Trans ID

[Vladislav]

Double-checked my book. The particular figure, the way it was typed there, was .000-.002.

So I guess (pretty sure so far) it should be read as 0.000-0.002.

Yes, for both the shafts, togeher. Each one will figure out its needed share.

[Vladislav]

Checked out a cut through draw of TRD-72/720 tranny I have in a H-model parts list. The rear cover of the countershaft bearing is flush mount with the housing outer wall. It gets in indeed where it pushes the bearing race but the surrounding area (over the studs) would show a gap if the shim pack's removed. Sorry, now draw for a TRT-72 in my cabinette.

[Licensed to kill]

3 minutes ago, Vladislav said:

Checked out a cut through draw of TRD-72/720 tranny I have in a H-model parts list. The rear cover of the countershaft bearing is flush mount with the housing outer wall. It gets in indeed where it pushes the bearing race but the surrounding area (over the studs) would show a gap if the shim pack's removed. Sorry, now draw for a TRT-72 in my cabinette.

Yes the rear cover is flush so, if both shafts work in tandem then the adjustment should be able to be made from either end. That being confirmed, I will do my adjusting from the back. Don't want to sound like a dimwit by repeating stuff, just want to make sure I understand correctly. I will go out and see what I can accomplish and report back.

[doubleclutchinweasel]

I meant to look in one of my manuals, but forgot.

Wait, I may have something here at work.  Let me look and get back to you.

[doubleclutchinweasel]

I sent you a PM.  Contact me when you get it.

[doubleclutchinweasel]

But, here's a teaser...

[Vladislav]

23 minutes ago, Licensed to kill said:

Yes the rear cover is flush so, if both shafts work in tandem then the adjustment should be able to be made from either end. That being confirmed, I will do my adjusting from the back. Don't want to sound like a dimwit by repeating stuff, just want to make sure I understand correctly. I will go out and see what I can accomplish and report back.

You can only do the adjustment at the rear end. The front bearing is not a cone, it's cylindrical and floats when you manage the position of the two shafts together by the rear bearing. See the diagram, not difficult to figure out understand the design.

[terry]

1 hour ago, Licensed to kill said:

Yes the rear cover is flush so, if both shafts work in tandem then the adjustment should be able to be made from either end. That being confirmed, I will do my adjusting from the back. Don't want to sound like a dimwit by repeating stuff, just want to make sure I understand correctly. I will go out and see what I can accomplish and report back.

It is definitly set on the rear of back countershaft.    terry

[Licensed to kill]

Soooooo, I was unable to get the dial indicator set back up after removing the shims to check So I removed .0265 in shims and reassembles with three bolts and was just enough lash that is barely noticeable that I will call .001-.002. However, according to the diagram posted by doubleclutchinweasl, unless I misunderstand it, it shows that there should be no end play but, rather, a preload. I know this was discussed in earlier posts was was never able to understand what the end consensus was. I am set up to paint the aux box right now but, if I understand that preload thing correctly, in that it requires preload, not end play, I can readjust that after (once I procure a fish scale). I was going to ask about the gear backlash but see it is to be .002 - .012 so I will check that also and if it is out of spec will be back to ask how to adjust that. Thanks to all for the help.  

[Joey Mack]

yes to Pre load.. 

[Licensed to kill]

2 hours ago, Joey Mack said:

yes to Pre load.. 

So the .027 of end play was a bit "out of spec" 😂. Good thing Terry suggested checking it or I would have just put it in. 

[Joey Mack]

I just read this thread again..  I was concerned that I gave wrong info.   I said ''Pre-load''  I just went out and looked at one of my 200 series books, and it says .002''-.006'' pre-load measured at the rear bearing cover..  I beleive Mack used that spec on the TRD's and on through til today...  I beleive I am right..  I also said .002''-.005'' on re-used bearings, and .003''-.006'' for new bearings..  I know that is true in both transmissions and Mack rear's..   I say that .002'' pre-load is just fine for what you are doing..  now ... you have .027'' endplay..  is the center case gasket wrong?  causing the endplay?   my guess is you have steel shim's under the bearing covers?   

