Finally ... Repairing a traction gearbox.

gerrypro said:
Whoops Shane! I am afraid that you have the synchro drum in back to front.
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GOT IT!!! The gearbox arrived here with the front covers and top covers already dissassembled. I just sat the top cover on and the selector fork is trying to engage the wrong side of the synchro cone. I would have worked that out once the diff was back on and everything together (as the last step in the manual is to engage one of the gears).

you just saved me a couple of hours pulling everything back apart! I hadn't noticed one side of the synchro drum was about 1mm narrower so the selector fork wouldn't fit (now I know its obvious, as the wider side of the drum is shiny in the pictures from the selector fork ).

Is there anything I haven't had to do at least eight times yet ? :clown:
 
Whoops Shane! I am afraid that you have the synchro drum in back to front.
DoubleChevron said:
DEFINITELY BEARING OUTER. The outer is a press fit, the inner slides on/off readily :) If you press from the inner, you would damage the bearing!

Hey Gerry, really .... I'll have to have another look and see how the synchro drum is directional!
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The flange for the selector fork gas to be positioned to the rear, otherwise you will never
be able to fit the gearbox lid. Drawing 26 of the manual! Sorry to be such a pain, but fixing it now will save heart ache later on if you do as I do and fit the box to the car, and then try to fit the lid!
 
"DEFINITELY BEARING OUTER. The outer is a press fit, the inner slides on/off readily. If you press from the inner, you would damage the bearing!"

If that is the case, I would suggest the bearing being fitted to the case prior to the main shaft would be part of the normal assembly sequence.
One could freeze the bearing before fitting to the alloy case.
What holds the bearing & shaft in place in this particular transmission?
Holding that makes the bearing one with the shaft that stops end float that would continually affect 2/3 synchromesh adjustment/s.

Also unless parallax error, the gears don't appear to be meshing centrally, indicative of perhaps a shaft & gear depth shimming issue.
A shimming issue that also affects the synchromesh adjustment/s.
 
Artificer said:
"DEFINITELY BEARING OUTER. The outer is a press fit, the inner slides on/off readily. If you press from the inner, you would damage the bearing!"

If that is the case, I would suggest the bearing being fitted to the case prior to the main shaft would be part of the normal assembly sequence.
One could freeze the bearing before fitting to the alloy case.
What holds the bearing & shaft in place in this particular transmission?
Holding that makes the bearing one with the shaft that stops end float that would continually affect 2/3 synchromesh adjustment/s.

Also unless parallax error, the gears don't appear to be meshing centrally, indicative of perhaps a shaft & gear depth shimming issue.
A shimming issue that also affects the synchromesh adjustment/s.
Click to expand...

Its quite interesting the way this all works. Pre-fititng of the bearing can't be done. To position the shaft into the casing, you need to build the tail half of the shaft outside the box, then install the shaft. Now you can fit the front gear and synchro drum at this time,... then fit the bearings both ends.

I can't see a way of fitting these rear bearing without pressing them. Possibly you could heat the gearbox casing (which would also involve heating the pinion and reverse idler shafts to a high temperature) then trying to fit and build the shaft inside the hot casing without burning yourself ....

This would all be so much simpler if you were the person that pulled the thing apart (rather than partially pulling it apart, and someone else doing the first part)..... and not leaving it in bits for years so you forget everything!
 
Not trying to be critical or smart, but helpful ~ I understand what happens when one doesn't pull transmissions apart then has to put back together with parts missing & parts sometimes added.

In the 1990's, in the US, I ran a large Municipal Fleet & Workshop with 1000 plus vehicles & 80 odd mechanics [53 when I left 18 months later] & that was the type of crap they used to play on their buddies.
Like disappearing parts or putting in extra gears or bearings from something else or mixing parts from 2 transmissions together.
Eventually that & other type specialist work was contracted out & most of these so called mechanics did little more than scheduled PM's & minor repairs.

Have done many transmissions of this era [including road rangers] & most have lots in common.
In cast iron the bearing is position adjusted, is always tight on the shaft & locked up in place with a very highly torqued nut. The bearing now becomes 'one' with the shaft & assembled gears & in many cases it is locked between [contained tightly] between 2 housings like on the crank? end of the shaft in this traction transmission.

These type commonalities usually include having to use a dummy shaft in the cluster gear & only finally fitting this countershaft & cluster in position when the rest of the main-shaft synchro's etc. are fitted & shim adjusted to get in the correct position with correct synchro to cone clearances.
One doesn't want the shaft to be moving @ all under load & unload as that continually alters all the critical adjustments.

I asked "What holds the bearing & shaft in place in this particular transmission?" as that shaft including assembled gears, synchro & sliding sleeve need to be positively held both ends & all the gears in constant engagement with the cluster & reverse idler should be fully engaged with gears they match with & why I also mentioned "the gears don't appear to be meshing centrally, indicative of perhaps a main shaft & gear depth shimming issue."

Any help I can give, is offered.
 
