Engine/Transmission (1994 - 1998) Finally found a 12-valve... couple of Qs

[Johnstra]

I finally found the truck I've been wanting. It has a 53 Block, but I'm not going to worry about it. 146k, one PO, stock, and it's in great shape. I'm ordering gauges and a KDP kit today. Couple of questions...



Has anyone done and Auto-RX treatment on their 12-valve? I'm an engine clean freak and I'd like to run an Auto-RX clean cycle.



My fuel gauge drops out intermittently. Is this a common problem. How can I figure out if it's the sending unit or the qauge?



Truck came with LT255/85R16 tires. Is there a way to calibrate the speedo? Right now it's about 7. 5% off.



Thanks,

-john

 

[gitchesum]

Can't comment on the Auto RX question



The fuel sender is bad. It is too common of a problem. A new unit should only run about $50 at the dealer. You'll have to either drop the tank, or raise the bed to access the top of the fuel tank to replace it. Here are some pretty detailed instructions on how to prevent the new one from meeting it's untimely demise



You could probably take the truck to the dealer to have the speedo calibrated. I think the last time I checked, it was around $80 to have it done.

 

[K5IP]

I too think you can count on the sending unit being bad. Mine was also intermittant and the fix was not all that bad. I dropped the tank and replaced the unit using a floor jack (back end) and rope sling (front end of tank) in about three hours. Parts were $43.

Both my spedo and odometer were off about 8% when I bought my truck new. The pinion/speedometer drive gear located in the transfer case (4/4) makes about an 8% change. Cheap part, easy plug and play change.

Rog

 

[Johnstra]

What's the pinion drive gear fix? What part do I need and where does it go?

-john