Toploader trouble

[crazydane]

Hi.

I´m a danish guy totally addicted to American Iron from the 40´s and up.



I have recently overhauled my toploader transmission (big in/output, originally from 1968 torino sj or scj, according to the decoding), new bearings, seals, a fresh paintjob too.

Everything has been checked, cleaned, and put back in the correct order, according to the manual with exploded wiew and the numerous pictures i took while doing it so there is no doubt that everything is correct and in great shape.

When i had assembled everything, (and prelubed everything before doing so, naturally) i checked that it worked, shifted and spinned as it should and it did, to my great satisfaction)

BUT when i tightened the tail housing bolts on to the casing, it started to offer some resistance?? the top axle does not turn as freely as it did without the tail housing, when i loosen the bolts on the tailhousing again it goes back to turning loose ??

It seems like i´t is stuck in the sync rings, they seem to "wedge in", making the turning of the transmission difficult (but in no means impossible).

I tried to put one more gasket on the tailhousing surface and that very thin spacing solved the problem, but that fix seams to be a little too easy in my eyes!!

Is this a question of the sync rings are in need of a good burnout to break in or am i up a certain creek without a certain instrument????

Any ideas would be very appriciated here..................................

Thomas.

[Jac Mac]

Have you replaced the large bearings on the input & output shafts. If so were the new bearings the same width as the old ones ( some bearing manufacturers make wider bearings with the same shaft & outside diameters).
Also check that the detents on the 3-4 syncro hub are in the matching slots of the synchro rings for 3rd/4th ...... the syncro rings should turn with the 3-4 selector hub.... if they are not in the slots they will force the ring up on the cone when you tighten the tail housing.

Jac Mac

[crazydane]

Originally Posted by Jac Mac

Have you replaced the large bearings on the input & output shafts. If so were the new bearings the same width as the old ones ( some bearing manufacturers make wider bearings with the same shaft & outside diameters).
Also check that the detents on the 3-4 syncro hub are in the matching slots of the synchro rings for 3rd/4th ...... the syncro rings should turn with the 3-4 selector hub.... if they are not in the slots they will force the ring up on the cone when you tighten the tail housing.

Jac Mac

Yes, i have replaced everything incl. the main bearings,i must admitt that i did not measure the bearings, since they, by the look of an eye seemed the same, not the same brand, but the same type, grooves etc. the detents for the syncro hub are checked and in place, the function of the transmission have been checked using a powerdrill to make it turn and everything shifts, turns troubleless untill i tighten the tailhousing bolts.

I´ts a matter of a 100" of an inch.

[Anthony]

if I remember correctly, the detents for the 1st-2nd synchro's are a different size (length) than the detents for the 3rd-4th synchros, and they cannot be interchanged

[Jac Mac]

Another possibility would be a roller from the front of the mainshaft where it spigots into the input shaft that may have slipped out of position into the recess of the input shaft during assy.
Also check that the hex screws which locate the selector forks on the shafts are actually in the correct positions- one in particular sits quite deep in the fork when correctly fitted.

Jac Mac

[crazydane]

Originally Posted by Jac Mac

Another possibility would be a roller from the front of the mainshaft where it spigots into the input shaft that may have slipped out of position into the recess of the input shaft during assy.
Also check that the hex screws which locate the selector forks on the shafts are actually in the correct positions- one in particular sits quite deep in the fork when correctly fitted.

Jac Mac

The roller is not a possibillity, but i thank you for your kind and very constructive answer.

BUT the detents are (damn) how does one determine wich detent goes where??

Does anyone have an exploded wiew??

would the gearchange mechanism function with the F¤¤¤kers swapped??

[Excaliber]

The synch rings will NOT require 'bedding in' or 'burning in' as you call it. There should be plenty of clearance even with totally new parts for them to be 'free' with slight movement back and forth even.

If the synchro brass RINGS are binding upon final assembly I would have to conclude they are not installed correctly, they are being 'crushed' when the tail shaft is installed. This could be due to the incorrect use of the detents in the synchro hub(s), as noted above. I know of no way to determine which detents fit which hub, if one set is longer than the other then you have your partial answer. The question then becomes, do the longer detents go in the front or the rear hub?

