| From | Message |
Bob Lincoln
Dodge Dakota
JOIN HERE
4/15/2004
20:13:51
|
 Subject: RE: OVERDRIVE
IP: Logged
Message:
No problem. We all are learning every day. I bought my Dak off my brother, trying to solve two nagging problems:
1) Tranny:
Symptoms:
Get onto highway and drive level at 65 mph with light throttle, no upshift to 4th for almost 3 miles. Engine is already warm. Finally shifts, dropping from 2600 RPMs to 1900.
2) 2 miles later, get off highway and as I slow at end of ramp, I get shudder as torque converter fails to unlock. I pop it into 2nd to release it.
3) A half-mile later, I'm coasting downhill at 40 mph, tranny is still in 3rd. It should have dropped into 4th.
4) Run an errand, 10 minutes later I pull out onto the road. At the next light that turns green, slight uphill grade, tranny shifts 1st-2nd-4th, then as I climb more, shifts back into 3rd. It repeats this at the next light, and then shifts normally as I go onto the highway.
5) 4 miles later I get off at the next exit, next stop and start yields 1st-2nd-4th shift again. I know this because at 25 mph with light throttle, it should go 2-3, but RPMs drop to 800. I punch the O/D OFF button to confirm, and it shifts down into 3rd.
Fluid is pink and clean. Scary thing is that my brother, original owner, can't remember if he last had the fluid changed at the dealer or at...Jiffylube!!!!
As soon as I can find weather and time, I plan to change fluid and filter, adjust bands and possibly replace the solenoid pack.
2) Battery has drain on it since new. My brother said the dealership never found the problem. After two weeks it's down to 11.2 volts. I have to pull the fuses one by one while I put an ammeter inline between negative battery post and negative clamp, til I find the circuit that's doing it. Then I have to find the device or wire on that circuit that's at fault.
It's NOT the alternator, battery or regulation cirfuit. The alternator and battery are fine, puts out 14.4 volts at idle, battery holds its voltage when disconnected at 12.6 volts.
Ideas appreciated.
|
wadak
Dodge Dakota
JOIN HERE
4/15/2004
20:50:59
| RE: OVERDRIVE
IP: Logged
Message:
Try a filter and fluid change. I have a friend with a Dakota 94 318, he had similar problems. The filter and fluid change solved his problems. There is a temperature sensor in the fluid line near the radiator that can affect shifting times into over drive.
|
Bob Lincoln
Dodge Dakota
JOIN HERE
4/15/2004
21:32:32
| RE: OVERDRIVE
IP: Logged
Message:
I've heard that, and I looked underhood tonight, but saw only the tranny lines. No electrical wires, nothing that looked like a sensor. My factory service manual doesn't mention it. I suspect it wasn't there for '92.
I did siphon out 4 qts this winter, put 4 qts of Quaker State ATF+3 in. Now that the weather's warming, I plan to do the fluid and filter tomorrow, along with band adjustment and examination of solenoid wiring, possible cleaning. I was going to run a little Marvel Mystery Oil through it shortly before changing. It's partly mineral spirits, which is what Chrysler says to use for a flush, so it may unstick the solenoid check valve the way it does with valve lifters.
|
Marcel
Dodge Dakota
JOIN HERE
7/17/2004
11:12:08
|  RE: OVERDRIVE
IP: Logged
Message:
Seems like my O/D on my '93 Dakota is "stuck" on the "on" position. Feels like when i an driving at 80km (50mph) and press the O/D switch, the switch light goes on, then when i depress it again, it turns off but i should hear and feel the engine change. It just seems like it is running too high. Is it possible that the transmision's O/D is sticking on the ON position?
Thank you!
Marcel
|
J and J Auto
GenII
7/17/2004
19:54:08
| RE: OVERDRIVE
IP: Logged
Message:
First thing you need to do is find out which trans
you have
42RH hydrolic gov presure control
3 wire plug oblong shape neer shift linkage
this is the older models
42RE electric gov presure control
round 5 or 6 wire plug same location.
this is the newer trucks
First check level of fluid while running and at
operating temp
Not all the trucks came with the temp sensor the
ones without will not shift lockup under 100 on
the engine temp.
Physicly remove this plug and clean the conections
with carb or break cleaner, scrape the connections
with a small wire and plug back in and test,
follow this plug back towards engine there is
another plug you must also check.
If cleaning these connections solves the problem
go to auto zone or any parts store and get some
dielectric plug grease and fill the connectors
with this and plug back togather this will keep
mosture and water from entering.
RH and RE lockup and O/D are computer controled
with 12 volt always there and the circuit is
completed with the computer supplying the ground.
