My 1992 caravan 4spd won't shift into O/D until I hit 50mph no matter if its warm or cold. Is it in a dummy mode or is it normal.

 

They shouldn't go into OD until at least 45mph, so I really don't see an issue with it. As long as it doesn't slip, I wouldn't worry about it.

 

That's not true. 4th can apply can be as low as 35mph fully warm and generally 45mph when cold. more information would need to be provided to determine cause of this problem.like at what speed does it downshift on a coast down? a partial list can include TPS, ECT, MAP just to name a few.

 

it will shift back out of OD when i go to 40.. its annoying. I hate driving at 45 because its at 2500rpm so I gotta speed up to 50 to get OD

 

when you let your foot off the gas and coast, the transmission is not suppose to downshift out of 4th until you slow down to approx 24mph. Understand the a coast down-- down shift is like when you are comming to a stop. Say if you're out in the middle of nowhere and have the trans in OD, let off the gas and let it coast, do NOT touch the gas or brake. as the vehicle slows, see if you can detect when the trans does the coast downshift. If you feel it significantly higher than 24mph you need to have someone with a quality scanner read the data information which should lead to the cause of this abnormal shifting problem

 

chester22
When was the last time you had the TCM ck'ed for any updates? I would ck the fluid level. And have the a scanner hooked up and ck the CVI's. The piston seals could be hard and not allowing the trans to shift right.

 

fluid level Is perfect, I changed the fluid and what not last week. I'll have a scanner hooked up and check, can I bring it to any autozone or advanced

 

NONE of the auto parts stores can help you because your van is tooooo old. Besides, they only provide PCM related codes 1996 and newer vehicles. If any transmission codes showed up in the PCM, they are very ambiguous and not of much value. So you have few choices, throw guesses at the problem and hope it fixes it, take it to someone with a real scanner for diagnostics, buy your own real scanner and see what's happening, junk it and buy another vehicle, ignore the problem and hope it goes away.

 

Considering it is a 1992 (18 years old), perhaps if you have dragging brakes that are putting a load on the engine, this would delay the shift into OD, a bad wheel bearing, sticking parking brake cable, a soft motor or several other potential causes that are not associated with the transmission.

Too much drag (tires, brakes mechanical, brakes hydrualic, wheel bearings, etc.) or too little engine power (collapsed muffler, low compression, etc) will also cause this issue.

Before doing too much, how easy does it roll in neutral? Is it easy to push on the level? You could jack up each corner and verify how easy each wheel assembly turns. My 1985 Caravan had the parking brake cables replaced because they would "freeze" and cause the rear drums to drag.

Try to identify as many or rule out as many other symptoms as possible.