I Have a 1991 Camaro RS 305 TBI with a 700R4 Trans i Replaved my rear gears to 4:10 and now my speedometer is off i know your supose to replace the drive and driven gear but my trans is electronic and cant figure out how to do it i figured a computer flash for GM Dealer but they say they cant do it and the tranny shop ive been talking to is trying to figure something out for me but havent got back ahold of me yet so i am lost Help me if you can or atleast point me in the right direction PLEASE

 

http://www.dakotadigital.com/index.c...cat/cat287.htm

 

Sweet thank man i was also wondering if it has full instructions on install and i am guess you have to cutwires and just strip them then place them in corasponding holes

 

See the sticky up top of the forum:

Sticky: 700R-4 speedometer gears

The 700R4 transmission is not electronic. For the VSS it is still driven by gears, and can not be corrected by re-flashing the ECM.

RBob.

 

The TBI / 700-R4 in those years could theoretically be corrected by gears but...

There aren't available gears to correctly match it to stock height tires & 4.11 gears.

And, it didn't pass the signal through the ECM on it's way to the speedo like RBob said, so that won't work.

That's why the electronic solution posted by TTOP350 is one way to go.

Enjoy your new gearset.

 

Ok if it dosent go though the ECU then why dose it shut down at 80 mph. Or is it because its off the rpm and gear its in and not the mph its going

 

It ends at the ECM. It doesn't pass through the ECM.

Some vehicles send VSS signal from trans. to ECM and the ECM feeds the speedo. That's not the case for a TBI 305 third gen.

The ECM still receivessignal and the EPROM still has a speed limiter. Yours is erroneously at 80 due to speedo gear mismatch.

 

So jmd will fixing the speedometer also fix the shut down cause it never sut down at 80 mph before i put in the new gear set

 

It depends upon how the fix is done. On the TBI cars the VSS is buffered by a separate 4-out buffer box. Usually yellow and mounted under the dash on the passenger side. The VSS goes to the box as an AC signal (magnetic output VSS @ 4K PPM).

The box then outputs 4 digital pulse streams, one to the ECM (2K PPM), one to the speedometer (4K PPM), and one to the cruise control (2K PPM), (4th output is not used).

If you correct the input to the buffer box it affects everything. This can be done either via the gear change for the VSS or the SGI-5 Dakota box.

If you don't have cruise control can eliminate the 4-out buffer box and just use the outputs from the SGI-5 for the ECM & speedometer.

RBob.