Transfer Case Seal Replacement (1 Viewer)

[rstoddard]

Can the TC be removed without pulling the tranny? I have the engine dropped about 1-1/2 inches and the rear e-brake drum is clear of the crossmember and off. The engine is supported at the BH and the tranny is supported. I read that reinstallation could be difficult as a single unit and I'm concerned about damaging the clutch and rear seal reinstalling without being able to get any assist from above, so I just wondering if unbolting the AA Adapter from the tranny and pulling the TC off is a viable option at this point or not. I'm just not sure if I can pull it out far enough to separate from the tranny output shaft of he tranny at this point and clear the crossmember..

Does anyone have experience with this or any advice?

 

[rstoddard]

Keep in mind that if the flange moves up and down when you push on the driveshaft, the new seal is not going to last.
Also consider the possibility that the yoke of the flange may be scored and you may also need a replacement flange.

Mark, I'm assuming this applies primarily to the front TC driveline flange. I understand that the flange may need to be replaced if it is worn/scored, but are you just throwing the flange movement issue on re-install out as a caution, or is this a common mistake/problem for which there is a proscribed solution? Your comment suggests that anytime you might replace a driveshaft, i.e., change a U-Joint, there is an opportunity to ruin your seal if there is flange movement. Are you recommending blocking the flange from the top to prevent movement as a preventative measure?

Thanks for the clarification.

 

[peesalot]

The front flange movement he refers to is due to bearing wear and when that occurs it causes the leak, hence a seal wont fix it if the bearings are worn and when that happens it can wear bad grooves/patterns on the seal surfaces necesitating replacement yoke, if yoke is good reuse it. You can rebuild it. The adapter you have has a spud shaft in it which may let you unbolt tcase from adapter and move tcase back far enough to drop the adapter and spud, it may be enough to just drop tcase off back of adapter, open the cover on back of tcase and see if the spud/input has the gear bolted on or does it go all the way thru and maintain the rear bearing. If it is bolted on, remove gear and you can remove tcase, looks like you have room for that.

 

[65swb45]

Ron

The same prudence that cautions you to overhaul the transfer case should be advising you to pull the transmission out as well, even if you pull them separately. The imput seal on the trans is too often overlooked, and will bite you in the a** when it leaks out into your clutch and you say ‘I could have prevented this.’

Happy to evaluate the flange/bearing/etc in real time when you drop it off.

 

[rstoddard]

The front flange movement he refers to is due to bearing wear and when that occurs it causes the leak, hence a seal wont fix it if the bearings are worn and when that happens it can wear bad grooves/patterns on the seal surfaces necesitating replacement yoke, if yoke is good reuse it. You can rebuild it. The adapter you have has a spud shaft in it which may let you unbolt tcase from adapter and move tcase back far enough to drop the adapter and spud, it may be enough to just drop tcase off back of adapter, open the cover on back of tcase and see if the spud/input has the gear bolted on or does it go all the way thru and maintain the rear bearing. If it is bolted on, remove gear and you can remove tcase, looks like you have room for that.

Good feedback. Maybe you could help understand what is the right approach to this:
I spoke to AA twice and was told 1st to take the take the cover off and remove the nut holding the input spline shaft (is that what you are referring to as the “spud shaft”) and then unbolt the adapter from the tranny. The second time I spoke to them, another guy said just unbolt the adapter from the Tranny and pull it back off the tyranny main shaft about 2-1/2” and pull the TC and Adapter off the Tranny.

The second approach sounded like the best approach to me. If I understand your comments correctly, you seem to be suggesting I unbolt the input shaft and pulling it out from the Adapter, which I guess would also free the TC from the Tranny and Adapter.

The point is, I believe the tranny main shaft goes into the adapter about 2-1/2” and the Input shaft comes in from the TC through a bearing into the adapter probably 2” or 2–1/2” so it’s either sliding the adapter off the tranny main shaft of pulling the input shaft.

Which do you think is going to be easier?

