Aloha, I've been keeping an eye out for an R1HD manual trans to rebuild as a backup for my high mileage ranger and finally found one. Guy on Craigslist was selling an engine/trans with 120k on it for dirt cheap, figured it would be a great base to start with and I'd get an extra engine to boot.

Once I got into the trans, it's pretty clear its in good shape. Probably could have just swapped it and gotten another few years. Well, it's apart now so might as well replace the bearings, block rings, and seals.

The block rings all have carbon coatings on the friction surface, anyone else rebuild one of these and get a good source on these besides ford? Ford wants your firstborn for these, the 2nd gear block ring alone is $100.

There's a rebuild kit for the M5OD-R1 that has the same block rings but they dont have the carbon, just plain brass ridges. I'm curious what difference the carbon makes, seems like it would just increase the friction coefficient. Anyway, I'd love to get some tips or things to look out for on the rebuild.



Here's the guts

 

Found these part numbers, looks like I can use the R1 synchros for the R1HD aside from 1st and 2nd?

 

Okay, so these are all 1st gear block rings.
Furthest left is a new M5OD-R1 ring.
Middle is a new M5OD-R1HD ring.
Right is the used ring out of the M5OD-R1HD I'm working on
The only difference between the R1 and the R1HD rings is the carbon coating.


The serial number is on the new ring. Used ring is from transmission. Looks good to me.


New Vs Used the carbon layer is the same thickness, no wear at all.

I'm thinking I'm just going to reuse the carbon rings. I can't justify spending $500 on rings that look perfectly fine. I wonder if the used carbon has better grip than the new brass rings from the R1. I'm almost curious enough to try out the older rings and see how bad the shifting is.

 

I don't think it would matter that much, the carbon coating is for longevity and in the M5OD transmission's the synchros didn't wear out that fast, in other transmission they could wear out so carbon coating became a benefit in those models, and it just carried over to all other transmissions as an option

And it would depend on drivers "need" for fast shifting, the carbon coating doesn't make shifting any faster, just less wear when FORCING RPM matching

The synchros RPM match the output shaft RPMs to the selected gear RPM, so it slows down or speeds up the selected gear when its disconnected from the engine RPMs(clutch)
All the gears in the transmission are turning at rear wheel/driveshaft RPMs all the time, at 70MPH 1st gear is spinning at a "gazillion" RPMS, lol, so very very hard to shift into 1st gear at 70mph, you can't slow it down enough, even with synchro, to match output shaft RPMs
General speaking there is usually only a 300-500rpm difference between gear ratios, so not much slowing or speeding up is needed, the bigger the RPM difference the longer it takes to shift/get synchro to RPM match

Prior to synchros drivers would have to double clutch and either rev engine in neutral or let engine rpms drop to select another gear, so manual RPM Matching
And you can still do that for faster shifting

 

Thanks Ron, that makes a lot of sense. I'll most likely reuse the carbon rings as there's very little wear. Also if I reuse everything besides bearings then there's less chance I'll have to change shim or thrust washer thicknesses, still gonna check tolerances though.

I really appreciate the help, you have a knack for explaining this stuff. Never heard the rpm to gear ratio relation explained so clearly, definitely helps.

 

Strange that you were able to find a full brass synchro ring for the 1L54 trans. I have one, and 1st/2nd are unique to that transmission and all subsequent models after the revision. 1st gear is physically larger than the older R1 models.
The 2nd gear double cone synchro is also quite expensive, for a ranger at least.

When I rebuilt mine, I was told by the ford parts guy that I purchased "the last 1L54 synchro in the U.S. parts warehouse database" that he could find, LOL.

As far as the carbon is concerned, keep it. Carbon rings are not only smoother, but they "grip" more and are generally a better component. If not for any other gear, make sure you retain carbon for 1st and 2nd. I am not even sure if anyone except OEM sells the 2nd gear double cone synchro.

*edit* I see your 2nd gear synchro is only 100 bucks. Buy it, LOL
I spent 350 dollars on mine, special order, no refunds, paid in full before order placed.