You can also put the truck up on stands find a
wire diagram and manualy supply the ground to
each O/D and lockup and see if it shifts this
is a forced shift to check operation
Ground O/D than lockup and see if it shifts
Be sure there are no bare or damaged wires.
Also check all the grounds especialy the main
strap from engine to fire wall back of motor.
Change fluid and filter would b the next thing to
try,
Chrysler ATF+4 is recomended in all these trans
now by Chrysler even if your manual says +3
Or Amsoil universal synthetic
Chrysler TSB tech service buliton
DO NOT use any dextron or El-Cheepo fluids
If doing these things does not solve the problem
you will need to go inside and check the solonoids
RH has 2 O/D and lockup
RE has 3 O/D, lockup and a presure sensor and
solonoid and there were some years the presure
sensor and solonoid were bad and would act up
If you are not familure with automatics find a
reputable shop to check these things before you
do a complete overhall to the trans.
You can check these with the valve body removed
and applying 12 volt and ground to each to see if
they activate the 2 or 3 depending on trans, do
not apply 12 volt to the presure sensor
From here it gets more complicated and you need
someone who knows transmissions
Larry
J&J Auto
|
Bob Lincoln
Dodge Dakota
JOIN HERE
7/18/2004
12:28:08
| RE: OVERDRIVE
IP: Logged
Message:
Marcel, are you running about 2600 RPMs at 65 mph, or about 1800? If around 2600, you're in 3rd gear all the time, and O/D isn't engaging. That's why no change when you turn O/D off.
I fixed my problem for $70 - new solenoids and fluid and filter change. I found that the screws holding the solenoid pack to the valve body were so loose, I could wobble the solenoids and had a fluid leak bypassing their check valves. Thus I never got O/D, and the lockup often wouldn't unlock as I came to a stop, until I hit 2nd or 1st gear. I changed the solenoids anyway, just in case they were sticking. Look to this problem first, if the RPMs are too high, and if you have a 42RH (V-6) or 46RH (V-8) transmission.
|
Marcel
Dodge Dakota
JOIN HERE
7/19/2004
20:57:31
|  RE: OVERDRIVE
IP: Logged
Message:
Thank you Larry and "Bob".
I will look at both suggestions.
I am not sure what is the RPM is. It does sound high. But nevertheless, i will check it all. I'll keep you posted with the results.
Thank you again very much!
Marcel
|
armand
Dodge Dakota
JOIN HERE
7/20/2004
23:09:26
| RE: OVERDRIVE
IP: Logged
Message:
linkage from throttlrbody to tranny had rust at pivots on sons tranny and would shift funny at times other times was good depending where linkage stuck . squirt of wd40 on pivot points alls well . ps got truck free cause guy had tranny rebuilt and still was acting stupid and he didnt want hassle LOL
|
04dak
Dodge Dakota
JOIN HERE
7/27/2004
23:14:15
| RE: OVERDRIVE
IP: Logged
Message:
There are three types of gear ratios. Under-drive(2.69:1), direct drive(1:1), and over-drive(.69:1).
Gear ratios worke this way. The first number is how much torque or HP leaves the trans (or rear end) as compared to how much went in. (ex. if you have 100 lb./ft. go in at a ratio of 2.69:1 you get 269 lb./ft. out. you also get fewwer rpm out by a factor of 2.69, 269 in 100 out)
Compare an auto to a manuel trans first in a man. is 4.0(or something like it):1 an auto is only 2.69:1 This is because of the torque converter in an auto. Most amplify torque by about 2.0:1.
Gear raito's stack up as well. you need to add in your rear end ratio too. 2.69:1 in trans 3.55:1 in rear end equal 9.5495:1 final drive.
at 100 lb./ft. you end up with 954.95 lb./ft.
The v6's end up with about 4500 lb./ft. max in first. (asumming 2.0:1 in converter 2.69:1 first gear and 3.55:1 rear end. Both 3.7 &3.9 have 235 lb./ft. of torque.)
|
Bob Lincoln
Dodge Dakota
JOIN HERE
7/28/2004
12:35:28
| RE: OVERDRIVE
IP: Logged
Message:
"Gear ratios worke this way. The first number is how much torque or HP leaves the trans (or rear end) as compared to how much went in." WHA????
Gear ratios have nothing to do with measured HP or torque. Gear ratios are the number of revolutions in/revolutions out - regardless of how much torque is applied.
Torque is measured in ft-lbs, not lbs/ft. Maximum torque is not attained in first gear, or linearly related to gear ratio.
Maybe you should read up on the subject more.
|
04dak
Dodge Dakota
JOIN HERE
7/31/2004
00:18:02
| RE: OVERDRIVE
IP: Logged
Message:
My degree says other wise. If what you say is true then a 4.10 rear end would have no benifit over a 3.55. The only differance would be how many revs the engine turns at a given speed.
