how much HP can 3400 handle

[schweppe23]

From the factory if I had a choice between the 4t45 and the 4t65, I'd most likely have gone with the 4t65.

My 4t45e was sufficient until I added the supercharger and new engine. Even with the increased line pressure via my dhp tune it only lasted like 4-5k miles. I last ran the car in September at ATCO raceway with the best ET of 13.75 and trap speed of 104.17. The transmission pretty much died that day. I trailered it home pulled it out and had it rebuilt here locally by Carl Rossler of Rossler Transmisson.

We had all kinds of problems getting parts for this trans....first Raybestos says they got the gen2 blue clutches and then they say they don't and after several calls back and forth we finally got them to start production on them. So we got the first two sets off the line. Then we couldn't find kolene steels for the unit so we had to have those made. Then Rossler made custom bilet accumulator pistons were made, the stock ones are PLASTIC! Then he did made his proprietary changes to the valve body/pump and new electronics. Well it was just finished a while back and I got held up on the return of my headers for a little bit. But I expect to have her up and running in the next couple of days. I will be posting my results of the unit and plan to take it to the track in a couple of weeks for an accurate comparison. I have no doubt that this trans will allow me to break my personal best by a healthy margin.

Todd I'd upgrade the accumulator pistons and possible have your input/output treated. Are you doing anything with the valvebody?

To get back on topic of the 3400...I've had mine reworked a little and put down 254whp, this translates to approximate 318HP and this was before I swapped to a smaller pulley. From the calculations that I've done I'm now making 277whp. Like everyone has said I'd worried about the trans and not the engine so much.

[Quinky]

What let go on your 45??

[tejohnson]

Todd I'd upgrade the accumulator pistons and possible have your input/output treated. Are you doing anything with the valvebody?

To be honest, we have been waiting for the Limited Slip before there is any forward progression... Why pull all the items out of the case seeing how it has taken 4 freakin months so far (There really is no excuse for this any longer, and yes, I'm a bit pissed).

So I assume you are gonna keep it

[Sorry for the multiple digressions I have placed in this thread. Perhaps it should be titled "how much HP can 3400 transmissions handle" ]

[lumination]

Overall I think when GM builds a transmission they build it not to last.....When the aftermarket steps in, it lasts...

I am a bodyman at a local kenworth dealership and can tell you for a fact that vehicle manufatures do intentially build some weak parts on their vehicles. American car companies build a vehicle that will break parts and when they do the customer cannot repair it themselves(specialty tools and cramped spaces and throw away cars) so they make money off the parts, labor and if your really fed up you buy another car from them. If they spent half the sticker price of a vehicle on making it they would build an indestructable car thus putting themselves out of business.

[v6h.o.]

Not sure why Todd hasn't posted here (maybe because the thread name doesn't bring up trannies), but here are some pictures of your "strong" tranny...

http://groomlakelabs.com/gallery/transmission

Know how many of those we see ONLY during winter months here in canada? The only reason those failures happen is because of either burnouts or people being stupid on ice giving the car full throttle with no traction on ice, then they all of a sudden hit a patch of solid ashphalt and WHAM the diff pin shears from shock of doing 50+kms per hour spinning to a sudden one wheel stop and then exits the case. ALL 4t40/45 diff pin breakages are from customer neglect.

I'm not getting into the 60 vs 40 debate. This dealer tech would rather stay out of it. I disslike both as they both have the same problem -AUTO.

[tejohnson]

Know how many of those we see ONLY during winter months here in canada?

I could only imagine. Mine happened in August tho... Mine wasn't really neglect, but obvious abuse, slamming the gas pedal with the wheels turned. Shame on me. But you have to admit that using a small pin through the diff pin to the carrier assembly to hold it into place is a rather poor design. Perhaps it would have been nicer to not create a weak spot in a pin which becomes heated due to spyder gear rotation by creating a threaded pin on one end going into the diff, or other suitable locking mechanism. But this is only my opinion...

[vsop4me3.1]

I'm not getting into the 60 vs 40 debate. This dealer tech would rather stay out of it. I disslike both as they both have the same problem -AUTO.

ain't that the truth. If I had a nickel for everytime I wished my 4t65 was a stick, I'd have a 5spd by now.

