Transfer case drain plug question

[Kirwin]

I was installing Geno's manual transmission filter and a Fab-Craft PTO cover with temperature sender on the 6 speed on my 03 Ram, I bought two Fab-Craft covers so that I could monitor the transfer case temperature (the same set up that I'm using on my 97) when much to my surprise I discovered that the NV 271 doesn't have a PTO cover to replace with the Fab-Craft cover! So I thought no problem I'll put the sender in the drain plug. Well that's funny a 1/2" plug doesn't seem to fit. Yup its METRIC. :--) Now I didn't know that they even made metric taper pipe bushings let alone ever had to try to find out where to buy one! So I'm asking. Has anyone out there found out where to buy a metric taper pipe thread bushing (about 16 MM I think) to a 1/8" pipe thread? Thanks Ken Irwin

 

[whamby]

Probably easier to drill and tap near drain. That way you can feel inside to make sure you don't drill into something.

 

[Kirwin]

Drilling the transfer case

The case appears quite thin as far as drilling and tapping a hole in it. I'm of the opinion that that will not work without taking the case apart and building up a boss to drill and tap. Otherwise I think the case is too thin to tap especially with a taper pipe tap. Ken Irwin

 

[whamby]

The chance of finding a metric to standard plug that is needed is slim to none I would guess. I doubt that there is a high demand for monitoring T case temps. Maybe I am wrong and someone will have a part # for you. Good luck.

 

[jawmail]

Thread ?

I don't remember exactly but I think that thread is 3/4NPT, not 1/2". The actual plug OD if it is 3/4NPT should be close to an inch or so. FYI there is no such thing as a metric tapered thread (Pipe thread). There is a BSPT but it is not that either.

 

[Kirwin]

Metric taper pipe threads

Thats what I thought too jawmail, but I've been researching and so far have found several companies that list them. Including an ISO standard for taper metric pipe threads DIN 158-1986. A website at Metric and Multistandard Componets Corp is quite enlightening. I think that based on a major diameter of 16 MM that the transfer case plug thread is possibly a M 16 x 1. 5 metric taper thread. I'll keep you posted. Ken Irwin

 

[rbattelle]

Hey Ken, why not just drill and tap the stock plug? Seems like there'd be plenty of room to do so... .



Fascinating idea to monitor tcase temps... I'm interested in the results.



-Ryan

Edit: removed a mistaken suggestion to use 1/16 NPT... won't work for a 1/8 NPT sender!

 

[Kirwin]

NV 241 HD temperatures

rbattele, my 97 runs a little less that transmission temperature. It is quicker to warm up than the 6 speed transmission but they eventually equal out to about the same temperature. Never really ran it very long in 4WD so I can't say if that would make a difference. Both get up around 180 F puling my travel trailer but it takes about an hour. Non towing I see about 20 F less. Still haven't found an adapter for transfer case drain plug as of yet. Anyone got any ideas? I could tap the OEM plug with a 3/8" pipe tap and then a 3/8" X 1/8" adapter. I may just refill the transfer case and get the stuff to do it later though. Got my TST PMCR yesterday! Oo. Can't road test it with the transfer case empty!