hammer74

Can a 3.0 A4LD trans be converted to work with a 4.0 A4LD trans and if it can what does it take to do it? The trans in my 91 aerostar 4.0 is bad and I have a A4LD trans from a 3.0.

Thanks

johnydep

Hi hammer74.
Most automatics are designed & built with a certain torque & power range in mind, when the manufacturer starts putting the trans behind different engines the trans is usually modified for reliability & durability, by adding extra clutch plates, different friction material, valve body calibration, etc. Normally an ID tag is attached to identify the model changes.

But with the advent of cost cutting, some manufacturers will design & build one unit that will accomodate more than one engine type.

The A4LD is designed to handle; 600Nm of torque. But the Torque Converter can only handle 234Nm.
The trans suffers from high temperature, so instal a decent trans cooler.

Some links;
http://www.fordpowerproducts.com/pdf...ec%20Sheet.pdf

http://www.ford-trucks.com/forums/ar...index.php/f-33

http://www.google.com.au/search?num=...G=Search&meta=

hammer74

So will the 3.0 A4LD bolt up to the 4.0 A4LD and work correctly?

Thanks

johnydep

I don't know.

Find out the torque rating of the 4.0L, if it is under 234Nm it should be OK. Make sure you install a good cooler with about a 24,000 Btu rating.
If it is over 234Nm get the torque converter rebuilt & remove the Lock-up clutch. That is what some manufacturers do with turbo vehicles, no Torque Converter Clutch.

For a definite answer go to http://www.ford-trucks.com/forums/a.../index.php/f-33 and ask the guys there.

johnydep

According to this http://auto.consumerguide.com/auto/u...ex.cfm/id/2156
The 4.0L came with a heavy duty trans.
They always say heavy duty. But like I mentioned before, overheating was a big problem, this caused planetry gear sets to die from lack of lubrication & pump seals to blow out.
Heavy duty could mean; redesigned lube channels, or a standard cooler fitted.

hammer74

So I assume the bolt patterns are the same and 3.0 trans will bolt to the 4.0 and everything else will work also? Wiring etc?

johnydep

You mention; Just compare both of them, unplug the wiring loom from trans & compare, look at the bellhousing & compare, check out were the starter motor fits & compare, inspect the extension housing & compare the mounting bracket, measure the trans's.

I hope you find some one with all the answers you need.

But since that trans is popular in America you should be asking at here; http://www.ford-trucks.com/forums/index.php

Good luck.