no reverse and shifts at improper points on 700R4 - Third Generation F-Body Message Boards

slayer_taunu · 08-31-2006, 01:44 PM

700R4 will no longer go into reverse, and when i drive it drive under light throttle, it will rev up to like 2500 rpms before shifting. i have not driven it any faster to observe the behavior of the other shifts.

i will state that this started happening after i was trying to check/adjust my TPS. does the TPS affect shift points at all? and if so, maybe i fried the TPS?

i will also state that i was sitting on top of the motor to change my oil pressure sending unit a few days before that, so maybe i kicked the TV cable by accident and kinked it?

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Shagwell · 08-31-2006, 01:47 PM

TPS has nothing to do with shift points, 700r's are not computer controlled in any way, just tc lock-up. - You may have tweaked the cable, but if so you should still have reverse.

slayer_taunu · 09-01-2006, 01:29 AM

so what controls reverse then?

Shagwell · 09-01-2006, 02:55 PM

reverse is low gear clutches plus the reverse drum clutches, all control via the valvebody which is direct from the shifter. - I'm not sure about the probem your having other than if the trans has worn out.....

the TV cable is simply the controling mechanism for a valve in the vb that raises/lowers the line pressure(internal trans psi) depending on the position of the valve. When pulled out it max's the pressure in the trans, thus causing the governor to raise shift points.

slayer_taunu · 09-06-2006, 10:24 AM

checked the TV and shift linkage last night

TV appears to be operating fine, and the shift linkage looks ok, but i'm not 100% sure i checked the linkage correctly. i loosened the nut, put the shifter in neutral, then verified the shift lever was in 'neutral' (i put it in the middle notch, pointing down), then tightened it back up.

i did notice that when i try to put the car into reverse, i hear a noise from the underside of the car that sounds similar to the sound you'd hear under the hood when the fuel system pressurizes. maybe i'll get lucky and its just some fluid passage that is just sludged up from the car sitting for a year and it just needs a filter and flush...

at this point i'm about to call a tranny shop to look into it.

toliveis2die · 09-11-2006, 05:31 AM

Funny you should post this and I read it. My car is actually STUCK in reverse! how did you go about adjusting the shift linkage? Did you just tighten it with no slack in neutral on the adjusting bolt? it says in my Haynes manual that it must be tightened to 96 in lbs exactly with a torque wrench. Maybe you adjusted it wrong?

Shagwell · 09-12-2006, 02:31 PM

tightening the shift cable with a torque wrench? you have got to be kidding me.......I guess if you don't spec' it someone will probably leave it to loose and sue......

Tight is tight on the shift cable bolt. You put the shifter in neutral, the trans in neutral and tighten the cable down. - If you're stuck in rev, the first thing to check is whether or not the linkage is moving.

toliveis2die · 09-13-2006, 06:20 AM

I fixed it, it was just the bracket had fallen causing the brackets weight to hold the cable down and therefore it couldn't shift. =) The neutral bolt on the transmission has to be 8 ft lbs torque not the rest of the bolts on the shift linkage.

slayer_taunu · 02-23-2009, 04:13 PM

so i was searching for something else, and stumbled across an old thread of mine that i forgot to post up the results for

my problem ended up being the 'sun shell' had broken the end off, and essentially the car was shifting from 1st to 3rd in drive. $40 part, $900 rebuild

ed o · 02-24-2009, 11:23 PM

you need to make sure you put a "beast" reaction shell in or you'll be doing the same thing again. no reverse, late delayed upshift and sometimes a noise..!
The beast is thicker metal and harder metal to resist breaking. Seen lots of stock shells broken, but yet to see a broken/stripped "beast"