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DoubleChevron said:
Its quite interesting the way this all works. Pre-fititng of the bearing can't be done. To position the shaft into the casing, you need to build the tail half of the shaft outside the box, then install the shaft. Now you can fit the front gear and synchro drum at this time,... then fit the bearings both ends.

I can't see a way of fitting these rear bearing without pressing them. Possibly you could heat the gearbox casing (which would also involve heating the pinion and reverse idler shafts to a high temperature) then trying to fit and build the shaft inside the hot casing without burning yourself ....

This would all be so much simpler if you were the person that pulled the thing apart (rather than partially pulling it apart, and someone else doing the first part)..... and not leaving it in bits for years so you forget everything!
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I usually just tap that rear bearing into place with a drift and ball pein tapping progressively around the perimeter of the race. Does no damage what soever. If yours was very tight maybe it needed a light clean up of the bore of the casing with wet and dry before installation. They usually cause no problem at all.
You are correct the shaft gets installed with the second gear, synchro hub and thrusts and then the third gear once the shaft is part way in. A little jiggling of the synchro and all falls into place. A quick rotation of the third gear and second gear to make sure the hidden key way still engages in the thrust rings and then the forward thrust and front bearing cage fitted with the race completes the installation!
 
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gerrypro said:
I usually just tap that rear bearing into place with a drift and ball pein tapping progressively around the perimeter of the race does no damage what soever. If yours was very tight maybe it needed a light clean up of the bore of the casing with wet and dry before installation. They usually cause no problem at all.
You are correct the shaft gets installed with the second gear, synchro hub and thrusts and then the third gear once the shaft is part way in. A little jiggling of the synchro and all falls into place. A quick rotation of the third gear and second gear to make sure the hidden key way still engages in the shrust rings and then the for ward thrust and front bearing cage fitted with the race completes the installation!
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I put a dab of grease around the hidden key to keep it in position. The bearing isn't super tight, I just didn't want to risk tapping it in without some sort of guide (incase it went in on a slight angle .... I've trashed more than one seal trying to insert it... so didn't want to ovalise or damage the case doing the same thing).

Artificer, I wasn't offended at all by your suggestions. Its plainly obvious within 1 sentence you know way more about this stuff than I ever will. This is just a hobby for me .... I often break stuff and get it wrong. But that's half the fun in trying. Your suggestion of freezing the bearing is probably how the factory did it if they considered it necessary. My understanding of what retains it all after having it apart ... is the front bearings. They are within a very tight captive nut and become "one" with the case when the front plates are bolted down. The rear bearings don't appear to locate the shaft or prevent any in/out movement. the pinion depth is set by shims behind the front bearing retainer for example.

The gearbox is actually really simple compared to anything made later ..... I just make it seem hard and complex :ROFLMAO:

thanks again ( everyone as always :) ).

seeya
Shane L.
 
Artificer said:
These type commonalities usually include having to use a dummy shaft in the cluster gear & only finally fitting this countershaft & cluster in position when the rest of the main-shaft synchro's etc. are fitted & shim adjusted to get in the correct position with correct synchro to cone clearances.
One doesn't want the shaft to be moving @ all under load & unload as that continually alters all the critical adjustments.

I asked "What holds the bearing & shaft in place in this particular transmission?" as that shaft including assembled gears, synchro & sliding sleeve need to be positively held both ends & all the gears in constant engagement with the cluster & reverse idler should be fully engaged with gears they match with & why I also mentioned "the gears don't appear to be meshing centrally, indicative of perhaps a main shaft & gear depth shimming issue."

Any help I can give, is offered.
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The forward double row bearing is a thrust/journal bearing 3305. It locates the shaft in the fore/aft plane and is held by a flanged cage that fits into the bore of the casing behind the front bearing cap. The rear bearings are merely journal races and fit as a slide fit on the shaft. They are retained by two circlips that fit in a groove on the shaft, one behind and one in front of the two bearings. The bearings are spaced from each other by a circular metal ring that fits onto the shaft.
The gears are different widths from their meshing pair on the lower shaft and consequently there is a fair tolerance for the meshing in the fore/aft plane. This is not critical to a quiet running gear train.
 
Well Gerry is going to laugh at me .... I just whipped the top shaft back out to reverse the synchro cone .....I checked the key was still engaged under the synchro cone ..... and happened to notice it was the 4 oilway shim I had there ... not the two ... (which is exactly what Gerry suggested above..... How on earth can he know this stuff without pulling it down and checking?). Anyway, So I pulled everything back off the shaft and swapped the washer/shims over ..... Then 2nd gear was perfect..... no wobble ... no binding ... absolute perfection .... The manual say 0.1mm is what we want though .... so pull back aparts, change the celeron washer for one that is 0.1mm thinner .... there is a little gear wobble there now ... its probably about right.

So I'm fittng the key back under the synchro hub .... and looking for the slot in the washer at the back of 2nd gear to key it into ....... and notice there is oilways showing in the washer ........... For crying out bloody loud, its in backwards. So I dissassemble 2nd gear assmebly again reverse the washer and re-assembled. Would you believe it .... Now there is to much slop in the gear (about 0.25mm) ..... ARRRRhhhh So i dissassemble 2nd gear again .... and put the celeron washer back in there that was there before.

