Transmission Flush or Drain & Fill?

1998 4x4, 5-speed manual, 167,000 miles

After reading many posts/threads about this on TW I came to the conclusion that a flush on my transmission with this many miles would not be a good thing.... I should just simply do a drain and fill on it.

However I came across this article/blog/post and am now asking for more opinions:

http://www.gadgetonline.com/TransFlush.htm

(S)he then goes on to talk about cooler line flushes vs pump inlet flushes, if you click on the link you'll see the post.

(S)he then also talks about when not to flush, eg when your tranny fluid is rancid, burnt and shot...

Since I don't believe everything I read on the internet I want to ask this question on the internet so I can read the answers:

Should I just drain and fill or get the transmission flushed? As far as I know my transmission fluid looks fine. It's just been a while since anything has been done to the fluid.

Thanks

 

Flush it + new filter( mostly to see condition), then just drain and fill after that.

 

What you read is pretty spot-on. When done properly, a flush is the correct way to service your transmission. Of course like the article states, if the fluid is already burnt, then you are not going to do any good, because burnt fluid is a sign of a transmission that is already on the way out due to slipping clutches.

I agree mostly with SDSam in that at your mileage you should flush it, then replace the filter, and do regular service intervals after that.

 

Okay, I must be "special"

I'm assuming that guy's article is about automatic transmissions, no?

Does my manual transmission have any of that stuff or is it just a gear box full of 3 quarts of fluid?

I don't know wtf is going on here because the FSM only speaks to auto trannies.

 

OP if you have a 5 speed manual this does not apply to you. You do not have a torque converter or cooler lines or a transmission fluid pump. On a manual you have 2 plugs like on the rear diff. One for filling one for draining. Instead of a torque converter you have a clutch in its place. Hope this helps a bit.

 

Yes, his article would be about automatic transmissions. If you have a manual then they are usually not serviced as long as there is no leak for around 100k miles. While Toyota and other manufacturers talk about not having to service a manual at all, I find that over time wear occurs significantly enough after 100k miles that it would not hurt to drain the gear oil and refill with fresh oil.

 

Thanks guys.

I'm going to switch to full synthetics and do a transmission drain and fill and both differentials.

 

your 4x4 transfer case houses its own fluid so you can change it as well.
quit confusing us

 

I gave the specs of my truck in the first sentence

Will do the transfer case as well.

 

Let us know what oil you use, price and place of purchase. I did mine using Valvoline 75w90 because I couldn't justify 20$ a quart of RP. Also Mobil1 was 12$ a quart at advanceauto and technically isn't a true synthetic since it's base stock isn't synthetic.