Transmission new and something ain’t right...

1941 - 1945, MB, GPW Technical questions and discussions, regarding anything related to the WWII jeep.
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Bill H.
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Re: Transmission new and something ain’t right...

Post by Bill H. » Sat Oct 26, 2019 8:55 am

Heck, over the years I’ve built 100s of different transmissions and it still takes me a lifetime compared to how fast an assembly line worker can do it and they just might be a woman! :shock:
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Re: Transmission new and something ain’t right...

Post by Klaas » Sat Oct 26, 2019 11:36 am

Bill H. wrote:
Sat Oct 26, 2019 8:55 am
Heck, over the years I’ve built 100s of different transmissions and it still takes me a lifetime compared to how fast an assembly line worker can do it and they just might be a woman! :shock:
Hey Bill, I thought that there were to be no derogatory remarks on this forum, but now you have all the women in this world against you with that last remark :lol:
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Re: Transmission new and something ain’t right...

Post by Wolfman » Sat Oct 26, 2019 2:01 pm

Well, considering what was going on in 1942, Klass, they might have been. There was a shortage of men.
With that in mind, any ladies out there decide to take on the task, come on down. Be proud to help you out ! 8)
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Re: Transmission new and something ain’t right...

Post by Joe Gopan » Sat Oct 26, 2019 2:11 pm

There was no limit to what Rosie the Riveter put together in WWII. There was a Life Magazine article about the Fat Ladies of Aberdeen, they had women tank test drivers at APG.
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Bill H.
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Re: Transmission new and something ain’t right...

Post by Bill H. » Sat Oct 26, 2019 4:01 pm

Klaas wrote:
Sat Oct 26, 2019 11:36 am
Bill H. wrote:
Sat Oct 26, 2019 8:55 am
Heck, over the years I’ve built 100s of different transmissions and it still takes me a lifetime compared to how fast an assembly line worker can do it and they just might be a woman! :shock:
Hey Bill, I thought that there were to be no derogatory remarks on this forum, but now you have all the women in this world against you with that last remark :lol:
Boy oh boy we’re stretching now! :shock: That was meant as a compliment :lol:

Picture all our boys off to war but they need supplies! Weapons, ammunition, vehicles and all the gals sitting at home dreading the day the telegram guy comes rolling up. Or just maybe she helped the war effort by going to work in a factory building T84 transmissions. Can you imagine 50 years later her husband struggling with a WWII jeep restoration. He just can’t seem to get that transmission together right! Does the wavy washer go on top or the bottom of the shift plate??? :mrgreen: Out of the house comes his lovely wife with a glass of ice tea and she sees he’s frustrated and getting more so by the second. She says step back, let me at that thing and has it back together just like she just did one 5 minutes ago!

;) :lol:

Don’tcha just love it :)
Bill H.

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Re: Transmission new and something ain’t right...

Post by Chuck Lutz » Sat Oct 26, 2019 5:20 pm

Before we move on to tilting at other windmills, Sancho....here are some more of those pesky measurements some guys abhor...

The main shaft snap ring and the front bearing retainer snap ring are the same part number and should be 1 9/32" I.D.x 0.089" wide....

And...some more T84 info....some prefer to assemble the T84 to the T/C and torque the bejesus out of the castle nut BEFORE checking that 3rd gear slop and adjusting the SPACER width or adding shims to get it to match the 2nd gear slop.

Some prefer to use a clamp to hold the bearing to the rear of the T84 case.

Others have simply taken a blown up T/C and cut off the front to use to check the slop on 3rd gear after torqueing the castle nut.

What is the difference how you do it you may ask?

Well, assembling the T/C to the T84 (and using your reamed out rear bearing) is as close as you can get in my book.
Second to that is using a piece of the front of an blown up T/C to do the same task.

However...those who are simply using a clamp to pull the rear bearing FORWARD into the T84 cavity for it are missing the point: when assembled, the rear bearing (and the main shaft) are not held in a FORWARD location against the void in the T84 case at all. When assembled, the castle nut pulls the main shaft (and the bearing) REARWARD as it is tightened.