 

[peesalot]

Exactly, It is close to as wether you have room to leave the adapter & spud shaft attached to tcase and remove , if you find that you dont have the room then you could always get the input gear off and separate the adapter and tcase, if there is room to leave them married then great. And if you go see Mark tell him Hello from Peesalot, if he gets cranky just burp him.

 

[rstoddard]

Unbolting the Adapter from the Tranny turned out to be a little harder than it appeared. It was just hard to get at the bolts. For at least half the bolts, I had to take them off with an open ended wrench a quarter turn at a time. In retrospect it would have been easier to take the Input (Spud) gear out and take the TC off the Adapter.

In any case, I got the TC off. It was tight, and took a little shifting around to clear the Adapter from the output gear and clear the input heat of the x-member, I was able to get it down without much trouble and no damage to any component.

I think I’ll reinstall by putting the Adapter on the Tranny first, and bolt the TC on and add the Spud Gear and torque it down.

 

[rstoddard]

Ron

The same prudence that cautions you to overhaul the transfer case should be advising you to pull the transmission out as well, even if you pull them separately. The imput seal on the trans is too often overlooked, and will bite you in the a** when it leaks out into your clutch and you say ‘I could have prevented this.’

Happy to evaluate the flange/bearing/etc in real time when you drop it off.

Mark, I conceded and pulled the SM420. Could I ask a few stupid questions?

1) I dropped the tranny taking it out. It probably fell 8-10 inches and his the ground on the side of the case pretty hard. I realize it’s a pretty tough case, but is there any chance any of the internals could have been damaged?

2) the bolts holding the bearing retainer weren’t particularly snug. I also found that three of the bolts had Internal tooth washers and one had a spring lock washer. Very odd. Should they all have a spring lock washer? What is the right lock washer for that retainer?

3) I noticed some horizonal movement outward in clutch gear and bearing. Perhaps as much as 1/2". Of course, that is without the bearing retainer mounted (whose job, obviously, is to hold the bearing in place). Just want to be sure that is normal and is resolved when the retainer is bolted back up. I'm just surprised that there is that much play just pulling on the clutch gear.

4) Is it best to replace the Bearing Retainer GASKET as well as the lip seal? If so, do you put the gasket on dry, or use a sealant? If a sealant, what kind?

5) Is there risk of damage to the bearing when I’m reinstalling the retainer? I’m just wondering if that is why the retainer was on so weakly. Is there a way to check to make sure that I’m not going to stress the bearing?

 

[65swb45]

Mark, I conceded and pulled the SM420. Could I ask a few stupid questions?

1) I dropped the tranny taking it out. It probably fell 8-10 inches and his the ground on the side of the case pretty hard. I realize it’s a pretty tough case, but is there any chance any of the internals could have been damaged?

The housings are pretty stout. I would only worry if one of the shafts was impacted. Just spin the input and output while watching the other. If there is no wobble, should all be good.

2) the bolts holding the bearing retainer weren’t particularly snug. I also found that three of the bolts had Internal tooth washers and one had a spring lock washer. Very odd. Should they all have a spring lock washer? What is the right lock washer for that retainer?

I have seen both over the years. My preference is for the split washer.

3) I noticed some horizonal movement outward in clutch gear and bearing. Perhaps as much as 1/2". Of course, that is without the bearing retainer mounted (whose job, obviously, is to hold the bearing in place). Just want to be sure that is normal and is resolved when the retainer is bolted back up. I'm just surprised that there is that much play just pulling on the clutch gear.
Not understanding exactly what is moving. If the bearing is showing signs of internal freeplay, it obviously needs changing. If the bearing is sloppy on the fork, that is a second issue. If there is freeplay between the static ‘parked’ position and the pressure plate, that is a third issue.
4) Is it best to replace the Bearing Retainer GASKET as well as the lip seal? If so, do you put the gasket on dry, or use a sealant? If a sealant, what kind?
I replace the gasket if it needs it. If it comes off intact and can be wiped clean and reused (since you don have a kit for it) I would glue it. FIPG is fine.
5) Is there risk of damage to the bearing when I’m reinstalling the retainer? I’m just wondering if that is why the retainer was on so weakly. Is there a way to check to make sure that I’m not going to stress the bearing? Once you have the retainer off, you will understand the situation better. The bearing should have an external snapring which rests against the case. The retainer has a corresponding groove in it for the snap ring. DO THIS!!! Before you remove the retainer, note how much resistance it takes to spin the input shaft while the trans is in neutral. IF THERE IS MORE RESISTANCE when you reassemble, something is wrong. And that something will affect the ability to shift the trans properly.

