High RPMs when shifting for 75' C4 automatic. Problem or Normal?

[Onecaras]

I'm a new owner of a 75' three speed automatic. 302 V8 It shifts to second gear about 28 mph, then shifts to third gear at about 50 mph. At 50, it levels off nicely and cruises and is strong. To me, the RPMs seem high for the speed but this is my first EB and 3 speed 70s vehicle. Dont know the gears, but the front end was replaced with Dana 44 many years ago and glove box plate ends in B9J
if anyone can decipher the ratio for me. Thanks all.

 

[Slowleak]

Thats a really late shift. You might want to check your vacuum modulator.
Here are the axle codes. The "J" means you have power steering.

Rear Axle Code
A3 4.11 2780Lb w/Trac-Lok
A5 4.11 3300Lb w/Trac-Lok
B8 3.50 2780Lb w/Trac-Lok
B9 3.50 3300Lb w/Trac-Lok
03 4.11 2780 Lb
04 4.57 2780 Lb
05 4.11 3300 Lb
08 3.503300 Lb
18 3.50 2780 Lb

 

[Onecaras]

i will look into the modulator, thanks. This issue is inconsistent. I took my family for a ride tonight and it shifted beautifully and at the right speeds. Not one high rpm issue. Our weather is mild to warm outside and the truck was running earlier in the day but sitting for at least 6 hours before i took it out tonight That said, On the way home from dinner this evening, after sitting in the parking lot for 1.5 hours, the ride home was the same high rpm shifting problem. Shifting way late. 2nd gear 28 mph and 3rd at 50 mph. I dont get it. Could it be the vacuum modulator is going bad?

 

[DirtDonk]

Not very normal from the sound of it. Most, if not all EB C4's shift very early between first and second. To the point that most people ask it that quick shift is normal.
Many times with a light throttle you'll be lucky to get up to 10mph before the first shift.

The second-third shift often happens right where you're getting the first-second!

So yeah, check the modulator and stuff. Should be vacuum controlled from the back of the intake manifold. I forget which modulator is supposed to be on an EB, but "green stripe" comes to mind.
Several good C4 gurus here though and they'll chime in too I'm sure.

Paul

 

[Rustytruck]

Make sure there is a return spring on the down shift rod attached on the lever at the carb.