[Vladislav]

Seems a bit strange to hear continue on the pre-load/end play discussion since that was told in this thread above already.

To point out once more. There are two different ways of managing a bearing unit. One way is when you set two bearings with a gap between them. So they're a bit free from each other, and when you make a check during assembly of such a unit you measure the play. And as you usually do it at a end it's called end play.

There may be different way, when you forse one bearing agains the other. In that case rollers or balls are always under pressure during the operation. To achive that you assemble the unit forcing bearing's cone or race by a certain part (cover, nut etc). As long as you need a certain particular amount of that force (to not overtight and burn the races) you have to measure it. Usually two procedures are used for that: adding a certain distance to the part you tight up the bearing with, or measure of the spin torque. This way you put pre-load to the bearings.

What's important is the way the bearings should be set up is determined in the design of the unit. And when you see a "pre-load" procedure in a repair manual you set pre-load. If you see "end play" you check the play. Which sure means a gap or clearance.

Actually pre-load is a "negative end play".

[doubleclutchinweasel]

When I looked at the drawing this morning, it looks like it actually has an "END PLAY" spec on the MAINSHAFT and a "PRE-LOAD" spec on the COUNTERSHAFT.

But, I have no personal experience with this transmission.  So, don't take my word alone for it.

[Vladislav]

Judging by the drawing you are right. Pre-load on the countershaft. 

When I read LTK's post in the morning I haven't looked the diagram over. So didn't understand why the way of things went off the end play to pre-load.

[Licensed to kill]

51 minutes ago, doubleclutchinweasel said:

When I looked at the drawing this morning, it looks like it actually has an "END PLAY" spec on the MAINSHAFT and a "PRE-LOAD" spec on the COUNTERSHAFT.

But, I have no personal experience with this transmission.  So, don't take my word alone for it.

Had not noticed the endplay spec for the main shaft but, then again incas focusing on the countershaft. After reading your post it took me awhile to FIND J&K in the drawing, again, I was focusing in the wrong place, the main box rather than the aux box but I did eventually find it. I will check that out as well. Thanks for the heads up. I am finding the figures in the drawing hard to read on my screen (and I have a rather large screen) but if I look long enough I can make it out. 

[doubleclutchinweasel]

I tried to upload that manual to the WIKI section, but it is too big.

[doubleclutchinweasel]

Yeah, this PDF file is a little rough!  My physical manual is far easier to read.  If you have any specific sections you would like to enhance, let me know.  Maybe I can take a picture of them and send it to you.

I guess end play on the mainshaft makes sense.  After all, there are several shafts in the center of that box (main input shaft, main mainshaft, aux input shaft, aux mainshaft).  Might want  little clearance between the ends of each one!

 

Technically, I guess the front mainshaft is the rear input shaft.  Sorry about that!

Edited October 19, 2023 by doubleclutchinweasel
Added a thought

[Licensed to kill]

11 hours ago, Joey Mack said:

  I say that .002'' pre-load is just fine for what you are doing..  now ... you have .027'' endplay..  is the center case gasket wrong?  causing the endplay?   my guess is you have steel shim's under the bearing covers?   

Yes there are shims under the bearing covers. I removed some to get to .002 endplay, will remove another to get to the prescribed preload. This will be a different adventure for me as I have never played with a trans much before in fact only once when I tore the 3spd from my model A down. Just a LITTLE bit different than these. This measuring torque to determine preload is also something new for me. The only time I recall setting preload is on wheel bearing and, IIRC, I torque them to 200ft lbs, turn the wheel to set the bearings, then loosen them off and torque to 50ft lbs for proper preload. Something like that anyways. I will check the end play on the main shaft and the lash on the gears today, if they are out of spec I will require guidance to make the necessary adjustments. 

