I have an 05 Cummins with the 48RE. Last year at 31K miles I did a pan drop and changed fluid and replaced filter. This year I will drop the pan and do it all again except this time I was thinking about doing the preceedure outlined on this forum where I disconnect the line coming back to the transmission from the cooler and replacing two quarts at a time until it runs clean. It has 46K miles on it now and I pull a 9000lb 5th wheel so maintenance is important.

My main question however is this. Since it now shifts and runs perfectly, with only 46K miles should I do the band adjustment???? Some say don't touch it until you notice problems or it slips, others say do it at regular intervals.
My position on adjustments is that if it is not broke don't fix it.

Apprectiate any knowledgeable comments.

 

I can appreciate the "if it aint broke dont fix it" attitude. But... when it needs to be fixed, it'll cost a LOT more than the price of checking. I don't always adjust but I do check the adjustment whenever I drop the fluid and filter, afterall, the pan's off and the fluid is gone so the rear adjustment is easy to get to and don't take any effort to measure, so it aint no big deal in my opinion, check it and if it needs it do it.
As far as draining while running, well, I wouldn't do it... While I'm dropping the filter and fluid, I loosen the 10 bolts holding the VB on and it'll allow the fluid in the converter to drain out as much as possible and you'll end up replacing about 18 qts! How's that for a complete fluid change?
there's no gasket between the VB and case so don't worry about that and there's nothing to loose or fall out if you only loosen them enough to allow the fluid to drain out, go have a cup of coffee and when you get back if it aint streaming out, you're ready to tighten it back up and finish the job.
just my thoughts, and my stock trans at 185K miles with a Banks chip and spped loader stacked is still performing flawlessly and I ocassionally pull our 40 ft 3-axle GN enclosed trailer loaded so make your own decision. I think an ounce of prevention is worth a pound of cure.

 

I'm not sure what a " VB " is. Could you explain in greater detail or post pictures? Many thanks for your input and suggestions.

 

valve body,its what the filter is mounted to.

 

So I have to be careful and loosen the bolts to the valve body but not let it drop or parts may come out with it?? Just loosen them enough to allow fluid to seep out?? I've never read about this method before and thought pulling the return line off seemed simple enough. Dropping this valve body sounds risky if it comes down too far.

Has everyone done the band adjustment like the owners manual says?? I don't want to void my 7/70 warranty by not doing it but I also don't want to take a transmission that is performing perfectly and turn it into a bucket of worms.

 

i would not pull the valve body do not even touch it the amount of fluid you are going to get out isnt worth it in my opinion

 

Change the filter and replace the fluid you drain from the pan. Leave every thing else alone.