Chevy astro willnotr go into overdrive

i replaced the water pump, replaced the ATF aND FILTER, no leaks…she will not shift into OD…any thoughts? She is a 1998

Does your van have an overdrive lockout switch?

I do not know, where would it be? I have an OD lock out on the gear shift of my Mazda protoge’, but never saw one on the astro van.
Thanks for the reply!

A note: the fluid was burned(dark brown/grey) when removed. The magnet had a lot of gak on it, the term slipping may be appropriate here as she goes through the gears up to OD then revs like crazy and will not kick to OD.
Could it be the computor needs to be cleared as the issue may have been recorded and then as I understand it, the “limp” mode (second gear) would bethe default. Second is all I had before changing the fluid and filter, now at least I have third.

Thats the 2-4 band and possibly the 3-4 clutches which are shot. Its overhaul time.


Transman is THE man on tranny problems here. Take his advice.

The dark/burnt color/smell of the fluid is not a good sign.

ok…as a neophte that is learning as I go, what does an over haul entail?

Heres what I do when I overhaul any automatic transmission:

I first talk with owner, if the transmission is going to be used in a vehicle which will do a lot of towing of campers, boats etc or for racing applications, I would need to know beforehand. The transmission will need a heavy duty upgrade meaning HD internal parts and tweaking of valve bodies/ shift kits etc.

Complete disassembly. EVERYTHING gets vatted (Case and all) All internal parts are miked and evaluated, worn and questionable hard parts hit the scrap bin, case gets conditioned, valve body is disassembled and vatted, valves polished, ridges removed then reassembled using any update that is called for. Transmission is reassembled using new bands, clutches, steels, seals, sealing rings, bushings and thrust washers. Pump overhauled, electronics replaced. Clutches, drums, servos, and accumulators are air checked for hydraulic integrity. I stamp a unique ID# on each unit for my own warranty purposes, install new or rebuilt Torque converter and send it out the door with a bottle of Lube-Gard red and cooler flush and instructions on how to flush a transmission cooler.

Each individual shop has their own overhaul procedures. If I were you, I would stay away from large chain type shops. They are basicly get em in, get em out, collect the money. Try to find a small, independant mom and pop type transmission shop. You usually get more personal service at these. You could also look into a junk yard unit, but I would stay away from that. Do you plan on keeping the Astro??


Thanks! The oil did not smell burned, it was just dark in color. I never did this work before so some of my descriptions are not dead on yet. I will be keeping the van. Best van ever. I rescue wildlife and the van is my work van. I will have to do the work myself as a shop is not an option due to funds, thats why I replaced the water pump and tranns fluids and filter myself. I (and my Hanes guide) am doing my best, that is why I needed to ask experts such as you whats doing.I really appreciate your help and will do what I can to do the overhaul right. Jen