3RD Gear Issue

Just got the truck back together and after a couple pulls and some street miles it wont go in 3rd gear under hard acceleration. Letting off for 2-3 seconds will let the shift into 3rd, but not under power. Fluid was low so I filled it back up and still having the same issue.

98 12v Full trans build
-Billet shafts
-Manual VB
-B&M Ratchet Shifter
-2nd Gear Lockup
-New FLuid
-New Derale Trans Cooler W 1/2" Lines

I've tried in lockup, out of lockup, O/d one and O/d off. Same Results.:doh:

Any Ideas?

Thanks in advance

I would say it isn't a manual vb. Who did the vb?

I would question your TPS, and brake light switch. The brake light switch has an extra set of contacts that can cause issues like this. They are under $20 at napa. The TPS is more expensive. Perhaps trying a pot mod to verify the issue might make sense.

47RE transmission troubleshooting chart. - Dodge Cummins Diesel Forum