Advice on play, chipped gears in M5OD-R1 rebuild (take 2)?

[lowspeedpursuit]

Okay, so the TL;DR is I screwed myself over*, and now I get to rebuild my transmission more carefully a second time.

First question: I have a couple of chipped corners on the input shaft gear after removing the bearing. I'm leaning towards replacing it, but I wanted to double-check if that's necessary, because it'll delay reassembly for two weeks. Forgive the picture quality, USPS has decided they have "no access to my property" to deliver my new phone.




Second question: My original input bearing shim is part J (.129). I also have an input bearing shim kit with a .112 base, 3x .005, and 3x .010. Obviously this affords me different combinations than the other factory shims, which are available in increments of .004. I've read on here that rather than being comfortable anywhere in the manual's play spec range of .002-.006, it's better to target .002 specifically. How true/important is this?

Basically, if I end up being able to build play to, say, .004 with what I have, is it actually worth it to go out of my way to source a Ford shim that could bring me down to .002 instead?


Third question: Are there any other gotchas about this rebuild? I'm assuming excessive ISB play is my continuing problem, but I do not want to take this thing apart a third time.

Thanks in advance.

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*I take like 90% of the blame on this, but I give some to USA Standard Gear, whose "full rebuild kit" includes neither new stake nuts nor input shaft bearing shims. I measured ISB play of ~.014 and could only come up with a .006 shim in a workable size. So, I ran it even though that's slightly above spec, figuring I needed the truck, and it had to run better than when I inherited the trans. Apparently I was wrong.

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EDIT: Input shaft is ordered, since it seemed silly just to wait around. Still curious if the chips on the old shaft are dealbreakers. Measured play in the 3rd-gear bearing snap ring somewhere between .002-.0025 vs. a spec of 0-.0019, so part D there is getting replaced with E8TZ-7030-E, which is .002 thicker. Will update as parts come in.

 

[lowspeedpursuit]

USPS found my house, so you get:

Better pictures of the old input shaft!



A brief overview of third gear bearing snap rings!



Probably try to put the shafts back and sort the front shims out this weekend.

 

[Jazzer]

USA Standard gear hosed me the same way, even leaving out two needle bearings.

-Jazzer

 

[lowspeedpursuit]

I don't want to bag on them too hard; it's shaping up to look like I made a pretty big mistake regardless of whether their kit contained shims or not. I didn't even know they sold the needle bearings as a kit. When I talked to them on the phone, they told me needles weren't included in the master kit because "they almost never fail", and also that the 5th-gear needle was NLA.

In any event, I've gone to reinstall the shafts, and the crux of the problem has become apparent: when I rebuilt this the first time, for a variety of reasons, I didn't run the measurements with the transmission vertical. I now believe I was unable to get the input shaft bearing race 100% seated horizontally. So rather than running a "close to spec" play of .008, my true play was that, plus whatever amount I failed to seat the bearing.

For bonus bullshit points: now that it's seated? The race spins in the goddamned housing. I don't think that's ever okay. I can't even get a .0015 feeler in there. I do have Loctite 609 (press-fit bearing retaining, gap fill .15mm = .006").


So, the new question is, which is the move:

1. This trans housing is trash, don't even bother running it.

2. Run with 609 only.

3. Pull everything back out, punch dimples, run with 609.


I'm gonna go with #2 if I nobody has any ideas.

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EDIT: Ran the measurements as it sits (no loctite). Countershaft shim is damn near perfect: original is part E (.106). Bearing depth is .037, retainer bore is .080, and target play is .006-.010, so I'm only .001 loose at the outside. Bought E8TZ-7C434-F (.110) to tighten it up.

Input shim is a shitshow. Original is J (.129). Bearing protrudes .099, retainer bore is .258, and target play is .002-.006. So I'm .024 looser than the outside tolerance. No wonder the thing makes so much goddamned noise. Target shim in Ford parts is E8TZ-7029-A (.157), which is almost the thickest one they made.

I found the post again where AllanD says he targets .002". I didn't remember reading this, but he also says the output shaft cone bearing race spinning in its bore eats away at the rear retainer. I assume my race(s) spinning, over time, is where my crazy play is coming from.