And you are right about max torque not being in first, it is in reverse (reverse is a larger ratio than first).
BTW HP is not meassured it is calculated. (eng. trq. X Eng. rpm at given trq.)/5252 = HP
Can you even tell me the power flow of a third member? Lets start easy how does it get from the drive shaft to the wheels in a open diff.?
|
Bob Lincoln
Dodge Dakota
JOIN HERE
8/01/2004
11:28:05
| RE: OVERDRIVE
IP: Logged
Message:
My mechanical engineering degree says not to listen to your "degree". Max torque is achieved at a certain engine speed, regardless of what gear you're in. You can achieve max torque in R, 1, 2, 3, or 4. Max torque for the 3.9 Magnum V-6 is 225 ft-lbs at 3200 RPM.
"If what you say is true then a 4.10 rear end would have no benifit over a 3.55. The only differance would be how many revs the engine turns at a given speed."
That's not what I'm saying at all. A 4.10 rear end will get you to higher RPMs at a lower vehicle speed, which means more low-end torque. That's why the numerically-higher ratios are better for towing/pulling, vs lower ratios for better mileage and longevity. What you were saying is that you can determine or calculate torque from the tranny gear ratios, which is ridiculous. You can identify trends (numerically higher gears give more torque at lower vehicle speeds), but you can't directly calculate torque from the gear ratios.
BTW, let's see you apply 4500 ft-lbs in first gear without something exploding. The stock engine puts out 225 ft-lbs.
|
04dak
Dodge Dakota
JOIN HERE
8/02/2004
21:02:55
| RE: OVERDRIVE
IP: Logged
Message:
My 04 has 235 lb/ft
"A 4.10 rear end will get you to higher RPMs at a lower vehicle speed, which means MORE LOW-END TORQUE."
You said that gear ratios didn't affect torque.
THAT is exactly what i am saying.
Ok let's say you are right and you put 235 lbs of force on a 1 ft bar at the exact center of a rear axle. do you think it will be enough to move 3500 lbs of vehicle up a 6% grade?
I would also like to say that I am not upset that you are challenging my knowledge, as a person with a higher education(mechanicall enginering degree) you know that you need to have an open mind when it comes to learning here is a few parragraphs from my text books about gear ratios:
A drivetrain consisting of a driving gear with 24 teeth and a radius of 1 inch and a driven gear with 48 teeth and a radius of 2 inches will have a torque multiplication factor of 2 and a speed reduction of 1/2. Thus, it doubles the amount of torque applied to it at half the speed.
Do you agree that if you have a different number of teeth on the pinion and ring gear (more on ring gear) that the speed out will be reduced? As I know you do, you also have to look at it not as gears in mesh but as two levers. the pinion (with fewer teeth) has a small radius the ring gear(most teeth) has a large radius. So if you put 1 lb.ft. on the pinion you will get more out of the ring gear.
If it is still hard to understand go jack up the rear end of your truck hold the drive shaft and have somone turn the tire. Then hold the tire and try to turn the drive shaft(trans in neutral).
Or if you have a stick put it in any gear and use a lug wrench to turn the tire(one must be left on the ground) the eng will turn and it will be easier to turn it in first than fith.
BTW i have seen a toyota celica with a half shaft broken in half. Realise that it has a hardened solid steel shaft that is aprox. 25mm (1 inch or so) in diamiter. So yes it does break stuff.
|
Bob Lincoln
Dodge Dakota
JOIN HERE
8/03/2004
08:56:26
| RE: OVERDRIVE
IP: Logged
Message:
""A 4.10 rear end will get you to higher RPMs at a lower vehicle speed, which means MORE LOW-END TORQUE."
You said that gear ratios didn't affect torque.
THAT is exactly what i am saying. "
No, again, you are not listening. I didn't say that gear ratios don't affect torque. I said that maximum torque can be achieved in any gear, not just first. And torque CANNOT be calculated from gear ratios alone. If that were true, a 4-cyl could have the same torque as a V-8 with the same tranny. Use your common sense in thinking about this, don't just spout formulas out of a book.
|
Winston McGee
Dodge Dakota
JOIN HERE
3/05/2008
09:21:58
| RE: OVERDRIVE
IP: Logged
Message:
I Have a 2000 dodge dakota 3.9 v6 magnum
noticed my trans temp indicator turned on,
then the check engine light followed, took the vehicle for a diagnostic and they said it was my
overdrive solenoid switch, need some advice on repairs
|
| | <<Oringinal Post <<Previous Page P 2 |
|
Post a reply to this message:
Username Registration: Optional
All visitors are allowed to post messages
|
