The "Doug Nash 4+3"...

[unleadedbrew]

:eek :eek :eek :cry :cry :cry

Thanks, Ken, maxrevs. Looks like re-build time. Gonna turn the stereo up for now!

Gordon

 

[WhalePirot]

If the OD doesn't need anything, wouldn't it be just a regular 4 speed re-work
<< yes, it was, for me.
does the OD unit have to come apart? << No, however.... The answer may depend upon other issues, like the epth of your pockets vs. how long you plan to keep the car, what kind of care the O/D has had, etc.

The swap to a 5 or 6 speed is not free either, and while the unit is removed from the car, it may be time to go through it. The O/D is best serviced by someone who really knows it, but the forward section can be done by any decent tranny shop. I removed mine; sent the back unit to Florida and had the T-10 done by John's Four Speeds, in Anaheim. I plugged 'em back together and bolted the sucker in.

 

[unleadedbrew]

Thanks, Mike........that's about what I needed to hear, except for the deep pockets, of course.

 

[SurfnSun]

Well guys I guess I'll go ahead and join this thread. Im currently having trouble with my 4+3.

I had intended to have an SKspeed unit put in my car. I asked Aamco to remove my unit and let me send it off. Well to make a long story short, they told me they wouldn't do that and wanted 400 for the removal and inspection of my tranny. OR they could rebuild my which ended up costing me 1800. And its never worked

The unit will sometimes delay upon trying to shift into OD. Sometimes it will delay 3 seconds sometimes 10+. Mostly its an annoyance, but when Im in the speed where OD is forced I need it to kick in.

 

[8388]

Josh, the 1st thing I would check is the fliud level. The 2nd would be the valve body and the filter.These units require re-checking of the fluid level after filling it for the 1st time after a rebuild or fluid change. The fluid lines and the cooler (radiator) don't get fluid till the OD pump has had a chance to pump the fluid throughout the entire system.

 

[SurfnSun]

Josh, the 1st thing I would check is the fliud level. The 2nd would be the valve body and the filter.These units require re-checking of the fluid level after filling it for the 1st time after a rebuild or fluid change. The fluid lines and the cooler (radiator) don't get fluid till the OD pump has had a chance to pump the fluid throughout the entire system.

Sam, i did that. The pan was clean and fluid level was correct. The unit hasn't worked right since I got it back. There has been excuses left and right. Im going back next week. If I don't get something resolved I'll be contacting an attorney.

 

[LD85]

Got a 4+3 here on a new 406, I guess we'll see how long it lasts. I do not abuse my vehicle but enjoy the occassional 2,3,4 gear run when in a safe spot. Car has 75K on it.

 

[hAZcAT]

ok, how do you check the oil in the OD unit?

 

[unleadedbrew]

There's a check plug on the side just like the manual trans.

Gordon

 

[vdogamr]

So I just bought a 1988 Corvette. I am still getting the hang of this Overdrive system. From what I have read, am I right to assume that I should (but don't have to) use the clutch when engaging or leaving OD? And I should only worry about being in OD while coasting in 4th?

And also, I seem to have a slight issue. The overdrive button turns on and off the overdrive, but the car never does so on its own. Except when I come to a stop and then it comes back on when I start again (I should check if it comes on in first). I know there are a lot of people out there that make their car intentionally do this, but it just started after having both my transmission fuilds replaced. Is this a sign of a pending problem?

 

[vetteoz]

When the computer "sees" the right conditions programmed in the chip it will automaticaly engage the O/d in 2nd and above.You can prevent this by hitting the button before you drive off.
It should kick out of O/d on hard accel.It should also drop out as you come to a stop .
Using the clutch will make O/d last longer as it take the load off as the O/d shifts.
As you are aware you can engage / disengage anytime by using the button.
As the button is working correctly ( button sends a signal to computer to operate the O/d ;not direct to the O/d itself), it means the wiring / relay / solenoid are working.

 

[vdogamr]

Thank you. I guess my first question is, does the OD light go off when the computer takes it out of OD.

Right now the OD light only goes off by itself in first gear. The moment I put it in second that light is on for good. Now I know this was all designed to save gas, but my experience with stick shifts is to down shift going up hill. The indicator light always tells me to up shift any time I pass ~1600 RPM and like I said OD is always on.

Currently I have just taken to using the OD switch as 5th gear. Which on the interstate is an awesome gear to be in. (70mph at 1500 rpm )

 

[vdogamr]

It occured to me that this all started happening after I had a new exhaust system installed. Is the OD computer-controlled based on things like exahust pressure or temperature?

I know the car is in overdrive because of the significant change in RPMs when I hit the button. Again as long as when I start the car I remember to turn off OD then I am fine using it as 5th gear. But if I forget, the shift from 1st to OD2nd is not usually as smooth a transition as I am used to.

I am just wondering if this is some kind of sensor or computer problem. And, if so, can driving the car make things worse.