Trans ID

[Joey Mack]

the input shaft cover may have shims under it.  End play on the main shafts is needed because of the spigot bearings at the ends of the shafts..  oil needs to enter those bearings.  the main shaft spins at many different rpm's as gears are selected to get you down the road..  I had also asked if the gasket between the cases was too thick, which would give you the excessive end play..  I feel like you are very close, if not, close enough to run it as is..  I like that you are continuing to check the shafts..  After you get this done you will have gained a wealth of knowledge to add to your current wealth of knowledge..   I like this thread...  I have built many Mack transmissions and this helps me keep my mind fresh about transmissions...    Jojo

[Licensed to kill]

In the pages of the manual that 'weasel sent me the link for it says (under assembly), regarding the internal oil pump

Pressure of the pump is low and therefore difficult to measure. A functional check should be made on the pump, prior to in- stalling the transmission cover. This can be accomplished by pouring oil into the pump pickup trough, while revolving the main driving pinion. If the pump is functioning, oil will appear at various outlets along the mainshaft. This practice will also insure initial prime to the pump.

I looked but have no clue where to find this "pump pickup trough". Didn't see it located on the schematic either. I would really like to do this before buttoning up the trans (when that time comes).

[Joey Mack]

I believe the is a long skinny piston that rides inside the input bearing cover. The cover is cut in the shape of an egg, and as the input shaft rotates, the piston moves in and out of its bore, and pumps the oil as it moves.. it's a small plunger pump..  I am not very strong on the older transmissions, like I am with 200-300 series Macks.  I seem to think this pump was used in 100 series transmissions like the X-107's I used to build..  I really need to get a Transmission re- build in my shop.. Im losing knowledge. :(. 

[doubleclutchinweasel]

Did the trough run around the top of the case and drip down on the gears?  I may be thinking of some other gearbox, though.  Old age, you know?

[Licensed to kill]

While there was no description of the "oil trough" in the pages specific to the TRTL-72 in the pages that I printed, It occurred to me this morning to look elsewhere in the manual and found it. It is on the side of the case. I copied and tried to post the page but images don't transfer

 

[doubleclutchinweasel]

13 minutes ago, Licensed to kill said:

While there was no description of the "oil trough" in the pages specific to the TRTL-72 in the pages that I printed, It occurred to me this morning to look elsewhere in the manual and found it. It is on the side of the case. I copied and tried to post the page but images don't transfer

 

[doubleclutchinweasel]

[Licensed to kill]

Yup, that's the page I found. It also prompted me to go out and check the magnet. While it had a glob of goo on it, I rolled all of the goo between my fingers to see if there was any substantial "pieces" in it and only found one spec that I could feel, the rest had the consistency of grease which should be just normal wear.

[doubleclutchinweasel]

Good deal!

[terry]

What are you referring to when you say pinion gear in a transmission? Maybe I’m missing something?    Terry

[Licensed to kill]

4 hours ago, terry said:

What are you referring to when you say pinion gear in a transmission? Maybe I’m missing something?    Terry

the input shaft gear. They refer to it as the "pinion gear" in the manual. I know, that was news to me also. 😀

[terry]

Learn something new every day! Guess i just never heard it called that.    terry

[Licensed to kill]

Picked up a fish scale today to check the preload on the countershaft. Manual says 4 - 5 1/2 lbs and I get 5 lbs. sounds good to me. Went to put the drain plug back in and noticed the threads aren't great so gaunt to find a new plug. As near as I can tell the threads in the case look OK. Tried an "experiment" on the shifters. Didn't want to take them apart to remove the rubber boot to powder coat and didn't want to paint sooooooo, I bought a 4' stick of 3/4" heat shrink and put that over them, shrunk it on and looks pretty decent. Of course it formed to the shaft shoeing most of the tooling marks that were there but that's OK. Should help quell any vibration noises coming up from the trans also. Pretty happy with the way that turned out. Also had a broken bolt in one of the PTO covers so got that out. Powder coated the PTO covers (that I had to make since one was missing and the other bent) as well as the shifter rods for the aux box. Making a little progress.

[Licensed to kill]

10 minutes ago, terry said:

Learn something new every day! Guess i just never heard it called that.    terry

Me too, been learning all sorts of stuff as of late. 

[Vladislav]

The main shaft end play is managed by the main box main shaft rear bearing assembly. There are two cone bearings in a housing and also some special "nut" in there which you turn to tight up the bearings and which is set in its (new) place by a set screw you need to drill new hole for its new location. That procedure can only be done with the main shaft removed from the transmission. It gets off together with the rear bearing assembly and requires the compound box to be off the tranny. When I was doing mine I honestly forgot about that and when both blasted and painted boxes were together with a gasek on a sealer I just cheered myself up with checking up and down end play of the main shaft front end and feeling "Ok in general" rest it as it was.

Haven't understood did the discussion went along the in-between the housings gasket. Maybe it worth to point out its thikness influences the countershaft pre-load/end play. So the figure which exceeds the specs may be result of thicker gasket installed in the past.

[Licensed to kill]

Trans is all cleaned up inside and out and ready for install. The cross shaft for the release bearing had some wear on the "action" side, not a lot but there was some. Couldn't bear to put it back in that way, even though the side play was minimal so I turned that part of the shaft and made an interference fit sleeve to Bring it back to a true 1.25" all the way across. The bushings were still perfect. 

[Licensed to kill]

OK, last instalment then  I will let the thread die peacefully. I installed the trans but had a minor issue. The shifter knobs from the 6spd were 2 different sizes, one 7/16" thread and the other 1/2". Both shifters on this trans are 7/16" so that left me short one knob. Soooooo, even though I really like the little original knobs, I decided to make a couple and thought that the guys here would "get it". This was not my first idea and I will likely make another set so I can swap them out from time to time. The first idea was to use the 9 and 1 and turn the 9 upside down to a six to make it "61" as in B-61. The yellow of there 9 and 1 would go MUCH better with the colour the truck will be but thought 5 and 3 would be rather appropriate in this case.