 

I was using the wrong terminology, I purchased a 1st/2nd gear block ring for $100. The whole synchro assembly is indeed $350ish. The all brass ring came from a third party m5r1 rebuild kit. Cheap rings, but I was so curious I just had to get my hands on them. The bearings are all koyo and look like the same ones on the R1hd, gonna check the serials to be sure.

​​​​​​As far as I can tell, if I'm just replacing the bearings and seals I don't need to disassemble the main shaft synchros. I was just gonna clean everything up and pop it back in the case, check tolerances and let er rip. Is there anything else from your rebuild you'd recommend I add to that list?


Edit* Lookie what I found...

 

Yeah, when I bought pats for mine, I got the rebuild kit that had the old model synchros in it, which work for 3-R. I discovered I had the newer one, with the larger 1st/2nd gear only after I took mine apart. My 1st gear blocker ring was 50? bucks. My 2nd Gear blocker ring assembly (the 3 piece synchro blocker ONLY) was the 350 bucks I mentioned. I actually tore mine down because I ruined the 2nd gear blocker rings one day when my slave failed and I had to hold it against 2nd to get the truck off the road. Had I known at the time I could of shut the truck off, pulled the NSS up to start it in gear, and synchro shifted it back home, I would of done that. But I was pretty young at the time, and didn't know better, so I drove it for 3 years after double clutching 2nd like a big rig LOL

The FSM/rebuild guides all mentioned having a specific amount of endplay in the mainshaft/countershaft when you install the front bearing retainer/seal retainer. Even after doing it numerous times, I never got the amount of play I felt was sufficient so I used an old mitsu/DSM trick, and used solder to find the total play between the bearing and the front retainer. And then I shimmed the main/counter shaft for zero to very minimal preload. Personal preference.

I did not torque the large output shaft bearing retaining nut to spec. I just put the trans in 1st and 3rd at the same time, fixed the trans in place, and put "the strength of Thor" into it. By my weight and calculations based on wrench size etc, I'm sure I got it close. I wasn't going to spend the money on the FoMoCo special nut tool (big socket on a long pipe that fits over the output shaft) to use a torque wrench, for something that was spec'd to 200 ish ft-lbs

If your kit did not come with it, I also suggest removing the shift shaft seals on the back of the shifter rail assembly and replacing those with brass/steel freeze plugs. You can feel free to add a minimal of sealant to the plug before install, but that is also preference. If you do, use red loctite or a similar type of thin liquid anaerobic sealant. Set the plugs flush to slightly "below grade" on the case, they do not need to be installed too deep.

Make absolutely sure you do not forget the input shaft oil slinger, and also be very careful with RTV placement/volume. The grooves in the bearing retainer cannot be clogged, or you're going to have a really bad time. Like mentioned below, after that is sealed, is a great time to fill the oil slinger trough with you roil of choice and get those front bearings well pre-lubed before final assembly and install.

I'd recommend using synchromesh for both assembly as well as after you install the transmission. Mine shifts like butter. When you have the trans assembled, but before the tail housing and the top cover is installed, use that opportunity to shift through all gears, and give the shaft/synchro slider assemblies a good splash of oil while turning the output shaft. You should also consider replacing the shifter stub seal, that rubber likes to degrade and crack. Mine wasn't all that expensive, I think 10-20 bucks at max. Your tailshaft seal is on the transfer case, since you're running a 4x4 unit. I'd personally replace that as well.

Other than that, I cannot say I did anything special. I did tear both shafts down to bare cores, save for the bearing sleeves on the counter shaft. They mic'd like they were brand new (both old and new were exact same size) and while it's not the "proper way" as new bearings should get new races etc, it was a calculated risk I was more than willing to take considering the pristine condition of the parts.

 

To start, thank you so much for the info, this is seriously helpful and I appreciate it. I now know how to get this heap back home when my slave gives out.

