Transmission fluid replacement 87 mh 325

[realpank]

Went to a do quick tranni fluid/filter replacement only to find a front side bolt under the cross member.

What is the trick to get at this bolt? Do I have to loosen the cross member and lift the tranni to get at it?

Is there a tutorial on this?

Quite disappointed as this is typically a pretty easy job!

BTW: read on another site that putting in a drain plug is a good idea as tranni fluid should be replaced often. My point would be that I don't drive it far...yet and am not keen on making another possible leakage point

Thanks in advance,
Chris

[bobmiller1]

Yup, did mine last year, remove the rear transmission mount then jack the transmission up until you can get a Snap-On 1/4" swivel socket onto the three front pan bolts. You should be able to get a NOS 400/475 transmission pan from Rock Auto with a drain plug already installed in it. My best advise is to take it to someone that has a transmission flush machine so that you can flush the torque converter and cooler in the radiator as well.

[bkahler]

Originally Posted by bobmiller1

My best advise is to take it to someone that has a transmission flush machine so that you can flush the torque converter and cooler in the radiator as well.

I have mixed emotions about this process. The one time I did have a transmission flushed it failed in the next 1000 miles. I'm not saying the flush caused the failure but I can't rule it out either.

Brad

[J. Morgan]

What I do is leave tranny fluid alone so long as the color is right.

Once the fluid turns dark is is pretty much game over for the tranny anyway. (Trans fluid doesn't really get dirty until the clutches start burning, at this point the trans is done anyway)

Which means I never change tranny fluid till the transmission is rebuilt.

Changing trans fluid and filter is a zero sum gain that is usually done after the transmission exhibits problems and is on the way out anyway.


Brevi tempore!

[Jammer]

Originally Posted by realpank

Went to a do quick tranni fluid/filter replacement only to find a front side bolt under the cross member.

What is the trick to get at this bolt? Do I have to loosen the cross member and lift the tranni to get at it?

I'm not an expert on Classic MHs, but in my experience on other GM automatics, it's almost always possible to gently lift the transmission with a floor jack just enough to get a wrench in, without removing the cross member. There should be that much play in the motor mounts.

BTW: read on another site that putting in a drain plug is a good idea as tranni fluid should be replaced often. My point would be that I don't drive it far...yet and am not keen on making another possible leakage point

Opinions vary widely even among the informed.

Trans fluid fails not only by burning but also by progressive contamination with wear products from the clutches and by shear. It should be replaced at intervals for this reason. In general, the filter should be replaced at the same time, making a drain bolt of doubtful utility.

If you're using Dexron VI, its useful life is considerably longer than older formulations, and it makes sense to extend the drain interval somewhat.

[J. Morgan]

The clutches are paper thin, (often they are literally made of paper) once there is enough debris to plug the filter, well, the clutches are toast anyway.

It is my opinion that changing fluid and filters is a waste of money.

I might be wrong, but if I am,, I must be lucky, I run all of my vehicles well past 200K miles. (My current Tahoe has over 220K miles on the factory trans fluid and filter.


Brevi tempore!

[ROBERT CROSS]

Thats a very obtuse observation, color is the reason?

Regular service can bring to light what doesn't show up on the dipstick....


FWIW....burnt clutches do not='transmission is done'.

...'course what do I know, I'm just an old retired 'knuckle buster'.

Bob

[J. Morgan]

It means it needs rebuilt, once they slip it is game over.

The filter is meant to keep the trash trapped on that magnetic plug out of the works...

JustSayin...


Brevi tempore!

[J. Morgan]

http://www.hindawi.com/journals/isrn/2013/739202/


Brevi tempore!

[realpank]

Thanks for the replies fellas,

As I thought I should be able to loosen and lift.

This unit is new to me so I'm replacing all the basics and see how she handles after that. Any opin's on tranni treatments?

I'm of the opinion that fresh fluid and filter can't hurt. Has been running very well on the trip home from Florida to Ontario.

Cheers,
Chris

[dadstoy]

My '82 280 has 140k on the original engine and tranny. It's still on the road. Both run strong. I have multiple records of my dad having the tranny fluid and filter changed. Three yrs back when I had my all time favorite shop do some work, I had them "flush" the tranny. I've maybe put 5k on it since then. I'm happy!


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[ROBERT CROSS]

Chris & DT,

The flush is your best service option as it changes all the fluid. The torque converter, cooler & lines hold quite a bit.

I added an external filter and temp gauge on our first 454, the added capacity helped a little, plus easier annual filter change. (it doesn't replace the internal filter change, I did that every three years)



Bob