4l60 / Transfer Case Grinding / Is this normal? (2 Viewers)

[TexasLandCruiser]

Mine did this same when I had a vacuum issue if I recall (4L65)

 

[cruisermatt]

“2wd” transmission conversion is a neat trick isn’t it.

Transfer case had new bearings already, right?

 

[Dubs2017]

“2wd” transmission conversion is a neat trick isn’t it.

Transfer case had new bearings already, right?

Yeah new bearings all around from a rebuild kit I got from cruiser outfitters. They all look good to me at this stage (with 8 miles on them).

I got the half the mating surfaces cleaned up and the gears dropped in this afternoon. Everything lines up and spins. Still hoping to find something to explain the noise.

 

[Dubs2017]

Mine did this same when I had a vacuum issue if I recall (4L65)

Interesting. Where was the vacuum issue? Curious if it was transfer case or something else

 

[Dubs2017]

quick video to verify things are in the right place. Let me know if anyone sees anything that is incorrect or questionable.

 

[Dubs2017]

Got everything buttoned up and back in the rig. Whine is massively reduced. I have about 40 miles on it and will continue to monitor it.

Hi/low gear selection behavior is exactly the same as before.

Strange that I didn't find anything wrong during the rebuild.

 

[dbbowen]

Bringing this thread back, can rule out the tcase rear output shaft gear from the whining pool. I just tried increasing and decreasing the preload on that bearing with the flange and it doesnt change the whine. When the preload is too loose it makes a grumbling noise and the whine is still constant.

Its gotta be something inside the case. It only happens when power is involved from the transmission, so accelerating or coasting. If you pop the trans into neutral the noise goes away

 

[dbbowen]

Actually i think the entire output shaft of the tcase can be ruled out. I was able to take all of the play out of mine and its still making the noise. Its got to be either coming from the input shaft or the idler shaft.

 

[tmxmotorsports]

Are you thinking it's coming from spud shaft or idler shaft within the transfer case?

 

[tmxmotorsports]

My buddy that has a mechanic shop has this kit that has microphones that you can place in different locations to see where noises are coming from not sure where or how much they are but might be something to look into.

 

[dbbowen]

I honestly think its coming from the idler shaft or idler gears in the tcase. When i put the foot to the floor i can hear a very faint kind of scratchy noise that i kinda feel like is the oil slinger on the back of the idler gear hitting something. Either the idler gears are slightly tilting some how or the input gear is slightly tilting somehow, or the idler bearings arent getting lubricated maybe?

The noise completely stops if you put the truck in neutral. It whines on acceleration and deceleration, and on acceleration it is not throttle dependent as long as youre giving it gas it whines. Pop it into neutral it is dead silent.

I tried the rear output shaft bearing on the back of the tcase because the pinion nut came loose on my wifes 100 series and kind of made a similar noise because the bearing wasnt preloaded enough but it is definitely not the rear output shaft bearing

 

[tmxmotorsports]

Got any hills around? See if pop thr tcase in neutral leave transmission in gear?

 

[dbbowen]

Got any hills around? See if pop thr tcase in neutral leave transmission in gear?

I actually have a lot of hills around. So put the case in neutral and transmission in gear and just coast down the hill with no gas pedal?

 

[tmxmotorsports]

I actually have a lot of hills around. So put the case in neutral and transmission in gear and just coast down the hill with no gas pedal?

Yeah I'm just throwing stuff out there just cause you have done it the other way around

 

[cruisermatt]

same exact noise with old and new transfer case?

 

[dbbowen]

Yeah I'm just throwing stuff out there just cause you have done it the other way around

Ill try both, about to head out the door anyways. Ill let you know how it goes when i get back

 

[dbbowen]

same exact noise with old and new transfer case?

for me, yep. Same noise through 3 different transfer cases. first was a 34mm tcase that i messed up unrelated but still made the whining noise. Second was another 34mm case shell but still used the first tcase gears, but all new bearings and input shaft. Thought the gears was the source of the whining, so i bought a brand new in box 38mm tcase with brand new everything and long spline input gear... still got the same exact noise. Thought it might have to do with the shifters because you can feel it vibrate through the shifters so i did a twin stick. Still got the same noise haha

 

[tmxmotorsports]

for me, yep. Same noise through 3 different transfer cases. first was a 34mm tcase that i messed up unrelated but still made the whining noise. Second was another 34mm case shell but still used the first tcase gears, but all new bearings and input shaft. Thought the gears was the source of the whining, so i bought a brand new in box 38mm tcase with brand new everything and long spline input gear... still got the same exact noise. Thought it might have to do with the shifters because you can feel it vibrate through the shifters so i did a twin stick. Still got the same noise haha

Don't see how it could be related to the tcase if it's been the same through 3 different ones and now different axles and driveshafts.

 

[dbbowen]

This is the whine. Its louder than it seems on the video

 

[tmxmotorsports]

Is it more of a Humm / whine ? Not really a grinding noise?