Adjusting Bands on Auto

[WadeMetzinger]

What are some of the thoughts on band adjustments:



I just changed my fluid at 30,000 and didn't adjust them, should I have? Is it ok that I skipped this time but need to do it next time?



I tow an 8k enclosed trailer on the weekends the rest is highway driving. About 30% towing.

 

[Fireman Dave]

My understanding is the band adjustment thing is an outdated practice. The bands today are different than 20 years ago - much thinner. One of the trans gurus told me it's not necessary unless something is wrong. Then why is it in the manual to do it? Who knows - maybe to create income for the dealer, or maybe they just haven't gotten around to thinking it through lately. I didn't do it when I changed my fluid either. Still operates like it always did - just fine.

 

[Bigramguy]

You should have done it ! It is not very hard,and should be part of every fluid change. It is quite easy and takes all of a few mins when you have the pan off to drain. I have found the one band adjuster (external one) to "seep" fluid sometimes,so I usually back it out a few turns,and wipe the thread with a dab of teflon sealing compound,then screw it back in and adjust. Prevents any leaks. The procedure is linked below.



http://www.dodgeram.org/tech/transmission/automatic/AT_band_adj.htm

 

[RustyJC]

We changed fluid, filter and adjusted bands on our 1996 3500 V-10 automatic every 12,000 miles as we were pulling a 5th wheel almost exclusively. Don't know what the results would have been if we hadn't, but we've never had a bit of transmission trouble in 45,000+ miles.



Rusty

 

[Joe G.]

No need to adjust the bands at all unless there is some sort of problem. The lining is really thin and doesn't wear because of the way it works. It grabs the drum with little or no slip. What you are adjusting is the clearance of the band to the drum. This affects the overlap or gap between when the band is gripping and the clutches are gripping. Too loose and there is a noticable "slip" feel to the shift when both the clutches and the band are not gripping. Too tight and you get a bind for a moment when both the band and the clutches are gripping. The last time I adjusted mine was when I installed the DTT VB and TC. At that time I replaced the lip seal in the front drum. I usually give it a check when the pan is off for a fluid change. The gap between the piston and the lever is still 1/4" so no need to mess with the adjusting screw.

 

[Dieselnerd]

Right you are Joe and Dave, old style bands had thick linings like brake shoes. They wore and needed adjustments from time to time. New ones are very thin and seldom show any wear. No harm is done to your transmission from bands that get too loose. If they ever get too loose there will be a RPM rise between shifts like something is slipping. There is no harm caused from that. Adjust them too tight and although you will feel nothing unusual, you are getting excess wear since the band is still engaged at the same time the internal drum clutches engage causing them to fight each other for an instant before the band lets go. If you ever get the chance to tear an automatic transmission apart and look at how it actually works you would see exactly what I mean.