700R4 lockup kit

[flomulgator]

Hi I'm starting to look into a consistent "problem" with my 91 burb (which has a 700 transmission and this might hint at and be a fix for my problem.

What I got going on is that the truck won't use 3rd gear unless it is in "D". If it is in "OD" it just skips from 2 to 4th (overdrive) gear and back. Full disclosure, I despise automatic transmissions and don't really know what the difference between calling it 4th gear or overdrive is and what "lockup" really is.
Anyways this is a real problem at highway speeds having it go from 4th to second all the time, especially since my gearing is too tall due to larger 33" tires. A very reputable shop tested it and told me it is working fine, which makes me think that is how it is designed? Crazy if true. This product sounds like a cure for that, sounds like it modernizes the transmission operation. Whaddya think?

[Robyn]

IN the OD position the tranny should display 4 distinct actions.

Starting off, the 1-2 shift then the 2-3 shift then 3-4 and finally the lockup at about 45-50 depending on the throttle position

In the D position you should see 3 distinct actions
The 1-2 the 2-3 and then the lockup. The lockup in D position may be very hard to feel but should be there

The 1-2 shift is a long reach as the ratio of 1st gear is 3.06:1 and then it jumps to 1.63:1 then to 1:1 the OD is .7:1

If you dont see basically what I am speaking of then there is an issue.

The Kit I spoke of is not a fix for some problem but instead an add on to iliminate the need to the electronics to control the lockup.

Hope this helps

Robyn

[flomulgator]

Yeah I definitely don't have that many gears. I only have:
D: 1,2,3
[D]: 1,2,"3", OD
So now I am wondering if I even have the 700 transmission? I looked at the stamping and everything and it all made sense that I had 700 but I definitely don't have a 4th gear so now I'm kinda at a loss.

As for the problem though, I looked up "overdrive" on wikipedia, learned about it, and thought about what you said. What my problem is is that overdrive is locking up too early and releasing too late. Basically it never gives 3rd gear a chance to show itself. So when my tranny is in [D] there is often only 2 shifts.... 1, then 2, then OD. The exception is when I am climbing a grade at such high speed that the tranny would explode if it shifted into 2nd; then it finally goes to 3.

Any idea on how to get the lockup to occur "later" and give me back my 3rd gear?

Any idea what transmission I have?

Thanks for your help!

[Petescraft]

Hi, I'm running a 700 and everything has worked well until recently. I installed a switch to control the lockup into 4th. The truck would shift normally up to 4th gear and the lockup would engage as expected. Then, with no real symptoms developing, the truck now stays locked up in all gears, however it comes out of lockup when I step on the brake and when I flip off the switch. The truck is completely driveable and this is more of a nuisance than anything, but anyone have an idea of what to check first. Thanks.

[Edahall]

Hi, I'm running a 700 and everything has worked well until recently. I installed a switch to control the lockup into 4th. The truck would shift normally up to 4th gear and the lockup would engage as expected. Then, with no real symptoms developing, the truck now stays locked up in all gears, however it comes out of lockup when I step on the brake and when I flip off the switch. The truck is completely driveable and this is more of a nuisance than anything, but anyone have an idea of what to check first. Thanks.

That sounds like a completely normal symptom when you install a lockup switch. If you don't want it to unlock when you step on the brake, you'll have to bypass the switch that's connected to the brake pedal. Does the transmission shift normally with you flip off the switch?

[Robyn]

Is the 91 Burb a 2500 truck ???

[flomulgator]

Is the 91 Burb a 2500 truck ???

I'm guessing you're asking me since I was the one who referenced the '91 burb, and although the post is 8 months old the questions still stand

No, my '91 burb is a 1500.
D = 1,2,3
[D] = 1,2,3, overdrive.
Overdrive engages waaaaay too soon, so I end up switching between D and [D] constantly as if it were a manual.

[chvycmnslvr68]

Yeah I definitely don't have that many gears. I only have:
D: 1,2,3
[D]: 1,2,"3", OD
So now I am wondering if I even have the 700 transmission? I looked at the stamping and everything and it all made sense that I had 700 but I definitely don't have a 4th gear so now I'm kinda at a loss.

As for the problem though, I looked up "overdrive" on wikipedia, learned about it, and thought about what you said. What my problem is is that overdrive is locking up too early and releasing too late. Basically it never gives 3rd gear a chance to show itself. So when my tranny is in [D] there is often only 2 shifts.... 1, then 2, then OD. The exception is when I am climbing a grade at such high speed that the tranny would explode if it shifted into 2nd; then it finally goes to 3.

Any idea on how to get the lockup to occur "later" and give me back my 3rd gear?

Any idea what transmission I have?

Thanks for your help!

Hello Flomulgator ... I am new on this site and I see that this thread is quite old but I thought I might add a bit to it .. the way your tranny is shifting it sounds like there may be a problem with the "torque valve" in the valve body ... or your torque valve control cable maybe set wrong ... my '66 chevelle acted alot like that when I put a 700r4 in it .. I was not aware at the time of how critical the " kickdown cable " was .. it is actualy a torque control cable... it does control the kickdown of the trans but it also controls the amount of hyd pressure is put to the clutch packs in the trans ... so that whatever throttle position your running at the tranny should shift about the same ..
another thought is that you may have a TH350LU tranny which is commonly mistaken for the 700R4 because they both ust the same electric torque converter lockup ... and both have the same square plug on the seft side of the casing ...
and as far as a " manual lock up kit " for the 700 R4 trans .. all you need is a fairly hard 5/16 rubber ball ... you just drop the elect. solonoid for the lock up down out of the valve body and set the ball on top of it and stick it back in .. works just like the electric lock up w/o the electronics hooked up ... this is a trick that a trans expert taught me when I was first putting the 700 tranny in my '66 chevelle ... a trick that most tranny professionals do not want to get out