Beafing up your 4T40-45E transmission- Tips & Tricks

Well , these are not your mom & dad's Hot rod's :grinno:

I'm not going into great detail,
but I am going to tell you and show you what happens when tiny things go wrong.
Whether you are wanting to rebuild due to failure, or beaf up your trany to handle more HP good Luck and bring your credit cards :D

I am in the process of rebuilding a 4T45E-MN5 for my SE - SS project.
I will say now right off, I AM NOT A TRANS REPAIR MAN.
I am only doing this because I refuse to pay someone else when I am capable,
and I am thinking about doing more trans work myself........ maybe.

Most likly no one will attempt this work on thier own,
but this will give you a guide to help someone who can rebuild your trany
and an idea of how much cost.
You could spend $10,000 and these tranys would still crap out.

Here are "some" of the parts (http://i28.photobucket.com/albums/c242/xeroinfinity/Transmission/4T40e_45e.jpg)involved.

Most every thing in the blue squares come with a new clutch kits.
Except for the left three parts in the "B" section.

Right now the best clutches out are Raybestos Blue plate Clutch kit- # RCPBP-29 (http://i28.photobucket.com/albums/c242/xeroinfinity/Transmission/RayBlueplateclutchpac.jpg).
Cost around $350 full kit.
In the next year or so thier will be better ones on the market, that is what I will be installing on my 99' 4T45E for test for Raytech .
This site also sells the Blue plates, http://www.transmissioncenter.net/alto_2.htm

So, here is a picture of what the OEM clutches & band assortment (http://i28.photobucket.com/albums/c242/xeroinfinity/Transmission/burnt-wimpyclutsmll.jpg)look like.
AS you can see the one in my hand is about 3" acrossed.
All the rest under are only about 5" , very whippy. :disappoin

Those from my trans were smooth and burnt, should have groves but are groveless.
The one in my hand is the only one with any groves :(

Here is a pic , this is an 03' with the updated Valve body.
Housing & gears (http://i28.photobucket.com/albums/c242/xeroinfinity/Transmission/45eshaft-housing.jpg) Limited Slip differential (LSD) driver gears and shaft are still intact.
This is what I am rebuilding, the 99' had groves and scratches (http://i28.photobucket.com/albums/c242/xeroinfinity/Transmission/housingscratches.jpg) that were not repairable.

Initially the part in the First pic, section "D" red/blue square broke causing the clutches to slide/slam back and forth. :shakehead
That is what caused this to happen finally killing (http://i28.photobucket.com/albums/c242/xeroinfinity/Transmission/45ELSDwasted.jpg) the trans.

As you can see on the left(yello arrows),
the teeth are chipped bad and a piece of one is stuck inside the gear spline.
The pin was so sloppy it fell out of one side :disappoin
That explains the clicking sounds :lol:

Btw... that was also my core for the EP Limited slip differential (LSD) (http://www.engineered.net/eplsd.htm)
They sell two different LSD's a street version and a race version. I bought the race ver.
- EP LSD cost $500 + shipped old LSD back$70
another $70 on the order :banghead:
- Total cost $647

So in that parts list above(first picture) everything in red & the blue I had to replace because they failed and were broke. Which is recomended when rebuilding a trans.
OH Kit -- 4t40e-4t45E 95'+ -- Approx $260

Along with a new torque converter, which always should be done if rebuilding.
Shoot for a reinforced heavy welded fins.
- Cost around $250 + core return.
- 03' Trans core for parts cost $75-ends up being the "one".

- Pressure switch40-45e Cost $160
- OD band cost $45
- A&B shift solenoid 45E cost $88
- VSS cost $46
- Then you have fluid approx cost $65
- Filter cost $35

Here is a pic of the front trans housing (http://i28.photobucket.com/albums/c242/xeroinfinity/Transmission/4t45etranstempplug.jpg).
* Notice the orange caps, this is where the trans lines go.
- The blue arrow is what holds on a steal plate which holds in the hoses.
- The red arrow below, is the ellusive trans temp plug :D

** In order to install a temp gauge sending unit
you'll need to cut off the very bottom of the steal bracket which covers part of the Line test plug.
Other wise the sending unit will be in the way of the said bracket.(I'll try and post a pic of this later).
- The nut holding black bracket on is 10mm.
- Also use teflon tape on the threads or she'll leak.

Total cost so far - $ 2021 :eek7:

More later......

I should receive the EP Limited slip differential today or tomorrow... I hope !

I actually bought a manual for this model transmission off ebay for $35 used.
I also hope it all goes back together with no leftover parts :cwm27:

soooo thats where that damn plug is lol... *saves pic*

Yes Gir it was hidden.
I knew it was there, but just couldnt get a pic of it in the car.

On with more build talk.
If this work is being done for you then expect to pay for around 9-10hr of labor on extraction/reinstall.
- Aprox Cost $500-800
- On rebuilds I also suggest getting the radiator trans cooler lines Hot flushed to clear out old fluid/debrie.
probly Cost $60-80

For the actual rebuild labor work(not sure on the hrs) though I would expect it to cost $500+.