Typed replies next to questions

 

[65swb45]

I got most of the t-case disassembled and cleaned a little while ago. It definitely was time to service.

Idler shaft cut thru the hard facing.

 

[rstoddard]

3) I noticed some horizonal movement outward in clutch gear and bearing. Perhaps as much as 1/2". Of course, that is without the bearing retainer mounted (whose job, obviously, is to hold the bearing in place). Just want to be sure that is normal and is resolved when the retainer is bolted back up. I'm just surprised that there is that much play just pulling on the clutch gear.

Not understanding exactly what is moving. If the bearing is showing signs of internal freeplay, it obviously needs changing. If the bearing is sloppy on the fork, that is a second issue. If there is freeplay between the static ‘parked’ position and the pressure plate, that is a third issue.
I’m referring to the Clutch Gear, output gear to the Clutch/engine. With the Clutch Bearing Retainer off, it pulls outward a half inch. See photos.

5) Is there risk of damage to the bearing when I’m reinstalling the retainer? I’m just wondering if that is why the retainer was on so weakly. Is there a way to check to make sure that I’m not going to stress the bearing?

Once you have the retainer off, you will understand the situation better. The bearing should have an external snapring which rests against the case. The retainer has a corresponding groove in it for the snap ring. DO THIS!!! Before you remove the retainer, note how much resistance it takes to spin the input shaft while the trans is in neutral. IF THERE IS MORE RESISTANCE when you reassemble, something is wrong. And that something will affect the ability to shift the trans properly.

Notice the photos above. The Snap Ring is 3/16 from the end of outside bearing flange. The Snap ring sits up flush to the case when the Clutch shaft is pushed all the way in. As you can see it pulls out about 1/4” then stops.

The Tranny seems to be neutral and both shafts turn easily without and noticeable play. The only thing I noted was the clutch gear pulling out 1/4”. Probably not an issue but I thought I would ask.

One last issue: I believe the Bearing Retainer that was on my tranny is a Toyota bearing retainer. Here’s a picture. What do you think? Should that be the case? Does that mate up properly with the bearing?

Typed replies next to questions

I think I installed an Advanced Adapter pilot bushing that is supposed to be a little longer to hold the input shaft but I don’t remember. I haven’t taken the clutch out or the flywheel and I really don’t want to but I’m beginning to worry about that. Looking at the tip of the input shaft suggests to me that it’s only grabbing the far end of the shaft. It’s been fine for 20 years.. but?

What do you think?

 

[65swb45]

DONT DO THAT!
You run the risk of collapsing the needle bearings inside that shaft if it moves too far forward, as well as having the forward synchro get unsynchronized.
When I pull a 3speed Tcase off a 3speed transmission that I am not planning to service, I put shipping tape around the transmission as soon as it is separated to make sure THAT doesn’t happen.

 

[rstoddard]

Got it. Hopefully (knock, knock) no harm done.

 

[65swb45]

3) I noticed some horizonal movement outward in clutch gear and bearing. Perhaps as much as 1/2". Of course, that is without the bearing retainer mounted (whose job, obviously, is to hold the bearing in place). Just want to be sure that is normal and is resolved when the retainer is bolted back up. I'm just surprised that there is that much play just pulling on the clutch gear.

