How often to change 4r70 fluid?

[97exploder19]

My truck has 171k miles on it. I changed the original fluid and filter when I first bought it at 135k (or around there) miles. Used Castrol Transmax Mercon V fluid.

Should I change it again? Ive had no problems with the trans besides torque converter shudder in OD. That was fixed with a little tube of Dr. Trannys instant shudder fix.

 

[skpyle]

I say yes. Based upon what I have read on this forum, you want to change the fluid around 2 years/30,000 miles.

My '99 Explorer Limited 5.0L AWD is a daily driver. It is coming due for its second trans fluid abd filter change since I have owned it. PO had it done by the dealer at 85,x.. miles. I did it in July of 2014, at 137,x.. miles. I drained the transmission and torque converter. Refilled them with 13qts of Mobil 1 Synthetic ATF. Odometer now reads 170,5xxx miles. Transmission has not skipped a beat.

Granted, you will be just fine using the Castrol Transmax.
Clean fluid makes a happy 4R70W.

Good Luck!

Seth K. Pyle

 

[1997XLTRollover]

What's the owners manual say? I forget if it gives a change interval. Depending on use I would do it every 30-50k. If you do heavy towing I'd do it much more often. If it's mostly highway like myself 30-50k is probably ok. The most important thing is having a clean filter IMO. Now my moms Acura MDX POS we do every 20k because the damn thing burns up transmissions if you don't. Not to mention Acura decided to make the trans filter internal and not serviceable so all the thing has to go on is clean fluid. Thing is on its third transmission now.

 

[97exploder19]

Thanks guys, looks like I'll add it to the list of things to get done.

Mobil 1 synthetic is only $10 more per pack of 6 so Ill switch over to that while im at it.

 

[skpyle]

I've been happy with Mobil 1 Synthetic ATF in mine. Its not so expensive since you are only doing it every two years or so.

I also run the Mobil 1 Synthetic ATF in the Borg Warner 4044 AWD tansfer case and the power steering system. Over 30,000 miles with no issues. :shifty_ey
Granted, the transfer case and power steering fluids get changed every year.


Seth K. Pyle

 

[koda2000]

Owner's manual says 30,000 miles I believe.

 

[C420sailor]

I do mine every 30k. Filter every other change, primarily because getting the pan off a SOHC (mine, anyway) requires me to unhook the downpipes from the exhaust manifolds. My tranny has 220k on it, 80k since last rebuild. No problems other than torque converter drainback if you park it nose-up on a slope...so I park nose down hahahah