LS400 tranny in 92 SC4

[GhettoFabSC]

I just got this car from my brother and the speedometer doesn't work. He said has a LS400 tranny in there after his SC tranny gave out. He said something like the speed sensor from he sc wont plug to the ls tranny.

Is there a way I can hook it up so my speedometer works?

 

[GhettoFabSC]

Nvm got it to work. I just hope it has an accurate reading

 

[spf_lexus]

I have the same problem but in reverse. I have a 1991 ls400 with a trans out of a 1992 sc400. My speedo also does not work. What did you change/modify to get it working? I am swapping gauge clusters to see if its a bad gauge but I have a feeling its not. I swapped speed sensors as they are the same fit/plug and nothing changed.

 

[GhettoFabSC]

i found out that the SC4 speed sensor has 18 teeth that went into the tranny and the LS4 only had 16. (i think it was 18 and 16. ill comfirm tomorrow) i just swap the top half of the speed sensor. Am i making sense? hah

you should use the 18 teeth gear (bottom half) with the LS4 sensor. not sure if it would work but it worked for me.

 

[spf_lexus]

Yeah that makes sense. Is the wheel inside the tail shaft? I swapped sensors and it didn't work, probably like you said, the tooth count must be correct for the ECU to be happy. Thanks for the tip, I am selling this LS to my dad to use as a long commuter car and I was looking at swapping another transmission just to solve the speed sensor issue.

 

[GhettoFabSC]

Let me know if it works?

 

[spf_lexus]

Did you swap the plastic ring from SC into the LS400 speed sensor and it worked? If so I guess I would need to swap LS400 sensor into SC400 trans.

 

[GhettoFabSC]

What plastic ring? Trying using the SC 18 teeth/gear with the top half of the LS speed sensor

 

[spf_lexus]

The speed sensor has a plastic gear on one end and the transmission output shaft has another plastic ring gear on it. I dont know what you mean by toothed wheel (variable reluctor wheel?). Can you post a pic?

 

[GhettoFabSC]

hmm i got confused a bit.

just use the plastic gear from the SC with the LS sensor


the plastic gear in the picture is from a SC4 tranny

 

[spf_lexus]

Gotcha! I have 1 of each sitting on my floor so i'll try this tonight. Thanks for the pic and the added clarification.

 

[313sc3]

Quick question for you guys. Did you have any problem swaping your trannys in besides the speed sensor?

 

[spf_lexus]

I didn't. I kept getting a blinking TRAC light but it worked 100% w/o any hiccups.

 

[313sc3]

Ok. I am currently look for a ls trans.

 

[spf_lexus]

If you plan on swapping an LS trans into an SC, the car will feel a bit sluggish... the gears are taller than stock but your MPG should increase for sure. Just a heads up.

 

[313sc3]

I have no problems with that. Ill be riding slow anyway. Thanks for all your help.