Transmission/Transfer Case oil change

Well between life, kids, and work I’m at 200k on my 2003 2.7l 5 speed and I’m about to install a LCE SS kit. Would it be a bad idea to change the oil in the tranny and t-case due to the old seals? When I checked my bolt pattern on of the boots wasn’t even on correctly and the tranny had a lot of dirt and grime where the shifter meets the transmission.

Just seeing if I should just look away and keep rolling on or change it with everything else.

 

change transfer case oil. Drain/fill trans fluid depending on how it looks. If its nice and pink I'd do a drain and fill, if its dirty looking I'd leave it.

 

Those were my thoughts but it’s always a gamble at this mileage.

 

Why would you leave it if it's dirty? I get that this is conventional wisdom for an automatic, but he has the manual. I've changed my trans/t-case fluids twice already; at 40k, and at 75k miles, and yes it looked very dirty.

 

I was mainly talking about having 200k on it and supposedly only changed once at 75 to 90k miles. I can see where you are coming from though and thanks for the insight.

 

Redline mt90 in the trans.

 

10-4. I have seen where a lot of people on here run it.

 

I don't see where it would hurt to change it. I changed my entire truck over to amsoil synthetic at 120,000 miles. No problems. I tried the MT90 for a while and then went to Amsoils GL4 tranny lube. I couldn't tell any difference between the two.

 

I’m going to order up three quarts and just send it when I replace shifter seals and install short throw.

 

What difference does auto vs manual make on this issue?

 

High mileage automatics don’t like new fluid if it hasn’t ever been changed. The new viscosity allows them to start slipping etc.

 

Does that idea not apply to manual transmissions?

 

I have no clue, my 2005 Dodge Diesel (manual) had fluid changed on every scheduled service. I just never have done the t-case and tranny on this Toyota. It’s always been a work truck. That why I’m asking.
My old 2004 double cab had an automatic and was serviced on schedule as well. My brother on the other hand changed his automatic (98 V6 Prerunner) at high mileage and it started slipping. Could have been a lot of issues with his though, he was rather rough on it. So that is all the experience I have with transmissions.

 

Yup just happened to me

Almost lost the tranny...

 

My brothers had a full come apart.

Did you just get it rebuilt?

 

No, I don't believe it does. Fresh fluid should only do good for the manual.

 

auto needs fresh fluid just as bad as a manual, but you have to be careful if the pan isn’t cleaned

 

I just changed the atf and then had some tranny issues right after likely cause I didn’t clean the pan

 

My choice of wording was poor- I meant that it will be an improvement / won't hurt for the manual to get fresh fluid in there, not necessarily that automatic fluid shouldn't be changed using the right methods.

 

I don't know how these new auto's are these days but i heard the same thing back in the 70's, 80's and 90's about auto's. I bought a '73 Cadillac Coupe DeVille in '94. The tranny oil was yellow. I just changed it over and over again along with filters until it was a nice red as it should be. I drove that car all over the country at high speed for 18 years and when I gave it to a friend in 2013 that transmission still shifted like new. It had never been rebuilt.