Manual Transmission Fluid Change

[ab_slack]

Stock 5 speed manual in my 87 BII.

It has been on my list to change the fluid on this as I am uncertain of how old the fluid is. Never done this before. As I understand this takes ATF. Any suggestions or concerns I should have particularly as I have never changed trans fluid before?

I have two minor drivability issues with it now. One is in very cold weather (like below 10 degrees) it does not like getting into second gear. If I let the engine warm, or skip 2nd leaving the house, by the time I am half a mile down the road it is working fine. The second is after long drives in hot weather shifting starts to feel a bit stiff. It is really hard to tell as it isn't significant but just enough to make me question. I don't know if these can be related to fluid or not. I figure regardless the fluid probably should be changed.

 

[Die.Fledermaus]

Which transmission do you have?
Flat bottom pan w/drain plug and detachable bell housing = gear oil

http://www.therangerstation.com/tech_library/ManualTransmission.shtml

 

[ab_slack]

Unless it was swapped out at some point it should be a FM145 according to the trans code on the door panel.

A visual check is flat bottom with large plug in the center. Matches shop manual diagrams of the FM145 so I am inclined to believe it is the original.

So that be gear oil, I must have half read something or heard wrong to think ATF so that's one detail straitened out.

 

[Die.Fledermaus]

Its simple. engine oil change simple.

About the only thing I differently than the shop manual, is I don't bother will the side fill plug as the shifter is often removed (as in I only change gear oil if I have removed the clutch or like) and I just eye ball slightly less than 2 1/2 bottles/quarts of gear lube down that opening.

This method is not without peril, as a spill will result the gear oil stink/stain on the inside of the cab. If you are worried about over filling the box just remove the fill plug to force a self leveling.

FWIW I only use middle priced Valvoline 75-90 'ish oils that are rated for limited slip diffs because my rear end requires this and am far to lazy to have two different oils on hand.

 

[ab_slack]

Good info, thanks.

I guess now the question comes to mind, given the heavy viscosity and cold temperatures if it would be beneficial to get it warmed up before changing so drains better, or just after it has been sitting and the gear oil has had plenty of time to settle.

 

[Die.Fledermaus]

I don't know how one could get that trans very hot on a street driven vehicle, maybe warm at best if you could hooligan and not die/get arrested.

Myself I try to drain it after a long drive and over night. I really doubt it matters much.

If you were serious about getting it as clean as practical on a budget;

• Maybe add 1 cup of marvels oils 500-1000 miles before draining
• Just pull that inspection plate off (see my album http://www.therangerstation.com/forums/album.php?albumid=2720&pictureid=10998 and what not to expect http://www.therangerstation.com/forums/album.php?albumid=2720&pictureid=10870)

 

[ab_slack]

• Just pull that inspection plate off (see my album http://www.therangerstation.com/forums/album.php?albumid=2720&pictureid=10998 and what not to expect http://www.therangerstation.com/forums/album.php?albumid=2720&pictureid=10870)

Sometimes ignorance is bliss, but maybe I will give that a whirl.

I have quite the sizeable list of things I have in progress that I have stewing in my brain to do so not sure if diving in more than fluid change gets me anything.

 

[ab_slack]

About the only thing I differently than the shop manual, is I don't bother will the side fill plug as the shifter is often removed

Now this is one of those times the shop manual is driving me nuts. I look thru the whole FM145 section and general manual transmission service and nothing explain changing the trans oil. Just for the automatic trans.

Most annoying is I can't find anything illustrating the fill plug location, but there are three other plugs (with springs behind them?) for when tearing it down.

I presume the fill should be like to fill it up to the level of the fill plug and worst comes to worst I can measure what goes in like you said, but without IDing the fill plug clearly I aint got a place to fill unless the only place is thru the top like you do.

Maybe it will be obvious if I looked at with "FILL PLUG" stamped into the casting.

 

[adsm08]

See the black dot on the pic? That's the plug. Its a decent sized bolt head, should be hard to miss.

 

[ab_slack]

Thank you Adsm, just the pointer I needed. Done with the change it went well as Die said, as simple as an oil change. The only glitch I didn't expect is that where the trans is located I couldn't easily feed the gear oil into the trans. I could only get a bit over 2/3 a quart in. Fortunately since it takes roughly 2 1/2 quarts, I was able to put what I couldn't get into it from each bottle into one bottle to get the last portion in.

When draining I noted both on the drain and the fill plug a layer of silver sludge. Very similar to those testors little metallic silver paint. I assume that was some wear. I don't know how normal to see that. I have no idea if it was changed before. If not, it has 100K or 200K miles on it.

 

[Kowboy]

I'd say it was normal for you to see that sludge. It looks a lot worse on the drain plug when it is smothered in the old oil. I'll say that if you wiped the plug off onto a paper towel, it would look a lot less menacing. I do that as I want to inspect everything.

 

[Slammin Sam]

Not often, but occasionally the fill plug is frozen. Before you drain, break loose the fill plug. Then drain the transmission.

 

[ab_slack]

Yep I made sure I could fill before draining

 

[OTS]

I have a question your illustration says 80 - 90 weight I have an 87 and it has atf which should I use

 

[Shran]

I have a question your illustration says 80 - 90 weight I have an 87 and it has atf which should I use

Your 87 most likely has an FM145/146 transmission and therefore you need gear lube but you need to ID your transmission first to know for sure. If it has had an M5OD swapped in at some point then ATF or engine oil is what you want, NOT gear lube.