Transmission Input Shaft Play

[bjde0b]

I am replacing gaskets and seals on my NP 435 transmission as I mentioned in previous posts. I found that there is more play on the input shaft than I would expent to see. The motion is allowed because the roller bearing that go within the input shaft that support the output shaft is a little lose.

I don't see any remediation because the journal in the input shaft looks good and the output shaft also looks good. The bearings themself do not show wear. It appears that this is just inherent part of the design.

Has anyone else noticed this before? The output shaft does not have hardly any play at all.

I would show a picture but I am on the commuter bus to work. Anyone that has done work on a 435 will know which roller bearings I am speaking of.

[Alvin in AZ]

Heck, BJ. :)
Replace the input bearing/s ...then see what you've got. :)
Replace the input bearing/s while you've got it apart, play or no play.
Call the numbers into a bearing shop and ask for price and availability.

Alvin in AZ

[bjde0b]

Alvin,

I see your point. I think I found what might be causing part of the looseness. The bearing is pressed onto the input shaft. The input shaft is tight agaist the thrust bearing against the output shaft. The race of the input bearing is pressed into the cap/bearing retainer. It appears that it may have been pressed too far in. Couple questions. How do I get this thing out? Second question, How do I know how far to press it in?

If a picture is required let me know.

[averagef250]

The 435 main clearance shims under the bearing retainer. You stack gaskets to get the correct clearance. If you aren't familiar with this work you need a dial indicator to measure the main bearing clearance. If you are too tight it will come apart. You want .003-.006 clearance for a 435. You can go tighter, but only set them tighter with new bearings.

There is absolutely no reason whatsoever to replace the input bearing if it's good. The 435 input bearing is usually the last bearing to show wear. The rear mainshaft ball bearing is the one that goes.

Bearing races must seat all the way. There's no such thing as pressing a bearing partially into a bore to set bearing clearance.

To remove the race from the bearing retainer without the right tools spray the retainer down with anti-spatter and weld a heavy MIG or 70 series stick bead all the way around the ID of the race. As the weld cools it shrinks the race and it will fall out.

[bjde0b]

Good advice. I did some reading in the Tutorial section about that. I will reread it. They show in the tutorial (which is actual scans of a manual) that it can be measured in the casing with a feeler gauge. I will take a picture and post the gap. I agree with you that there shouldn't be a gap, but if the race is pressed further in, then there will be even more of a gap.

The bearings show no sign of wear.

[bjde0b]

I circled the areas where I think the gaps don't make sense. As you said, the race should be pressed all the way in, but there is a gap at the back of the race. The front of the retainer has a chamfer, but the race is pressed further than the edge of the chamfer. I drew yellow lines (poorly) to show exactly were the edge of the race and chamfer is.

Click on the picture to make it biger so you can see the lines I drew.

[averagef250]

The space behind the bearing is a step in the bore to allow the removal of the race with the right tools.

If you were to leave a gap there during assembly the race would bottom in the bore the instant you drove the vehicle. The forces inside transmissions are fairly great.