I just purchased a low milage trans for a 97 sc400 and am wondering what things i can do to make it shift firmer and prolong its life? Are there any benifits to shimming the acumalators and increasing line pressure? Im just looking for some simple "SAFE" do it your self things that i can do to it before i put it in, any info is very apreciated!

 

This is bad news for the trans all around and is a "rig" to get it to shift firmer the real way to do it would be to send the valvebody to IPT and have it reworked to improve the shifting.

 

does this company have a web site? How much do u think something like that would cost?

 

Damn i just found the web site, wasnt expecting a modified valve body to cost that much! Oh well, guess its going to stay in stock form. Thanks xspsi6

 

Here is a mod I did on mine. You'll be surprised at how well it works.

http://www.toyotanation.com/forum/sh...045#post485045

 

Shimming accumulators and increasing line pressure isn't "rigging". Shimming the accumulators is just like increasing spring preload and there's a freaking **** for turning up the line pressure. That's like saying putting a boost controller on instead of changing a wastegate spring is "rigging".

As far as bad for the tranny, smooth long shifts generate more heat and wear than a hard shift.

My "rigged" auto was holding 11PSI w/o a cooler before I went 5 speed.

 

hope this helps
http://www.supraforums.com/forum/sho...ers-take-a-nap)

 

Umm yea it is a rig as you are putting a rod or a shim to shorten the piston travel so do you know what this does to other components in the trans?

It is a huge rig and while yes it will shift firmer and faster you are doing it at the expense of the life of the transmission and if it were as simple as a shim or a rod then why would'nt IPT or Titan or Bl use them in their built transmissions? There is a very good reason why, Think about it.

 

i guess this would be the same for the Sc400 trans as well, i still have alot of pages to go... very long thread lol Thanks for the link

 

Why don't you tell me what it does to the other components in the transmission? <Seriously - not trying to be a smart A$$ here - I'm not a tranny tech> Yes, it puts more stress on some of them - which it can obviously handle as this is a very common mod on the A340.

The link posted above to supraforums was created by a transmission tech, so it seems a safe rigging to do.

Rigging is a matter of opinion. In my opinion running a thicker headgasket to lower compression is rigging - but effective rigging. Milling a head could be considered rigging as it has minute effects on valve timing, compression, and component fitment, but it's a widely accepted solution for "fixing" a warped head.

 

Nothing wrong with shimming accumulators IMO. I build fast cars and have for years.

 

It will achieve fast hard shifting no doubt about that but as I said puts stress on other components (hard parts) in the transmission and I know the guy is an ASE tech who wrote that however I have debated this with people (auto trans gurus) many times over the years and I was proven wrong every time and one of the people who was telling me how this worked and why not to do it was John at IPT who has extensive knowledge of the toyota autos so if you guys really wan't a good explanation as to why you should or should not do this give him a call as he will take the time to talk to you about it and hopefully you will have a better understanding as to why.

I my self don't really like to do things the inproper way so I tend to weigh all options and make the best choice based on the r&d I do on the subject.

I worked 10 years in a transmission repair shop so I have seen it all over the years but I will put together a long drawn out answer for you guys when I have time and hopefully help someone in the proscess and fwiw these transmissions are disposable and cheap so if you really don't care about how long it will last then go for it as it will for sure achieve the result you are looking for just don't expect 50k or more miles out of it

 

So... should i shim or should i not..That is the question lol.

 

It's a cheap way to get the trans to shift hard and fast but not the proper way however the choice is up to you in the end.

If you can do your own wrenching and can pull the trans down when it gives you trouble then go for it but if you are paying someone to do it then I say no way.

 

Then explain a trans kit vs shimming the accumulators and adjusting the kickdown. Reducing the heat something makes, when heat is detrimental, is a mod (a good one) IMO. Im not saying, nor is anyone, that this makes the tranny bulletproof. Yes it may be harder on other hard parts but what is doing ANY kind of mod? Putting lots of power through the auto is harder on the sprag, but thats a risk you take. Seems like there are QUITE a few guys making 300-400 on the auto with a Cooler and these mods. Unless youve done this specific mod to your car and have spent the time that people doing it or "recommending" have researching it, building it and driving it have... DOnt try to dissuade anyone. Move on.

Dont take this the wrong way, but you are talking out of your ***. Seems like people that want to stay auto and make boost, myself included, see this as a workable mod to make this tranny last while waiting to do a swap or build a better trans.