Not understanding exactly what is moving. If the bearing is showing signs of internal freeplay, it obviously needs changing. If the bearing is sloppy on the fork, that is a second issue. If there is freeplay between the static ‘parked’ position and the pressure plate, that is a third issue.
I’m referring to the Clutch Gear, output gear to the Clutch/engine. With the Clutch Bearing Retainer off, it pulls outward a half inch. See photos.






View attachment 2884702View attachment 2884703

5) Is there risk of damage to the bearing when I’m reinstalling the retainer? I’m just wondering if that is why the retainer was on so weakly. Is there a way to check to make sure that I’m not going to stress the bearing?

Once you have the retainer off, you will understand the situation better. The bearing should have an external snapring which rests against the case. The retainer has a corresponding groove in it for the snap ring. DO THIS!!! Before you remove the retainer, note how much resistance it takes to spin the input shaft while the trans is in neutral. IF THERE IS MORE RESISTANCE when you reassemble, something is wrong. And that something will affect the ability to shift the trans properly.

Notice the photos above. The Snap Ring is 3/16 from the end of outside bearing flange. The Snap ring sits up flush to the case when the Clutch shaft is pushed all the way in. As you can see it pulls out about 1/4” then stops.

The Tranny seems to be neutral and both shafts turn easily without and noticeable play. The only thing I noted was the clutch gear pulling out 1/4”. Probably not an issue but I thought I would ask.

One last issue: I believe the Bearing Retainer that was on my tranny is a Toyota bearing retainer. Here’s a picture. What do you think? Should that be the case? Does that mate up properly with the bearing?

Typed replies next to questions



I think I installed an Advanced Adapter pilot bushing that is supposed to be a little longer to hold the input shaft but I don’t remember. I haven’t taken the clutch out or the flywheel and I really don’t want to but I’m beginning to worry about that. Looking at the tip of the input shaft suggests to me that it’s only grabbing the far end of the shaft. It’s been fine for 20 years.. but?

What do you think?

Take a peek through the disc. It should be a bronze bushing. If it is wallowed out, you will be able to see if the deeper part of the bushing looks smaller. That said, your contact wear mark looks more like that of a standard bushing, not the AA bushing. And unfortunately, you can’t get a great view through the disc of the whole of the bushing to see if it’s the ‘extra long’ one.

 

[rstoddard]

Take a peek through the disc. It should be a bronze bushing. If it is wallowed out, you will be able to see if the deeper part of the bushing looks smaller. That said, your contact wear mark looks more like that of a standard bushing, not the AA bushing. And unfortunately, you can’t get a great view through the disc of the whole of the bushing to see if it’s the ‘extra long’ one.

 

[rstoddard]

Would you recommend pulling the clutch and flywheel and replacing the bearing with a AA bushing if it’s not a bushing?

The thing is, I have a bright pink tag I’m staring at right now that says: “This pilot bushing is made of an polite bronze material which does not require any type of oil or grease. If oil or grease is applied, this material will bond the input shaft to the bearing causing internal damage.”

That is why I think I have a bushing.

Does that mean not to put grease on the top of the shaft, or not to use grease when installing into to pilot bearing hole?

 

[65swb45]

That sounds like an AA tag. Just polish the tip of the trans with an emery cloth…AFTER you look inside the hole.

 

[rstoddard]

I can't see n there very well. Old eyes. Here's some pics I took. Can you tell anything from them?

 

[rstoddard]

I actually measured from the face of the BH to the front edge of what looks to be the bushing, and it measured 5-7/8." Ther face of the Tranny to the tip of the Clutch shaft is 6-5/8." Therefore, I should be getting ~3/4" of penetration of the clutch gear input shaft tip into the bushing, which should be adequate.


Do you see any issues with the Bushing that warrant concern?

Do you see any problem using what looks to be a Toyota Bearing Retainer?

I received an SM420 Gasket set today. Question is whether I should take the old gasket off and replace or not. Thoughts? (You can see the old gasket in the photos above)

 

[65swb45]

Bolt the bearing retainer back on dry and see if you can pull the input shaft forward.