5 replies to this topic

[lildeucecoop72]

I am hoping the Gearbox gurus can come to my rescue again. I am trying to understand how the Double roller bearing should behave.

 

Should a newly installed, and unused RHP double roller bearing have lateral movement? The inner race and balls/cages have a fair amount of play if I push and pull on the mainshaft (this is before adding the pinion gear, mind.)

 

Back story: I wanted to remove the 1st roller bearing (as I thought had damaged it when installing but that's another story), I struck the outer race from the back and at the top (as I have seen on vids) but he bearing wasn't moving - I used more force. Still no movement.

This is where I went wrong - I should have done what I did last time...use the slide hammer on an old input gear, so that the motion force was linear.

The result of the force could have done 3 things:

 

 

1. the outer race got jammed at an angle in the case

2. as the 1st motion shaft was now misaligned, it might (?) have pulled the main shaft behind it out a bit and damaged the double roller bearing.

3. possible damaged the smaller 3rd motion nose bearing in the shaft.

 

I didn't notice this yet, and proceeded with the build as planned, eventually noticing the main shaft was 'loose' before adding the retainer and bolts.

The double roller inner race/cage and bals was moving in and out on both sides with the main shaft, but the outer race was still stationary...

 

Video that shows movement.: https://youtu.be/IcDZ9qEgK7U  

 

When I originally installed the double roller bearing, I tapped the INNER race, using a steel tube over the shaft.

 

Ok so then I was maybe a bit quick decided to remove the double roller bearing to inspect compare with old one before adding the pinion gears and nut to test. The removal went OK.

Now I could compare the bearing with the old one, which does the same.
Weirdly, both only allow this lateral movement if you pull the two opposing inner races slightly apart. You can push-click them back together and then it seems to be solid again.

 

Questions:

Is that normal, or is it from the result of removal?

Should I not risk it and just buy another or is it still useable?
would this lateral movement not be an issue if the pinion is installed and torqued up?

 

Thanks again. Its all part of the learning curve (that is still steep in my case!)

 

[DeadSquare]

The double roller is there to contend with the side thrust generated between the crown wheel and the pinion, not the end thrust due to the helical gears.

 

I have stripped boxes with very sloppy bearings that have left me wondering why they still worked, but it is a case of not being able to assess the lateral movement once the correct shims have been fitted between the bearing retainer and the Web, and the pinion has been tightened.

 

An email to "Guessworks Gearboxes"  (google it)  can explain it, better than I can.

Edited by DeadSquare, 16 April 2023 - 02:52 PM.

[Spider]

The Pinion needs to be fitted and the nut tightened before any slack in this bearing assy is taken up.

 

It's a double angular thrust bearing.

[lildeucecoop72]

Thanks for your replies, DeadSquare and Spider! :) 

 

The Pinion needs to be fitted and the nut tightened before any slack in this bearing assy is taken up.

 

It's a double angular thrust bearing.

 

OK with the pinion on and tightened it probably won't be capable of any lateral movement, but I just wondered - it seems that the space between the 2 rollers in the bearing be moved outwards in relation to eachother if you 'play' with the inner races and the spacer between them, and wondered if that was normal on a new bearing.

 

It was just a bit weird, like the bearing had 2 settings; 'open' (lateral movement) and 'closed' (no lateral movement).

I dont have a brand new out of the box unused bearing to compare this to, so wondered if anyone had observed this aswell?

[Spider]

Thanks for your replies, DeadSquare and Spider! :) 

 

The Pinion needs to be fitted and the nut tightened before any slack in this bearing assy is taken up.

 

It's a double angular thrust bearing.

 

OK with the pinion on and tightened it probably won't be capable of any lateral movement, but I just wondered - it seems that the space between the 2 rollers in the bearing be moved outwards in relation to eachother if you 'play' with the inner races and the spacer between them, and wondered if that was normal on a new bearing.

 

It was just a bit weird, like the bearing had 2 settings; 'open' (lateral movement) and 'closed' (no lateral movement).

I dont have a brand new out of the box unused bearing to compare this to, so wondered if anyone had observed this aswell?

 

The outer Race, as you have no doubt seen, is one piece, however the inners are 2 separate races, with a spring clip that stops them from falling apart until it's inserted in the gearbox.Because the inners are not 1 piece, they do move until clamped up by the shaft.

[lildeucecoop72]

 

Thanks for your replies, DeadSquare and Spider! :) 

 

The Pinion needs to be fitted and the nut tightened before any slack in this bearing assy is taken up.

 

It's a double angular thrust bearing.

 

OK with the pinion on and tightened it probably won't be capable of any lateral movement, but I just wondered - it seems that the space between the 2 rollers in the bearing be moved outwards in relation to eachother if you 'play' with the inner races and the spacer between them, and wondered if that was normal on a new bearing.

 

It was just a bit weird, like the bearing had 2 settings; 'open' (lateral movement) and 'closed' (no lateral movement).

I dont have a brand new out of the box unused bearing to compare this to, so wondered if anyone had observed this aswell?

 

The outer Race, as you have no doubt seen, is one piece, however the inners are 2 separate races, with a spring clip that stops them from falling apart until it's inserted in the gearbox.Because the inners are not 1 piece, they do move until clamped up by the shaft.

 

 

Thanks Spider.

 

In that case, though it looks a bit sloppy in the video, from what you describe, it sounds like its OK/normal, and solved by until torqing up the pinion and bolt. 
I guess it was like that before too just didnt notice it. :)