hockeyhead019

Hey guys,

Just wanted to see what the consensus was on the strength of the auto 4spd used in the C4's was. I would love a standard however I might have just stumbled onto a deal on an auto I won't be able to pass up.

I'd like to do the usual upgrades, open up the intake, put headers on there and have a full exhaust. Plus some other things when the funds free up. I just want to make sure I'm not tying my hands when it comes to the auto trans.

Cheers

C409

..... The '87 and newer trans is better ... has all the factory upgrades in it ... Look for a cam lobe shaped casting line on the passenger side of the case with the nose of the "lobe" passing near the fittings for the oil cooler lines ... if the pan is off you can see a pipe leading from the front pump housing across the valve body to an auxiliary valve body at the rear ... plus the later trans had a 30 spline input shaft vs. the older 27 spline ... easier to find performance torque converters .....

c4cruiser

You could certainly rebuild an A4 to make it stronger, but also consider that the auto trans cars came with a slightly weaker Dana D36 differential. Manual trans car got the D44 which is stronger.

You didn't say how many miles are on the car you are looking at, but if the driveline is original (not rebuilt) then everything will be weaker than when it was new.

An '87 and later car would be a better choice simply because of the improvement made over the years. You can swap in a D44 and rebuild the trans. Don't forget to check all 6 of the u-joints!!

Headers and true duals will be an improvement, but consider adding a mini-starter as part of that install! Not a lot of room for the OEM large starter and the install will be a royal PITA! Just went thru that with my '87/

hypntyz

Not strong at all. I broke mine with a stock 85 iron head TPI motor with air filter, long tube headers and full exhaust. Accelerating to pass a truck on an on-ramp and heard a terrible grinding noise on the 2-3 shift and that was it. That's what prompted my LS6/T56 swap.

RF1

It depends.
Age and current condition are the variables.
If it is a fresh overhauled trans with no upgrades, it should work for what your doing.

If it is the original trans, the output seal (in the drum) is probably rock hard.
Eventually, they crack, starve the rear planet for oil, and they let go.
One example but you get the point.

hockeyhead019

Ok thanks guys, it's still the orginal non-rebuilt trans with 65k on it

Joe C

on my 85, I've got 155K on the clock - original automatic - never rebuilt. seems to be holding up just fine.

hypntyz

If you keep the car completely stock and/or grandpa it around, it will last forever. IF you run it hard at all or modify it much at all it will break.

Joe C

- although my 85 is stock, and pretty much a daily driver, I wouldn't say I've "garanpa'd" it too much - been through a "few" burnouts over the years - if it breaks, it breaks, but I hope it lasts forever! on the other hand, my son use to have a 86 trans-am - similar 700R4, and that puppy puked it's guts out around 100K!

hockeyhead019

Thanks guys... the verdict seems to be, it's a craps shoot depending on how the car has been treated and modified. Pretty much what I expected just wanted to see if there was any evidence pointing heavily one way or the other