes through the stop lamp switch, and then on to the shift interlock solenoid. This means that in order to get the car out of park, the tail lamp (brake) circuit must be "completed" in order for the Shift Interlock Solenoid to disengage allowing the shift out of Park.

The '99 Park Avenue Ultra (C body) uses what they call an Internal Mode Switch which basically is a module in itself. Instead of being powered by Ignition Voltage, it is connected to the PCM and BCM via Class II serial data lines. The Auto Trans Shift Interlock Solenoid (notice the name change) is on a completely different circuit, yet controlled by the BCM. On that circuit, the PA utilizes a Lamp Control Module (Park Gear Input), a Stop Lamp/Auto Trans Shift Lock Control Switch (which opens when the brake pedal is pushed), and then on to an Auto Trans Shift Lock Solenoid.

In a nutshell, the '98 Riviera uses only the PCM to help control the trans.
The '99 PAU uses the PCM to control the Internal Mode Switch, and the BCM to control Shift Interlock system.......2 completely different systems as far as communications and solenoids/switches are concerned.

The plugs and harness into the 2 transmissions ARE different, although both 20 pin connectors, the setup is different and will not plug into each other as different wires go different places. I've been staring at the complete 4T65E trans schematics for both the Riv and the Park for about an hour now. Without posting both GI-NORMOUS schematics for you to see, that's about all I can tell you. If you want to know more.....ask and thou shalt recieve

Well, that deserves a "+" vote. Thank you! Without posting the schematics, how difficult would it be to convert a '98 Riv to use internal mode?

AA wrote:

Without posting the schematics, how difficult would it be to convert a '98 Riv to use internal mode?

As far as I can see, a re-wire of the harness in the Riv may be possible. The Park and the Riv both use the same basic operation, as the trans is the same. It's just the way it is controlled. I'm sure with some planning and good thinking we could wire it up, as the PCM controls are the same. A few "extra" wires may be left over, but maybe a good programmer could erase the function of those wires?

I'm up for a good challenge....

I'm not looking for the challenge, I'm looking for something inexpensive I can swap in at some point down the road.

Here's an idea: let's make a list of cars that use the Riviera's 4T65eHD transmission, the cars you can just take out the trans and drop-in plug & play.

'97 Riviera SC (I assume this year used HD version?)
'98 Riviera
'99 Riviera

'97 Park Ave Ultra
'98 Park Ave Ultra

Anyone know some more?

Gotchya covered.....

2 RPO codes are used for the 4T65E trans. RPO M15 is the "standard" trans, and RPO MN7 is the "heavy duty" version.

The heavy duty is only used in the supercharged versions of the 3.8L....Grand Prix, Monte Carlo, Riviera, Park Avenue, and I believe the V8 Aurora (and the rare SC LeSabre).

Here is a list of ALL the cars the 4T65E is used in.....

C body = Park Avenue
G body = Riviera and Aurora
H body = Bonneville, Olds Eighty Eight, LSS and Regency, Lesabre
W body = Grand Prix, Intrigue, Lumina, Monte Carlo and Regal

If you are going to take the trans out of one of these cars, check RPO code on the Service Replacement Transmission Assembly (SRTA) plate on the rear face of the trans to make sure what you are getting is the same. As far as the Internal Mode concern, I'll do some more digging later and post EXACT matches for our Rivieras.....I have to go put an oil sending unit in an Intrepid

Thanks for the info. I know what cars use the 4T65e, and I know the SC engines use the HD version. I was hoping we could identify which ones had the correct mounting config and the webbing structure in the case (some GTPs did not, for example), so we could know which will work - eliminating the need to check the actual unit. I am trying to conduct a search with salvage yards around the state, so would be nice to know which cars have the EXACT same unit - drop-in, plug & play - as '97-99 Rivieras.

For that matter, is it a fact that all '97-99 SC Riv transmissions are the same?