New tach, need some readings

[paccool]

Put in a "TinyTach" last night. Did not have a tach before, tried 2 different ISSPRO units and never got them to work off the truck tach lead.



Since this is new, thought maybe someone could help me determine if the tach is reading about right. Here is the numbers I got this morning on the way to work-



60 MPH - 1680 RPM

65 MPH - 1820 RPM

70 MPH - 2000 RPM



I have the auto transmission, stock converter, 3:54 rear end. Can any one help me out here? Thanks

 

[PPeters]

I've got the factory tach, so my numbers are a guess if not exactly on 1500, 1750, 2000, etc. My numbers are just about what yours are. Cruising last night at 70 MPH and needle was *just* below 2000RPM. When I looked at it I wondered what others get with the same setup, thinking that if RPM's at a given speed were lower, that might give me some insight on the health of my transmission. Yes? No?



Pat

 

[paccool]

I was thinking along the same line. Could show transmission problems and/or slippage in a torque converter. The numbers looked about right to me, sounds like your tach is right there also.



Top unloaded RPM in the driveway last night was about 2600 RPM. Sounds like I need to kick that up a little.



Stan

 

[Case500D]

Stan,



Numbers look about right. My 1992 runs about the same with 3. 54 gears and the stock T/C. I have my high RPM set at 3000 on both trucks. Sounds really cool to wind it up that far.



Jeremy

 

[formula]

That's about where mine runs... . give or take a bit. RPM will vary some with temp of the transmisison. For a given road speed, you'll see somewhat lower rpm as the trans heats up. This is most noticable in the winter months.



Cheers,

Sean