I need to know the details on adjusting the bands on the a4ld 4-speed automatic. I just picked up a '91 2x4 for $250 but, the engine has to be revved to 1200 before the trans will engauge in ANY gear. Fluid is fine (full/clean). Any advice on the cause. Once the trans engauges it holds strong until rps'm drop below 1000.

 

Welcome to FTE.

If it doesn't slip once it goes into gear, then it doesn't sound like a band adjustment is going to fix this problem.

Sounds like maybe it's a pressure problem, or maybe something like a valve or solenoid sludged or varnshed up a little & hanging up, or maybe the tranny filter is clogged up.
You said the fluid looks ok, but the fluid could have been changed, but not the filter!!!!

So maybe do some pressure checks, perhaps it's a lazy pump, clogged filter, or just deposits.

If you think it's dposits, maybe consider trying a can of SeaFoam TransTune. It'll tidy things up inside, without getting after the clutch bands material, seals, gaskets, plastics, or composit materials.

I've made limited use of it, with positive results, in both my 94 Taurus AXOD & 99 Ranger 5R55E trannies, for delayed shifting & in both those vehicles P/S systems, for off center "shudder".

After a treatment had cleared the problems, I flushed P/S systems with new fluid & on the trannies I did a filter change & full fluid pump outs.

Never did see anything untoward in the way of deposits, debris, or even color change in the fluids, so whatever my problems were, they must have been caused by some small deposits of sludge or varnish.

If you still want to do the band tightening, here is a link with pictures. https://www.ford-trucks.com/forums/s...d.php?t=158160

If you think the SeaFoam might be for you, check it out here http://www.seafoamsales.com/transTuneTech.htm

Let us know how your troubleshoot goes.

 

PawPaw... Thanx for the reply. Found a crack internally when I tore it down.

 

I have not seen a band adjustment fix anything in all my time. If they are worn enough to need adjustment, they will not last for long after, as they will be lacking a lot of their friction lining, and the lining is very thin.
Did you check the frictions in the clutch packs? Bet they look just like the steels. Be very careful putting the center support in. It *SHOULD* fall into place of its own accord if everything is lined up.
The symptoms you described are common when the clutches are worn out.
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