tacho pickup

[oka065]

G/Day all, I am hoping 1 of the experts out there can tell me where the tacho pickup is on a 6.5 TD. I have fitted it to my OKA 4x4 with a 4L80E trans & need somewhere to plug the rpm sensor for the trans comp (GM part No 12489491)the motor doesnt have an electronic injector pump, there is a sensor at the front of the motor & the No on it is 207064 is this rpm ? hope someone can help soon as we only get 1st gear at the moment

cheers

merry christmas smile.gif

[Dihrdbowti]

My understanding is unlike the gassers that come off the distributor the 6.5TD is taken off the frequency of the alternator pulley. Hopefully someone more technical will correct me. G'day envy your summer. :D

[CareyWeber]

Originally posted by Dihrdbowti:
My understanding is unlike the gassers that come off the distributor the 6.5TD is taken off the frequency of the alternator pulley. Hopefully someone more technical will correct me. G'day envy your summer. :D Dihrdbowti,

You are correct the alternator is the scoure for the diesel tach.

IIRC it's the "P" terminal on the alternator.

The pulley can cause the speed of the alternator to be off if you don't have the correct dia pulley which will then affect the tach's reading.

Carey

[oka065]

Thanks for the info Phil & Carey. Hope to have it all running soon will keep you all posted. smile.gif

[whatnot]

The tach signal for the transmission comes from the sensor in the back of the engine where the distributor would be on a gas engine. If the engine originally had an electronic pump or a manual transmission then it won't have the sensor.

[oka065]

The motor is a late model centre turbo from a van or a suburban. I cant see that there is a tacho senor at the rear of the motor! Motor runs sounds good through a 3 1/2" exhaust. Hopefully P on the alternator will make it change gears.

[whatnot]

You should be able to get the sensor and put it in.
It is part of the oil pump gear drive. You just take the bolt out of the hold down clamp and it should pull out. The one with the sensor looks almost the same but has a plug on the top. Any 6.2 or 6.5 with mechanical pump and electronic transmission had them.