One thing for sure:
The detents (actually called synchronizer keys) ARE different for the two hubs in question. I would guess it DOES make a difference, especially if their 'mixed' in that you have two rears in the front, one front in the rear hub, etc.

Also bear in mind the synchro HUBS are a 'matched set'. What this means is the inner hub splines fit into the outer hub splines in a such a way that the two parts move very smoothly within each other. While the inner hub will 'slip into place' within the outer hub at any position there is only ONE position that 'feels' smoother and fits better than any other position. While this will NOT impact your binding problem it WILL impact how smoothly the trans shifts under load. Once you have lost the correct relationship between the inner and outer hub it almost impossible to determine it's optimum position again. They should be marked before tear down. You can get pretty close by using a magnifying glass and looking for the 'marks' left on the 'spline' of the outter hub by the synchro keys. That gives you a one out of three chance of correct installation. Put the inner hub in and slide it back and forth. Hangs up just a little? Try the next position, keep doing that until it slides as freely as possible.

[crazydane]

Originally Posted by Excaliber

The synch rings will NOT require 'bedding in' or 'burning in' as you call it. There should be plenty of clearance even with totally new parts for them to be 'free' with slight movement back and forth even.

If the synchro brass RINGS are binding upon final assembly I would have to conclude they are not installed correctly, they are being 'crushed' when the tail shaft is installed. This could be due to the incorrect use of the detents in the synchro hub(s), as noted above. I know of no way to determine which detents fit which hub, if one set is longer than the other then you have your partial answer. The question then becomes, do the longer detents go in the front or the rear hub?

One thing for sure:
The detents (actually called synchronizer keys) ARE different for the two hubs in question. I would guess it DOES make a difference, especially if their 'mixed' in that you have two rears in the front, one front in the rear hub, etc.

Also bear in mind the synchro HUBS are a 'matched set'. What this means is the inner hub splines fit into the outer hub splines in a such a way that the two parts move very smoothly within each other. While the inner hub will 'slip into place' within the outer hub at any position there is only ONE position that 'feels' smoother and fits better than any other position. While this will NOT impact your binding problem it WILL impact how smoothly the trans shifts under load. Once you have lost the correct relationship between the inner and outer hub it almost impossible to determine it's optimum position again. They should be marked before tear down. You can get pretty close by using a magnifying glass and looking for the 'marks' left on the 'spline' of the outter hub by the synchro keys. That gives you a one out of three chance of correct installation. Put the inner hub in and slide it back and forth. Hangs up just a little? Try the next position, keep doing that until it slides as freely as possible.

Oh yes, i´m very aware of the tiny, allmost invisible marks on the hubs, and i HAVE found them with a magnifying glass and they are correct installed, they looked almost like a very small welding electrode had hit the metal.

I believe that it´s time to tear down the tranny and check if the trick is to swap the detents, wich sound rather logical in my ears.

I shall spare you for the unholy language.

[Excaliber]

Don't forget to make SURE you have the reverse gear detent spring and shaft thingy (not a ball bearing if I recall, but more like a 'pin') in the correct position while your in there. Goes in the from the side and it's EASY for it to fall out of place and drop to the bottom of the trans during final assembly. Without it the shift forks will hang up between 1st and Reverse, not all the time, but it WILL happen sooner or later.

[crazydane]

Originally Posted by Excaliber

Don't forget to make SURE you have the reverse gear detent spring and shaft thingy (not a ball bearing if I recall, but more like a 'pin') in the correct position while your in there. Goes in the from the side and it's EASY for it to fall out of place and drop to the bottom of the trans during final assembly. Without it the shift forks will hang up between 1st and Reverse, not all the time, but it WILL happen sooner or later.

Yessir, it´s all in place, not easy but if you fill the holes with greas, attaches a small tube to the vaccum cleaner, let the plug "suck on" to the tube, you can rather easy put all these pins in place!!

[trularin]

It sounds like either one of the support bearings is not on all the way or there is something in the way allowing the shaft to settle.

I know this sounds like a pain, but you may want to disassemble the transmission and reassemble it...slowly.

