700R4 shift help....

myclone

Donating Member
I scored a freshly rebuilt 90' 700 a while back for 300 bucks which included a new GM TC. It was going in a NICEstreet rod (behind a TPI 350) but the owner hadda have a "divorce sale" and thats how I scored it so cheap.

Anyway..... Heres whats up. Trans shifts HARD.. I mean TOOO hard on the 1-2. With the TV cable adjusted properly it wont shift until over 6k rpm and its brutal. If I back the tv cable off enough to soften it up it shifts WAAAAYYY too early 1-2.

I forgot to ask if the guy had a shift kit installed when I bought it but Im assuming it did considering how hard it shifts.

Can I swap the gov outta another trans I have laying in the garage to lower the shift point and at the same time tighten the TV cable up where it should be??

This is a driver so the brutal 6000 RPM 1-2 shift aint gonna cut it.

TIA...

(BTW, no this aint for a syty but if I put it in off topic I doubt wallyworld or Brian H would see it. It is a 700R4 so it has a little to do with sytys :) :wink: :wink: )
 

E-Rue

New member
hu ryde is lying.

its not that easy.
your gonna need to do the following.

1. bend the cover when you remove it
2. splash tranny fluid in your eyes and nose when it finnaly does pop off. (just to be safe rub some in your hair too)
3. be SURE you bend the cover when your trying to reinstall it. (what you want to do is dent the dome in with a hammer)
4. have the front propshaft out while your doing it, so the truck rolls down the ramps and squashes your redneck ass!

oh.... and be sure your over top a mudhole when your under the truck on your back, so you can ruin at least two shirts :)
 

myclone

Donating Member
E-RUE said:
hu ryde is lying.

its not that easy.
your gonna need to do the following.

1. bend the cover when you remove it
2. splash tranny fluid in your eyes and nose when it finnaly does pop off. (just to be safe rub some in your hair too)
3. be SURE you bend the cover when your trying to reinstall it. (what you want to do is dent the dome in with a hammer)
4. have the front propshaft out while your doing it, so the truck rolls down the ramps and squashes your redneck ass!

oh.... and be sure your over top a mudhole when your under the truck on your back, so you can ruin at least two shirts :)

Thanks Hu Ryde I'll swap in the gov from the orig trans and see what happens. Nothing like having a TBI 305 (165hp on a good day) that gets a full sized truck sideways on the 1-2 and gets scratch on the 2-3. The novelty of it all wore off right when the across the bed tool box broke loose and bout flew out the back of the truck along with all the garbage that was on the dash ended up in my lap. :roll:

Umm E....You cabbage head.... Look at the last line of my post right above my sig. The trans swap is for towclone (GMC1500). No prop shaft, plenty of room to work, etc. However, I do have a couple of shirts and old ratty jeans just for swapping trannys. I dunno of a freakin messier job myself.

I just wanna know what moron at GM decided the trans cross member should be made in such a way that you have to remove it to get to the rear trans pan bolts. STUPID!!!!
 

Hu Ryde

Donating Member
One thing to add though, the seal is very sensitive because it is easy to cut, pinch, or rip, if you use a RTV type sealer make sure none of it gets in the case because it will clog bores and such. Have fun!!!

What E????? I am not!!!! PUNK!! :lol: :lol:
 

myclone

Donating Member
Update (FWIW):

Swapped out the gov from the orig trans and now the 1-2 shift happens at the correct time (IMO) with the TV cable adjusted correctly. Still pretty harsh 1-2 shift but as I said, Id say the trans had a shift kit installed. I just know the way the locals think around here.

Anyway, last probs. The 3-4(OD) shift happens almost immediately after the 2-3 shift at light throttle. At WOT trans shifts fine (harsh but timed correctly) but at light throttle its funky on the 3-4. Any way to change the 3-4 shift point without dropping the pan or pulling the trans (again)?

