lar bear

gentleman and ladies, i am new and need some info. i have a 4 plus 3 transmission from a c4 and wish to install it in my 1963 c10. my questions are: 1. how does the overdrive circulate fluid to the cooler? is the overdrive fluid pressurized like the coolant in an engine? 2. with ref. to the overdrive, is there a specific in and out flow for the overdrive fluid to the trans cooler and which port is which? 3. is there a way to test the solenoid on the overdrive to see if it engaging? thank you for any assistance you may have. Larry

lar bear

my family does own a few corvettes. we have a c6 built by Andy Green out of Cali, a c4 pace car convert., a c3 convert., a couple of c4 parts cars which is were i picked up the 4 plus 3.

c4cruiser

There is a pump in the OD unit that circulates the ATF to the cooler. The "cooler" is simply what you find in a radiator for an auto trans car; there is no separate cooler such as you may see on pickups that have a unit in front of the radiator.

I don't think the fluid gets that hot to where additional cooling would be needed. The "cooler" in the C4 radiator is just a pipe that is in the passenger side tank of the radiator. The two lines from the OD simply connect to each end of that tube. It should not make any difference which way the coolant lines are connected.

lar bear

thank you c4cruiser. why is the 4 plus 3 crapped on? i suppose if i owned one in a vette i could have some personal feedback. my goal is to use this transmission as a 4 speed with the overdrive as needed. i believe the first gear is 2.88 and the first gear on what i have is 3.50. i have a 3.73 ring and pinion, so, i'm good from stop light to stop light. real good. the old style truck bell housing has its own frame mounts so i don't need to use the torque tube thing. next is to test the solenoid and see if a momentary on or an on/off switch will work to make it hot.

jv9999

The early 4+3's had some weaknesses and didn't hold up well. Also shifting is kinda clunky with long throws. One of the biggest problems was that people (including oil change places) forgot that the OD unit has it's own ATF which needs to be changed fairly often, so they tended to die young. I have one in my '87, I like it for it's uniqueness, but for an everyday driver I'd take a 6-spd any day.

lar bear

thank you jv9999, i remember my dad telling me if i take a truck and make it look and handle like a ferrari its still a truck. so now i need to do some thinking. either way, i need to make sure this transmission works. game on.

lar bear

i took the 4 plus 3 to eagle transmission here in dallas for a little advise and to see if they could go through it and make sure it was worthy. the man was honest with me and said he had no idea of the overdrive and not much more with this old of a 4 speed. he said he has built one or two manual transmissions a long time ago but would have to do some research. he said he could figure it out. what? 1987 is not old! oh man, maybe it is.

hcbph

At least he's honest. Guessing most transmissions they work on are front-wheel drive automatics from 5-10 yrs old max. You're looking at a 25+ yr old unit that was discontinued somewhere around 1989.

DanZ51

Do a little more research. Regarding DNE4+3 (or 83MM Chevy speak), the four speed part was basically a BorgWarner super T-10: 'good old school trans with a kinda crappy factory shifter. The OD portion is essentially an automatic trans without a torque converter (utilizes planetary gear and friction plates. It was the execution of the OD that had problems: the front input/carrier bearing is oil starved/under designed. There's only really one place that really knows these ODs (commercially) that's S&K speed out of NY.

Personally if you got a good running one, I'd sell it to someone restoring an earlier C4. And take the money for something better....