 

[Jazzer]

I’d do #3, but that’s just me, others with more experience may chime in.

The fifth gear needle bearing was what I was missing too, but the original was in excellent shape. Plus they supplied a crappy single seal output shaft seal that others have had leakage with. The original had three points of contact with the shaft.

Strangely, I watched a video where the rebuilder just dropped the input shaft bearing race into place and I remember thinking “That ain’t right.”

-Jazzer

 

[lowspeedpursuit]

So I didn't go straight for dimpling because I wasn't sure if the races could be too tight, since you can't get a punch in there and have to knock them out using the shafts. Does that sound stupid?

I'm actually even more curious about this on the countershaft; the entire front countershaft bearing spins in its bore as well. Again, that feels like it's not right, but at the same time, I don't think the countershaft moves far enough to knock its bearings out before the gears hit the case. They just kind of work themselves out as you wiggle the shaft back and forth what little bit it moves. If they were firmly press-fit, would they not be impossible to remove?

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I don't think I saved my original seals to compare. I know I specifically ordered the reverse needles, and USA only sent me 1 when the trans takes 2, but to their credit they ended up expediting the missing bearing for free.

My last few orders have been from Transmission Parts Distributors, since they were the only people in a cursory search to offer a t-case rebuild kit or M5OD-R1 input shim kit. They're also in Jersey, which means I get the parts in 1-2 days.

I do have questions about the pocket bearing they sent me:



The rollers fit super loosely into the cage, and can even be deliberately popped out and reinstalled. I'm not an expert, but I've never seen a bearing do that.

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EDIT: Still just waiting on USPS to not misplace my package / muff up their delivery estimates lately. And waiting, and waiting.

 

[lowspeedpursuit]

Still working on this. I decided to buy the Ford ISB shim, and it took so absurdly long to get my hands on it that I got busy with other things as well.

ISB shim E8TZ-7029-A is in:



Countershaft front shim E8TZ-7C434-F is in:



Upon inspection, rear bearing races were not spinning in their bores. So, the shafts were removed again, and all four bearings have been Loctite 609'd, but only the front bores have been dimpled. Things are tight. I can't imagine taking this apart again. If it blows up, it'll be time to just grab a whole new trans.

I also managed to snap off the first bolt I tried to torque (to 14 goddamned ft-lbs.) on the front cover. So, everything came back off, I chased the threads in the bolt holes (M8 x 1.25), and put it together with new hardware. No problems.

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Aside from the three parts I've already addressed, there are three more places in this trans with play specs and variable spacers, all of which have to do with reverse: the reverse counter split washers, the thrust washer that covers them, and the reverse idler assembly snap ring. My idler play measured .006 on a spec of .0039-.0078, so that's okay as-is.



Per the manual, you only need to check the split washers and thrust washer if you replace something on the countershaft in the tailhousing. I didn't, but checked the play anyway. Spec on the split washers is 0-.0019, same as the third gear bearing snap ring. Mine was <.0015, so that's good.

The guy who wrote the manual was apparently getting bored with this chapter and kind of starts phoning in the explanation, but for the last play spec, you install the reverse counter and idler, and measure off of this "thrust washer" behind the reverse counter:



But you're adjusting the thickness of this "thrust washer" in front of the reverse counter:



Spec is .010-.014, but I measured ~.0185, so I guess the manual is wrong about when you need to check this.



My original is part A, so it's being replaced with E8TZ-7C340-B, which is .008 thicker. And now we wait, again, for that to show up, as my truck sits on jackstands in the garage.

 

[Shran]

Hey. Fun.

Input bearing race being loose inside the bore is totally normal. No worries there. I have had a lot of these apart and they are all like that. Countershaft is the same way, it should be "loose" within its bores until you shim it with the front bearing retainer which should bring your end play there down to not much. I will mention that the shim specs in the shop manual for the countershaft are IMO wrong - if you shoot for the tight side, it'll be too tight and lock up the trans when you put the bearing retainer on. Too loose and it can cause the trans to pop out of gear. I had a hell of a time finding shims for this, you can get those specific sized spacers but several times none of them were perfect so I had to visit a local truck shop and dig through their box of random shims till I found some that would work.

