Well I have over 20k on the Monty during my ownership and no real idea when the ATF was last changed.

My truck has high miles: 225,000k on the original transmission.

The reason that this has been brought to my attention is that the truck is experiencing a very slight bearing shudder, but it is not the drive shaft bearings as it shudders at higher RPM just as it is shifting into the next gear. There is also a slight "rattle" coming from the transmission area at high RPM shifts that I do not think is the catylitic converter. I've banged on the cat and there doesn't appear to be anything loose inside.

My first step is going to be replacing the tired ATF. It is not brown, but it is also not bright red.

I see that...

The owners manual recommends Mitsubishi Diamond ATF SP or Dextron II.

Chilton recommends Dextron II.

Haynes recommends Mopar 7176.

Mobil One has always been my choice of lube for all of my machines. Mobil specs their Synthetic ATF as a direct replacement for Diamond SP on their web site .

Any body have any specific recommendations based on experience with the Monty SR transmission.

Diamond SP only, i wouldn't use anything else.

X2 first mitsu auto I bought I bought a case of mitsu ATF from the dealer.

Welp, I appreciate the help. But I am a creature of habit. I went ahead and used the Mobil 1 ATF. Seems to run and shift good and crisp. We'll see how it goes. I'll keep ya posted.

Thanks for the help.

Previous owner of my Montero used that Mobil 1... 3 transmissions later she shifts smooth as silk. <img src="/forums/images/graemlins/lol.gif" alt="" /> <img src="/forums/images/graemlins/shiner.gif" alt="" />

seriously??

what symptoms lead to the failure?

Sure it's a direct replacement... <img src="/forums/images/graemlins/lol.gif" alt="" /> <img src="/forums/images/graemlins/lol.gif" alt="" /> <img src="/forums/images/graemlins/lol.gif" alt="" />

from what I remember you lose OD at times due to the wear clutches dissolving and you finally lose OD all together and your rebuilding or replacing your trans...

Have fun <img src="/forums/images/graemlins/shiner.gif" alt="" /> <img src="/forums/images/graemlins/shiner.gif" alt="" /> <img src="/forums/images/graemlins/shiner.gif" alt="" /> <img src="/forums/images/graemlins/barf.gif" alt="" />

Why doesn't somebody just come right out and say it...you'd be best off, based on the collective experience here, to flush this expensive transmission fluid out following the 'Alex' procedure, with the Mitsubishi fluid?

Sounds like cheaper long-term insurance.

John B.

I did quite a bit of searching prior to posting my question, but didn't turn up those posts.

The post quoted by Offroader does not appear to be applicable to my scenario, as he is running a different transmission than me and he apparently overheated his tranny multiple times due to a faulty or clogged cooler. I would not consider those results to be conclusive.

I have over 500,000 miles on 80's BMW auto transmissions (which also call for Dextron II, just like the Mitsubishi tranny) with Mobil 1 ATF, so it is going to take more conclusive evidence to persuade me that Diamond SP II, which is no longer available apparently, is somehow better or different than Dextron II replacements.

Not trying to be a pain, <img src="/forums/images/graemlins/butwiggle.gif" alt="" /> just would like more facts before drinking the cool aid. Does anyone have a link handy to any posts documenting overdrive failure?

Thanks!