Speaking of the slave, I ordered a pre-bled LUK master cylinder for my next replacement and it's a plastic housing on the master. My old master is cast. I kind of want to return it and just re-bleed a new LUK cast-metal housing master rather than using a plastic housing. Am I being paranoid?

So you used solder crushed between the bearing and housing as a gauge? Smart. Never heard that one. I know there's a plastic stick they use for crank bearings, wonder if that's the same theory. My hope was that I could reuse the current shims, since the trans is in great shape and I'm not changing anything aside from bearings.



Same, I've got a wrench head that fits a cooling fan rentaining nut with a 3/8" adapter built in, and it fits that nut with a bit of slop. Gonna be careful and see if I can hit 200, and if not I'll just crank on it with a pipe wrench lol.

Quote:

Originally Posted by Turismolover22

If your kit did not come with it, I also suggest removing the shift shaft seals on the back of the shifter rail assembly and replacing those with brass/steel freeze plugs. You can feel free to add a minimal of sealant to the plug before install, but that is also preference. If you do, use red loctite or a similar type of thin liquid anaerobic sealant. Set the plugs flush to slightly "below grade" on the case, they do not need to be installed too deep.

I'm a permatex sleeve retainer *****, use it on every press fit setup aside from ball joints. I've never had an issue getting bearing races off after using it, and at the very least it acts as a lube to prevent galling when you press stuff on. I had planned to use it on all the races. I have some anerobic seal and the anerobic surface prep agent for the front/rear bearing retainer plates, do you think that would be preferable for the plugs?

Quote:

Originally Posted by Turismolover22

Make absolutely sure you do not forget the input shaft oil slinger, and also be very careful with RTV placement/volume. The grooves in the bearing retainer cannot be clogged, or you're going to have a really bad time. Like mentioned below, after that is sealed, is a great time to fill the oil slinger trough with you roil of choice and get those front bearings well pre-lubed before final assembly and install.

You mean the "manual transmission oil pump"? As ford calls it? Lol, after seeing that oil slinger, I instantly wondered if there's an upgrade or mod to supply higher oil pressure.

Quote:

Originally Posted by Turismolover22

I'd recommend using synchromesh for both assembly as well as after you install the transmission. Mine shifts like butter. When you have the trans assembled, but before the tail housing and the top cover is installed, use that opportunity to shift through all gears, and give the shaft/synchro slider assemblies a good splash of oil while turning the output shaft. You should also consider replacing the shifter stub seal, that rubber likes to degrade and crack. Mine wasn't all that expensive, I think 10-20 bucks at max. Your tailshaft seal is on the transfer case, since you're running a 4x4 unit. I'd personally replace that as well.

Yep, already running RP synchromesh in my currently still working R1HD, can confirm shifting is acceptable.
In regards to the shifter stub seal, I've got a new one on my in service R1HD and it "farts" air into the cab when shifting if the trans gets hot or overworked. I assume it's the "vent" for the trans, I was thinking I could tap the housing for a fitting and add a one way valve to vent it like a diff. Seem like a good plan?

Quote:

Originally Posted by Turismolover22

Other than that, I cannot say I did anything special. I did tear both shafts down to bare cores, save for the bearing sleeves on the counter shaft. They mic'd like they were brand new (both old and new were exact same size) and while it's not the "proper way" as new bearings should get new races etc, it was a calculated risk I was more than willing to take considering the pristine condition of the parts.

So this is interesting to me. I'm not very experienced as a mechanic, just hobby stuff and my own vehicles. I rebuilt my rear diff last year, because I tried to replace the pinion seal the year before. While I was in there, I replaced the outer pinion bearing but not the race. I did the same thing, checked the old race against a new one and was satisfied it would be fine. A year later, the new bearing and cage I had installed self destructed and the race still looked fine. I assumed I fudged the preload, but I never could shake the thought that it was using a new bearing on an old race that caused it. Now I'm gun-shy about doing that again. Probably gonna press off the countershaft races just to put my mind at ease if nothing else.

 

I've had bad luck with cast metal housings, in that they have all leaked at the top (where the pedal shaft goes in). But that's also cheap parts store garbage.

