Transmission clicking issue

[sluna13]

I have a 2000 ch613 that recently started clicking in the high range gears. It's a 10 speed and it mostly does it in gear 4, which is the 1st high range gear. And it only does it when I let off the accelerator and the engine is slowing the truck down. It clicks and feels like it's coming out of gear. Not sure what it might be please help!!

[Joey Mack]

can you post the transmission model?  4th is not the first high range gear in most 10 spd. tranny's.  I suspect you have an Eaton FRO16210C..   or possibly a T-2010 Mack..

[sluna13]

I know it's a mack transmission but not sure of the model. I think it's either 4 or 5th gear that's the 1st high range, not sure which one. But it's clicking in the 1st 3 high range gears now. It only does it when I let off the accelerator and the engine/transmission is holding the truck back. Feels like it wants to come out of gear or something. Where would I find the model # of the transmission? 

[sluna13]

So it's an 8 speed. I can post the vin if that will help...

[Joey Mack]

ok, now it makes sense..  that transmission does not shift like a typical 8/9 10.. and so on.  so when you pre-select before going to 4th, is it not shifting right as you pass through nuetral?

[sluna13]

It shifts fine from low to high range, and through all the gears for that matter, but if I let off the accelerator in high range it begins to click and seems like it wants to come out of gear. It does it about every 2-3 seconds and it's getting worse where it will do it very quickly once in a while and I'll have push the accelerator to make it stop. I have to drive with my foot on it very lightly when going downhill, I can't let off completely and let the engine slow the truck down...

[Joey Mack]

well that sounds like a worn sliding clutch.  what gears in high range are doing this?  and does it do it in the low range gears.. ?

[sluna13]

It does it in 4th, 5th and 6th gears. No issues in low gears, only in the highs. I bought a new range shifter slave valve hoping that's what it was but I don't think so

[Joey Mack]

before I go to the synchronizer, have you rebuilt the range cyilinder, or at least looked at it?  I'm still on the fence about this..  I have seen this many times and it was the rear end gears sending the sound through the driveshaft to the tranny, and it will fool you..  Mack rears??

[sluna13]

Yes I'm pretty sure they are mack rear ends. It is a gold dog Mack so I'm guessing it's all mack even the rears? I'm going to tear into it the next couple of days remove the slave valve and top cover. I've never done this before so any advice you can give me would be much appreciated 🙏🏻

[Joey Mack]

my advice is to not tear into the tranny..  drain the oil from the top of the rear rear end into a clean pan and see what comes out, then pull the side cover and inspect the bevel gears..  the drain plug is at the bottom left corner, hard to see for a first timer..  

[fjh]

Agre also check the rear yoke bolt on the transmission!

[fjh]

51 minutes ago, Joey Mack said:

my advice is to not tear into the tranny..  drain the oil from the top of the rear rear end into a clean pan and see what comes out, then pull the side cover and inspect the bevel gears..  the drain plug is at the bottom left corner, hard to see for a first timer..  

another thought also if you have a power divider lock out lock it in ! If you have un even tires can cause a click sound! If the click goes away you have your answer!

[terry]

9 hours ago, Joey Mack said:

before I go to the synchronizer, have you rebuilt the range cyilinder, or at least looked at it?  I'm still on the fence about this..  I have seen this many times and it was the rear end gears sending the sound through the driveshaft to the tranny, and it will fool you..  Mack rears??

I know a guy years ago that swore noise was his quad trans, took it out, had it rebuilt and yeah same noise, it was front rear end!  Terry

[fjh]

55 minutes ago, terry said:

I know a guy years ago that swore noise was his quad trans, took it out, had it rebuilt and yeah same noise, it was front rear end!  Terry

Yep seen that a few times Terry! We got to verify if this is a click or a chatter Or grinding sound ! Its kind of un clear at this point! We had a guy come in once that had a whining sound he could only hear while driving by a rock face or guard rails on the hyw  ! Turned out both diffs were done the hard surface off most of the teeth on the top set in both! 4:17 and  4:42 ratios were bad for this! The problem with the mack diffs was they were designed around 300 or less Horse power! 

[Joey Mack]

I too have replaced/repaired Mack rears, for the same issues..  More rears than tranny's for this complaint..  the drive shaft is a hollow pipe that carries sound to the transmission...

[fjh]

Yup all we can do is listen a wait for what he’s experiencing an see if we can lead him down the right path! My first thought was syncro however! Because of his symptoms!

[Joey Mack]

Agree'd fjh..  definately need more info..  I had gotten to the point with these compalints, if I dont see an obvious issue with drive line yokes, bearings, and shaft's,,  I go ahead and pull the side cover on the rears.. Power divider peanuts and cams have been a common cause for these noises as well..  OK, now we wait..   Jojo

[fjh]

31 minutes ago, Joey Mack said:

Agree'd fjh..  definately need more info..  I had gotten to the point with these compalints, if I dont see an obvious issue with drive line yokes, bearings, and shaft's,,  I go ahead and pull the side cover on the rears.. Power divider peanuts and cams have been a common cause for these noises as well..  OK, now we wait..   Jojo

👍

[Mark T]

If it makes the same noise in it's direct gear (7th) in this case it's likely not the transmission.  Clicking at  even intervals usually is a tooth missing.  Has anything been drained and checked for metal?  

[sluna13]

So I didn't have time to pull the side cover today but I will get to it hopefully tomorrow. I did notice that the rear rear is leaking from that cover. I'm really hoping it is something in the rear ends, better than the transmission!  But to me it really sounds/feels like it's coming from the transmission. Or the range selector. It's a clicking and I can feel it in the shifter, like a little bump. Also, when I go over bumps in the road the gears feel loose like they are shifting around a bit.

[fjh]

10 hours ago, sluna13 said:

So I didn't have time to pull the side cover today but I will get to it hopefully tomorrow. I did notice that the rear rear is leaking from that cover. I'm really hoping it is something in the rear ends, better than the transmission!  But to me it really sounds/feels like it's coming from the transmission. Or the range selector. It's a clicking and I can feel it in the shifter, like a little bump. Also, when I go over bumps in the road the gears feel loose like they are shifting around a bit.

Lock out the power divider if it has one! See if that changes the situation! no effort on your part!

[mechohaulic]

block the wheels/ let the brakes off / jack up one of the front drive wheels and by hand spin the wheels . WITH ENGINE OFF . you won't spin it fast enough to create the clicking noise. but possibly can hear/locate a problem in rear end or drive line. this will also take tension off the drive line so you are able to  go  under and check for an issue with drive shaft. just a thought from an ole man. everyone else covered the rest.

[mowerman]

Can’t help you, but my transmission also makes some sort of weird clicking noise when it’s in neutral. Engine running I don’t know what it is, but my transmission is junk and I will be changing it anyway, but curious to see what you come up with.. bob

[sluna13]

It seems to be connected to the range shift or something to do with that internally. The clicking noise sounds just like the range shift thump from low to high. But like half a thump, if that makes any sense. It only does it when I let off the accelerator and it's worse in the 1st high gear, which is 4th. But it does it in every high gear just not as bad the higher the gear. I did drive with the power divider locked and it still does it...

[Joey Mack]

ok...  My next question is meant with respect...   Do you know how to repair this transmission?  In-chassis wil require special tools..  out of chassis, will require a strong back..