ChocoTaco369

Towards the end of the winter/beginning of spring, I want to put a little money into my transmission. Now that I have full exhaust, intake, gears in the rear end (which I understand helps the transmission) and will have a dynotune around Christmas time, I'll be pushing significant horsepower over stock levels. I figure since I'm getting into these power levels, even with a stock converter, the transmission could seriously benefit from a few very minor mods.

I plan on getting a truck 4L60E pan along with a 28,000 GVW transmission cooler. Those two mods I'm definitely set on. I'm closing in on a year and a half and ~20,000 miles since my last fluid/filter change, so I figure I'll upgrade those parts in the process. I also plan on doing a flush this time, not just a fluid change, as there are 45,000 miles on the trans at this time. I plan to simply feed several quarts of ATF through the transmission as a flush - not use a high pressure machine as that makes me uneasy.

Anyway, the question that I'm asking myself is, should I get the aluminum accumulator pistons? They're very inexpensive, so price is certainly not an issue. I have a few questions regarding this mod:

1.) Is this a good mod to do on a completely stock transmission? I'm not getting any other internal upgrades. I do not want a shift kit, I DEFINITELY do NOT want a converter...the trans will be 100% stock with just aluminum accumulator pistons (and, of course, the cooler and deep pan).

2.) Are the accumulator pistons difficult to install? With the pan and filter removed, can they be installed without touching the valvebody? I DO NOT want to remove the valvebody, I don't want to have to drill into anything...I only want to do this mod if it's as simple as taking off the pan and filter and they're simply right there.

3.) Will there be any difference in shift firmness assuming there are no problems with the stock accumulators? I understand that if the stock plastic accumulators are cracked, the aluminum accumulators will add to shift firmness, but will the trans shift firmer if the stock accumulators are in perfect condition? Firmer shifting is definitely a plus IMO

Thanks for any assistance in advance.

Gilbert@Ace Racing

In order to replace all of the accumulators the valve body and plate must be removed. I see no value in replacing those alone without any other mods. The only benefit would be the fact that they would rule out piston failure.

Everything else looks like very well planned PM.

g

ChocoTaco369

How hard would you say an accumulator piston install is? Is it a 15 minute thing or something that'll take awhile? I'll take it to a shop if need be, so I'll have access to a lift, and the pan and filter will be off anyway. No modification to the valvebody needs to be done, correct? It would just have to be removed? I'm not sure how hard it is to remove a valvebody, if it's a complicated thing littered with pitfalls or if it's as simple as undoing a few bolts, unplugging a few sensors and taking it off.

Sunset'01Z

iTrader: (10)

its just a few bolts to remove the valve body, but i think if you're doing that, you should install a shift kit too. at light throttle, the shifts will feel firmer and more solid. aluminum accumulator pistons will only prevent problems that occur when the plastic ones crack. i'd suggest a corvette servo too, if you are willing to go through the hassle of replacing accumulator pistons.

FLT

iTrader: (1)

This is a picture of a kit that we sell with a link to our page. http://finishlinetrans.com/store/pro...products_id=67


Here is a photo of the valve body bolted to the trans along with the 1-2 accumulator housing. Bottom left is where the 1-2 accumulator is located. Bottom right is where the forward accumulator is located.



In order to replace the 3-4 accumulator the valve body and the spacer plate would have to be removed as well. This piston is aluminum from the factory so it may not be necessary to replace. The 3-4 accumulator is located in the lower left of this picture in the case.


Here are some more photo's of what you would be looking at in order to reinstall the valve body.

This first picture here is a trans ready to have the valve body installed. I have out lined the two holes in red that are required to align the separator plate, valve body/case gaskets, valve body, 1-2 accumulator housing and the spacer plate support. These pictures were taking when refreshing a unit for a customer. This a vacuum modulated unit.

I install these two bolts first to get the spacer plate and gaskets aligned using grease to stick the gaskets to the plate. Here is the Photo.

Then I install the the spacer plate support with the three bolts in the rear of the case along with the 1-2 accumulator housing. Here is the photo.

Then torque the bolts to 8ftlbs. Here is the photo.

ATSG (Automatic Transmission Service Group)recommends using this same procedure and then install the valve body after cleaning. Then I will remove the two alignment bolts and install the valve body. Make sure to install your wiring harness into the case first and also the lockup solenoid in to the pump. Torque the bolts for the LU solenoid to 8ftlbs. Then install the valve body using the two correct valve body bolts to align the valve body.

Making sure to install the two alignment bolts first, along with the three bolts that have 8mm heads in the correct position.

The bolt second from the right is the one to really watch out for here. These are the ones if they are in the wrong position will lock the gear train. Here is a picture of the different length bolts.

Picture of all bolts placed in the proper positions.

After lightly tightening your bolts down don't forget to do this. 8ftlbs



Enjoy the photos. Vince

ChocoTaco369

Wow Vince, I was hoping you'd reply That certainly was a lot of info and I appreciate it. It seems like it'll be way too much work to simply replace the accumulator pistons. Would you agree? Perhaps I'll just stick with the cooler and deep pan.

I would like a shift kit, but I don't want to risk any mishaps and I'd rather just leave the tranny alone. I feel that the install of a shift kit is more risk than it's worth, even though I'd like it.

Just to let you know, LS1 f-bodys with the 4L60E come with a Corvette servo stock. The upgrade from that would be the Superior/Sonnax billet servos, and for the price, I don't feel I want to go that way. Plus, I've heard people say over the years replacing the servo on a totally stock transmission may be a little harsh on the components. Not sure how true that is? I hear the Sonnax 4th gear servo is a good upgrade on a stock trans, though.

FLT

iTrader: (1)

It would be pretty easy to just replace the 1-2 and the forward accumulators. Like I said the 3-4 is already aluminum and it will probably be just fine. We do sell a factory deep pan kit and I can get you a cooler as well. Give us a call if you have any questions. Vince

ChocoTaco369

In your opinion, is replacing the accumulators something I should get done at a transmission shop or is it something an experienced mechanic (not a transmission specialist, but has put shift kits in 4L60's before) can get done on a lift in about 30 minutes?

If I plan on getting the accumulators, I'll give you a call for sure Vince. This might be a late Christmas present to myself.