Hello guys, i have a 1986 xlt lariat single cab 4x4 f150 with the 351w engine and like to know the type of rear differential it has, allso i just repaired the whole engine opened the block to 10 and changed all componets and pumps, before i repaired the engine i felt the tranny slipping a few times when shifting from first to second this was only a few times. Im worried the rebuild engine will be to powerfull for the tranny and messing my tranny. I need sugestions on what to do or what to try beffore thinking on changing the tranny.
If new tranny needed what over drive tranny can i use?

 

Probably the Ford 8.8" rear. Does it have a rear inspection cover? That's it. The other option is the 9". That was phased out in 83-ish but they lingered, I guess as they uncovered them they put them in...

What's the door tag code for the axle?

 

The diff is either an 8.8 or a 9". The 8.8 has a cover on the rear that comes off, while the 9" doesn't. Look for a tag under a bolt at the 11 o'clock position. And, look for the axle code on the door jamb and post it.

On the tranny, you need to change the fluid if it hasn't been lately. Makes a huge difference. And don't forget that there is a large amount of fluid in the torque converter that must also be drained.

As for an OD tranny, you are pretty well stuck. The AOD isn't very robust and probably wouldn't like the 351. And the M4OD takes a controller. You cold go to the manual ZF5 though.

 

Ok, great ill look for the cover, is any of the 2 positrack. And regarding the oil change for the tranny what oil do you recomend and how do iget rid of the oil in the converter?

 

Either diff can be LS. The tag will tell, as will the Cert Label on the door post.

There's a drain plug on the torque converter. Pull the inspection cover and rotate the engine by short taps on the starter to find it. The rest of the lube comes out by lossening the pan and prying a corner down. Makes a big, big mess. Brand on the ATF isn't a big deal - I use the parts store's house brand.

 

When you drop the pan, take out almost all the bolts. Leave a few at one end and just loosen them up a little. When I did the E4OD in my 90 Bronco as soon as I had enough bolts out fluid started coming out, there wasn't much prying. Others I've had to pry. Go to home depot and get a big pan that's used for mixing concrete by hand in. They also sell them at Harbor Freight sometimes. You want something that's much bigger than the size of the pan because when you drop the pan fluid will run out from all sides...

I suggest finding the converter drain plug first, then drop the pan, then drain the converter.

The axle code on the door will tell you if it's a limited slip (posi) or not. Typically codes that start with a letter are LS and codes that start with a number are not. So H9 is a limited slip, 8.8" 3.55 gear axle. 19 is the same thing with an open diff.

The AOD can be build to handle a stock 351, but it's not advised if you use your truck heavily - i.e. heavy towing, heavy loads in the bed, etc. Also, the gas savings aren't really enough to justify the swap unless you do a lot of driving. Going from memory I think I figured about 20k miles to break even with a swap. Also, the C6 you have now will cost less to get rebuilt and is MUCH stronger. C6's don't really break, they just get old. AOD's... That's a different story. The economics on the E4OD are even worse because you need a $600 controller as well...

If you do end up swapping in the AOD you will need a flexplate from an 89 Crown Vic with the 351 and AOD. Everything will bolt up with your C6 flexplate, but the C6 plate pushes the converter into the front pump and you will destroy the trans in about 3-4 miles... Also, you'll need to hook up the TV cable properly. It's not like the C6 where it can be left off. Without the TV cable working correctly you will cook the trans.

 

Cudos to you, David! I'd rep you if I could. That's a good description with LOTS of detail. Good job.

 

Great, now i know i have the h9 so this is good enough for me. The trasmission oil is brand new i think cause is not dirty and red still. I got this truck a few months ago and my plan is to restore it as close as i can get to the original way, i do whant tho use on the sand dunes every once in a wile so im asking all of this so i can invest in quality parts for it.
I forgot to tell u guys the truck has an LPG system as well so i plan on using LPG for a good 70% of the time i just got a brand new edelbrock 1406 to go with it simce the old one was no longer good cause the previous owner never used it with gas we rebuild the whole engine we put a rancho suspenssion kit for a 4" lift and im keeping it with 31" tires so i dont loos torque.
What do u think about the transmission since the oil looks new?

 

Did the truck sit for a long period w/o being driven? If so maybe the governor is gummed up. Either drive it for a while before worrying about it or add a can of SeaFoam trans tune to it. I had a C6 that had sat for 2 years and didn't want to shift properly. A can of SF and 500 miles cured it.

 

Tom give u guys an idea, the truck has a 200 gallon LPG tank and the old mand that sold it to me keep a log of when he filled the tank, he had used the truck for about 15 months with out refueling i used it for 550 miles and run out of LPG (the gauge did not work) so the truck was not used much