Hi folks,

Pedro (my '91 Dakota 5.2 v8) has had a rough spring... A month or so back, I blew the upper radiator hose while on the highway - and limped slowly to the next town where I got a new hose & refilled with antifreeze/H2O after it had cooled down. (Hose had been swollen - and finally gave way on the road)

This last 2-3 weeks, I have noticed a problem - in which it FEELS like the cooling fan is engaging and it's riding at higher RPM's at highway speeds and feels like it's working hard - but in reality (I presume) - it's the transmission not going into overdrive. (temp gun on the thermostat shows ~195 deg. F.)

ATF checked - and is of a good color (looks new - but no telling how old it is - I bought the truck about a year ago, and it's now got about 220K miles on the ticker). My cruise control IS working. No CEL codes being thrown. - and I *DID* change out my PCM 2 months ago to fix my battery charging problem.

What would be my things to check to see about getting my overdrive back? 18 gallons of gas is only getting me 250 miles right now. What quick & easy things to check first? (vacuum hoses / valves?, etc?)

 

I've never "felt" or sensed for that matter a cooling fan kicking in. I think on your model they are a continuous running fan unless you have electric.
I get the feeling of no OD. My 94 has an off on button does yours? Just thinking out loud. Here's a webpage for looking into MPG's. Mine got way better after wires, plugs PCV, Coil, Switch Plate, O2sensor, Cap, rotor, new EGR.
http://www.ericthecarguy.com/faq/fin...es-of-poor-mpg

 

I dunno - When the fan clutch kicks in on a vehicle - I can generally can feel and hear it as the fan forces more air through the fins of the radiator...

I changed plugs/wires/O2 sensor earlier in the year. It's definitely not going into overdrive. Thank you for the link - and I'll look at it in detail later in the weekend.

Rex

 

@ 60miles/hour whats the rpms at?

 

Right at 2200 RPM. Where should it be?

 

Depending on gearing and tire size I'd love my truck to spin 2200rpm.
My 3:55's and 33's spin my engine around 1600 at 60.
2200rpm sounds good to me.
What do you other guys think?

And can you not feel your shifts?
I notice each gear and the locking up of the converter.
Feel and hear.

 

Wasn't implying anything Harmony, I guess I'm not tuned into my motor that well.
Some other simple things that come to mind reading other OD posts; The light on the OD switch being on means the OD is off. You may need to adjust the TV cable or the Tranny bands. Your OD solenoid may have failed same for the OD off/on switch. I'm not sure if there is a relay for the OD but if there is that could have failed to.

I do not know how to make sure of any of these before changing or adjusting them. Maybe its time to find a good tranny shop?

 

https://dodgeforum.com/forum/1st-gen...agnostics.html

From that page 4th gear is OD
NO 3-4 UPSHIFT
1. O/D Switch In OFF Position.
1. Turn control switch to ON position.
2. Overdrive Circuit Fuse Blown. 2. Replace fuse. Determine why fuse failed and repair as necessary (i.e., shorts or grounds in circuit).
3. O/D Switch Wire Shorted/Open Cut. 3. Check wires/connections with 12V test lamp and voltmeter. Repair damaged or loose wire/connection as necessary.
4. Distance or Coolant Sensor Malfunction. 4. Check with DRB® scan tool and repair or replace as necessary.
5. TPS Malfunction. 5. Check with DRB® scan tool and replace if necessary.
6. Neutral Sense to PCM Wire Shorted/Cut. 6. Test switch/sensor as described in service section and replace if necessary. Engine no start.
7. PCM Malfunction. 7. Check with DRB® scan tool and replace if necessary.
8. Overdrive Solenoid Shorted/Open. 8. Replace solenoid if shorted or open and repair loose or damaged wires (DRB® scan tool).
9. Solenoid Feed Orifice in Valve Body Blocked. 9. Remove, disassemble, and clean valve body thoroughly. Check feed orifice.
10. Overdrive Clutch Failed. 10. Disassemble overdrive and repair as needed.
11. Hydraulic Pressure Low. 11. Pressure test transmission to determine cause.
12. Valve Body Valve Stuck. 12. Repair stuck 3-4 shift valve, 3-4 timing valve.
13. O/D Piston Incorrect Spacer. 13. Remove unit, check end play and install correct spacer.
14. Overdrive Piston Seal Failure. 14. Replace both seals.
15. O/D Check Valve/Orifice Failed. 15. Check for free movement and secure assembly (in piston retainer). Check ball bleed orifice.

 

Well there's the problem. You know too many Trannys that are all in a band.
One tranny is one too many to know.
Now, hopefully you can figure out your transmission without a Trannys help.

 

Sheepish admission... I was wrong. Not a transmission problem at all.

Remember my 1st post - where I mentioned that a radiator hose had been swollen and burst while on the highway?

Well - It was an emergency repair - I got a hose, and put in about 1/3 gallon of 50/50 premix of antifreeze... then 2 gallons of 100% antifreeze, then topped up with water.

Guess what that did? It had too high of an antifreeze to H2O ratio, and actually overheated quicker (through my old corroded radiator tubes) and WAS causing the fan clutch to kick in.

A $3 antifreeze tester from the auto parts store told me where I was at - and I drained off some antifreeze, and topped back up with distilled H2O - so that I'm back in the right ratio range - and guess what? The radiator is doing a better job of cooling now - so the fan clutch kicks in less.

I know I still need a replacement radiator - and I'll do that down the road... but I just wanted to follow up on my diagnosis & repairs.

Rex S.