4T60-e Shift Kit Write-Up

[AWeb80]

First off- I give major credit to 3400-95-Modified on 60*v6 for helping me w/ this


A shift kit firms and quickens a shift.

I did mine by shimming the accumulator springs.

In the 4T60-e, you have two choices of accumulator housings, a "4AFW" and a "4CMW". The "4AFW" housing will look like the "second design" (this is the one I have in my GP) and the "4CMW" will look like the "third design". You can find out which design you have by looking at your tranny tag on the back of the trans on the diff housing.


http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/Accumulatorpumps.jpg
http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/Accumulatorpumps2.jpg




I looked at several 4T60-e's in a local J/Y and the 4AFW looked to be pretty common.

Now, even though the accum housings and pistons look different, I am going to assume that the pistons will all be the same shape and size when taken apart.


I shimmed my 1-2 springs and the 2-3 springs w/ a 3/8" thick bushing (which I made at work), I measured the inside of the pistons and you can see them on the following pics. You won't need to make/get a bushing like I had, a few washers spaced to your wanted thickness will do the trick.

you just need a washer with an outer diameter of 1.5" and a inside diameter of .625". as to how thick the washers are spaced will determine how hard the shift will be. I would recommend making the 1-2 shift bushing thinner that what I have it. I'd go with around a 1/4" thick. Mine is a little too firm, my next fluid change, I will change it out for a thinner bushing. But, I would highly recommend staying with the 3/8" bushing for the 2-3 shift, it works great, not stiff, but quick.



http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/IMG_0389.jpg
http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/IMG_0392.jpg
http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/IMG_0391.jpg



Here are some pics w/ the accum pistons w/ the bushings sitting in them.

the 2-3 piston is thicker than the 1-2 piston on the 4AFW accum housing design.



1-2
without
http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/IMG_0372.jpg


With
http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/IMG_0373.jpg




2-3
without
http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/IMG_0374.jpg

with
http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/IMG_0375.jpg





here are all the internals laying apart with each set of springs sitting next to its respective piston.

http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/IMG_0376.jpg





here is the housing in the trans.

http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/IMG_0400.jpg

http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/IMG_0399.jpg



to get the housing out of the trans, just release the 4 bolts show here

http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/IMG_0402.jpg


then gently rotate it down and then side to side to release the tubes out of the housing....don't break them.




once out, just pop the 7mm (IIRC) bolts out of the top of the housing and take it off.

put the bushings in the correct places in the pistons...use "shim 2" that I have labeled here.....the bushings must go there.

http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/land1.jpg






there is a small chance that a spring could break....Mine were not broke, and a local trans shop said they have never had broken accum springs, but 3400-95-modified said he has seen them break.

here are the spring part numbers for a 4AFW housing

1-2 outer, 8682700
1-2 inner, 8668631
2-3 outer, 8668487
2-3 inner, 8681456



replace the top of the accum housing a put back in trans like you took out.

you will need to add ~ another quart of trans fluid to replace what was lost from the inside of the accum housing.



here is a vid of the shifts right after I was done.

http://www.youtube.com/watch?v=rt3SNEOd1Zg





I'll update this if I need to. Or if any questions come up.

[AWeb80]

here is the inside of the accum lid

http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/IMG_0381.jpg





here is looking down into the accum housing

http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/IMG_0382.jpg




here is the 1-2 piston in the bottom of the housing w/ the shim in it

http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/IMG_0384.jpg

[MonteCarloDude]

nice write-up, i have been thinking about doing this to the monte when i do the filter, if i do, it is going to be nice to have a good write-up. :high5:

[mediabandit]

sticky!!!!!

ya i wanted to do this as well... now i have the info, pics and everything, i am gonna go ahead and do it as soon as i have time.
thanks for the great write-up adam.

[AWeb80]

IIRC, the 4T60 trans has the "1st design" accum housing in the pic I listed up above.


Very similar to the "2nd design" that I had.

[AWeb80]

Move This To The FAQ Section Please

[Robby1870]

Nice job Adam!

[badassoldspower]

Shimming accumulators is not a very good approach to making a shift kit, a shift accumulator only controls shift quality, and your only result is going to be very abrupt slamming into gear and possible cracking of the pistons or breaking springs, the best approach however is to study the hydraulic schematics of the transmission and to oversize the orifices that feed the accumulators. The rule of this is that if you are to double the radius of the hole of the orifice, you quadruple the fluid volume while maintaining pressure. Thus making the accumulator apply at a much faster rate with the desired quickness, without the loss of shift quality. IE: A very firm yet un-abrupt shift pattern will result. Now my plan is to supply the w-body crowd with modified spacer plates, where all the orifices are drilled out, a stiffer double spring set for the accumulator for proper durability, and an adjustable vacuum modulator. Many worry about internally failing the 4t60E, but the truth is these are a very strong transmission with the exception of the differential which can be swapped for the 4t65EHD differential, and the reverse reaction shell which when broken will result in loss of 2nd, 4th and reverse. I believe all of these components must be corrected before one throws in spacers into the accumulator pistons.

