Is it time for a new automatic gearbox ?

[firstv70volvo]

Phuuu !!!
Busy day.... got the old gearbox out and of course it took longer then expected.
This was the first time for me so there is time for improvements ( the left axel was a pain in the as to remove.)

20211023_204143_2.jpg

Tomorrow I will open the R box and change the diff. So now I need a little help.
Should I replace both 1 and 2 from this image or is 1 enough?,
Capture.JPG

Both gears (1 and 2) must be swapped if the final drive ratio is different between the two transmission. I don't know for sure if you can do this but it may also be possible to unbolt (12 bolts) the larger ring gear from your existing transmission differential and just swap the big gear to the R differential carrier so that the preload is maintained. This assumes the AWD differentials are the same.

In either case of swapping just the big gear or the entire differential the small pinion gear must be swapped too. To remove the large nut for the pinon gear I'm thinking you can engage park which will lock the shaft so you can remove the nut but I haven't done this myself so Vtl can provide better input on this.

It would be a good idea to replace the filter and O-ring around the oil pump while you have it apart.

You'll need to remove the oil pump and with this you'll have the 2nd gear and 2nd coast clutch packs on the back side to reassemble. It's best to get the inner hubs for these 2 clutch packs engaged in all the frictions before putting the oil pump assembly back in the case. To keep the inner hubs from sliding out you stand the transmission vertically like the way it sits in the car and insert the oil pump/2nd clutches in this way. The video shows how this done.

[cuhfs]

This is an important part of the strategy when when breaking up the filter after drilling thru the case : an external Magnefine insert a Magnetic Inline Transmission filter (in addition to regular drain and fills.) I've put one in on a few C70s even if the car had no problems... just to play it safe.

[greffel]

Little bit confused..
Should I try to enable Park to lock this assembly and then remove the nut (Nr1) and just replace the upper cog(Nr2).
Or should I remove the hole assembly and just change it to my old one ?

By the way, what kind of grease is safe to use inside the box to hold things in place and lubricate o-rings?
Is silicone grease the way to go ?

[firstv70volvo]

Little bit confused..
Should I try to enable Park to lock this assembly and then remove the nut (Nr1) and just replace the upper cog(Nr2).
Or should I remove the hole assembly and just change it to my old one ?
Capture3.JPG
By the way, what kind of grease is safe to use inside the box to hold things in place and lubricate o-rings?
Is silicone grease the way to go ?

You could replace the entire 4-5 planet and driven gear assembly but if it were me I would just replace the pinion gear (in addition to the diff ring gear) on this assembly for the following reasons. The large driven gear (see photo) in the 4-5 planet assembly is matched to the large transfer drive gear, you should see some notches on the gear teeth and the number of notches need to match between the two gears. Also, because you have 3-4 shifting problems with your current transmission you don't want to use your original 4-5 clutch drum and I don't know how mixing the R transmission 4-5 drum with the 4-5 assembly from your current car is going to work out. There's also the two sealing rings in the assembly that seal the fluid path to the 4-5 clutch that could be a part of the problem with current transmission.
Vtl's input would be good here too, I don't know exactly what he did.

About the grease to use, use only a transmission specific grease for assembly. I like the Lubegard green assemblee goo because it's thick and tacky, good for holding the parts together during assembly.
https://www.amazon.com/Lubegard-19250-T ... B000B8YDUO

Here's all what's part of the 4-5 planet and driven gear assembly
[attachment=0]4-5 planet driven gear assembly.jpg[/attachment

[greffel]

Putting everything together right now, so if I miss understood something please stop me now

Using this entire assembly from the R box and using a press I just changed this cog. (There where 3 more teeth on the R box.)
Then I used the complete Diff from my original box and checked the preload, got a little bit lucky and no shims where needed.

Correct ?

[firstv70volvo]

Putting everything together right now, so if I miss understood something please stop me now

Using this entire assembly from the R box and using a press I just changed this cog. (There where 3 more teeth on the R box.)
Then I used the complete Diff from my original box and checked the preload, got a little bit lucky and no shims where needed.

Correct ?
Capture5.JPG

What you've done sounds correct to me.

You've swapped out the smaller pinion gear in the R transmission with the pinion gear from your original transmission and you've swapped out the R differential with the differential from your original transmission. You've checked the preload in the R transmission with differential from your original transmission now in the R trans and it checks out okay. Did you check the preload of the differential with the 4-5 planet assembly pulled out or with pinion remove so you were just looking at the preload of the diiff spinning the case bolted together?

Couple of questions; what's the teeth counts of the R transmission ring and pinion gears and what are the teeth counts of your original transmission ring gear and pinion gears?
With the pinion and differential from your original transmission now in the R transmission case does everything appear to rotate smoothly and with no apparent backlash play or binding?

There's one other clearance check before putting the case halves back together that should be done because you've swapped out the pinion gear. It a check for end play clearance of the shaft with the pinion gear. with the shaft in place and with thrust bearing on the outside end of the shaft, you take a flat edge and with the flat edge against the case mating surface and with the edge extending over the thrust bearings there should be some clearance and I need find what the end play clearance specs are so I'll look for these specs now and post them soon.

[firstv70volvo]

Putting everything together right now, so if I miss understood something please stop me now

Using this entire assembly from the R box and using a press I just changed this cog. (There where 3 more teeth on the R box.)
Then I used the complete Diff from my original box and checked the preload, got a little bit lucky and no shims where needed.

Correct ?
Capture5.JPG

What you've done sounds correct to me.

You've swapped out the smaller pinion gear in the R transmission with the pinion gear from your original transmission and you've swapped out the R differential with the differential from your original transmission. You've checked the preload in the R transmission with differential from your original transmission now in the R trans and it checks out okay. Did you check the preload of the differential with the 4-5 planet assembly pulled out or with pinion remove so you were just looking at the preload of the diiff spinning the case bolted together?

Couple of questions; what's the teeth counts of the R transmission ring and pinion gears and what are the teeth counts of your original transmission ring gear and pinion gears?
With the pinion and differential from your original transmission now in the R transmission case does everything appear to rotate smoothly and with no apparent backlash play or binding?

There's one other clearance check before putting the case halves back together that should be done because you've swapped out the pinion gear. It a check for end play clearance of the shaft with the pinion gear. with the shaft in place and with thrust bearing on the outside end of the shaft, you take a flat edge and with the flat edge against the case mating surface and with the edge extending over the thrust bearings there should be some clearance and I need find what the end play clearance specs are so I'll look for these specs now and post them soon.

Here's the spec clearance between the thrust bearing and edge of the case using a straight edge. Disregard my previous post about placing the straight edge on the case, the straight is placed against the thrust bearing. This measurement should be fine but it's good to check just to make sure everything was assembled and in place correctly.

1.269mm - 1.645mm
or
0.050 in - 0.065 in

Place the straight edge flat against the thrust bearing (end roller bearing removed) and extend the straight edge over the straight edge over the case edge and then measure the clearance between the straight edge and case edge. This measurement method and spec is from the ATSG manual.

[greffel]

Best time is when father and son have some time in the garage. Couple of highlights from this weekend.

[firstv70volvo]

Best time is when father and son have some time in the garage. Couple of highlights from this weekend.

...

You're making a lot of progress and it's good there's two of you working on this project, it's a lot of work. Also good that you had a puller and press to deal with the pinion gear.

[greffel]

Here are the measurements measuring with a ruler across the case: 1.3 mm
The number of teeth difference
R=23
My = 26

Diff
R=61
My=58 ( little bit hard to count with everything back together)