Is it time for a new automatic gearbox ?

[firstv70volvo]

Hello again.
First of the "new" gearbox is still working just fine, as an extra bonus the transmission swap also cured my problem with long crank times. Sometimes the car would take extra long time to start.
But that problem seems to be gone also

I'm now thinking of do a "light" rebuild of the old transmission and sell .


...

Glad the hear the "new" gearbox is still working well, all your hard work paid off.

Not sure fixing your old transmission could be done with a light rebuild. From the photos there looks to be some hard-parts damage like the 4-5 clutch inner hub with what looks like damage from the friction plates inner teeth. If the teeth indentations aren't too deep in the hub you may be able to file down the damaged area some so new friction plates can slide freely as the clutch is applied or released. With the damage it looks like the friction plates teeth could get hung up on the inner hub damaged area, they do need to be able to slide back and forth on the hub some. I think this hub piece will need to be replaced.
It also looks like the 4-5 frictions plates were worn so badly there's metal pieces (all friction material worn away and enough metal worn away to turn the rings into pieces) from the friction plates floating around in the clutch and elsewhere.
At minimum you'll you have to replace the frictions and steels due to the heat damage and this assumes you can salvage the inner hub or replace it and confirm there's no damage elsewhere in the transmission. You should inspect all the other clutches, bearings, bushings, gears for any wear or damage and then decide what to do. It might be best just to sell the transmission for parts only or if you do a light rebuild disclose the history of the transmission and what's been done to remedy the problem.
You know how much work it is to remove and install the transmission so in my mind it would be best to do a complete rebuild of the old transmission if sold to someone else that would also have to do all the removal/installation work or just sell it as-is for rebuilding or for parts only. I think you mentioned the valve body in the transmission is relatively new, which is a plus, that's a valuable part by itself.
I'm surprised this transmission shifted from 3-4 at all based on how badly those frictions plates are worn, there's not much left of them at all.

[vtl]

Heat mark is never a good sign I guess ....

I've been told some parts are treated with nitrogen for stronger surface and, thus, come blue/blackened from the factory. The bluish spot here, in fact, is the only spot that was has seen less thermal stress.

[greffel]

When I examined the bushings with my finger I found this ??
Som kind of thread ?

I would be fun to rebuild the hole gearbox. But I my self would never pay/buy a rebuilt gearbox from som random person, so I think the investment i parts is useless. If only friction and steel plates where needed then I would sell it cheap.

So the flare I have had for a long time must have happened like this.
1. The friction plates started slipping
2. Then the steel plates made the teeth marks
3. The assembly could no longer move freely and the engagement where more and more delayed. 3-4 Flare
4. gearbox R.I.P

[firstv70volvo]

When I examined the bushings with my finger I found this ??
Som kind of thread ?
20211121_140328.jpg

I would be fun to rebuild the hole gearbox. But I my self would never pay/buy a rebuilt gearbox from som random person, so I think the investment i parts is useless. If only friction and steel plates where needed then I would sell it cheap.

So the flare I have had for a long time must have happened like this.
1. The friction plates started slipping
2. Then the steel plates made the teeth marks
3. The assembly could no longer move freely and the engagement where more and more delayed. 3-4 Flare
4. gearbox R.I.P

The thread is an interesting find, not sure where that came from.

I don't know what the rest of the transmission looks like but the 4-5 inner hub/planetary is definitely damaged and the metal pieces from the worn out frictions can't be good for other parts of the transmission.