View Full Version : VSS questions


itsmillertime
04-26-2011, 06:50 PM
I'm installing a 02 LS1 with a 4x4 Dodge NV4500 manual transmission and Dana 300 transfer case behind it into a 85 Toyota 4Runner. The VSS for the 2wd transmission is in the tail shaft but the 4wd transmissions don't have a VSS. The VSS for 4wd's goes in the transfer case. The Dana 300 has a mechanical speedo.

What are my options for getting a VSS signal to the ECM? I planned on using the tach and speedo outputs from the ECM for electrical gauges.

Tongboy
04-26-2011, 09:36 PM
I was going to say - what cluster are you using for speedo and ask if that had a VSS output...

tach output from the ECM is simple enough but the speedo output is (to my knowledge) only output via the serial interface that is chevy specific.

there are a few companies that make analogue to digital converters, dakota digital comes to mind. there are also ways of measuring driveshaft speed and related with various setups.

Docked Wage
04-26-2011, 09:57 PM
I did quite a bit of research on this and installed a VSS in the GM Factory adapter between the trans and the transfercase. I know you have a different trans but hopefully this gets you pointed in the right direction.

I followed what this guy did. Scroll down to post #542

http://www.pirate4x4.com/forum/showthread.php?t=735270&page=22

The trick is to find the reluctor ring that fits your transmissions output shaft. If Advance Adapters does not have it try Jags That Run. If neither has the exact ID you could put a Speedisleeve on the output shaft to make up any differences.

Other options are a Jags that run kit that installs at a Ujoint yoke. Their website shows it on the rear axel but I've seen guys install them at the output of the transfercase.

Since you don't need the VSS to help the transmission decide shift points, the JTR option would be an easier install and would not go to zero when the clutch is pushed in.

Hope this helps.

Ken

Docked Wage
04-26-2011, 10:10 PM
I've also seen guys take an upper timing gear from a 4 cylinder chrysler engine (it has 40 cogs) and machine it to fit on a yoke. Fab a bracket to hold the VSS and presto.

I found it in this old thread here on this site. http://www.ls1tech.com/forums/conversions-hybrids/867247-cruise-vss-electronic-throttle-question.html

itsmillertime
04-26-2011, 10:32 PM
I was going to say - what cluster are you using for speedo and ask if that had a VSS output...

tach output from the ECM is simple enough but the speedo output is (to my knowledge) only output via the serial interface that is chevy specific.

there are a few companies that make analogue to digital converters, dakota digital comes to mind. there are also ways of measuring driveshaft speed and related with various setups.

Making my own cluster out of Marshall gauges. The tach and speedo should work as long as i can get the proper signal to the ecm. This is the speedo I plan to use: http://www.marshallinstruments.com/products/5152.cfm


I did quite a bit of research on this and installed a VSS in the GM Factory adapter between the trans and the transfercase. I know you have a different trans but hopefully this gets you pointed in the right direction.

This sounds like the answer. And this way the ecm will get the right info whether I am in fwd, rwd, 4wd, 2lo or 4lo. Now just to find the right reluctor wheel. What am I looking for? I read 40 teeth for auto's and 17 teeth for the T56. Or can I just find one that fits and make appropriate changes in the ecm?

itsmillertime
04-26-2011, 11:00 PM
His transmission appeared to have more output shaft to work with than I do. And the tailhousing also seemed easier to modify. My output shaft is 1.5" but I'm not sure how far the transfer case will slide onto the output shaft's splines. Here are a few pics of mine:
http://i465.photobucket.com/albums/rr13/itsmillertime0/IMAG0256.jpg
http://i465.photobucket.com/albums/rr13/itsmillertime0/IMAG0257.jpg
http://i465.photobucket.com/albums/rr13/itsmillertime0/IMAG0258.jpg

itsmillertime
04-27-2011, 01:10 AM
Also the kit he used was $250. I'm thinking about scavenging the speedo gear/ sensor from a T56 now and jerry rigging the gear onto my shaft and attempting to attach the sensor to the inside of the tail housing.

Docked Wage
04-27-2011, 09:31 AM
This sounds like the answer. And this way the ecm will get the right info whether I am in fwd, rwd, 4wd, 2lo or 4lo. Now just to find the right reluctor wheel. What am I looking for? I read 40 teeth for auto's and 17 teeth for the T56. Or can I just find one that fits and make appropriate changes in the ecm?

I am only familiar with the 40 tooth application. You may want to have a discussion with the guy that is programming your PCM regarding how many teeth you should use considering your gearing ratios.