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2.9 + Auto trans questions pls advise


SinnTax

Well-Known Member
U.S. Military - Veteran
Joined
Jul 29, 2009
Messages
64
City
Oregon
Vehicle Year
1986
Engine
2.9 V6
Transmission
Manual
I have a 1986 2wd king cab Ranger, 2.9 and Auto Trans.

Background: Recently had to do lots of stuff to get the 2.9 running again after wich it runs GREAT. I am very satisfied with the engines current running. After researching potential performance upgrades on this site I will Prob be putting a K+N conversion, Port match uper and lower intake, 180 thermostat, 4.0 Radiator and electric fan, headers and dual exhaust, better coil and wires/plugs.

My tranny scares me though, generally works ok, but just seems to have some shifting oddities... I get the fealing that I a going to have to rebuild it or replace it.

So my question is more just for opinions.

these are my options as I see them:

1. Continue with 2.9 upgrades, rebuild/fix tranny before/after problem

2. Continue with 2.9 upgrades, Search for 4.0 tranny (if so which years will work with out major computer issues)

3. Scrap a GOOD 2.9, Search for used 4.0 engine and tranny package (if so what years will go in without major wiring/computer mods)

pls advise keep in mind this is a low budget project, I do intend lower and paint (i have the ability to paint this cheap) the truck. this is deffinately not a through money at it situation.

Pls feel free to chime in with your opinions + details

Thank You
 
IMO, do a transmission quick flush (drop pan, clean magnet/bottom pan, replace filter) and see if that helps.

Skip the performance upgrades (you'll run into a small quirk with dual exhaust, the 2.9L only has one oxygen sensor) and do a good tune up. 4.0L radiator could be a benefit. Most of the other mods won't do much with out improvement elsewhere. The upper and lowers do match up pretty crappily though.

I've built one of these motors up with a cam, low budget is going to be very difficult to achieve. And to make that money worth the "bang for the buck" is probably impossible.

FWIW, I just ripped my old motor apart the other night, and the cam (.435 int/.455 @ 1.43:1 ratio 111 LDA) appears to be still good shape. I want to say it has 20K on it, but I am likely going to try and sell it. Won't run on a stock computer though, you'll either have to upgrade to MAF or run some other sort of engine management.

Pete
 
yeah, the basic Tranz maintainence is on the list, hopefully it will help. Not looking forward to dealing with tranz probs.

Full tune up was included in the work I did to it already my 2.9 runs great. Well the dual exaust isn't required. Thanks for the tip.
 
Bump

Anyone else?
 
If the trans isn't acting right, it's going to give you problems. I have an 89 Ranger with the 2.9. I bought it used and the auto trans went in 6 weeks. I bought a used trans and it lasted a year. I rebuilt one and the torque converter (new) was bad and of course it wouldn't work. I got disgusted dealing with the auto and changed it over to manual using a M50. It was the best thing I ever did. It made a big difference in my truck. Better gas mileage, better pick up, just an all around better truck. The A4LD auto trans is trouble waiting to happen.
 
The only A4LD's that'll go right in without any electrical/electronic/computer issues is an '86-87

The 4.0 trans WILL work but you'll have to change computers ('89-92)
and add some wiring from the trans to the computer.

Basically the later A4LD trans has two computer controlled solenoids
the early A4LD only has one.

Dual exhausts are nice, in theory, but the best bang for the buck on a 2.9 is simply putting a less restrictive muffler onto it.
Most of the factory replacement mufflers neck down to ~1.5" just
inside the body of the muffler

Headers for a 2.9 will cost you almost as much as the ideal budget 4.0 swap.

Frankly the 2.9s are setup pretty tight from the factory, they make more power relative to displacement than a 5.0HO or a 5.8Lightning and are within a fraction of the 5.0Cobra engines there simply isn't much "up" to be had.

The few people that talk up the 2.9 and talk down the 4.0 relative to each other simply don't know how to drive a 4.0.

Frankly You can put a 3000rpm limiter (temporarily) on a 4.0 and
stomp all over someone with a 2.9. the simple reason for this is by
1000rpm the 4.0 is already making more torque than a 2.9 CAN make
and the torque continues to build for another 2000rpm.

NONE of the swaps are without wiring issues, but if you take the time to
get the proper manuals, learn how things are done you'll learn fairly quickly
that even on the difficult swap of a '90-92 engine and wiring into a gen1 truck
isn't THAT hard.
You can literally do the job with a bag of wire ties a roll of harness tape
and a couple bags of the shrink sleeve/hot melt glue filled butt splices.

Hell, I swapped a 1993 engine wiring and power distribution into my '87
which in every respect is identical to your truck.

AD
 
For the trans try adding Lucas Tranmission Treatment. Changing the fluid and filter is a good idea also,if you do that then add the Lucas at that time. The stuff really works. Just don't overfill the tranny :)
 
so if I was to find a 4.0 donor truck and get the engine and tranny what is the dependability comparison of the 4.0 A4LD and the 2.9 A4LD

is there that big a difference?
 
The 4.0 trans is "Beefed up" internally but with more power the reliability ends up being too close to call

It's like getting a stronger anvil AND a bigger hammer to beat on it at the same time.

The 4.0 is more reliable...

BTW, one other thing I forgot to mention, running a 2,9 with a 4.0 A4LD ha some "interesting effects"

You must understand the natur of a torque converter...
Most people mistakenly believe that "the stall speed is the stall speed"
simply put, it aint'

The 2,9 toirque converter literally has fewer vanes welded into the body
while the 4.0 converter has a full set (look at a torque converter on your bench
and count the welds)

This means that a 4.0 converter on a 2.9 will stall at a much lower speed
and the vehicle will feel very "tight", because the torque converter won't slip, the trans will also run cooler.

The immediate feeling is that you are driving with the parking brake on
while accelerating, because you don't get that extra boost from the torque converter.

Frankly if I were building a truck with a 2.9 and an auto for crosscountry runs I'd do exactly that, intentionally... great mileage... giving up a little acceleration is a fair price to pay...

But I'll never own another 2.9 except to pass it on as parts to someone else.

Frankly if your 2.9 is running well now don't mess with it, though I would recommend a 4.0 trans AND torque converter behind it.

but be very suspicious of junkyard auto transmissions in vehicles that haven't had been in a major collision, because other than collision/rollover damage a dead auto is one of the likeliest reasons for an explorer or 4.0 ranger to be in a junkyard in the first place.

AD
 
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so is it possible to run the 2.9 converter in the 4.0 trany (onbviously would get a good aftermarket one it they fit) or perhalps there is a 4.0 aftermarket converter to address this
 
If the trans isn't acting right, it's going to give you problems. I have an 89 Ranger with the 2.9. I bought it used and the auto trans went in 6 weeks. I bought a used trans and it lasted a year. I rebuilt one and the torque converter (new) was bad and of course it wouldn't work. I got disgusted dealing with the auto and changed it over to manual using a M50. It was the best thing I ever did. It made a big difference in my truck. Better gas mileage, better pick up, just an all around better truck. The A4LD auto trans is trouble waiting to happen.

+1 on all of the above. I also found that the overheating problem I had on hot days disappeared after the M5OD R-1 was installed.
 

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