[v6h.o.]

But you have to admit that using a small pin through the diff pin to the carrier assembly to hold it into place is a rather poor design. Perhaps it would have been nicer to not create a weak spot in a pin which becomes heated due to spyder gear rotation by creating a threaded pin on one end going into the diff, or other suitable locking mechanism. But this is only my opinion...

This is how all Diff pins are made, Diff pins always have a hole in one end for either a bolt or a roll pin to hold them in place in the differential. wether it be a 4t40e, 4t80e, a 5spd getrag, isuzu, or a 10 bolt gm rear end ect/ect/ect. They all use a diff pin that is held in place by a pin/bolt that goes through the one end.

[geoffinbc]

Yea no shit they have been like that since the beginning of differential time.

I supose you could use a snap ring to hold it aswell. But the pin works fine as long as you do not over torque it when installing it. Once you do this you can bet it will snap if you try and remove it in the future.

[v6h.o.]

I am a GM trans tech that works with Colin. And the way i see it is that Hydra-matic better not stop making the 4T65-E. I plan on sending my kids through collage, and I have 3 of them.

The 4t40/45 is by far a better design right from the word go. It uses progressive shift like it's big brother the 4t80-e. and for all of you that dont know what that is it applies one clutch and then another. It does not have to remove any clutches on an up shift. then to down shift it only has to remove one clutch to achieve the next lower gear. This eliminates shift tie ups and delays like is on the 4t60/65. Also if you look at the internals of both transmissions the hard parts are larger and stronger in the 4t4x than in the 65's. The 65 uses 2 drive link chains that run one tooth out. this is for a quiet operation. but by doing that it removes alot of strenght out of it. the 45/45 uses a single chain witch is larger and stronger. I have seen a brand new set of chains installed in a GTP break just because of a set of 20" wheels.

The input carrier in the 4T65e are prone to bearing failure. The shell breaks apart and goes through the planetary gear sets. To this day I have not yet seen a 40/45 take out a carrier.

To address some peoples concers about shift quality in the 40/45. There is an updated pressure regulator valve and spacer plate for them. it is a minor repair.

Diff pins shear in both transmissions. The only thing is that if it happens in a 45 you will need a new case.

In my eyes the 4T40/45 are a better trans. But like i said in my first statement I hope that the never stop production of the 4T65-e. GOD BLESS THE GENERAL!!

[Quinky]

In my eyes the 4T40/45 are a better trans. But like i said in my first statement I hope that the never stop production of the 4T65-e. GOD BLESS THE GENERAL!!

My shop totaly agrees... GOD bless the 60/65's.. For ever will they keep us transmission shops in buisness...

[sharkey]

In my eyes the 4T40/45 are a better trans. But like i said in my first statement I hope that the never stop production of the 4T65-e. GOD BLESS THE GENERAL!!

My shop totaly agrees... GOD bless the 60/65's.. For ever will they keep us transmission shops in buisness...

i deffinitly agree with that. the 60/65 is one of the great things that happened to the transmission buisness. those and the chrysler a604.

[tejohnson]

There is an updated pressure regulator valve and spacer plate for them. it is a minor repair.

Part numbers please

So, does this mean that the 4T45-E can technically handle more horsepower than the 4T65-E?

[v6h.o.]

There is an updated pressure regulator valve and spacer plate for them. it is a minor repair.

Part numbers please

So, does this mean that the 4T45-E can technically handle more horsepower than the 4T65-E?

95-2001 UPDATE, (2002+ does not need this as it has the updated regulator valve and spacerplate) spacer plate kit, 24224336
and while your in there put in a new pressure control solenoid 10478146

besure after this to clear your trans adapts, (will need tech2 to do so)

[94Camaro]

Tiago had his rwd 3.4 (i know i know, not the 3400 but the block is the same and so are the pistons (just a different dish), crank, rods..etc..) up to 16psi at one point and time. if you wanna know bout turboing the 3.4L (RWD or FWD) talk to him, he might know a thing or two.

hes on this forum somewhere...

-R