Difficulty shifting into 1st, 3rd, and 5th - M5OD-R1

[sgtsandman]

It could just be the lighting but that fluid doesn't look right.

 

[Uncle Gump]

Agreed... that fluid doesn't look good.

When you changed the lube in the transmission... what did you put back in it?

 

[1992redranger]

Agreed... that fluid doesn't look good.

When you changed the lube in the transmission... what did you put back in it?

Gotcha, sounds good. I'll probably tackle the clutch fluid first.

I put Mercon V in it

 

[Brain75]

I'm surprised you could feel it, cause usually it is so subtle only someone who has driven a more "persnickety" trans would even notice.... so where you are describing a sticking is the synchromesh gears are not engaging before guiding it to final gear contact. 2 things I know of that cause that - bad synchro's & wrong fluid. Your very first post also agrees with that now that I think about it more... if the synchros aren't engaging right on the first try, what you do when you pull back out of gear and try again they will spin back up and hit on another tooth. I drove my '48 original trans (square cut gears with no synchro's at all) for a while and got used to driving it like a semi - no clutch at all other than first gear from dead stop, you do all your syncho with engine rpm's.

That "brake fluid" in your clutch looks like brand new motor oil /gear oil to me (with sediment/cruft in the bottom)... too yellow and thick to be brake fluid.

I don't know if a hydraulic clutch could give the feel of bad synchro's/wrong trans fluid, but that MC clutch fluid is no go in my book...
Step 1 for me - flush all the fluid out of the hydraulic clutch.

I'd put a rubber bung/inflatable stopper/shop rag in the throat and scrape off the sediment with a pick/screwdriver, then suck all the extra fluid and sediment out the top (keeping it from going down into the MC) then start the process of fluid exchange with it all in the truck rather than pull the MC.

 

[Brain75]

I'll also say that several folks here advocate mercon 3 over mercon 5 (valvoline still makes it)... since I have a naughty reverse I am considering doing a trans fluid flush and have read a few several thread and the tech articles. That said, there are more than a few folks who swear mercon 5 is fine - so I wouldn't rush right straight to throw away 2 month old expensive fluid.

edit: almost forgot - and one guy who swears gear oil is just fine.

 

[Brain75]

I completely missed the invoice the first time... guessing my crappy internet and the picture didn't load.

So the 1st subitem text description that is the master.
the 2nd subitem is the slave?? the part description led me directly to napa with the exact same part number and text desc:

https://www.napaonline.com/en/p/NCF74025

that doesn't look like the full slave, just the external plumbing.

So from that invoice it looks like they replaced the master but not slave ("have to pull the whole trans out")... how on earth did you get cruft like that in 6k miles on a new MC?

I'd guess they didn't drop the trans since there clearly is a note about it and there is no charge for pressure plate and disc.

 

[Bill]

I have the same problem. If I shut the engine off I can shift into any gear with ease. This means there is torque on the input shaft when there shouldn't be. It can be caused by air or a failing master/slave cylinder. In my case, there is two inches of travel before the clutch engages. Spec states it should be an inch. I suspect I have air in the master cylinder, or it leaking internally. I plan to order a new one, bench bleed it, then install it.

I can let it "slip" into gear when moving when the input and output speeds match, so that is what I do. Every once in a while it can be difficult to get into first when the light turns green.

 

[1992redranger]

So the 1st subitem text description that is the master.
the 2nd subitem is the slave?? the part description led me directly to napa with the exact same part number and text desc:

https://www.napaonline.com/en/p/NCF74025

that doesn't look like the full slave, just the external plumbing.

So from that invoice it looks like they replaced the master but not slave ("have to pull the whole trans out")... how on earth did you get cruft like that in 6k miles on a new MC?

I'd guess they didn't drop the trans since there clearly is a note about it and there is no charge for pressure plate and disc.

Yeah there’s definitely something going on with the invoice. The previous owner worked at the shop that did the work/knew a bunch of people who worked there, so they may have just short-handed the items on the invoice to keep certain work under the radar/unbillable. The previous owner also gave me a separate receipt which lists a clutch set (MU19961) and slave cylinder (LSC003B) purchased for the vehicle at Advanced Auto Parts…although the receipt is dated a year and a half prior to the invoice I shared above. Maybe he bought those knowing he would need to replace them eventually, idk The previous owner did tell me he had the clutch and slave replaced at the time of that invoice, but I guess we all know how that goes: no telling. And even if everything had been replaced, like others have mentioned, “new” doesn’t always mean “good”.

Anywho, I think I’m going to start with replacing the problematic fluid to see where that gets me! Will keep y’all posted happy new year!

 

[scotts90ranger]

@scotts90ranger the diaphragm was in there (I removed it for the pic), although I guess the fluid could be too full? Any guidance on this or the stuff that seems to have settled in the bottom?



Are you saying that the transmission isn't worn in enough yet and that's why these gears are hard to shift? I'm at 129K: engine, transmission, truck.

Thanks for all the insight, y'all!

If it was full with the diaphragm in (usually filled to the step in the housing with the diaphragm out is where it's full with the diaphragm in) then you're good to go, we see a lot of people fill the diaphragm when the reservoir is empty so just clarifying...

Every transmission is different, I've had 4 different M5OD's over the years and the one in my '97 Ranger is more crisp and picky about shifting than the others have been... but have been around long enough to know that they are all picky about going into gear at a stop, it's just because the geartrain is stopped and the synchro's don't have anything to spin with to align the teeth, for whatever reason they like to line up tooth to tooth so they don't engage... a LOT of people don't like how these transmissions shift anyway, myself I've got hundreds of thousands of miles and millions of shifts under my belt so it's just second nature anymore...

 

[1992redranger]

Small update: shortly after receiving y’all’s advice (thanks again!) I gravity bled the old clutch fluid out with new DOT 3. I hadn’t had the chance to drive the truck extensively until this past Saturday, but it seems like shifting has improved (if not my attitude about it, haha). Shifting is smooth if I go relatively slowly (not super slow) but every now and then I feel that “sticking in the synchromesh gears” I described before (that Brain75 helped to identify). I’m going to drive it around some more before deciding what (if anything) I need to do next!