Why, you may ask is this not as good a way to do this? Because the void between the T84 and T/C plus the thickness of the rear gasket (especially those horrid BLACK ones for a T90!) make the space wider than the bearing is. Since in the end, your torqueing the castle nut PULLS the main shaft REARWARD, no matter the amount of the void in front of the bearing, trying to hold the bearing FORWARD when checking the 3rd gear slop is not a good idea as you can see.

Our French Army amis once again came up with a shim to be placed between the bearing and the T/C to take up some of that space by the way!
Chuck Lutz

GPW 17963 4/24/42 Chester, PA. USA 20113473 (USA est./Tom W.)
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Re: Transmission new and something ain’t right...

Post by dinof » Sat Oct 26, 2019 7:24 pm

I think your on to something Chuck because the slop changed when I went from clamping the bearing up and then bolting up the T/C. I think I had more slop after the T/C was bolted up. Not sure. Either was that, or it decreased slop. Before Luc was banned. I think he had a transfer case that was cut up just for fitting up things. I do know the slop changed for me from clamped bearing to T/C bolt up.
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Re: Transmission new and something ain’t right...

Post by artificer » Sun Oct 27, 2019 1:56 am

Chuck wrote:However...those who are simply using a clamp to pull the rear bearing FORWARD into the T84 cavity for it are missing the point: when assembled, the rear bearing (and the main shaft) are not held in a FORWARD location against the void in the T84 case at all. When assembled, the castle nut pulls the main shaft (and the bearing) REARWARD as it is tightened
We have been through this many times & the statement + highlighted are definity not correct.

If the shaft & bearing are assembled properly tightening the nut moves the bearing & other shims etc on the shaft till they are seated against the circlip & become one with the shaft.

Should the shaft nut not be properly tightened, with the bearing clamped to the housing as it should, no matter how, the shaft may move back slightly when tightening the nut. The CLAMPED bearing does not.
After this has been done is when one checks 2/3 baulking rings.
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Re: Transmission new and something ain’t right...

Post by Chuck Lutz » Tue Oct 29, 2019 12:54 pm

That is correct, when you tighten the castle nut you pull the main shaft to the rear. If you used a clamp to hold the main shaft together you did indeed compress the assembly together....however the compressed assembly still is not giving you the DEPTH into the 3rd gear & blocking rings until you tighten that nut by adding the T/C (or a dummy) to stop any rearward movement. When tightened inside the T/C (or a dummy), you are not only compressing the assembly like using the clamp does, but pulling the assembly REARWARD until the void in the T/C stops the compressed assembly from any further movement like it will be once it is fully assembled.
Transfer Case GPW-7705 Front LATE.jpg
Transfer Case GPW-7705 Front LATE.jpg (191.58 KiB) Viewed 357 times
THIS is when you can check the 3rd gear slop compared to 2nd gear.

The only way that using a clamp on the rear to hold the bearing while torqueing the castle nut to check will work is if the VOID between the cases is the exact width of the bearing....or you used the French Army method of adding a shim!

Your method: compresses assembly but the assembly is only held forward into the main gear & rollers is based on how tight the clamp can be and if there is no "extra space" when you finally DO install it. Unfortunately this method does not allow for the way the castle nut pulls the bearing and shaft assembly rearward against the wall inside the void in the T/C bearing opening.

Kinda makes you understand why the French Army came up with those "shims" found between the T84 and the T/C....and why they are found between the bearing and the T/C....because that would eliminate rearward movement which would open up the 3rd gear slop which artificer's method will do. Again, the French Army did REBUILDS and knew about shims for the SPACER on the main shaft and shims in between the ear bearing and T/C.

Looking at your drawing, it is possible to understand where you went wrong...you added the bearing and the gear in the T/C and tightened the assembly together...so far, so good....however the wider opening between the cases means when you tighten the nut THIS time (assembled in case or using a dummy case) the assembly itself can move rearward until it bottoms out in the T/C void and thereby pulls the main shaft assembly rearward from where you clamped it FORWARD to check the 3rd slop....and that opens up the 3rd gear slop.
Some Assembly Required.jpg
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Re: Transmission new and something ain’t right...