[doubleclutchinweasel]

Were you able to access the PDF file from the link I sent you?  I can always post some individual pages on here if I need to.

[Licensed to kill]

18 minutes ago, doubleclutchinweasel said:

Were you able to access the PDF file from the link I sent you?  I can always post some individual pages on here if I need to.

Just did. Will try to get the pages I need printed. Thanks. 

[doubleclutchinweasel]

I guess it looks kinda like this with the 5-speed section removed!

The instructions are not clear on setting the mainshaft end play at the 2 indicated points.  Maybe it would be obvious if you were in there.  Almost looks like the main box and the aux box are set separately.  But, it looks like the countershafts are all set from the same point on the aux box.

[doubleclutchinweasel]

1 hour ago, Licensed to kill said:

Just did. Will try to get the pages I need printed. Thanks. 

Incidentally, the Triplex section might be of some use to you too, since it shows only a "married" box without the break in the picture for the 5-speed.  I'd say the only difference between the Duplex and Triplex would be the rear box.  The front mainshaft would likely look the same.

Best of luck to you, LTK!

Weasel out...

 

Edited October 19, 2023 by doubleclutchinweasel

[terry]

On 10/19/2023 at 7:43 AM, Licensed to kill said:

Yes there are shims under the bearing covers. I removed some to get to .002 endplay, will remove another to get to the prescribed preload. This will be a different adventure for me as I have never played with a trans much before in fact only once when I tore the 3spd from my model A down. Just a LITTLE bit different than these. This measuring torque to determine preload is also something new for me. The only time I recall setting preload is on wheel bearing and, IIRC, I torque them to 200ft lbs, turn the wheel to set the bearings, then loosen them off and torque to 50ft lbs for proper preload. Something like that anyways. I will check the end play on the main shaft and the lash on the gears today, if they are out of spec I will require guidance to make the necessary adjustments. 

I know it’s your transmission but with .002 endplay I would call it good, the only place I have set gear backlash is on PTO’s, different gasket thickness’s, there is no way to set backlash between main and countershaft gears. Terry

Edited October 20, 2023 by terry

[Licensed to kill]

29 minutes ago, terry said:

I know it’s your transmission but with .002 endplay I would call it good, the only place I have set gear backlash is on PTO’s, different gasket thickness’s, there is no way to set backlash between main and countershaft.  Terry

Having .002 end play when I need .002 preload requires a .004 shim to be removed so, while I agree that it would be good as is, I'll try to get it a bit better. The Lash I was referring to was not between the main and counter shaft gears but, rather, pinion gear and main shaft. I checked it and it was also WAY out, .005 - .012 in the book and I have .027. I have no clue how to adjust that and, to be honest left me somewhat concerned. With the counter shaft out of spec by .029, @ .027 end play when it is SUPPOSED to have .002 PRE LOAD, now the pinion lash over double the prescribed max, I'm thinking "is this thing just too wore out to even bother with or what??". I called my brother (HD mechanic for 40 years) and told him my dilemma and asked how to adjust the lash on the pinion and/or is this thing just too wore out. He said " Don't assume that all the tolerances being so far out is the result of wear. It could be that Jed Clampet put the thing together at some point and didn't set any of the tolerances correctly." He also said that "if the bearings were wore to the point of the counter shaft being .027 end play when it is supposed to be .002 preload, the bearings would have piled up a long time ago. They can't wear that much  and survive". He suggested that, since it turns easily and smoothly and the teeth all look good to just dial in the countershaft to spec (because it is easy) and call it good. For the record, the main shaft is supposed to have end play and I can not get ANY movement from either main shaft (main or aux box). This could also be an indication of a poor  assembly at some point since this is not like valve lash that tightens with wear. I don't know but think I am going to just get the counter shaft right and call it done. I REALLY appreciate your suggesting I check the counter shaft as I would otherwise have just cleaned the thing up and put it in the truck. No telling what groovy noises would have come out of it with the CS the way it was.