D4D Bevel gear tooth contact

[G Bilecki]

Hello everyone
cat d4d 83j power shift
I'm having issues with the contact of bevel gear and pinion gear in the rear end of my
appears to be eccentric tooth contact in one spot
I have converted bevel shaft and pinion gear to the updated nut type pinion
replaced with new cat bevel gear and pinion
Second hand bevel gear shaft
New bearings etc
Radial run out on internal to bevel gear mounting on shaft is .02mm
Is this enough to effect the tooth pattern
Please help
I'm on my knees


View attachment 233532 View attachment 233533 View attachment 233534

 

[Dave Neubert]

almost looks like the pinion is too deep I like to see it more toward the middle. the erratic contact is probably not a huge concern it will most likely look a little different under a load. I like .010- .012 back lash too

 

[G Bilecki]

Hello
I've moved the pinion a number of times with the same uneven patten regardless of where pinion is
Best I could get it was 3/4 of the crown wheel pattern to look ok ( 30% from the toe )
The other 1/4 to far on heal
just that one spot when loaded up will walk toward the heal and tooth contact even further
When I close up back lash it locks up in that spot where the marker pen is marked the bevel gear

 

[Cmark]

.02mm is .0008" in old money so shouldn't be significant IMO. Have you checked axial runout? Bevel gear not sitting flat on the shaft due to debris/ burrs maybe?

 

[Dave Neubert]

Is the pinion a after market does it get tight on the same place on the ring gear or same place on the pinion

 

[Nige]

You mentioned the "bevel gear shaft" is second hand. Are you talking about the pinion shaft or the crown wheel shaft.?

 

[.RC.]

https://www.dropbox.com/s/uncjtpj45...ssembly_Assembly_D4D_Tractor_REG00892_01_.pdf

 

[G Bilecki]

New caterpillar pinion ex usa special order, new caterpillar bevel gear ex Italy,
Second hand crown wheel shaft.
My first thoughts were burrs or not seating correctly so I took crown wheel off and crack tested the shaft, was all good so just machined face as it looked like old chafing marks
refitted crown wheel = No different

Issue is in the same place on the crown wheel

https://drive.google.com/folderview?id=1zKWYpHcU1uVAEDHEald5iXxBXd1N4AA6

 

[Nige]

I realize that the "master bolt hole" will be off but for the purposes of a test is it worth a try to index the crown wheel 90/120/180 degrees on the shaft from its current position and repeat the test to see whether or not the "tight spot" stays in the same place on the gear or the same place with respect to the shaft..? If it stays in the same relative position with respect to the shaft that would indicate to me that the shaft is not running true.

 

[DB2]

Was just thinking along those lines.

 

[G Bilecki]

Yeah good idea

 

[Dave Neubert]

Like Nidge said try to index it different if it stays in the same spot on the ring gear my guess would faulty machining on the ring gear

 

[G Bilecki]

Hey thank you everyone
Up and dozing
Found the issue, the boys at caterpillar heat treating devision must of been sleeping. The new bevel gear was warped

 

[Nige]

Found the issue, the boys at caterpillar heat treating devision must of been sleeping. The new bevel gear was warped

Just because parts are new does not mean they’re necessarily right. Glad you found the problem.

 

[Welder Dave]

Good thing you checked everything and didn't just put it back together.

 

[G Bilecki]

I know, and the one time you get a issue it's on your own machine, not many people would come across this issue.

 

[Welder Dave]

A lot of people would have just put it together thinking the new parts were good.