04 LM7 into 87 K5

[K5Rob]

Can anyone explain what they did to make their 4L60E work correctly with an NP208 ?? I have searched for weeks and can’t find anything. I know there are Several VSS options but when i dig a little deeper nothing seems to work correctly or put out the right signal. Which leads to poor performance, not shifting past 2nd gear, even no shifting. Is this why people scrap the 208 for a 241? Then of course the 4hi/low switch which seems a little more forgiving but I still am unclear on the tuning aspect - coming from a 2wd PCM would i need to source a 4wd pcm, or are the tables simply cut and paste for the tuner? Lastly I am assuming the factory shift linkage mates up to the 4L60E without too much hassle but I couldn’t find anything on this either. This is strictly for curiosity as i have decided to stick with the 700r4 for the above reasons.

 

[Ricko1966]

Yea, this gets into what every LS swapper faces... the issue with 60e/80e swapping is you NEED vss , and if 4x4 you'll need your hi/lo switch off the t case


The expensive solution (due to rarity) is to run a passengers side drop NP241 OR 208 from a 90 or 91 suburban , (maybe k5?)
Which has vss.

Then run a 90/91 burb/k30/k5 electronic speedo instrument cluster .


Optionally---

You can visit dakote digital for a adapter to turn the cable speedo output on your 208 to VSS .... ORD might have also, idk.



The 700r4 is the easiest, cheapest methos (go on fleabay and price a np241 or vss 208 and you'll see why)

IDK so throwing this out for someone who might shed some light. I'm pretty sure Camaros starting in 1984 used an adapter at the mechanical speedometer location that went in just like a mechanical drive but put out vss for electric speedo. Anyone,anyone,Bueller, Bucket.

 

[Vbb199]

Speedometer 8K Pulse Generator

Dakota Digital manufactures digital instrumentation and accessories for the automotive, motorcycle and car audio enthusiast.

www.dakotadigital.com

The adapter to give the PCM a speedo signal.

The pulses per revolution (a calculation based off of the number of teeth on the reluctor wheel inside your transfer case) is a programmable variable inside your P59 pcm.

As is the VSS pulses per mile, gear ratios, tire size and axle ratio.

 

[Vbb199]

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[Vbb199]

Then of course the 4hi/low switch which seems a little more forgiving but I still am unclear on the tuning aspect - coming from a 2wd PCM would i need to source a 4wd pcm, or are the tables simply cut and paste for the tuner?

the tables for 4x4 stuff should be in the PCM by default..

edit, i looked in the tune repository on HPtuners website, and a 2wd 04 truck does have the 4x4 stuff in it. you should be good. its not much thats really needed... its just torque calculations, the most important part is the VSS signal

 

[Vbb199]

There is also a low 4x4 shift table ,

It tells the trans what mph to shift when in low 4x4.

 

[K5Rob]

There is also a low 4x4 shift table ,

It tells the trans what mph to shift when in low 4x4.

So if using the 4L60E and NP208, the PCM needs VSS from the transmission, transfer case or both?

Would I keep the factory VSS on the transmission plugged in and also add the Dakota Digital pulse generator at the transfer case cable input?

 

[Vbb199]

So if using the 4L60E and NP208, the PCM needs VSS from the transmission, transfer case or both?

Would I keep the factory VSS on the transmission plugged in and also add the Dakota Digital pulse generator at the transfer case cable input?

If im not mistaken your 2004 2wd 60e has the vss output at the tailshaft housing.

You'll be removing that to mate the 208 to it.

THe pulse generator goes where the old speedo gear housing went on the 208

 

[K5Rob]

If im not mistaken your 2004 2wd 60e has the vss output at the tailshaft housing.

Yes it does, good call. So i am wondering now if i should keep the 4L60E or the 700r4

 

[K5Rob]

All i found when researching was problems getting the 4l60e to work correctly. Maybe just bad tuning?

 

[CalSgt]

So if using the 4L60E and NP208, the PCM needs VSS from the transmission, transfer case or both?

Would I keep the factory VSS on the transmission plugged in and also add the Dakota Digital pulse generator at the transfer case cable input?

When I did my 4L60E + 208 combo all of the information I found claimed the Dakota signal wasn’t good enough for the factory PCM to shift correctly.

I ended up with a custom VSS and reluctor wheel from a 241 and modified my tail housing because I couldn’t find an adapter.

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Now there’s an adapter that mounts in the Speedo gear hole for like $150

https://www.walterseandp.com/product-page/np208-electronic-vss-conversion-kit-r2