Would agree with your plan of shooting for a larger shim/smaller tolerance on the shims. I read a post on here a while back where AllanD suggested that they should be shimmed past zero since they are a tapered roller bearing... not sure if I agree with that or not. I tried it and the trans failed within 5000 miles although I can't attribute the failure to that specifically.

As far as the chipped teeth go: I would smooth the chipped sections off with a sanding disc on a die grinder and run it. That's probably not the right way but I've done it without issues.

I'm not a big fan of USA Standard Gear aka Zumbrota aka several other companies. I am not an experienced transmission rebuilder but I have done enough to know my way around them and am pretty meticulous about following specs and measuring correctly... so far using their parts I have had one catastrophic failure, one premature failure, another one that has lasted about 25k but has a 3rd gear synchro going out, and one good one...all M5ODs... have used their parts on a NP205, FM-145, FM-146 without issues though. I am just not convinced that they supply quality parts for M5ODs, especially the bearings.

 

[lowspeedpursuit]

Well nuts. Between the new countershaft shim and the dimpling, my trans could definitely end up being "too tight" if that's a common risk. I will say that with both retainers torqued, everything spins; nothing is totally locked up or experiencing a ton of friction. Countershaft front play is .007 and ISB is .002, both on the tight end of spec, but not past.

Since getting this trans, I've put something like 20k mi. on it with some play specs loose, and the ISB very loose, and all I got was an obnoxious rattling noise, especially after reaching operating temperature.

I wish we had any sort of competent local truck shop anywhere around here. This whole problem started when my local Ford dealer told me the ISB shims were NLA. That turned out to be bullshit, I just had to work with a dealer an hour away to order them.

 

[Shran]

If it still spins when you get the bearing retainers on, it's probably fine. I was finding that it would lock up if I went any tighter than .003ish. You would know right away that something is wrong.

I went through one of mine twice and replaced damn near everything in it, first time as I said it lasted about 5k and then started popping out of gear. There was a good bit of wear on all the bearings and the fluid was full of ground up metal. 2nd time, replaced a bunch of other parts and it started doing it again after about 3k. I have yet to tear into it. Guessing I have about a thousand bucks worth of parts in it and no idea what is causing the problem. Hope you have better luck than I do.

I hate dealing with Ford parts departments. There is just no rules about "this is how to sell parts"... it's just whatever they want to do. For example McKie is my local one, often time when I need an RBV part they want me to buy a whole box of them and pay freight. 4.0 oil filter adapter O-rings for example... a 5 cent part would have cost me almost $35. Some other dealers will just sell me the part and not play games like that. It's annoying.

 

[lowspeedpursuit]

If this trans fails or starts acting up again remotely soon after I've gone to all this trouble, I'll probably be fairly upset with USA Standard myself. I had actually forgotten about this, but their rebuild kit also provides identical 1-4 synchro rings. The manual makes a biiig deal about the fact that the 3rd-gear ring is unique, to "eliminate upshift crunch".

I talked to USA about it, and they told me an identical ring has superseded the unique ring. I also talked to my local Ford dealer, who told me the unique ring is NLA. But, what do you know, I have sometimes felt like 2nd->3rd is a bit notchy since installing the new parts. I guess if I ever rebuild one of these transmissions again, I'll make more of an effort to look for the old ring.

If I start popping out of gear, I feel like I'd be suspicious of the synchro sliders and shift forks. USA has the 3/4 slider, Transmission Parts Distributors has 3/4 and 5/R sliders, and both have the 1/2 and 3/4 forks. But, neither seems to have the 1/2 slider or the 5/R fork, so that's fun. IIRC 1st gear itself can be difficult to find as well.

The dealer in "the city" can actually get their hands on parts, but it takes awhile, communication is poor, and they do make me buy by the package for old applications. That made the ISB shim (pack of 2) cost $43, but there was no other way to get one. In the past, I didn't go to the dealer to replace my adjustable hood bumpers because they wanted me to buy 8!

 

[Shran]

Oh yes, the 3rd gear ring is an annoying issue as well. Every M5OD I've built has been a little crunchy going into 3rd and for that exact reason. I have some used updated rings that I will probably swap out when I get motivated to tear into the one that failed.

