I went to the track last friday for test and tune. I thought I would try out my new 3.73 gears. Well when I ran with the old 2.73 gears, I could cross the 1/4 mile line in 2nd gear at about 5500 rpm. I wouldnt have to shift to 3rd.

Now with the 3.73's, I need to shift into 3rd before the end of the 1/4. Only problem is when I shift from 2nd to 3rd, the engine just keeps going up in rpm and dont shift. I have to let off the throttle to get it to shift to 3rd.

I tried shifting from 1st, 2nd and then I hit my B&M shifter twice up into O/D. The trans would shift up into 3rd/Drive at this point.

What is going on? TV cable adjustment? Trans going out? I dont think this is normal?

What should I do? build the 700r4 or just swap in a TH350?

mods are in my sig
thanks.

 

are u sure it wouldnt shift? how high rpms did u let it go, my shifts high and at the track my 1 - 2 is around 5,200 rpm and my 2 to drive is around 5,800. its way high so i know i am losing some time in its shifting taking so long. i think my tranny needs some new fluid / filter, tv cable ( i have adjusted it over and over again the right way still no luck), and i think a corvetter servo might help alot.

my tranny is no way blowing apart yet. i mean reverse kicks right in, my light throttle shifts are still 2,000 rpm, shifts in overdrive fine during cruising on the highway.


i have researched and i think the items i listed should help, i think the 2 to 3 high shift is called "flare up" or something like that. where u can here the tranny wanting to shift but it takes awhile.

 

It could be the tranny going. A buddy had his start acting like that then about a month later it blew up. I would try adjusting the TV cable and see what happens.

 

well, at the 1-2 shift, I shifted at 5800. All I lost was like 200-300 rpm, then when I shifted to 3rd/drive, it wouldnt shift and go to like 6300 before I would let off the gas. Then it would shift on into 3rd/drive.

When I tried the 2nd-O/D shift, it went on into gear.

the reverse shift is fine, and it does fine in drive or O/D on the road. The trans seems to shift fine by itself. Maybe its just the TV cable. I just dont think the trans will last if I keep racing it without modding it.

Its not a daily driver, but it does see some road time. Would it be a big mistake to change to a Th350? I can get one built for cheap that would withstand the HP/tq.

what to do?

 

The trans is weak. I had the same trouble. Went to a Raptor 700 trans & it shifts fine @ WOT. The problem stems from the stock front pump cavitating at high rpm.

 

What do you suggest? Build mine? Get a TH350?

 

Mine shifts the same way. It takes way to long to shift into 3rd at WOT. With my 3.42's in the 1/8th Im at about 5500 when it hits 3rd at the line. I know if I could get it to shift into 3rd before the line it may help with the ET's.

I do have a transgo Heavy Duty shift kit waiting to be put in and I just finished installing my tranny cooler.

 

Yeah, Im going to talk to my tran builder about it. See what he says. I would like to build the 700r4 up to perform how I need it, and still have o/d on the street.

My motor is not even pushing 300hp yet, but I may swap to a 383 later. I wont to keep my car streetable.

The trans cooler is a great Idea. I have plans on installing one also. I just hope to not be out an arm and leg on the tranny!

 

I've got at new TCI 700R-4 Street Fighter and it does the same thing. I think that for what a performance tranny costs, this **** should be figured out at the factory but it is most likely a TV sleeve or circuit issue. Just slacked up the TV cable till it shifted into 3rd at WOT. It even goes to 4th at WOT now! The problem as I understand it is that in most performance trannys the line pressure is ramped up so high that governor pressure can not overcome TV pressure to allow a WOT shift unless the cable is slacked and the TV pressure is reduced. I am no expert by far but I don't worry because most aftermarket trannys have a ton more line pressure than stock anyways. So slacking up the cable should be no biggie.

 

The Raptor I have uses a 13 vane pump. This works much better a high rpm's. It has all the "standard" performance features that the Transmission Center offers. I previously had a rebuilt 700 with B&M parts & it just didn't cut the mustard, harsh low rpm shifts, lazy high rpm upshifts, plus all the other bad things you could say about a B&M & 700R4 in the same sentence. Went to the Raptor 2 years ago & now the car upshifts @ full throttle & 6200 rpm no problem. I used to have to coax the 2-3 shift at the track by letting off the throttle & getting back into with old trans. If you want keep overdrive, get a Raptor or get the parts from The Transmission Center or Pro-Built & have someone local do it.

 

five-7 your mailbox is full, so I will post the info here for you & anyone else who is interested.

http://www.transmissioncenter.net/highperf700r4.htm

Look about 1/4 of the way down the page

 

Sounds good, and looks like they have a nice web site. I will play around with the TV cable first, to see what happens. I dont have the funds for a new trans, but I will figure something out.

Yeah, it really sucks to have to lift off the throttle to change into 3rd at the track. Sure slows the et down.

You know the old saying " you lift, you lose"

 

I just talked to a guy that races at the local track. He has his own transmission shop.

He said he would build my 700r4 and put the same stuff he puts in his drag cars for $500. He also said he could send my converter off and have the it changed to a higher stall.

I think this will be the best way to go. I told him I might build a 450-475 hp 383, and he said the trans would have no problem handleing that kind of hp.

He also said it sounds like 3rd is going out, so I guess no more trips to the track. I need to build up my racing funds for the trans now. He said I could possibly pic up 4 tenths with the stall and new trans.

later

 

update!!

I checked the TV cable and readjusted it. I took it out for a drive and it did ok on the first pass. I shifted from 2-3 at 5k and it shifted at 5300. The second time it wouldnt shift untill I let out of the throttle.

Would a vette servo help? Im kinda low on funds right now, so a rebuild is out of the question.

What should I do?

 

I had the same deal a few years ago..new trans wouldn`t go into third under full throttle...I tried a B&M trans pack just because I hadn`t anything to lose at that point I figured, well it worked and I have at least 25 runs since then and few thousand hard street miles...it`s going on three years now still works great

 

I just got quoted a transgo kit and install for $170 in car. If they have to pull the trans, it would be another $50.

Think I should go for it? I will get my trans guy to drive it first. I dont want to put in the kit if the trans is going.