i want to out a transmission that has more than 3 gears in my 85 5th ave. Is there something i can do? or am I going to have to swap motors like a 360 or bigger? I currently have the original TorqueFlite 727 that came on the car.

 

318 -

Sure, you can spend some bucks on Tremec.

Just curious, what's wrong with the 727? Built up right they are pretty stout performers.

(Oh, and if you go to a big block, your current tranny won't bolt up.)

Archer

 

i do a lot of Highway driving and it doesnt seem to have the get up and go speed I need to get up to speed on the highway. I have a hard time passing people too and get horrible gas mileage. It could be just a carb issue but I am looking into all different areas. But yes I do know the 727 is a popular choice for drag racing, my 318 just doesnt have the power to use it I guess.

 

318 -

Sorry if I missed it from another thread, but do you know what rear gears you have? (Possibly a 2.73) Also, do you know that the kick-down linkage is working correctly?

Seriously, I'd make sure the engine was up to snuff first and then think about basic mods to give it a little more pep.

Archer

 

Let's back up here. Take a really deep breath. Walk back a few steps and take a very good look at your car.

1---What is the actual fuel mileage you are getting? What do you EXPECT it to get?

2--Have you taken any steps to insure the engine you have is in good shape, IE compression/ leakdown tests, check or tune it up, etc?

3--Is this a "lean burn" engine?

4--What is the rear axle ratio?

5-- What size tires are on the car?

You could spend a LOT of money on diddling stuff and even -- maybe make some improvement, but it might take a VERY long time to repay the cost of what mileage you gained, especially if you start blindly replacing parts and components

 

My gas mileage is around 6-7 mpg, I have 130 miles on a full tank and its at 1/4. Im pretty sure thers a leak but I have no puddles or drips on my driveway but you can smell a strong gas smell all the time, I expect to get at least 12-13 minimum with the 2 bbl. Axle ratio should be stock and I think its like 2.9 or something, was looking for the 8 1/4 from a police package diplomat or equivilent. The tire size is also stock. I just put carb cleaner in the engine and it does have a bit more pep to it, got some high perfoprmance MSD wires and some RapidFire plugs I will put in this weekend. As for lean burn, this is the second time someone has asked me and I have no idea what it is, does or even looks like, and if it can be removed.

 

What is a kickdown linkage and where is it located?

 

318 -

Do you know where your throttle linkage to the carb is? The kickdown should be right behind that. It's job is to drop the trans into 2nd gear when you try to accelerate while at speed, like in passing.

You can figure out the rear gears by jacking the car up from the rear (with the front wheels chocked) and manually rotate the rear wheels. Count how many times the drive shaft rotates for every complete rotation of the wheel.

Your tires are probably in the 26-27" diameter range.

Archer

 

You could adapt an early 90's 518 overdrive trans But it requires some custom fab work.. and it's not cheap maybe $2K do a tune up and compression test ... Make sure the engine is sound..
MAKE SURE THE KICK DOWN LINKAGE FOR THE TRANS IS WORKING and adjusted properly or the trans will burn itself up

 

Well I know by the way it drives that the trans does not downshift to second when floored on the highway to pass a vehicle, thats probably why it takes so long to speed up and pass.

 

318 -

When you jump on the gas during a passing maneuver, you should feel the engine rev up and the car accelerate. If that's not happening, something needs tweaking.

Archer

 

Post me a better pic of your engine

 

Passion Performance 5 speed overdrive manual tranny. Would be a blast to shift all five gears.

https://www.passonperformance.com/im...2010-11-18.pdf

 

I would love a 5 speed manual

 

I will try to, pm me your email and I will send a video of the entire engine compartment.

 

Ok, is that something I can do myself or do I need to go to a transmission shop?


Is there a direct bolt up manual transmission for my car? Or a way to convert it to a manual?

 

318 -

The problem may be in the linkage or in the transmission. Can't tell from here.

You can locate the kick down linkage, and check to see that it's activated by moving the throttle to full (ie it moves). If it's there, and moves appropriately, then you'd have to look at the other end, and that might require a lift and someone who knows what they are looking at.

The other end should connect to a lever on the trans near the shift lever/linkage, and it should move in response the the carb end moving.

If the problem is in the tranny, you might want to bring it to a pro.

Archer

 

The only direct bolt up is what is in your car.. conversion to a standard shift 5 speed is fairly easy. The clutch pedal linkage will have to be custom made - adapt B body parts.

Stay with an automatic the TCI 6 speed auto is another possibility

 

it may or may not kick down to the next gear depending on how fast you are driving. i know on my 67 the tranny wont downshift from 2nd to first after 30 or 40 and wont shift from 3rd to 2nd after 60.

 

Mine downshifts to first from second at about 15 miles per hour or less and from 3rd to second at about 45 and shifts to 3rd at 60, but it doesnt downshift to second from third when I gas it so I am wasting a large amount of fuel to get the pickup power out of the trans and Im not getting it. I takes about 20 seconds to pass someone when I gas it. I want a manual trans just because I love manuals and I really want another manual car.

 

manual is the way to go. i know my car even without down shifting will get up and move. the other way to do it is to manually shift from 3rd to second.

 

Will that put excess strain on the transmissiion though doing a manual shift? can I gas it then shift or should I wait and let it shift then gas it?

 

the best way is to give it some gas the shift then floor it. or just slowly roll the power on and let it slowly build up the speed.

 

WOAH guys hold on here!

This is an 85 fifth ave car! STOCK it would be most likely a 318 engine witha 904 lockup torque converter. 2.94 gears in a 7 1/4 rear axle. 2x10 1/2 rear drums disc brakes on the front.