From what I have been told and read elsewhere, popping out of gear can usually be attributed to movement in one of the shafts due to a worn bearing. That makes sense in my case because the input shaft bearing and pocket bearing were trashed when I tore it down after failure #1 and I am sure they are trashed again now. But WHY that is happening is the main question. Bad bearings, input shaft out of spec (it was new), shimmed incorrectly, something else? I don't know.

 

[lowspeedpursuit]

E8TZ-7C430-B is in. Reverse idler is torqued. New rear bearings are in. New stake nuts are in.



Tailhousing is on; final torque in 45 or so. Fill her up and put her back in the truck tomorrow, hopefully, but other things keep being added to my schedule whether I like it or not, so who knows.

Here's hoping this thing makes zero strange noises and outlasts my motor at this point.

 

[lowspeedpursuit]

Well, the truck runs, but god only knows if it drives, because I have no clutch pedal. Figured I accidentally let air in the master bleeding the slave, but as soon as I flipped it upside down and pumped it a few times, it started pissing brake fluid out the pushrod seal. Even if I wanted to pay $85, parts stores don't have it on the shelf, and it's Saturday, so the truck will stay down until next weekend I guess.

"Perfection Clutch", who supplied this prefilled master and hydraulic line like 1.5 years ago, can bite me.

EDIT: So I've got no idea how this thing works. It's tempting to think the white ring with the split in it is at fault, but it's rigid plastic, and can't be compressed enough to push the ends together, so I assume it's just a bushing the piston rides on.



This seems to be the only seal, but it looks intact, it's not a normal shape I can just find on the shelf, and I don't see how it could be removed anyway.



But I already ordered a LuK cylinder last night, and it'll get here when it gets here.

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EDIT 2: Nevermind, I'm an idiot. Here's the seal. I've also gotten the pushrod out of the piston using a bic pen cut in half lengthwise, which may be useful in the future:



But, I still don't see any appreciable damage to the seal, or piston surface where it sits. Regardless, without a source for the seal, this is all purely me screwing around.

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EDIIIIIIT:

While I was waiting, I sourced a random '5/8" Brake Seal' and tried to throw it in the old master. It was slightly smaller in height and OD (bore spec. is 16mm, which is slightly larger than 5/8") and especially in ID, which prevented installation. Guy at the good-old-boy parts store said rebuilding master cylinders was more common in the past. LuK e-mail support informs me they neither support nor supply for rebuilding.

Nevertheless, every once in awhile things do inexplicably break my way. I ordered empty master LuK LMC181, and I received a box marked LuK LMC181, but what's inside is clearly a prefilled cylinder and hardline combo. The cylinder is a bit shorter than my old one, and the hardline may be a bit shorter as well, so hopefully what they've sent is actually a boon, rather than totally the wrong application. This cylinder is also plastic, whereas the old one was metal, but that didn't actually translate to the old one being any sort of quality, so who knows. Fingers crossed, truck goes back together this weekend.

 

[lowspeedpursuit]

Well, I officially give up. Everything is back together, and the truck drives, but the noise is even louder than before. New parts, everything done by the book and checked to spec. Makes no sense at all, and I am completely out of ideas. 2nd gear specifically at high RPMs (3k+) sounds like the end of the world.

Next step is to replace the trans, but it's not worth $1000+ or whatever, and 2.3L 4x4 transmissions for this thing are like hen's teeth. Sure, I could grab a 2wd and swap the mainshafts, but then I'm just rebuilding a transmission for a third time, and so far I haven't got a great track record.

It's a pity, because this truck in manual is more fun to drive than any of my other vehicles, but there's not much else for it.


EDIT: Excuse me. To be accurate, some listings on car-part.com want $2-3.5k!! Since the Zumbrota reman. is $1500 shipped, I'm not sure what the hell those people are smoking.


EDIT again: After I was finished being all pissed off, checked fluid level and quality in trans and transfer case. Inspected the trans magnet (very little metal) and topped the trans back off. Drove up and down a dirt road in 4H and 4L a few times aaaaaaand... the trans mostly stopped making the noise. I daily this truck when it's working, so I'll know fairly quickly if the noise is gone or intermittent, and I'll operate under the assumption that this trans is not necessarily reliable in the long-term. As always, thoughts and advice are welcome.