Post by dpcd67 » Tue Oct 29, 2019 6:03 pm

Ok, I have not done hundreds of transmissions, only a few T84s and 90s; but I think it is not the nut that is the issue.
The nut can't pull anything in relation to the case because it is attached to the shaft and bearing which for all practical purposes is ONE solid object once the nut is tightened.
1. Positioning the bearing properly on the shaft is the only thing that governs the mainshaft depth and 2/3 baulking rings being equally adjusted
2. The final position will not change if the bearing is held tightly in the transmission case when fitting up
3. If the adjustement changes when the transfer case is attached there has to be measureable bearing float in between the 2 housings.
4. Shim must be on the transfer case end otherwise the depth adjustment won't be right.
Here is how I was shown to get the right mainshaft depth:
1. All parts assembled, snap ring, slingers, shims & bearing.
2. Fit gear, washer and tighten the nut.
3. The bearing must be clamped or held tightly in the transmission case bore.
4. This is when to check 2/3 baulking rings have the same clearance.
5. If correct, the mainshaft adjustment depth is correct and will not change on final assembly.
6. Done with the transfer case on, then you need to check with dial indicator if the bearing and shaft is moving in/out.
7. Shim between the transfer case and the bearing outer to remove play.
8. Easier to do on the bench than to explain.
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Re: Transmission new and something ain’t right...

Post by Chuck Lutz » Wed Oct 30, 2019 11:21 am

Read dinof's post again....

Think of it this way; you put a snap ring on the shaft and then the spacer and slinger and bearing. Then you installed it into the T84.
Then you bolted up the T/C. After adding another slinger and the bull gear in the T/C, you installed a flat washer and the castle nut.

As you tighten the castle nut, it pulls that main shaft to the rear until the stack of snap ring/spacer/slinger/bearing move rearward into the void in the T/C. When the bearing bottoms out against the T/C void, the main shaft stops its rearward movement and you are applying TORQUE which tightens the bearing against the T/C and has effectively pulled the main shaft....and the synchro assembly on it AWAY from the main gear which has 3rd gear and a blocking ring between them.

It is when you finally torque that castle nut that the main shaft assembly is captured and the slop for 3rd gear, the blocking ring and the synchro hub are evident.

Tightening the castle nut without a T/C or dummy T/C by using a clamp to hold the bearing to the T84 is a hit-and-miss affair at best. There is a reason you tighten that castle nut so TIGHT; to set the main shaft/3rd gear & blocking ring slop. That method tightens the bearing to the T84 yet when the T/C is added, the nut tightens the shaft and bearing to the T/C.

Remember, however you decide to do it, if you see too much slop, you have to ADD TO the SPACER width so the castle can't pull the main shaft assembly so far to the rear. Conversely, if, after you assemble it either way, if you have NO slop (or not enough), you have to ADD to the SPACER width to prevent the tightening of the castle nut from drawing the main shaft synchro hub so far AWAY from the 3rd gear & blocking ring.
Chuck Lutz

GPW 17963 4/24/42 Chester, PA. USA 20113473 (USA est./Tom W.)
Bantam T3-C 1947

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Re: Transmission new and something ain’t right...

Post by Wolfman » Thu Oct 31, 2019 7:26 am

Nice drawing, Chuck. Pretty much says it all.
All about position of the main shaft, in relation to the rear main bearing.
Add a shim, second oil slinger or thicker spacer between the snap ring and rear main bearing will position the main shaft forward, in relation to the rear main bearing, and transmission case when the main shaft assembly is installed in the case, with the rear castle nut tight.
Likewise, removing shims, a thinner spacer or an oil slinger between the snap ring and rear main bearing will position the main shaft to the rear, when the assembly is installed, with the rear nut tight.
The rear main bearing will be in the same place, in relation to the case, every time.
Oh, and moving the shaft forward or to the rear, in the case, increases or decreases the clearance of the 3rd gear brass baulking ring, when all is assembled. What this is all about.
:D You should have posted your picture and I should have said this back on page 1 ! :D
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Re: Transmission new and something ain’t right...

