3,000 Rpms in overdrive is this ok?

[pontiacgp]

if your doing 3000 rpm with the .68 OD and 3.42 gears with a 27" tire you'd be doing 103.6 mph

http://wahiduddin.net/calc/calc_speed_rpm.htm

is this the same transmission that is skipping 2nd gear?

 

[JBreu]

Yeah that's too high...You got something going on there, hopefully you get it figured out pretty quick and stay off the expressway in the meantine....I have a 700r4 in my car, 3200 non lock up converter, 28 " tire and 4.10 gears....2300 or so at 65 8)

 

[azmalibuwagon]

I'm betting on the Tach being wrong. No way you're doin 3000 rpm at 70 in 4th gear. It might be about right for 3rd gear .

Here's another calculator, this one lets you choose your transmission, plus you can see your speed and rpm for all the gears at once.

http://tri-5.chevyrides.com/rpm.php

 

[MPac]

If your tach is reading correct and it's lugging like you said, I would check your torque converter, sounds like it may be slipping?

Converters dont slip in lockup...hence the term :wink:

Could the luck up not be engauging right? I've not really worked on lock up coverters so I aplogize for the dumb question.
Also I know this is gonna sound dumb but we've all been there before you did check the fluid right? lol

 

[ZZ4CutlaSS]

Well sorry it took so long to respond.I borrowed a snap-on timing light with tach reading. I now know that my tach is reading 400 rpms to high! I think there is a cylinder setting on the tach I have I need to inspect further yet.

 

[olds307 and 403]

What height tires? 1850 at 60 mph with 3.42 gears and 25.6" tires.

 

[Clutch_Grabwell]

Also uses a 3.42:1 rear end: you need more gears. 8)

 

[79MaliCrazz]

Im having the same issues my car with the 1 legger was running at or a little under 2500rpm and now all i had changed was my rear to a posi unit and at 70mph im at 2800 to 2900rpm im hoping and thinking they disconnected my lockup and forgot to reconnect it due to them working on my transmission and installing my cross member.I will check in the morning.

 

[79MaliCrazz]

No plug there so maybe I have bigger gears.

 

[Nikyfingas]

Same problem here TH200C trans, 3000 stall 3.73 posi with 26" tire. i know i only have three gears in my trans but still 3000rpm at 60mph is no fun. im limited to very local trips till i figure out whats going on. If anyone has any tips they would be much appreciated. by the way i have checked the speedo and tach both are accurate and im running a 403 with 350 heads edlebrock performer cam and intake, double pumper and full length headders..... thanks