I also took my Valve body to a trans shop and had a guy map it out. He reamed a few holes to increase line pressure and make it have a more consistant line pressure during normal to hardcore situations.
Also the 2003 Updated Vb and the trans pump has a larger shaft and stronger fins on the pump. They also updated the gaskets.
-- Which any trans shop should be up to date on things like this, if not find a better shop.
They charged me $75 for "adjustments" , plus a road trip Cost $100

So to top off the rebuild you might consider installing a Transmission cooler.
I would suggest running it through the radiator contrary to what I run on my SE,
which by passes the radiator.
I do mostly none stop driving, so air always flows keeping it cool.
In the city stop and go, it gets very hot ! I'll either change that or install a fan on a relay w/switch.
I figure about $80 total for these parts.
* You dont want to cut the factory lines, they run about $75 each dealer only.

One other thing....
- Optimum operating temp is between 180-210 deg, just a fyi if you install a guage.


More pics later :thumbsup:

Bump on this (http://i28.photobucket.com/albums/c242/xeroinfinity/Transmission/2EPRevEd.jpg)one time :ylsuper:

Or two times :evillol:

I was concered at first because it looked different then the one on thier site.
So I called them and I guess this is the updated version.

I tried cleaning most of the cheap paint off those springs...
Kinda stupid even painting them,
that crap does not need to be in my pricey transmssion floating around :grinno:

I should have this thang all together this time tomorrow :evillol:




Any questions or comment post away!

holy crap that looks awesome... I want to know how it performs :D

It is pretty :D
Now its coverd in red assembly lube.

I Started soaking my clutches today, should be ready to put together by tomorrow. Hoping I can getter done in a day, might be a long one .....

Not sure when I'll swap the tranys out but soon :D

btw you see I scribed "XI" on the case :lol:

It is pretty :D
Now its coverd in red assembly lube.

I Started soaking my clutches today, should be ready to put together by tomorrow. Hoping I can getter done in a day, might be a long one .....

Not sure when I'll swap the tranys out but soon :D

btw you see I scribed "XI" on the case :lol:


awesome :D always sign your artworks!!!! :D

No not always, but when it cost $650 damtootin :p
I wished I could make my own instead :crying:

I Did get everything together today, only took 6 hrs..
It seems tight when I engauge/turned the shafts, must be the new clutches and heavy differential :grinyes:

Still not sure when I'll put it in the SE .......

I know a lot of you readers might think this is expensive but I totally feel its worth it.

Those Blue clutch plates from Raybestos are available for most all of our GA's automatic transmissions.
These alone will greatly improve performance and durability.

I looked at it this way, if my trany died and I just throw in a "used" trans,
it is not going to last as long as a rebuilt one because you realy dont know whats going on inside a used trans, even if it has low miles.

I just cant justify time & money being wasted on anything questionable on my car(s).
Anyone paying someone to do the work could spend big money just for a used one installed and 6 months later it could crap out then you'd have to spend more money again.

I personally would only give a customer a 6 month warranty on a used trans, 12month/12k miles on a performance rebuild.
If its a stock rebuild then I'd probly do a 2yr/24 k mile warranty.

And remember, you always get what you pay for :thumbsup:

I like this thread, I had hoped to do something simliar to this with a used low milage GT trans for when I eventually swap it out. rebuild it at a shop while im still using the SE tranny... just swap and fill... Good to Go!

+1 for moved to performance or sticky at the top or placed into your 'how-to' sub-forum XI, If you want, could ask AF Mods if we can have a performance 'how-to' section. Mostly being easy jobs, Gauge installs, Cold Air know how, performance myths explained :D lol (IAT resistor)... whatever sounds good lol

I like this thread, I had hoped to do something simliar to this with a used low milage GT trans for when I eventually swap it out. rebuild it at a shop while im still using the SE tranny... just swap and fill... Good to Go!

+1 for moved to performance or sticky at the top or placed into your 'how-to' sub-forum XI, If you want, could ask AF Mods if we can have a performance 'how-to' section. Mostly being easy jobs, Gauge installs, Cold Air know how, performance myths explained :D lol (IAT resistor)... whatever sounds good lol

Yes I thought of this Gir.
we have the Performance sub forum, and the Tips & Maintenance sub forum ....
It's kinda both :confused: :grinno:

Since this transmission is not just GA related(alero,cutlass,malibu) I'll probly move it to the Performance Sub Forum..... :D

Also I am thinking I am going to put it in this weekend. :naughty:
It'll take a few weeks for the clutches to breakin.

Something else I forgot to mention was the chain drive.

I just used the stock size gears & chain - 7/8" ,
which was replaced with NEW parts also.

Well its been over three months and over 5000 miles.
Everything seems to be working realy well, no leaks ! :thumbsup:

Which is something I expect down the road since my line pressure is well above 100psi when warmed up.

Going from 2-3rd at highway speeds(70-80mph),
it shifts so hard it feels like the dash is going to rip out ...............................................





.......................... :ylsuper:

Hope to get some new vids soon :p