Post by JeepdaddyRC » Thu Oct 31, 2019 8:52 am

Please help summarize for me.
Second gear blocking rings really have no adjustment for play.
If 3rd gear blocking rings have more play than 2nd gear, you add shims behind rear snap ring (somewhere between snap ring and rear bearing).
This moves the mainshaft closer to the input shaft - thus reducing 3rd gear blocking ring play compared to 2nd.
Are these statements correct?
I realize there are smaller diameter shims available if second gear is loose on the shaft. But these are not the shims we are talking about.
Where is the preferred location of shims that move the mainshaft forward - between slinger and rear bearing or between snap ring spacer and slinger?

Photo 1 shows shims to move mainshaft forward.
Photo 2 shows 2nd gear shim
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Re: Transmission new and something ain’t right...

Post by Chuck Lutz » Thu Oct 31, 2019 11:41 am

Mike.....you didn't recognize artificer's hand drawn sketch?

Jeepdaddy…..
1) how thick is your SPACER?
2) I would suggest if you had to use a shim that it be between the snap ring and the SPACER
3) what is the axial play of 2nd gear on the main shaft...if it is 0.004" to 0.010" and preferably on the tighter side and you can not wiggle it then the bearing in 2rd is OK...no internal toothed shim is needed.

I posted the measurements for components but they seem to be ignored and nobody comes back with what they measured theirs to be and just are flailing around putting in shims without posting the kind of feedback that would enable us to assist them further.

I long for the guy who actually takes the time to measure the components (often crap from Crown mixed with original or French parts) who can then ask what the problem is. Many of these "Help Me" posts are akin to "my T84 is messed up, can you help?" which means any of us trying to help have to try to pull the necessary information from the OP like it was some kind of national secret. I myself can't help you any further than the couple questions above and I would encourage anyone who wants to get some assistance from the guys here to give them as much info as possible in their FIRST post to save a couple days and multiple attempts to extract that info/measurements as well as the HISTORY of the transmission BEFORE the problem occurred.

Sorry for the rant, but there are probably 500-1000 posts on T84 issues which COULD be read before raising the white flag and asking for assistance. All key words such as SPACER, SHAFT, BLOCKING, GEAR, SHIM to begin with would give readers a place to start and maybe, just maybe answer their question or at least give them enough info to ask the RIGHT questions here.

We aim to assist all who come to the G503, but starting out by reading all you can to get ahead of things and being able to post what you find and what you measured seems like not too high a price for assistance I think...
Chuck Lutz

GPW 17963 4/24/42 Chester, PA. USA 20113473 (USA est./Tom W.)
Bantam T3-C 1947

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Re: Transmission new and something ain’t right...

Post by Wolfman » Thu Oct 31, 2019 2:25 pm

John drew that ! :lol: Looks like something I would do. He got all the parts in the right place. 8)
JeepDaddy. Your assumption is correct on the shims at the rear of the mainshaft. ( close your eyes, Chuck ) I put the shims, at the rear that adjust the mainshaft position, between the spacer and oil slinger. I have a reason. Don't want the shim, especially a thin shim, that is clamped tightly in place when the rear nut is torqued, up against a snap ring that is not a full circle. The shim between the thick spacer and oil slinger seems like a better position to me. Also, if a thin shim is used, next to the snap ring and the snap ring is loose in the groove, there is the possibility of it slipping out of position, into the snap ring groove with the snap ring, before the rear nut is torqued.
As for the internal spline shims used at the front, These are used if there is too much end play with the center splined synchronizer hub. When 2nd gear and the synchronizer are on the front end of the mainshaft and there is too much end play between the center hub and snap ring.
Note: a shim placed between the front snap ring and synchronizer hub would tighten the 2nd gear brass baulking ring. A shim behind the synchronizer hub would loosen the 2nd gear baulking ring.
What Chuck said about the front splined shim. This shim has nothing to do with how loose the fit is of second gear on the mainshaft. That is determined by the condition of the bushing in second gear and the where it rides on the mainshaft. Talking about gear wobble on the shaft.
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Comm./Inst. SEL
AOPA ( 46 yrs)
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