I have an 86 F-150 302 AOD EFI 176000 miles Long Bed extended cab 6" suspension lift wuth 33" mud tires. In the morning when I drive my truck after it warms up and kicks down, from time to time the transmission will slip from 1st to 2nd.

Also I was underneath and I can move my drive shaft about 1/4 -1/2 of play. is that normal?

While in 3 rd gear which is where I drive most of the time due to the fact that I still need to re gear(4.56). So I drive in 3rd. at 45 mph I take my foot off the gas put my foot back on the gas and due to that play it clinks, but not all the time. Is that normal should I worry about that?

One more question , what transmission do I have C-4, C-5 C-6?
If need be due to cost would it be cheaper to repair or replace?

Thanks guys

tony

 

You have an AOD transmission, 4 speed automatic overdrive. Those are pretty good transmissions when new, but they don't take wear and tear well.

I'd say that the fluid and filter need to be changed minimum on your trans. If it hasn't been changed in a while, it will cause it to slip as it runs out of friction modifier in the fluid.


The clink you are hearing is probably more than likely the universals... it sounds like they are on their way out.

Its possible it could be the torque converter, but if you are in Drive, then it shouldn't clunk like that.

If you do the fluid and filter change, go back with the recommended filter.

Also change those universals, i've had them seize and sling the driveshaft out from under the truck. (scary ride, lemme tell ya!.

 

I've thrown a driveshaft twice while driving (once towing a dump truck ), so I agree with desperado - change yours, but have an auto machine shop look at the slip joint first. You may be better off getting a whole new d'shaft built. Six States Distributors builds them from all-new Spicer castings using Spicer Gold u-joints and spin-balances them to 7000RPM (primarily for race cars). I had one delivered COD for under $300 in 3 days, and it's lasted thru plenty of abuse.

The clink when you get back on the gas is the same problem that's giving you the 1/4-1/2" play - u-joints or slip joint.

Replacement with a good used unit is almost always cheaper than rebuilding, but there's a reason: you don't really know what you're getting. But if you get a low-mileage transmission from a truck that looks fairly clean (even if it's smashed), you're probably pretty safe.

If you don't know how old your current trans fluid is, I'd recommend changing fluid & filter (as desperado did), driving ~1000mi, then changing both again. This clears almost all of the deposits that may have built up inside the transmission if the last change was more than ~50Kmi ago.

A drain plug kit is only ~$4 and will make future changes much quicker & cleaner.

It's OK to drive around in FWD (Front-Wheel Drive ) while your rear shaft is being rebuilt - just don't turn too sharp or ride the gas while cornering.

 

I changed the fluid about 4000 miles ago and you are right what a mess!!!!!!!. put in new filter gasket and fluid.

I have the long bed truck so my drive shaft has I think 3 sperate shafts, all those seemed fine they did not move at all when I held it and tried to move it. only the first one moved, comming from the transmission, back and forth.

I have been driving in 3rd gear for a while maybe the fluid is breaking down and possiably getting warm?

I put some slick 50 tranny fluid which is supposed to thicken up the fluid when it gets warm and so far no prob but only 1/2 a day?

So I have the C-4 trans?

thanks
tony

my big BLACK F-150 thanks you too.

 

No you have an AOD. The C4's, C5's and C6's are 3 speed trannies. See this web page for tranny ID http://pages.prodigy.net/kennethl6/_wsn/page8.html