T - 14 Whine, Whine

Took my build on its first test drive today. Found that the T 14 makes a whine noise when decelerating in 2nd and 3rd. No noise in first or when accelerating in any gear. Wonder how deep this will go. Anyone with experience please lend me your knowledge. Thanks

 

My T90 has the exact opposite. No whine in 1st or 2nd but get above 35 in 3rd and it is horrible. Let of the gas it goes away.

 

Mine is T 14

 

The Dana-18 (d-18) transfer case is famous for it's whine, so are you sure its the tranny not the transfer case?

 

Understood. Since first and reverse are on the same shaft (1:1) and they don't make the whine, I assume the noise is in the 2/3 gear shaft or bearings. There is no whine when decelerating in 1st. But, I know little about tranny workings. Wouldn't the transfer case whine in all gears?

 

With my fingers crossed, I wonder. The ole jeep sat since 92 before I got my hands on. When I got it, I drained the tranny and chocolate milk came out. Replaced with fresh just to flush it out. I have driven it twice. The second time was quieter. Wonder if a few more miles driven might clean up it up some more. Anyone have any experience like that?

 

Definately It could wear in and quiet down. My brother rebuilt a trashed t5 he replaced the thrust roller bearings with washers and it was noisy as hell except in 4th. He drove it a few hunderd miles it steadily got quieter now its almost normal lol. But yeah if the gears and bearings have rust on them it should smooth out after a bit.

 

Well, not exactly. The T-14 is a fully synchromesh transmission, so all the gears have a fixed location on the main shaft, and are engaged by sliding collars that lock or release them from the main shaft. The R-1-2 gears on the main shaft spin passively and follow the cluster gear speed unless they are locked to the main shaft by the sliding collar. The cluster gear below the main shaft meshes with the input gear and turns constantly.

Gear reduction happens when the power is transferred from the input shaft to the cluster gear and back to the main shaft by locking one of R-1-2 to the main shaft. In top gear, the main shaft is connected directly to the input gear by the sliding collar ("clutch hub" per Jeep) and all the other gears turn passively with the cluster.

Reverse is different in that 1) it's not synchromesh, and 2) it uses an additional small idler gear to reverse rotation and 3) it's straight cut (as opposed to helical) so it whines.

The T-90 and T-86 are different from the T-14 and T-15 and T-150 in using a sliding gear for 1st & R, instead of the moving clutch hub.

Given this, what could be happening to make 2nd and 3rd noisy on deceleration, but not otherwise? What do those two gears share? a clutch hub. They also share that the 1-R hub is in neutral when either of those are engaged. But I don't see an obvious place related to those parts that would whine.

It's also possible that your noise is coming from the transfer case, and either there is enough force on the gears when decelerating to take up the slack in 1-R, or there is so much more eingine and gear noise in 1-R that you can't hear the whine. Also, transfer case intermediate gear speed is a lot lower in 1-R, which could affect whether you notice the noise. Transfer case intermediate shaft noise is really really common in these Jeeps - the D18 just does not last long without needing service. All the engine power goes through the intermediate shaft at all times.

Did you drain and refill the transfer case? They share oil, but transfer between them is slow.

How does the pitch of the whine change with the gear choice and speed?

For both of these units, you can take the top or the pan off and take a look pretty easily. Not much you can do from there, but as the yogi said, you can often see a lot by looking.

 

Thanks Tim. I did change fluids in both at the same time so it shouldn't be a lube issue. The whine is only during deceleration which is why I discounted the TC. I haven't tried in low range but will today. Shouldn't I then have the whine at a faster rate?

 

Sounds like the transfer case to me. If it makes the noise when you are in 4th gear, it’s the tc.

 

T14. No 4th gear (unless I haven't found it yet. Finocj, do you worry much about the whine? Wonder if I hear it louder since I don't have the tranny cover off?

 

Well, I'VE heard it on this forum many times before - drive it and fix it later! Here I go

 

The Dana 18 is noisy. When the Dana 20 was introduced, it was called the "silent" transfer case. No spinning intermediate gear with the 20, unless in 4WD.

 

Ok, I appreciate that the 18 is noisy. Would having the transmission inspection cover off amplify the noise? Already ruled out throw-out bearing as it is quiet in its full range of movement.

 

Just had a great drive . The noise is nearly gone (well, as gone as a d18 might be). Guess adding some miles to the old bearings and needles made a difference. But, I think it allowed another noise to be heard. The brake shoes on the TC park brake are severely worn out so much that they rattle even when fully adjusted. In fact, I can see where some shoe material is completely missing. I already have the seals and shoes and was about to start that project. Now I wonder if I'll need a ned coupler