The TCC doesnt seem to be locking either (step on brake pedal RPM doesnt change) but I can prolly figure that one out (I hope). Suggestions on that are appreciated though. :wink:

The only thing I did to this trans was install the "pink" spring in in place of the white spring on the PR valve stack and grind the second land off the PR valve. www.transonline.com has a exploded diagram of all this under "total tech database" BTW.

Did I increase the pressure TOO much by doing this??? I can put the stock stuff back in if it will help soften the shifts just a tad and help the 3-4 shift timing.

I dunno, maybe Im just used to the worn slap out stocker that has been in there since I bought the truck.

TIA
 

Hu Ryde

Donating Member
Trans can be modified to shift hard without a shift kit, larger orfices, drilled pump holes bigger valves and so on. A shift kit like from B&M basically is a new spacerplate with larger bore holes in it with new gaskets. Who knows if it has a shift kit or not unless you pull the VB.

You can make the 1-2 shift hard in a normal 700 with the corvette servo, very simple install if the tranny is out.

Your checking the TC lock up at a steady cruise right? With the gass pressed at about 2500 rpm on highway then touching the breaks until the break light comes on? That's what unlocks the TC. Not to discredit your TC but are you sure its a lock up TC?

I think the spring is fine, it probably will effect the shift firmness some is a good idea because it makes sure the clutches are engaged not giving them a chance to slip if it were to happen.

Hope this helps some....
 

myclone

Donating Member
Thanks for the info Hu Ryde... TC is a lock up (yep, Im sure) and if I hadda bet money on what was done to modify the shift firmness/points Id say a "shift kit" (like a B&M or similar) was installed. Its the way the locals round here would do it. Most of em aint got the gray matter to mess with the case orfices or springs to change the shift charactoristics. They could prolly handle a "transpak" install though.

DAMMIT I dont wanna have to pull the VB... That thing along with all its little check balls just scares the crap outta me and I aint got a bit O problem admitting it.. :(
 

Hu Ryde

Donating Member
Pullingf the VB is not bad at all. There are so many places on the net that tell where they go. Plus they won't come rolling out leaving you no clue to where they went they will sit in the valley on the VB. If the TC is not locking up it might be a solinoid prob. Or possibly a pressure sensor. These parts can be replaced by Transstar for about $30 for the sensors, and solinoid. With this you don't need to pull the VB just disconnect the solinoid and sensors and replace them.

Shift kits are not bad it's just you could do what they do by simply drilling bigger holes in the VB seperator plate for free. You just can't go back to stock.

What about the 3-4 shift? Does it have a upshift valve? I have an extra if you want it. I also have the solinoid. When trying to find why I had no 4th gear all that was replaced and none of it was defective. The servo was the bad part, not really bad but just lodged in the bore and woulndnt move. I also changed the spring, and rebuilt my VB 2x's while it was in the truck. These trannys are cake once you get a grasp of how they work and how to trouble shoot them. Let me know on the parts, the only thing is I will be out of town for about a week and a half beginning tomarrow at 7:00. Let me know if you think it will help and I will ship it when I get back. What about your Sy? How's it's tranny? Stock?
 

myclone

Donating Member
FWIW... Trans is FUBAR.. :roll: :roll: :cry: Shoulda known if I bought a $300 trans that's exactly what Id get.... Oh well, for the money it was worth a shot and gives me another to take apart and learn on (like I need four 700R4s in the garage).

Trans slips on the 2-3 shift and once it drops into 3rd it immediately goes to 4th(OD). Down shifts are now as brutal as the upshifts. Manually shifting or WOT it works fine no slippage but just putting it in OD and letting it do its own thing it freaks the hell out.

Since you asked myclones trans was rebuilt right before I bough it. I did the PR valve "grinding" mod I spoke about before and a 9/11 TC. I had to put the bigger 3-4 upshift sleave in it due to no 3-4 shift at WOT after the rebuild. I run a TCI alum deep pan, temp gauge, biggest B&M cooler made, and Red Line fluid. Seems to work fine but dont let Murphy's law know I said that or it'll die on me sure as hell. :roll: :wink:
 
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