My stock 85, with 700R4 auto seems to shift too high...both 1-2 and 2-3 above 5000 RPM. During WOT runs...as in 1/4 mile runs...the 1-2 shift occurs at approximately 5100 to 5200, and the 2-3 at about 5000 to 5100. The 'seat of the pants' feel is that power is gone by about 4600, and I'm stuck waiting for the shift to take place...losing valuable time. :( :(
I am able to blip the throttle to get it to shift, but that kills time too. :cry
I tried adjusting the TV cable per the repair manual, but that didn't seem to change anything...thought that I read that TV cable adjustment only affects part throttle shift points anyway, not WOT.

One observation that I made was that the trans fluid appears to be over-serviced....level was ok with engine running when trans was cold, but when trans was hot the fluid was about an inch past the 'FULL HOT' range marks on the dip-stick. Over-serviced trans fluid have any effect on WOT shift points?? Trans had been rebuilt within the past 8000 miles by previous owner.

Anybody have any ideas as to what the problem could be, or what I should look for?? I really don't want to depend on a trans shop for help or repairs unless really necesary.

Thanks in advance for any help you may provide. :cheers:

 

I think you have to change weights and springs in the governor to change the shift points.

 

I adjusted mine to the manual too and had the same problems. I finally just pushed the button and let the cable snap back and it has shifted fine since.

 

What button are you talking about here. my 700R4 doesn't want to go into 3rd @WOT. This may help me.

 

I think your shift points are pretty close to being in the right spot. Im pretty sure the SOTP feel you get is because the L98 is topping out of it's power curve. Im not certain of the exact formula for this process, but you do need to run past your power curve just a bit so when the shift does land, you are right into your next power curve. Someone correct me if Im wrong here.

 

Thanks Bluevette85...I thought I had heard the same...weights and springs in the governor for WOT shift points. :) Manual says that the TV cable 'controls line pressure, shift points, shift feel, part throttle downshifts, and detent downshifts'. It isn't specific whether it is WOT, part throttle shift points, or both.

I spoke to one local transmission shop today and they told me that it should be just an adjustment of the TV cable. Is there any risk of transmission damage if I try TV cable adjustments? I don't want to make my problem any worse than it already is. :crazy:




[Modified by Blue85L98, 10:53 PM 6/26/2002]

 

Poppy...at about what RPM does your WOT 1-2 shift occur?...WOT 2-3 shift?



[Modified by Blue85L98, 10:49 PM 6/26/2002]

 

chucks88...There is a spring-tab...'button'...(manual calls it the 're-adjust tab') on the TV cable adjustment bracket, just along the LH side of the air plenum, aft of the throttle body connections for both the throttle cable and TV cable. This is where the TV cable adjustments are supposed to be made, according to the service manual.

Per the manual, you are supposed to depress the spring-tab and move the slider back through the TV cable fitting in direction away from the throttle body, until the slider stops against the fitting. Then release the re-adjust tab, and then ...with engine off....open the throttle to the 'full throttle stop' position to automatically adjust the TV cable. Sure sounds simple...


[Modified by Blue85L98, 10:50 PM 6/26/2002]

 

VetteNoob...I expected some degree of overshoot over the peak power RPM, but not as much as I'm seeing. First time I had it at the drag strip, my 60ft times were matching other vettes that were running mid 13 second(uncorrected for altitude, at 2500 ft altitude) 1/4 mile ...while my car was lucky to break 16 second times(uncorrected) . I don't expect my tired L98 to get me into the 13's, but would expect to run at least 14's... :yesnod: It just felt as if I was hanging in 1st gear way too long...about 2 seconds too long...before it shifted to 2nd gear. :crazy:


[Modified by Blue85L98, 8:41 PM 6/28/2002]

 

I went through the same problem with my 87. The solution was a govenor spring and weight kit from tci transmission. You have to go through a lot of trials to get the shift points you want. But it will work. Mine now shift at 4900 in first and 47to4800 in secont. good luck. :yesnod:

 

Thanks Blue. Yeah, that does sound pretty easy. I'll check my manual too

 

If you're planning on some simple air flow mods (exhaust & intake) leave the WOT shift points alone, they're about right. As you provide more air to the engine the HP/torque curve peaks will move upward in RPM.

Otherwise, get the spring/weight kit for the govener so you can lower them.


[Modified by 65Z01, 9:06 AM 6/27/2002]

 

Like these guys said, shift springs will do what you want it to do. May have to use some trial and error on the spring weight, but if you want it to shift earlier, use some lighter springs. If all your shift points are in the right range to each other, but just too high in rpm, you can try changing the weights on the governor to lighter weights. This way shifting for all the gears are changed by just changing the governor only so you dont have to change each shift spring in the valve body and their relation to each gear stays the same.

 

Check out B&M (www.bmracing.com) for their part # 20248, Governor Recalibration Kit for TH700.

BTw - You don't have to drop the pan to do this.


[Modified by Nitro Junkie, 7:31 PM 6/27/2002]

 

Thanks everyone, for all of the feedback. :cheers:

I spoke to more than one trans shop and they all told me that the TV cable adjustment controls the shifts at both part throttle as well as WOT. I made slight adjustment to TV cable...per shop recommendation. The result was that both the WOT and the part throttle shifts do occur at lower RPM..., and with less authority than when it was adjusted per the service manual(not as crisp). I guess I'll evaluate it with this adjustment for a while...I can always set it back per the service manual later, if I have to. May also try the B & M kit at a later date.

 

Sorry I just got back in to this thread but sounds that you might already be on the right track. It seems that when i adjusted it per the manual the car shifted at way to high rpm,s and jerked. So I just pushed the Re-adjust tab and let the cable snap back in place and the thing shifts smooth as silk. Go figure.