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Finally... my 5.3 swap

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I didn't realize the VSS was such an issue. I had tentatively planned to use a Dakota digital sender with an Autometer electronic speedo.

Man I would love to just pull the trans-tcase with the 5.3L and the run a hi pinion 60.... :D
 
mrk5 said:
I didn't realize the VSS was such an issue. I had tentatively planned to use a Dakota digital sender with an Autometer electronic speedo.

Man I would love to just pull the trans-tcase with the 5.3L and the run a hi pinion 60.... :D
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I didn't either until I was told an incorrect signal could lead to premature transmission wear. [emoji45]
 
MAX89K5 said:
I didn't either until I was told an incorrect signal could lead to premature transmission wear. [emoji45]
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Maybe I missed something, but I'm not clear on what the problem is. :dunno:

I know I'm going to be running a manual tranny so the only thing my sending unit has to do is supply vehicle speed to the PCM and that supplies the vehicle speed signal to my autometer gauge.

Bigblock72 said it would work for me, but what is different for you guys? Just trying to wrap my brain around it.
 
Words from Brendan at lt1swap

" There is not an inline sensor I would trust to correctly run a 4l60e. That signal needs to be very accurate to ensure proper transmission operation.* It might work with some inline sensors, but I have seen long term issues with transmission life. (the PCM constantly monitors shift times, and adjusts pressures during shifts to maintain proper shifts. If the info it gets from the speed sensor is not accurate, it can cause excessive wear on the transmission components leading to failure.)"

I would rather be on the safe side with an accurate OE type and signal sensor.

*
 
MAX89K5 said:
Words from Brendan at lt1swap

" There is not an inline sensor I would trust to correctly run a 4l60e. That signal needs to be very accurate to ensure proper transmission operation.* It might work with some inline sensors, but I have seen long term issues with transmission life. (the PCM constantly monitors shift times, and adjusts pressures during shifts to maintain proper shifts. If the info it gets from the speed sensor is not accurate, it can cause excessive wear on the transmission components leading to failure.)"

I would rather be on the safe side with an accurate OE type and signal sensor.

*
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Gotcha. That makes sense. It's not so much that it won't work but that you are worried about accuracy since it's not OEM. Since the only thing it's doing for me is running a speedo I'm obviously in a less critical situation.

Thanks for clearing it up for me... I can be slow sometimes. :D

I can't remember what tranny bigblock72 is running, but it would be interesting to have him chime in...
 
Sorry to hear you're having so much trouble with the VSS. .. Out of curiosity, could you still use the reluctor ring from the '88-'98 241 you grabbed and then drill and tap your existing housing for the VSS, similar to the JTR article you posted a link to earlier? Or are there any other wrecking yards nearby that you may be able to find a '90-'91 241 at? I know they're pretty rare but I went back to the PNP by me this weekend to get my 32 spline 241 from a '90 3/4 ton Burb and found two other '90 1/2 ton Burbs with the VSS equipped 241's we need so they are out there...

For the '90-'91 electric speedo, couldn't you just run a wire from the newer PCM straight to the speedo and bypass/eliminate the DRAC? I know you can adjust/correct the speedo output for tire size and gear ratio in the newer PCM's so I wouldn't think you'd need to keep any of the extra older tech in there or am I wrong?
 
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NorCalAnthony said:
Sorry to hear you're having so much trouble with the VSS. .. Out of curiosity, could you still use the reluctor ring from the '88-'98 241 you grabbed and then drill and tap your existing housing for the VSS, similar to the JTR article you posted a link to earlier? Or are there any other wrecking yards nearby that you may be able to find a '90-'91 241 at? I know they're pretty rare but I went back to the PNP by me this weekend to get my 32 spline 241 from a '90 3/4 ton Burb and found two other '90 1/2 ton Burbs with the VSS equipped 241's we need so they are out there...

For the '90-'91 electric speedo, couldn't you just run a wire from the newer PCM straight to the speedo and bypass/eliminate the DRAC? I know you can adjust/correct the speedo output for tire size and gear ratio in the newer PCM's so I wouldn't think you'd need to keep any of the extra older tech in there or am I wrong?
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That is exactly what I am doing! Got a electric cluster on eBay for $35. I'll use the reluctor ring and sensor in my t-case and have the cable driven vss housing drilled and a bung welded in for the sensor. I have 3 local pnp yards, and I counted 4 squarebodys, all lwb pickups pre 85...
 
