So ive got 111+k miles on my 2003 5.9L cummins and just got my synthetic oil in to do the change and wanted to see if anyone had input on the change or any general pointers to the trans oil change procedure.

Also I noticed today that some fuel is leaking from my stick lifter pump when running, anyone have this issue happen, and if so what was done?

Rhanks

 

When I did my switch over to synthetics (engine, trans, differential, and wheel bearings) I made sure to remove as much as possible before I introduced the synthetic stuff. On the engine, basic oil change with new filter, no big deal. with the trans (48RE) I went thru the usual fluid change process but before I put the pan back on I loosened the bolts that hold the valve body on and that slight seperation of the VB from the case allowed a LOT of fluid to drain from the converter that otherwise wouldn't drain. Tighten back up the VB, install the new filter and add the 16+ qts of fluid (ouch) as usual. On the rear end, I cleaned the gear set with carb cleaner as I also cleaned the housing the best I could, then a new gasket and pinion seal was installed and I added the appropriate amount of diff oil. The wheel bearings were removed and cleaned in solvent and repacked with synthetic moly lube and put back in one set at a time. It was a lot of work, it got done over a long period of time, (not in 1 weekend) and the benefits are noticeable I think.
Good luck.

OH, as far as the lift pump goes, if it's the one like mine was, attached to the fuel filter cannister, check the allen head bolts that hold it on, they might be loose. If they are the seeking leak might be stopped by this action. I got rid of mine long ago and went to two holleys hanging from the frame and haven't had an issue since. I did that at 107,000 miles and I have over 210,000 now.

 

Thanks a bunch! What do you mean two holleys?

 

ATF-4 is already synthetic

 

So there is an internal filter within the trans? and i also need to drop the pan for it? If anyone has a guide or walk through on this trans oil change, please let me know.

 

• Remove the pan to drain the oil
• Remove the filter
• Notwithstanding the above advice, please don't loosen the valve body to drain the converter. I had VB resealing issues after that.
• Install new filter
• Reinstall the pan
• Fill the pan till dipstick reads full
• Remove rear trans cooler return line from back driver's side of trans
• Attach a piece of clear plastic tubing to cooler return line with a hose clamp and let it hang down into your drain pan
• Put transmission in neutral and parking brake on
• Start engine and pump a couple of quarts into your drain pan
• Stop engine and refill
• Repeat until all old smelly fluid is gone and new clean fluid comes out
• Reattach cooler line to trans
• Drive truck and check fluid with trans in neutral, engine warm and running.

 

thanks! helps a bunch. just waiting on the filter and ill be doing the trans change.

 

Has anyone ever tried putting a vaccuum on that rear return line, and suck out all the old fluid intead of starting it in neutral (after new pan change/filter).

Just wondering if this would work?

 

I do the trans service this way, works great:

https://www.dieseltruckresource.com/...ghlight=tranny

Also, your lift pump might be going. Mine started to leak slightly just before it crapped out. Dealer replaced it with an in-tank version under warranty at 80k miles.

 

Yea this is a replaced one already....