I can't keep this idea to myself.. this one in theory is perfect.. and hopefully it will turn out this way!

As you all are probably aware, my tranny is in questionable condition, and I am sure there are many others of you out there. Now, I have never seen a TH440 fail, personally.. however I know they are prone to failure, as like all other FWD GM trannies. Now, I do not know what fails in our trannies, but I think it may be something as simple as a lack of fluid going to the TC.. however I could be wrong on this. As you may or may not know, the vacuum modulator controls how much pressure is applied to the TC, in pressure I mean fluid pressure. More pressure = less slip, less pressure = more slip. This is what lets you idle in gear without moving. Now, on our pre-electronic trannies, we have this controlled by vacuum, so when idling, the modulator pulls in, allowing fluid to flow elsewhere, when the car is at red line, the modulator pushes out, and forces fluid to the TC. This is what I am thinking to be true, correct me if I am wrong here.

Now, after that wonderful lesson TC operation.. let'* get to my idea.

We all have TCC solenoids.. [or at least we should]. Now, on my "dumb" car, the ECU controls TCC lockup, via some variables, like 3rd/4th gear engagement, 48+mph, and I think pre 1.5v TPS. However, I don't like the ECU controlling so many things [I know, my ECU controls 5 things, and has inputs from 10 sensors.. and I am complaining ]. Anyways, what if I mount a switch, where I can bypass the ECU control, and have the TCC stay locked up all the time. Then, either have a momentary switch, which will disable the TCC when I am idling, or just drop her into neutral when idling. Now, I looked in my FSM, and the TCC is easily replaced, just by removing the side cover thingy, so if mine dies, $20, and I am up and running.

Here'* where I am doubtful.. can the TCC actually handle 2100rpm torque, in first gear, with my right foot?

Also, as previously mentioned, I was thinking of just throwing her in neutral when idling at a light or whatever.. but wouldn't that be harmful to the clutches and such? And be a better idea to mount a small switch on the steering wheel, or something to momentarly disable the TCC so I can take off without transmission damage?


-justin

Err.. no clue.. on a lil side note though.. back in the SR days for me 2 years ago *look up SRS game.. and you'll know wat I mean ) was talkin to a guy who had a 88-89 Cavalier.. he said he has supposedly measured out the bolt pattern and said their manual tranny will bolt right up to our engines.. obviously he'* going to beef it up.. and look into reprogramming the PCM to bypass the auto shifting so it won't be throwing SES and doing funky stuff.. humm.. a manual Bonneville with bopping head christian manson doll shifter.. lmao !!!

EDIT: Remember this is hear say.. so I don't know how valid it is.. and he'* no ricer.. he has a nice sleeper that outraced a slightly modded 97 GA GT.. but can't keep up to the L67 but he was pretty damm close

Now a manual bonnie would be friggin awesome. You could have even more fun in a bonnie!

there'* a guy that dropped an L67 into a cavalier and bolted it right to his manual tranny.

http://www.cardomain.com/memberpage/526752

Merlin 91/97 just was at the track with that car and he has pics of it

I'd avoid those ideas with the transmission... There'* no reason to put it in neutral at a light, or do any of this... GM designed it to lockup at certain speeds, and such for a reason. You use the same amount of gas at a light in neutral as you do in Park as well.

uhhhhh....Jason? I don't think he'* talking anything about fuel mileage. Even then I doubt that the fuel mileage would differ from something like this. My thought on this whole thing is that, the TC would hold up to 2100 in 1st...but no way to make it lock....There'* more to doing something like this than just inside the ECM.

Wrong. Other way around. Less Pressure....HELLA HARD P TO R OR D TRANSITIONS. Equivelent to doing about a 1500 N bomb (I've had those lines break on me already) It'* so hard of a shift that it could trash a CV joint in no time. More Pressure = more slip. Less Pressure = Less Slip.

I think some one on here has done something like this before, I think maybe Damemorder? I dunno...But if your trans is still working alright...I wouldn't do it. Don't think that there could be any bennefit.

My 2 cents.

Jr's3800: the side pan removal doesn't look hard whatsoever. If I pull the wheel well shield on the Driver'* side, it doesn't look impossible.

I knew that the heat was the main problem.. but what fails?

Panic situation? Why don't I just drop it into neutral then? I was thinking of mounting one either on the shifter, or on the steering wheel. However, the steering wheel would be difficult, because the steering wheel controls have metal contacts that spin around on a spherical metal ring thing. And the sifter, well if I were to mount it there, by the time I can get to that, I could drop it into neutral.

Mine never engaged at 36mph.. mind you I had some temp sensor issues, and it would only do it at 48. And I think my FSM says 48 also.

LakevilleSSEi: What do you mean when you mention "there is no way to make it lock." Do you mean that the TCC wouldn't be able to handle the pressure? Also, when you talk about "it'* so hard of a shift, that it could trash a CV joint in no time" Are you talking about TCC lockup or neutral bombing?


-justin

I'm sure you could make a way to make the TC lock whenever you want, but I wouldn't even now where to begin to make it do that. And like what others said, the TCC solenoid is a PITA to deal with, and rewiring the TCC solenoid just so you can do something like this is gonna be more time, effort, swearing and bleeding than the idea'* worth. With the CV shaft comment, I was talking about having less or no pressure in the modulator. When it shifts it slams so hard that I'm sure it could mess up a CV shaft if you aren't carefull. As for trying to lock the TC at such low speeds. The TC can handle the pressure, but the engine won't power the car at that low of a speed. If you know anyone with a 5 spd manual trans (prefferably a 4 banger, best to use) and ask them to drive their car for a lil bit, and do this: Get up to about 20-25 in first, and then skip the rest of the gears and go straight to 5th and dump the clutch.....That'* exactly what locking your TC in first will do. It will lug the engine beyond all belief and probably wreck your motor. Now drive the car through all the gears normally, and dive on the binders like you're in a panic situation, like a kitty ran into the road and a lil girl went blindly chasing after it (Thanks for the situation Dame) and slam on the brakes but don't put the clutch in.....That'* exactly what your car will do if you manually lock your TC with no over-ride. All the TC does is pretty much act like a clutch to get your car going, and once the car is goin and there'* no more demand for acceleration, the TC will lock up and spin the input shaft of the trans in 4 gear at the same speed as the engine'* crankshaft. You can bump up the line pressure and not harm anything as long as you have adequate cooling for the trans fluid and a good pump, and get firmer and maybe quicker shifts, but just don't mess with the rest of the stuff IMHO.

My 2 cents.

Okay, so I guess this idea isn't going to work.

However, LakevilleSSEi.. when you mention increasing the line pressure.. how can I do that?

Jr's3800: It is possible that the 3rd gear switch does not work.. and the ECU thinks i'm going 48 in 3rd, when really in OD.. but since I don't have a scantool.. I won't know for sure.


-justin