No transmission oil change spec

[Rico567]

What are your views on vehicles that have NO transmission oil change spec in the manual (confirmed with dealer- no spec)? Forget about it? Try to find a way to change?

2002 Dodge Dakota, 3.9L V6, 5-speed manual (76K miles)

2004 SAAB 9-5 ARC, 5-speed manual (105K miles)

 

[cmf]

Are you sure the Saab isn't Saab MTF 0063 spec? I realize you confirmed with the dealer but there's definitely more incompetent people at dealerships than there are competent.

 

[Rico567]

Originally Posted By: cmf
Are you sure the Saab isn't Saab MTF 0063 spec? I realize you confirmed with the dealer but there's definitely more incompetent people at dealerships than there are competent.


Sorry, I believe I used the word "spec" incorrectly. What I meant is that there is no specified mileage interval to change the oil in these transmissions. As far as the manufacturer is concerned, it's permanent.

 

[cmf]

Ohhhh, haha, I read it wrong.

Most manual transmissions are lifetime fills as there is very little wear in them. As far as preventative maintenance goes, replacing it every 50k would be considered the 3k oil change interval of manual ATF changes, and 100k is roughly the "follow the owner's manual specs" interval. MTF fluid is generally some pretty robust stuff.

Although it's rare for me to recommend not doing something, you could just wait until you replace the clutch plates to refill the transmission if you drive the car hard (100-150k for hard driven clutch plates). If you drive the cars easy then I'd probably just replace them at the mileage they are at now and never worry about it again. All personal opinion of course.

I would suggest looking at the procedure for the replacement before deciding to do it. The replacement ranges from not much worse than an automatic to "I'm seriously supposed to fill it from there????". I personally have no experience with either of your cars so I couldn't even guess.

 

[SteveTheisen]

In my opinion Manual Transmissions change every 25k(They majority of them have no filter in them, and the oil serves as a medium for holding metal and dirt) A magnetic drain plug is recommended for extra protection.

Auto Transmissions I would say 50,000 if you are moderately hard and also stop/go driving. Heat breaks the fluid down a lot and it loses much of its lubricating properties when operating in a higher temp range. 75,000 if you are pretty easy on it and you do mainly 80/20% of your driving on highway/city respectively.
Of course replace the filter with any fluid service if it is user serviceable.

 

[SteveTheisen]

Of course another option could be fluid/filter change for the transmission at 15,000 miles then never worry about it again. The largest wear particles should be in the fluid by then.

 

[SteveSRT8]

My car recommends 30k miles severe and 60k miles normal.

I don't think I'd run any autobox I want to keep past 50k miles!

 

[Rico567]

Originally Posted By: SteveSRT8
My car recommends 30k miles severe and 60k miles normal.

I don't think I'd run any autobox I want to keep past 50k miles!


When it comes to automatics, I heartily agree.....my OP referred to the manual transmissions in the two cars noted, and neither manufacturer specifies a change interval.

 

[cmf]

For some figures off the top of my head for cars with change intervals. Mine is inspect for normal and 60k for severe, Hyundai Genesis coupe is inspect for normal and 85k for severe. Lincoln LS and Ford trucks are every 60k normal and "as required" for vehicles that tow (that's their only severe).

Hopefully these intervals (and SteveSRT8's) can give you a guide as it is a really difficult thing to say without actually being the people that manufactured the car. But you can assume that severe service is about the length of your warranty at the least, because they definitely don't want to replace any transmissions under warranty.

 

[Ken2]

Manual transmissions aren't as wear prone as automatics. In any case, the fluid does oxidize and replacement would be prudent.