How do I adjust A/T bands and pressure.

[D-dog357]

I remember seeing on another site somewhere a post on how to adjust the bands and pressure for better shifting and maximum towing power. I thought I had bookmarked it but I guess not.

Does anyone know how to adjust them or has a link to share?

Thanks much for any help or advice.

[CumminsPower59]

http://www.dieseltruckresource.com/dev/ ... 65745.html

[cmann250]

Get a good 8 point socket, not a cheap Chinese one. I did this a while ago and it makes the transmission feel alot more sporty.

[monoblock]

I just did this job when I had the trans pan off for a filter change and to install two plugs -one for draining and another for a trans temp sender.
The band adjustment -Only the rear requires removal of the pan.
I found that a regular 5/16" open -end wrench worked fine to hold the adjustment while tightening the lock nut. The problem was tightening the 5/16" adjuster with the torque wrench. No socket I have fits tightly. I thought about trying one of those 'fits-all' sockets with all the little pins in them .As the previous post mentions, the head of the adjuster is an inconvenient shape -a square with rounded corners.
The adjustment of the line pressure does not seem to be a fiddle and forget procedure. Once the pan is back on, the process of re-adjusting is quite time consuming and wasteful of fluid. The linked article is inconclusive on a great suggestion - install a drain bushing at the precise location where it's plug could be removed to allow insertion of an allen/hex wrench to adjust the line pressure from outside of the pan. O.K. you would loose some fluid but if you jacked up the truck at the rear,it would be minimal.
This would resolve all the hand wringing and confusion in the linked article about 'was it 2 full turns or partial turns ,or more , or less'. I think they finally decided 2 turns CCW was O.K.?
Has anyone on this Forum actually done this line pressure tweak? Has anyone done it from outside the pan via a drain plug?

[dunes450r]

I just did this job when I had the trans pan off for a filter change and to install two plugs -one for draining and another for a trans temp sender.
The band adjustment -Only the rear requires removal of the pan.
I found that a regular 5/16" open -end wrench worked fine to hold the adjustment while tightening the lock nut. The problem was tightening the 5/16" adjuster with the torque wrench. No socket I have fits tightly. I thought about trying one of those 'fits-all' sockets with all the little pins in them .As the previous post mentions, the head of the adjuster is an inconvenient shape -a square with rounded corners.
The adjustment of the line pressure does not seem to be a fiddle and forget procedure. Once the pan is back on, the process of re-adjusting is quite time consuming and wasteful of fluid. The linked article is inconclusive on a great suggestion - install a drain bushing at the precise location where it's plug could be removed to allow insertion of an allen/hex wrench to adjust the line pressure from outside of the pan. O.K. you would loose some fluid but if you jacked up the truck at the rear,it would be minimal.
This would resolve all the hand wringing and confusion in the linked article about 'was it 2 full turns or partial turns ,or more , or less'. I think they finally decided 2 turns CCW was O.K.?
Has anyone on this Forum actually done this line pressure tweak? Has anyone done it from outside the pan via a drain plug?

i installed a shift kit at the same time i adjusted my bands. the shift kit came with destructions for 3 different install modes, towing, high performance, and race only (something along those lines). i used everything for the middle performance, had some spacers, new springs etc, when it came to line pressure the kit had a stair step piece of card stock with it that you put between the sheet metal nut thing, and the framework (not a good description, but you'll know what i mean if your in there). the tallest stair (lowest line pressure) corresponded to the mild kit and so on. i upped line pressure to the highest on the card. i ran it like that for 30,000 miles without one problem. did a decent bit of heavy towing with it also. as i remember, it took 3-4 full turns from whatever setting i found it on to get to the spot the kit suggested


long read, but hope it helps some, i may be able to dig up the piece of cardstock i mention for a measurement, it might be awhile though

[monoblock]

That is very interesting and helpful because increasing line pressure is cheap/easy to do. Yes I know we all really want an NV5600 but who can justify the expense?
The reasonable increase in line pressure you indicate might just save the automatic transmission from being damaged by heavy towing loads?
We are still struggling with the same question :is it 2 turns,3 turns or perhaps 4? That piece of card could answer the question of "how many turns is enough" ?

[monoblock]

SOme extra info:
For those who have the Shop Manual, see page 21-311 and figure 118 to locate the line pressure adjusting screw.
Then go to 21-314 for the section on "Valve Body Control Pressure Adjustments".
First adjust the line pressure: 1turn CCW(means a complete 360 degree rotation) = 1-2/3psi increase in line pressure.But where/how can you measure the pressure? which port?What is the maximum 20 psi? 30 psi?Use an old engine oil pressure gauge?
Then, adjust the throttle pressure -but you need a special tool.It looks easy to fabricate(good drawing of it in Manual) if they gave the dimensions. Anyone have these dimensions?