I'm blowing the dust off my 1990 Iroc (305 tpi/700r4) and working on some of the gremlins that have creeped in after having it sit for 4 years. One of my latest issues is the 700r4. At 60 mph in 4th gear I am turning 2800 RPM's!? I have a stock 2.73 rear end. My first thought was that I was stuck in 3rd...moved the gear selector from OD to D and sure enough it downshifted to 3rd. Then I thought my torgue converter wasn't locking up so I grounded the A & F terminals on the aldl......same result 60mph = 2800 rpm? I could feel a difference in the shift from 2-3-4 with the aldl grounded so I know it was forcing the TC to lock.....anyone have any ideas why I'm turning so many RPMS a 60 mph? Tranny was rebuilt and worked fine right before I parked it 4 years ago. Fluid level is fine.

 

Does it sound like you are turning 2800 rpms? Some tachometers are known to read high as they get old.

 

yeah it sounds like it's revved up there.....I need another tach or something to confirm though.

 

Well....looks like I've got the dreaded 90-92 high winding tach problem......tach reads way high. Has anyone found a fix for this or swapped in the guts of an aftermarket tach behind the stock guage face?