Would manual shifting hurt my car? For about a year now, I have been manually shifting my tranny because I installed a new cam shaft that makes its best power above the stock shift speed 4500rpms. When I ran at the track, I manually shifted at that speed because I didn't know this. Right now, I shift my tranny at 5250rpms out of first, 5000 out of second (if I go further, the computer rev limiter kicks in), and by then I'm at 80mph. I don't go far past that. Is this hurting my transmission? I am getting a total rebuild done with a trans-go shift kit. The corvette servo and .500 valve body are included. The car has never had any rebuilds and it has 175,600 miles. Also, how frequently should I change my tranny fluid and filter? I have had it since last September and I have not changed either and I don't know when it was last changed. It is on my list of things to do, my car is just 100 miles away. I only shift manually when I race, so it isn't that often. Also, when I give my car about 1/10 throttle, the tranny shifts into OD at about 38 mph and the rpms drop to about 900. So I basically start slowing down. In that case, if I give it more gas, the car slows even more, but if I release the pressure a little bit, it kicks back down into D and waits until about 45 to shift into OD. Hopefully this problem will be fixed with the rebuild, and I plan to get the rev limiter taken out. I'm still afraid to take the car higher than 5500rpms, but it still keeps on pulling up there. I think the cam is good for up to 6000 or 6500. I'm not sure. Sorry about the length. Thank you for reading.

~Matt

 

It was brought up in the past, manually shifting all the time may not be the best, I think transfixleo said something about the line pressure will be higher, thus creating more wear...

At the track everynow and then shouldn't be too bad.

 

I read in Super Chevy magazine that manually shifting the 700R4 isnt as good as letting it shift by itself because it lowers the line pressure.

If u want it to rev higher try adjusting the tranny kick down cable. Theres an artical in the tech section.

 

so i can make it auto shift at the 5250 I normally shift at? Nice. I need it to shift higher, because I need the upper rpm power. Thanks guys. How often should the tranny fluid and filter be changed, and what about the OD kicking in early? Will the rebuild fix that?

~Matt

 

The fluid should be changed every 17,000 to 20,000 miles. What do u mean the OD kicks in early it shouldnt kick in that soon. Well at least mine doesnt. It should shift into OD around 50mph with light throttle.

Setting the tranny kick down is easy. Look at the tech artical. Mines shifts at 5250 in 1st and 5000 in 2nd. But remeber the TPI systems starts to lose power around 5000rpm. but with ur cam id say dont go past 5500. Going higher then thats isnt good. It will also be hard on that transmission when shifting that high.

 

Nevermind about the TPI thing, I just read ur sig and u have a LG4 sorry. but still dont go past 5500 id say. And Im not sure if the rebuild is going to help the OD problem. Try adjusting the kick down cable first that might help.

 

Not to be a jerk, but the cam in the LG4 probably doesn't make a great deal of power at higher RPM, nor does the whole car. The stock HEI doesn't really supply much power or advance past 4500, and the camshaft was designed to drop hp soon there after. The 305 has a great deal of potential, as the TPI 305 in my 86 iroc was a dog before I, among many other things, rebuilt it with a crane compucam 2040, and an MSD 6AL and remote blaster 2 coil. With those two modifications alone, and maybe some headers, carb jet, and some gears, this would be a totally different car! Getting back to the tranny problem. Transco makes a kit called the transgo valve body reprogramming kit, in which you can opt for full manual control, the trans will never shift unless you shift it, if you want it to start off in 4th gear, it will. (Don' do that whatever you do!) This, along with the b&m ratchet shifter, a better servo, and the full throttle 3-4 shift valve, you could have a fully manual forward pattern overdrive tranny. I love mine, it rips! I can't see how it would hurt.

 

yea it does kinda damage the trans more. Which is probably the reason my transmission craps out so fast. My trans only lasts about one year and then it fries. I down shift and upshift a whole lot. And also I lock up the rear end suddenly and violently alot too. Which probably also puts a **** load of stress on the trans. My trans just went out yesterday.

Anyoen have a T5 trans for sale? Private message me if you do. Thanks.

 

so in essence with that kit i would be manually shifting, only there's no clutch? That's pretty cool. Do you have a link and price for it for me? Thanks. Yeah, I need to progrm my tranny to shift exactly where yours does cragg. How does it work, do you dial in "5000rpms" or do you set it with the pedal? Sorry about all the questions. I'm probaby going to have a shop do it anyway, but i'd like to know. My car acctually does make the most power above 5,000rpms. It pulls really hard up there surprisingly. I'm glad I installed the cam. Down low, like before 2500 rpms, the car is really slow. It has no pick up or torque or anything. That is because the cam hasn't kicked in yet. I'm hoping a new TC with the 2,000 stall and the gears will help the low end and get me right into the cam's sweet spot. I'm so glad I put the cam in though, because i'd be well into the 17's without it. I will change the fluid and filter for the tranny and rear gear next chance I get. As for it shifting into OD early, yes it really does do that. It'll shift before I even hit 40 miles an hour unless I give it a decent amount of throttle before I hit that. It could be the kick down cable, but that is fine everywhere else for me. I'll talk to a shop and hopefully get it fixed over thanksgiving break. Thanks guys.

~Matt

 

OOOPS, I didn't realize you had done a camshaft swap....good choice. Then, you really do need to have that tranny holding gears later. The reprogramming kits costs about $125 or $130, the shift valve is about $30, or something like that. Also, if your cam isnt making alot of power below 2500 rpm, you are wasting your time with a 2000 stall converter, look into a 3000 or there abouts. The truth is, if you take out your transmission, you will see on the torque converter a factory sticker with a "DF" number or something like that. That will tell you the factory stall with the right decoding chart, you can probably ask a tranny shop to tell you what it is. The LG4 car probably came with an 1800 stall, or somwhere there about, it is definately under 2000, and that car had nowhere near the cam you probably have, especially if it not making power below 2500. you may have overcammed it...what did you use?

 

I didnt program the transmission to shift like that. I just adjusted the cable and set it so that it shifts where I want to.
And BTW a 3000 stall is way to much for ur car. Id go for a 2400-2500 stall. I know a guy with a 383 and hes got a 2600 stall and he says that its to much, but thats a TPI car so it might be a bit different. 3000 stall is way to much though.

 

oh another thing. If u are getting new gears, make sure that u match ur cam with ur gears. U will have better results that way. One more thing ur car probley came with a 1600 stall stock. I think thirdgens came with that stall converter.