So I drained the transmission pan. Fluid darker than I would have liked...
A few newbie questions:

1. Has a consensus on superiority of just 8qt vs full fluid exchange been reached? BTS recommends 8qts every 30k whereas some folks say it's like half an oil change.

2. How burnt is a burnt smell supposed to be in order to induce heart attack?

3. Is ATF analysis ala oil analysis possible?

4. Does the normal pan on. 7.3 hold 8, about 8 ? I replenished 7.5 as that's how much came out. I lack PHD in fluid dynamics and ASA master mechanic certification (both which are the requirements to correctly interpret the tranny dipstick).

Thanks for input!

While I am clueless on transmissions, I'll be watching this. I have to add - nice thread title.

My thoughts would be, if the fluid looks or smells bad, then you should do a full change. If you're just doing normal maintenance with no sign of trouble, then you might get by with just doing 8 qts at a time.

When we change our oil, we still leave a couple of quarts in the engine.

I'm with Chris and yes, oil analysis is possible.

Wow....title of the year right here?!

I originally planned to add for fun and profit, indicating I'll send out samples for people to smell along with a giveway of some kind.

Anyway, I would love to get my atf analyzed but searching forums yields same questions about regular oil repeated on and on.

Analysis is the thing I am most curious about. Also wondering what would the results include.

The correct way to check oil level is the old school way. Warmed up engine running in neutral. The dipstick no longer states this but it will not be accurate if checked any other way.

The normal pan question is harder to answer. My 4 wheel drive transmission pan holds exactly 8 qts. I think the two wheel drives had a smaller pan. BTS installs the deeper pan on everything they build.

In my opinion, BTS does the 8 qt change recommendation mainly because customers insisted they needed to do some kind of maintenance. The Schaefers synthetic oil can go much longer than 30k and the filter can also last much longer than 30k. I did not do my service at 30k and realized my mistake at 45k. I called Brian and asked If I screwed up and what the pan oil capacity. He laughed and told me not to worry about going over.

On my MB GL320 the transmission oil (synthetic) is changed at 40k but never changed again.

When you drain the pan, go ahead and remove the pan as well. Check the bottom of the pan for any metal particles - this will be a much better indication of a problem than by smell. Besides, some tranny fluids stink worse than others and I can drive myself batty wondering if there was a hint of burnt smell or not:-banghead. Schaeffer's really stinks, get that stuff on your cloths you smell it all week long along with whatever else goes in the wash with it }>. If all is well, change the filter add fluid & move on.

edit: The pan gasket is reusable so no worries there.

I've always done a full fluid change (about 18 quarts IIRC), but if BTS says the pan change is fine then it is just fine - I won't argue with the tranny pros.

Well, that ain't happening in the parking lot of my apartment :)

I also suspect that allergy to ATF shower is the reason many folks neglect tranny maintenance altogether.

If everyone just changed 8 quarts of ATF every 5th oil change we'd see our trannies hitting 200k.

I really don't understand what 'dropping the pan and looking at it' really accomplishes.

Here's an example of a tranny fluid analysis. Costs the same as an engine oil analysis and IMO a great tool in determining what course of action to take.

This is of the 4R100 transmission in my Excursion right after purchasing it. 191,00 miles and no idea how old or how many miles on the fluid or what brand it was..

http://i304.photobucket.com/albums/n...danalysis2.jpg


Some of the wear metals were crazy high and the fluid contaminants were high as well. A great indication of the fluids serviceability are the oxidation & nitration numbers. So this fluid was indeed finished.

When we dropped the pan all looked ok inside considering the miles & unknown fluid age. It had the normal dusty type build up on the bottom of the pan but no large particles. What the fluid analysis did confirm was the current condition of the fluid (lousy) and the wear of the internal parts. When the transmission was dissasembled I brought in a copy of the analysis and Jerry (Tranny guru) showed me which parts were the most likely sources of the wear metal numbers. The tranny wasn't damaged or ready to fail in the short term but he showed me how worn some of the parts were and that sooner or later it will need some attention. Overall he thought it looked pretty good for almost 200K and that the tranny did it's job. But warned me that if I'm gonna do power mods and drive it like I stole it it wouldn't be long before I'de see him again.

Since I planned on rebuilding the tranny when I purchased the Excursion we just went ahead with the rebuild as planned.

I'll explain that in the next analysis report

This $20 oil analysis of the tranny fluid (Schaeffer's #204 SAT Fluid) in my F-250 saved my a$$ big time. Sent in this sample in right after moving & towing our 5th wheel camper from Fort Sill, OK to South Dakota when my wife was done with her service in the Army. This analysis showed a severe wear metal (copper) reading. I noticed no symptoms or problem with the pick-up at all. It drove & shifted just fine.

http://i304.photobucket.com/albums/n...rannyfluid.jpg

I took it to the tranny shop and they drained & removed the pan. When the fluid drained it looked just fine, that Schaeffer's dark red. When they dropped the pan there was some metal chunks & pieces on the bottom of the pan. Something had started to break apart. The only choice was to remove the tranny and dig deeper. The problem wound up being the main support bearing. The folks at the tranny shop said the tranny was still functioning but it would not have been long before it failed completely and damaged other parts as well. We got lucky and caught the problem early.

Sure wasn't happy about the problem, but sure was darn happy I found out then and close to home. Especially considering we were leaving in a couple of weeks pulling the 5th wheel to the Missouri River to do some camping & walleye fishing, followed by a run to the Black Hills. It would have really sucked if we lost the tranny while pulling the camper and boat out to the river.

http://i304.photobucket.com/albums/n...uff/tandem.jpg

This $20 oil analysis saved me that experience as well as probably saving me some $ since more parts would have been damaged if the bearing let loose. So once a year in the spring before camping season I send in a sample of the tranny fluid. It cost the same as any standard oil analysis (@ $20). You use the same container & send it to the same address. The only difference is the info you fill out on the paperwork.

I think they are the same. For what it's worth, the pan on my 2003 2WD F-250 is the same as the pan on my 2000 4WD Excursion. What is different is the filter. The actual filter element is the same, but the pick up snout reaches deeper on the 4WD filter. But you can use the 4WD filter in the 2WD model, this is what I have been doing.

I agree :-X22, as you can see in the second oil analysis I posted the Schaeffer Tranny fluid has @ 30K on it (15K towing) and it was still looking just fine.....

Thanks everyone for excellent answers and advice.

I will be sending mine off for analysis for sure. Bucket awaiting sampling in my truck bed.

Is there some lookup table with interpretations of what the readings actually mean?

I was wrong on the 4x4 and 4x2 tranny pans being the same. Just reread the tranny flush procedures Mark K & Smokey had on the Diesel Stop back in 2008. The pans are slightly different. I think John must have put the different pan on my 2003 when he built my tranny back in 2006. Sorry for the mistake!