[douellette]

Shimming accumulators is not a very good approach to making a shift kit, a shift accumulator only controls shift quality, and your only result is going to be very abrupt slamming into gear and possible cracking of the pistons or breaking springs, the best approach however is to study the hydraulic schematics of the transmission and to oversize the orifices that feed the accumulators. The rule of this is that if you are to double the radius of the hole of the orifice, you quadruple the fluid volume while maintaining pressure. Thus making the accumulator apply at a much faster rate with the desired quickness, without the loss of shift quality. IE: A very firm yet un-abrupt shift pattern will result. Now my plan is to supply the w-body crowd with modified spacer plates, where all the orifices are drilled out, a stiffer double spring set for the accumulator for proper durability, and an adjustable vacuum modulator. Many worry about internally failing the 4t60E, but the truth is these are a very strong transmission with the exception of the differential which can be swapped for the 4t65EHD differential, and the reverse reaction shell which when broken will result in loss of 2nd, 4th and reverse. I believe all of these components must be corrected before one throws in spacers into the accumulator pistons.


ill probly take one if you make em haha

[Brian P]

:skep:

[douellette]

:skep:


what

[Crazy K]

4PBW = 1994 3.4 DOHC 4t60e appears to be a a slight variation of figure 3.

the figure is accurate and correct, except that there was no 1-2 accumulator cushion spring, and the 1-2 and 2-3 pistons are identical in design...

http://img.photobucket.com/albums/v639/AWeb/Shift%20Kit%20and%20Tranny%20cooler%20%204T60e/Accumulatorpumps2.jpg

[Crazy K]

so... I went and checked another transmission:

1990 TGP "remanufactured" (the one that doesn't hold up) that came out of Psychomatt's ex-TGP.
the accumulator assembly cylinders are part of the transmission case.
it has one large spring for the 1-2 piston
and dual springs for the 2-3 piston.

both pistons are part # 8656325 (same as 4PBW 94 3.4 4t60e)

[Imp558]

What's the consensus on raising the line pressure via PCM tuning? The 4L60E guys do that to firm shifts. The shift points can be changed as well in the tune. This is a pretty old thread, did badassoldspower ever produce any plates?

[augi]

Nice, I wish for a sticky as well.

[BXX]

What's the consensus on raising the line pressure via PCM tuning? The 4L60E guys do that to firm shifts. The shift points can be changed as well in the tune. This is a pretty old thread, did badassoldspower ever produce any plates?


Well, unfortunately the 4T60E trans in our cars are vacuum modulated, we lack a PCS so a tune cant raise pressure...

EXCEPT, if you wanna play with the Force Motor Current maps in the PCM tune.. Ive done it a little, if your not careful, you can trash the trans easily..

[jake91]

old thread i know but
adam was saying 1/4 for 1-2 and 3/8 for2-3 which is larger

but the 94 dohc pistons are the same so would i want to do 1/4 or 3/8, ect on both then

and in kens post about the 94 would those little differences cause any problems with following this write up

[jaustinbell]

I want to try to drill out the holes in the spacer plate larger in the 1996 Grand Prix, I haven't gotten the accumulator out of the car yet but will it be obvious which holes I am supposed to be drilling out? Can anyone say which ones in particular? Thanks

[Crazy K]

difficult to tell, depending on which piston orientation you have you need to isolate the correct holes. Don't forget the gasket is metal with paper on both sides, so if you damage that trying to drill it you will have a large problem. On top of that... they may not necessarily be the limiting factor for flow; the passages are pretty tight, too, IMO.

On my 4t60e vehicles I simply install a set of good used 2-3 springs in place of the 1-2 springs... and many vehicles have either one single 1-2 spring, or a single spring accompanied by a shorter backup spring. I shimmed the 1-2 with 1 washer and the 2-3 with two washers on the last vehicle serviced...

[jaustinbell]

OK, I found a transmission supply place here in Atlanta that will sell me individual OEM accumulator springs for 1 or 2 dollars apiece. My plan is currently to replace the 2-3 springs with new ones and the 1-2 springs with new 2-3 springs, and then shim them using a total of 3 1.5" outer diameter/.625" inner diameter washers. Does anyone know if I can find such washers at Home Depot, or, more likely, Ace?

Additionally, I have an auxiliary trans cooler that I pulled out of a 1995 Regal last time I was at the junk yard. I want to plumb it in when I'm doing the rest of this on spring break next week. Does anyone have any tips on that? Should I daisy chain it with the ATF cooler in the radiator? Will I have to fabricate lines with the special fittings on the end?

[Night Fury]

Most people daisy chain, But I didn't because it isn't as effective at cooling. I have an RV sized cooler and it still hits 200+ with spirited driving

[jaustinbell]

So I'm best off just hooking up the aux cooler in place of the one on the radiator?

[RobertISaar]

Most people daisy chain, But I didn't because it isn't as effective at cooling. I have an RV sized cooler and it still hits 200+ with spirited driving

i wouldn't say it isn't as effective so much as it allows the trans fluid to reach a normal temp faster while still giving the benefits of additional cooling.

but yes, running through the radiator first, then the auxilliary cooler won't reduce the temps as much.