Carb would be a really crappy holley 2 barrel carb, intake is a smogged cast iron with air pump stuff all over.

Electrical lean burn computer the plastic box on the side of the air cleaner with the vacuum hose sticking out of it.

I run a daily driver 88 fifth ave I got 12 years ago. I put on a 1970 intake and carb, changed the ignition to a properly wired and placed non lean system, that took a bit but is all stock looking with tape. Removed the original exhaust pipes which had catalitic convertes right under the manifolds, dont ask its a really stupid idea, and put on a regular ypipe under it.

I get about 30 mpg on the highway average even after 10 years. City I do about 21 mpg. Accelaration has never been a problem except when i burn out my carb intake gasket as the 70 intake has that cup choke design that gives off a bit too much heat and cooks the gasket on that side every 4 years or so.

My advice on this is to drop the transmission pan, in a shop of course this is not an home project, remove and clean the valvebody as its probably full of junk disabling the lockup torque converter.

Buy the 20$ intake gasket kit remove intake clean out the cross over passage that is garrenteed to be plugged solid. Do same on engine side but use a small dremel tool to grind out the carbon and a vacuum to catch the dust you dont want chunks of carbon to get into the cylinders and bust a valve.

Replace intake I would suggest a dual plane intake from 1969 unless you have pollution laws requiring the use of emission package in your area. Reguardless change carb to a carter 1 1/4 bb from 1970 as it bolts right in with a small change to the fuel line if any.

The lean burn computer almost never works properly and can be replaced easily enough with a mopar electronic ignition kit straight from dealer. Instructions are included for wiring it and its not that hard. If you want you can even just remove the wiring section from the engine itself where a simple connection is and not at the bulkhead. Wire in simply enough to that of the non lean burn package from an earlier aspen(manuals are available for the m body i did it without one myself) and your done. Better overall gas milage, less overall work.

I should note the replacement after market tank is listed as 16 gallons for this car however my car only holds max 12 gallons from dry so I don't know where this comes from.

A problem that is common to these cars is the fuel lines rotting out. They run along the passenger side of the car right along the rocker panel. Look underneath and if its rusty looking and wet there is your leak.

There is 3 lines. The main line is 5/16 tubing, the return line is 1/4 tubing, and the vent line is 3/16 tubing. each line from tank to the joint under the front fender (for 1/4 and 5/16 is 14 feet long. the 3/16 line goes right to the charcoal canister and is 17 or 18 feet long. General prices for raw brake line in these sizes are about 25$ each.

have fun.

 

i have a 86 5th ave i did the swap check out the thread "BIG TIME SWAP"
i detailed my swap with photos and comments lot's of help from all at the forum.
My set up...318 518 391 the motor is supped... comp cams, edelbrock, mallory ignition, the car is fast it eats up the rpms like nothing i need a shift light to keep up, and the other day going up the ramp onto the highway the back end broke loose and she got squirly real fast... my hy-way rpms at 70mpr is 2200 with out the lock up.
my mileage is not what i would like but the cam is pretty big and im still tuning her, i take my time and run her for a bit with the changes and i rod on her allot so that doesn't help the fuel economy. but i also have alot of problems with the ethanol,... boil overs and just poor performance ie "economy performance".
i'm removing the tank soon to replace the fuel lines at the top they are old and they probably wick off fuel and suck air, the fuel lines along the frame rail is solid "no salt in florida"
i miss real gasoline.
personal i would not use a manual trany to much shifting and in traffic forget it i will stay with the auto

 

Thank you for the much needed info, this is very helpful, especially the lean burn thing. The fuel line info is also helpful since I have a small leak under the passenger rear door.

 

cleaning out the valve bodies is a good idea i've done several here in my drive way never had a problem. you need a clean uncluttered bench top and a manual

you probbly have some worn parts in the trany ie goverener seals and pistons they are probbly mushroomed also you have a valve up in the valve body that wears out

727 / 904 / 42 / 46RH / 46RE / 47RE / 48RE Transmission

Common complaints with Chrysler RWD units are shift timing concerns, throttle buzz, poor kickdown and / or early upshifts caused by throttle valve and bore wear. When only the valves are worn, Sonnax’s drop-in replacement valve kit, #22771-03K addresses these issues. However, when these complaints are caused by bore wear, the valve body typically has to be scrapped. Sonnax offers an oversized TV repair kit, #22771-04K to salvage the valve body and restore throttle valve control by oversizing the bore and replacing the valve with an oversized version that restores proper clearances. Both Sonnax kits have been revised to work in all year models, including the 2005-up OEM units with a “motorized” style linkage. MUST USE F-22771-TL REAMER BELOW. Cost $44.00

most likely this is your problem with the dirt and also the bands probably need adjusting.

i have installed a couple of shift reprogramming kits from atc and some performance parts from "PACT". great result. transmissions are easy to work on at least mopars i've done several you only need a manual a few tools a shop press for the "518" od unit they are actually easier to rebuild than a motor.
so get a reprogramming kit and a floor shifter and have fun
http://www.transmissioncenter.net

 

to: jacilynn_s ... dump the 7 1/4 rear end, NOW. get a 8 1/4. and get lower gear raito. heres some info http://www.crankshaftcoalition.com/w...er's_guide

 

Why the car is all original, get very rusty though after 12 years of constant driving all year around through slushy wet and salty winters.

 

Off topic but I noticed a couple fellas mention their car did not down shift at high way speeds, I also noticed the age of these cars. Remember the part throttle kick down did not come out until about 72. Earlier trannies needed to be manually downshifted into 2nd, if you wanted to get up and go.