And I'll have to run the VSS wires straight to the PCM. Then run a 12v wire to pin 50 on the PCM green connector with a 1.5k ohm 1/4 watt resistor; then tap that wire between the PCM and resistor and run that to the speedometer.
 
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Sweet! Glad you were able to get it figured out :woot:

Bummer about the lack of square bodies in your area. I have 4 PnP's within driving distance and they all have tons to choose from... If any of the square bodies by you were diesels I'd grab the oil pressure and water temp gauges next time you're there. I've seen a few other guys do that when doing the LSx swaps since the newer engines run higher oil pressure and cooler water temps than the old SBC's. Not a necessity by any means but it'll help the gauges to match what the engine is doing a little better and they're a direct swap/replacement to the ones in your existing housing.
 
In the final stages of prep :

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Core support came out really good

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Spoke with the man I'm getting my 5.3/4l60e from, everything is pointing towards it being ready the 11th. I'm super stoked, only thing is I won't get any truck time this weekend. My girl is in town [emoji6]
 
Looks like you're off to a good start. That open engine bay is just begging to have that LS put in :woot:
 
Looks like I'm a little late to the party for the VSS discussion, but I'll post what I know for future reference.

4l80e/60e transmissions require a shaft mounted 40 pulse sensor with no exceptions.

If you are using a manual trans or an older t400 700r4 style trans then you can use a speedo cable mounted 2 wire 4 pulse sensor (I don't think three wire sensors are compatible, though I haven't tried either) but it will require changes to the software for the computer to register accurately.

Advance adapters makes an adapter that bolts to the back of a 4l60e that mounts a speed sensor that reads a tone wheel that attaches to the output shaft. The easiest thing to do is swap the output housing on a 241 with the correct speed sensor tone wheel set up. Just make sure you wire a low range switch to keep the computer happy with this option.

Speaking of 241s; it is possible to swap left hand and right hand drop output housings with some careful grinding of the ridge that locates the oil pump. This is what I did since I'm running a left hand drop t-case and I wanted to keep my mechanical speedo.

My setup is a 6.0l/4l80e/241, I machined a 241 style tone ring to fit over the input shaft of the t-case then drilled and tapped the adapter for the sensor. If I would have been smart I would have followed my own advice and used the factory 241 speed sensor parts and bought an electronic speedometer.
 
bigblock72 said:
Looks like I'm a little late to the party for the VSS discussion, but I'll post what I know for future reference.

4l80e/60e transmissions require a shaft mounted 40 pulse sensor with no exceptions.

If you are using a manual trans or an older t400 700r4 style trans then you can use a speedo cable mounted 2 wire 4 pulse sensor (I don't think three wire sensors are compatible, though I haven't tried either) but it will require changes to the software for the computer to register accurately.

Advance adapters makes an adapter that bolts to the back of a 4l60e that mounts a speed sensor that reads a tone wheel that attaches to the output shaft. The easiest thing to do is swap the output housing on a 241 with the correct speed sensor tone wheel set up. Just make sure you wire a low range switch to keep the computer happy with this option.

Speaking of 241s; it is possible to swap left hand and right hand drop output housings with some careful grinding of the ridge that locates the oil pump. This is what I did since I'm running a left hand drop t-case and I wanted to keep my mechanical speedo.

My setup is a 6.0l/4l80e/241, I machined a 241 style tone ring to fit over the input shaft of the t-case then drilled and tapped the adapter for the sensor. If I would have been smart I would have followed my own advice and used the factory 241 speed sensor parts and bought an electronic speedometer.
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Very good advice. I considered grinding the driver drop output housing but decided against it. My machinist can drill and weld a bung in my cable driven housing for $20. I am going to go that route and install a switch for 4 low. [emoji1]
 
Well damn, no motor today. Still not quite ready, but the plus side is he is delivering it early next week. That saves me a 450 round trip [emoji1].

Still making good progress, got my VSS issue straightened out and my electric speedo cluster came in yesterday. I still have plenty to do before it gets here. I am hoping to have everything buttoned up by the end of the month!

Stay tuned....
 
Sounds like you're moving way faster than me. good work! :)
 
Making a little progress today. My manifolds cane in so I've been cleaning them up.

Got the heat shields off, bosses cut off and ground smooth. And a good coat of VHT, we'll see how long it lasts.

d12a7a8c1b9c00e0a2ab376b85d55871.jpg
 
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