I reckon by the time this thing is back in the car, I'll be able to strip and refit all the shafts in my sleep ....... blind folded.

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back to where I was a week or so back .... It sure does feel nice and smooth to roll over.

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THIS TIME .... we check. Yes, the lid fit on .... The selectors in the lid doesn't seem to move. I'm going to have to look at the car and see how the linkages work so I can engage and check 3rd.
 
hawk said:
the clutch lock mechanism may be the reason.
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Clutch lock mechanism ..... I wish I'd pulled this thing apart so this wasn't sounding like chinese :) ..... I can't touch the clutch to see how that works or it will fall to the bottom of the bell housing .... More fun for sure :)
 
Clutch lock mechanism is a rod that goes down between the selector forks of the gearbox lid. You will see a T piece between the selector shafts at the rear of the gearbox lid. This must be pulled outwards to release the rods so that they will slide and change the gears. It is controlled by a fork shaped device on the top of the Thrust race casting. This is why I put the gearbox lid on to the box once the box is installed in the car. It is also a quick way to add Your Nulon G70 and you 80W90 gearoil. Just pour it in all over the gears and then fit the lid!
You are right DO NOT TOUCH THE CLUTCH IT SELF IN ANY WAY until the gearbox is in the car.
BTW what about the speedo drive? It is not in the box in the above picture. It can be fun fitting it at this stage! Good luck! I would fit it while the lid is off! It is easier to see what you are doing!
Well done by the way!
 
Hmmm.... the speedo drive looked simple to add later so I didn't fit it ... Oh well, everything else has been "fun" !
 
I've started that .... I fitted it up and tighten the bearing down so there wasn't any movement ..... and found the pinion depth looked completelly wrong ...... Just as I thought "bugger it .... I'll throw it under the bench and look in another 4.5 years" ... I noticed the bearing caps had a gap under them. It was sitting up on the pinion gear :clown: .... I loosened one side and tighten the other so the bearing housings were sitting flush there was some crown and pinion lash ....... And when I checked without any adjustment ... it was exactly 0.2mm lash. I figured that was to easy and I'd double check its alll setup right later (Surely it can't be right first time without messing around). I'm supposed to have to pull everything back to bits a dozen times!
 
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.2mm is very good ( .19---.22mm tolerance )Once that is correct the preload on the tapered rollers needs to be set. Lock the bearings up so that they are stiff to turn by hand ( turning the crown wheel ---no gears engaged ) then back each adjusting ring off by one to two slots (sight it by using the split pin hole ) so that each ring aligns for the split pin. Then lock up the tension on the diff carrier nuts using loctite again --- no tab washers. Recheck the crown wheel back lash. Hopefully it is unchanged.
Are you going to use Speedie Sleeves on the output flanges?
Seal the nuts and thrust ring of the output flanges with Silastic or equivalent ( oil can leak from here ). Then tighten the castellated nut and fit split pins!
 
Thanks, I was going to re-use the tabbed washers. I will remove them and use loctite as suggested. Its not as simple to measure the crownwheel lash as you would imagine. I was measuring barely 0.05 lash ... but it felt to be a lot more. When I watched the dial indictor its tip can move sideways and down the gear ever so slightly (when your measuring 0.2mm you can't have any sideways movement at all!). If I stuck my nail beside the pointer on the crown wheel to stop any sideways measurement it was about 0.2.

yes, I'll see if I can chase up some speedie sleaves for it! The local bearing place will have them.

seeya,
Shane L.
 
The dial indicator must be set perpendicular to the surface of the crown wheel tooth being measured. Measurements should be taken at four points around the circumference approx 90 degrees apart.
I saw a very good quality Dial indicator and movable arm mounting block yesterday at the 'Pombo Mart' situated just to the east of here on the Princes Highway in the little Town/Settlement of Pomborneit. It would have been ideal for you. Couldn't tell however but it was probably in Imperial measurement. I didn't buy it because I have always made do by using Dad's old measuring mount and a set of feelers and I probably will not do any more TA gearboxes.
 
gerrypro said:
The dial indicator must be set perpendicular to the surface of the crown wheel tooth being measured. Measurements should be taken at four points around the circumference approx 90 degrees apart.
I saw a very good quality Dial indicator and movable arm mounting block yesterday at the 'Pombo Mart' situated just to the east of here on the Princes Highway in the little Town/Settlement of Pomborneit. It would have been ideal for you. Couldn't tell however but it was probably in Imperial measurement. I didn't buy it because I have always made do by using Dad's old measuring mount and a set of feelers and I probably will not do any more TA gearboxes.
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I'm betting you'd find a lot of uses for a dial indictor if you found a nice one :) ...... The issues is the type of tooth on the crown and pinion. its not a flat surface you are measurings, the teeth curve down and away along the surface you are measuring!
 
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