Hi,
It has been 30,000 miles since I installed a rebuilt A518 transmission into my 1-ton (5.9L engine) Dodge van. So, I bought a transmission filter and some ATF +4 fluid in preparation of dropping the pan, draining the fluid, and replacing the filter.
My Haynes Guide, though, says it is also time to go ahead and adjust the Kickdown and Low-reverse(rear) auto trans bands. Adjusting these bands doesn’t sound too hard – am I right on that, or is it easy to mess up? Never done it before. I have the requisite torque wrench, etc.
Also, when cleaning out the trans pan, it says “clean the pan with solvent”. What kind of solvent?
Another point says to be careful not to damage the “delicate aluminum gasket mounting surface on the valve body”. Yikes. Just how delicate is it? What if I have to scrape off gasket material from it?
Can I use a gasket scraper tool, or would that be too harsh?
Any other tips for this job?
While I appreciate your desire to do this right, you might be over-thinking this just a bit.
I’ve never worked on an A518, but the band adjustments that I’ve done on other transmissions are simply a matter of loosening a lock nut, adjusting a bolt to a certain torque value, and retightening the lock nut. Does the adjustment procedure require a torque wrench that measures in inch-pounds?
As for the transmission pan, it’s just a pan. A big piece of metal. Clean it with whatever gets it clean (which is, of course, a facetious over-generalization, but it gets the point across). Paint thinner is a popular one, so is spray-on brake parts cleaner. Pour a few tablespoons in to the pan, slosh it around really well, and wipe it out with a fistful of paper towels or a lint-free rag.
The trans pan sealing surface isn’t a faberge egg or anything, you can scrape on it, just take care not to nick it or put big gouges in it. It’s part of the transmission case and the transmission case is a big hunk of aluminum. For added peace of mind, use a plastic scraper.
Even Gunk engine degreaser could be used. I use Gumout spray (carburetor cleaner). You probably won’t even need any cleaner. My transmission friend used to use lacquer thinner when rebuilding one.
Glad to see that you are doing a service at 30k. First of all let me know what your Haynes guide says on the torque spec for the bands. If I remember right I have a bulletin on an updated spec. I’ll check on it in the shop tomorrow. When I adjust them I usually do them by feel and sight, I dont use a torque wrench. Thats why I would need to look up the numbers for you. Make sure you use a torque wrench though. I have done so many of these that I can get them in spec by feel. The front band adjuster is on the outside of the case and the rear band adjuster is inside the pan. Make sure when adjusting that you loosen the locknut and turn the adjusting screw back and forth several times to make sure there is no binding in the threads, this will give you a false reading on the torque wrench and cause the band adjustment to be off because you are dealing in " (INCH) pounds, not foot pounds. Adjust the band then tighten the locknut while holding the adjustment screw firmly.
You can clean out the pan with any kind of solvent but I would use some spray brake cleaner on the inside of the pan last and let it air dry. Do not use any kind of shop rag. Just one piece of lint can mess up a valve body. I have seen it happen more than once. As far as scraping off the gasket, at 30k you shouldnt have much problems, it should come right off but if it doesnt, I would use a razor blade to get it. Just remember, when refilling the trans and checking the level, place the gear selector in “N” (NEUTRAL) and I prefer to use fiber gaskets rather than cork. Also, I would use a torque wrench on the pan bolts.
That should be it. I will check the torque specs on the band adjustments and post back.
transman
Well, having been guilty more than once of under thinking, I am trying to foreseee and eliminate any potential snags. 
Yes, the procedure requires a torque wrench that measures in inch-pounds, which I have.
Yes, I know the transmission pan mounting surface is not that delicate, but the Haynes Guide mentioned the filter gasket mounting surface on the valve body as being aluminum and delicate. I don’t want to mess that up, or I am looking at a new valve body. Hopefully the gasket will just pull off and I will be in good shape. Good idea on the plastic scraper. Thanks.
Pls forgive me if this ends up on here twice. I posted in response to Transman and then that post prompty disappeared into the vast void of hyperspace. OK here goes with my repost:
Here are the numbers from the Haynes Guide:
Kickdown Band: tighten to 72 in-lbs, then back off 2-1/2 turns
Low-reverse band:
32RH, 42RH transmission sub-models: tighten to 72 in-lbs, back off 4 turns
36RH, 37RH, 46RH transmission sub-models: tighten to 72 in-lbs, back off 2 turns
Now I need to figure out whcihj 4-speed A518 sub-model I have. I thiiiink it is the 46RH, but my memory is fuzzy on that. Is that determined by digit(s) in the trans ID number stamped on the side of the trans case? Or is it determined by characteristics of the trans such as 4-speed, with overdrive on-off switch on dash? or something else?
Thanks!
Transman, Did you have some updated guidance on the torque specs? Thanks.
Yea, those specs you have are fine. On the rear band (The L/R band) tighten to 72 inch pounds and back off 2 turns.
transman