My experience with LuK has been less than exciting as well. Here's the last review I had to write based on their hydraulic parts.

Master Cylinder:
"Might be an okay product, but it's the same one you would get from the house brand at the major auto parts stores. Nowhere is it marked as being from LuK, just has an AP logo like all of the ones I bought from the auto parts stores. Buyer beware if you're looking for genuine LuK products."

Slave Cylinder:
"After going through two parts store slave cylinders in a period of six years, I wanted to buy a quality slave cylinder to minimize the chance of having to do the job a third time. Well, quality part this is not, because I'm losing clutch fluid and after replacing the master cylinder, I'm still losing clutch fluid. So now I have a junk Luk slave cylinder in my truck that I have to replace yet again. This is getting real old, real quick. Buyer beware.

*UPDATE* After removing the old slave cylinder, I noticed it was stamped "FTE Automotive". That's interesting because so was the Duralast branded version I bought from Autozone. Apparently LuK doesn't make their own slave cylinders at least for this part number. Buyer beware for sure, this slave cylinder is no better than what you will buy at your local parts store."

Fun fact, FTE automotive (and parent company Valeo) is a competitor to Schaeffler Group, who owns LuK. No clue why FTE and AP stamped parts are coming in Luk boxes.

 

My OEM master is the plastic one. the ONLY reason I replaced it was because the quick disconnect end was so worn and damaged from use that it would not stay in the slave cyl quick disconnect side. The first time I had issues, the OEM slave melted due to a throw out bearing that got hot, during a date no less, and failed while I was taking the gal back home. Needless to say, didn't go anywhere with that one LOL. The replacement slave was defective, but that's for another story time. The real problems I had were with the quick disconnect end, eventually it wore down and sheared the retaining lip off, and popped out. This is what caused the 2nd gera issue, as it was during a snowstorm and I was not about to crawl under the truck with 30mph winds and 2ft deep snow. Then it happened a second time a year or so later after I had replaced the master assembly (the line was only available with a new master at the time) and I had enough of it. Had the entire line replaced with a -3 JIC steel braided line and left all that nonsense behind me. If you click on my name and search my comments/posts, you'll see the steps I wrote out to bleed the master/slave as one unit, in the truck, that has never failed me.

Its one thing Mitsu loved to do. You basically assemble the retainers as they are without any sort of shims, and then measure the solder where its crushed. It's the exact same concept of plastigauge, though there is no scale to mess with. Just find a soft enough solder that is large enough to be deformed, but small enough to not cause excess tension/preload.

Hell yeah

Any sealant that is applied properly and not in excess will work. I don't see there being an issue using Permatex

The slinger is really only meant to move the lube around to fully lubricate the two front bearings. The transmission, by design, throws excess oil uo against the shift rails and the top of the case, which splashes and drips down into that plastic trough that's on the "drivers side" of the main transmission housing. That's about the only way the front bearings receive full lubrication, so its important that the little catch tray is not missing or clogged up.

While I don't think it would be an issue, I do not recall having this issue myself. Modify at your own discretion.

Personally it sounds like the preload/play on the pinion was not set right. I replaced my pinion seal as well when I rebuilt my trans, among other items. I used the whole "count the turns and mark the nut with a sharpie" trick and it seemed to work fine for me.
Definitely a shade-tree method, but for a truck, and axle that had ~225k on it, if it broke, "oh well" I could use it as an excuse to toss an 8.8 in it and have access to cheap LSD's. An open rear in Indiana winters kind of sucks. But I've always been able to get by with weight and careful management of the fun-pedal. I might pony up for an auburn gear cone style LSD. While they are some 700 out the door before install, I would definitely not have to worry about losing momentum, the diff unloading to a single drive wheel, like I have currently.

 

Yeah I went as far as checking the preload with the axle shafts out and trying to duplicate it on reassembly. I hate the crush washer system in the 8.8. When I finally rebuilt it I used a crush washer eliminator and set preload with shims. Only took like 10 trys, lol. At least it's not gonna move on me now.