[Excaliber]

Sounds like you've done a good job crazydane and paid attention to most of the details. I'm betting the synchro keys are the problem. Long ones where the short ones are supposed to be, thus pushing the brass synchro ring to tightly against the gear it supposed to mesh with.

DO let us know what you find out!

Vacuum cleaner? Well theres a new one on me, I used a magnet. I also used Vaseline to hold those various nasty little roller bearings in place, but it would melt and the bearings would fall out. So I put some parts in the freezer to cool them down and 'worked fast'. Next time I'll get some of that 'trans assembly lube' I've heard about, maybe it's got a higher melting point?

I recently finished an Austin Healey trans and overdrive unit and the book (an old 1962 edition) actually recommended automotive GREASE for assembly, an idea which I quickly rejected. Concern being the grease won't mix well, or at all, with the trans oil. In comparison to a top loader that Healey trans was a nightmare, they must have used children with really small hands to install the dang counter shaft gear. Impossible I tell you!

[Anthony]

part numbers 52 and 43 are not interchangeable.

[crazydane]

Well, i took off the lid yesterday evening, and i can see no other reaon for the trouble then the detents being swapped.

It has not yet been run, so there is no damage,( ekcept on my pride perhaps, DAMN) as luck has it, so nothing else to do but to tear it apart and swap the detents. But again, i have been down that road once before, so it´s no big deal, a cup of coffee, a few cokes, some music, the toolbox and peace and quiet and it will all be solved easily tomorrow.

AND the guy who advised me to break it in, a danish Mustang "expert" will be told to F¤¤¤K off if he shows up.

I thank you all for your very constructive replys, it has been a great experience that makes the wish of visiting your great country even stronger.

But i do admitt that the box is going in a 1964 galaxie fastback,0,30 390, tripower, cast iron hedders , 3"" narrowed 9"" rearaxle with an extra leaf in the springs and underriders., detroit locker, twin 3"" exhaust, Hooker mufflers and Home ported heads with stainless 2.06, 1,65 valve car wich came from Moreno Valley CA december 2006 as a wreck, rust free, but VERY tired.

Thankyou

Thomas Larsen.

[crazydane]

As suggested earlier the detents for the 1-2 and 3-4 had been swapped around.

It was no big deal to fix and the transmission is running smmoth with no noise whatsoever, turns freely and is back in the car.

Thanks for the help.

[Anthony]

Originally Posted by crazydane

As suggested earlier the detents for the 1-2 and 3-4 had been swapped around.

Thanks for the help.

Do I get a prize ?

[Excaliber]

A happy ending! Thanks a LOT for sharing the good,
the bad and the ugly with us. It helps us all to learn.

'64 Galaxie! GOOD call, I like it!

[crazydane]

Originally Posted by Excaliber

A happy ending! Thanks a LOT for sharing the good,
the bad and the ugly with us. It helps us all to learn.

'64 Galaxie! GOOD call, I like it!

Yes, me too, stripped to the bare metal and painted satin black with Bubble scoop.

If i may add, the problem with installing the detent plugs that controlls the shifting rails can easily be fixed by rollong a coil around a schrewdriver with some ( i dont know what the exact word for it is in English, but it´s the wire you use for MIG welding.) thread, installing the plugs in the coil, bending the wire and placing the plugs where they belong, pushing the plug down through the hole with a shrewdriver, and pulling the wire off the plug while holding it down.

Took me 10 minutes to install the plugs with no hassle.

[Jac Mac]

While we are coming up with handy tricks on Top Loader assy, two piece's of alloy round bar with a hole drilled at right angle thru them that the shifter rail detents/interlocks will slide thru also make this part of re-assembly a breeze. Simply fit in the appropriate position in the shifter rail passages of the trans case and fit the detent/remove -fit shifter rail-fit next detent etc etc.
Glad we were able to be of help & Anthony I guess you get the Chocolate Fish!

Jac Mac

[crazydane]

If Mr. Anthony would care to PM me his adress, i´ll be sure to send him the well deserved prize in the shape of some very exclusive Danish Beer.

For after all, i could have used several evenings staring down the top of the tranny before the bell rang, I´m sure that i at some point would have had the "AHAAAAAAAAAAA" experience since i never give up, but keeps on untill it works, but i do admitt that those small bastards were the last ones i suspected.