Transmission/transfer Case Noise Okay?

I have a 1970 CJ5 with the Dauntless V6, T14 transmission, and Dana 18 transfer case. My question is how much transmission/transfer case noise is okay and when is ain't? Both shift without problems. While driving the noises cease when I depress the clutch or take the transmission out of gear. Definitely not the throw out bearing. Everything I read indicates that the D18 is normally noisy and so is the T14 to a lesser extent but, nothing indicates what is normal. The noise is a lot louder than average conversation volume (not including wind/tire noise).

I'm not sure of the mileage but the second owner said the jeep was only use on a ranch in Arizona for about 50 years before he bought it and claimed he didn't drive it that much; the original, non-working speedometer showed about 40M miles. I'm kinda new to jeeps (almost 2 years now) but the few "jeep" people I know tell me to just drive it until it won't and then fix it. I rebuilt two TR6 transmissions making a whole lot less noise.

So, when should I think about rebuilds?

Martin

 

Id say there is no use prolonging the inevitable. I wouldnt like to drive it like that either. My jeeps are all pretty quiet as far as gear noise unless i run in third gear low range trying to go fast. They really dont like that.

 

The biggest issue about a rebuild is the replacement parts are typically lesser quality than original and may sort of fit.

Make sure you are using the correct type and amount of fluid.

Here is how mine is, it does need rebuilt. Once we get on the blacktop you can hear the gears over the engine and we were not going fast at all.

 

Here is another video:

 

Well the transmission input shaft and mainshaft needle bearings are still good if you don't have noise in neutral. My approach to this would be to drain both and take a look at the gear lube. If it isn't mimicking metal flake paint, refill and run it. That should likely be done on anything that sat for a long time anyway. GL4.

 

Jw60: Mine is very close to that noise level.

duffer: After I first got "Old Yella" home I drained oil from the engine, transmission and transfer case, and front and rear differentials checking for metal and water contamination. All the fluids were extremely old and dirty but otherwise fine. I refilled the tranny and t/c with Sta-Lube GL4 W85-90; the same that I use in my TR6. I added a Saturn overdrive six months later and the t/c fluid still look good. The tranny, t/c, and engine (but not the axles) still leak but it's clean oil.

Thanks to both for your input. I think I've got a winter project now. I'm looking at Novak for the rebuild kits, any reason to use another supplier?

Martin

 

Thanks Glenn, good to know.

Martin

 

You may want to consider this "upgrade" for the transfercase. It replaces the needle bearings on the intermediate gear for tapered bearings.
The needles ride on the gear itself and once the inner race is worn on the gear it will never be right.
https://www.advanceadapters.com/4932
This does require access to a machine shop to bore out the gear. If the teeth on the gear are worn than this will not help.

 

I am NOT a fan of the AA kit, for several reasons-
1. The intermediate gear is made of extremely hard material, I had a helluva time finding a machinist to do the work.
2. It didn't make much difference in the gear noise coming from the tcase.
3. AA recommends adjusting the gear end play every 15K miles. This is VERY difficult to do with the tcase in the Jeep.
4. The bearings on mine didn't last very long...this may be related to #3.
When I did my 4 speed swap last year, I changed the tcase back to a standard intermediate shaft (Novak makes the only decent one on the market AFAIK)
This is just my 2 cents, there's other guys on here who like the AA shaft.

 

I agree with your comments. without Mike at the mill most people don't have a place to have the work done.
the gear noise going down the road is at the teeth. Where the whirling is from the bearings so if it's too late to save the gear it's not gonna help.

It seems like a good way to save an intermediate gear with only a scalled or worn out inside bore or end face.

I do want to try it on mine, doug if you wanna sell yours send me a pm.

 

You're another person I've read or heard who wasn't impressed with the tapered bearing switch.
D18's are inherently noisy by design. There are all sorts of things one can do to diminish it including a good sound barrier floor covering.
Of course swapping to a straight through case like a D20 is the best imho.

 

The original needle bearings also give exponentially more bearing surface area than two tapered bearings.

 

In theory maybe. But with the D18/D20 design, there is anything but even loading along the intermediate shaft so the actual total bearing surface area is pretty much a moot point. Most of that loading is on the front set of rollers. The tapered roller bearing arrangement is what is used in just about all the heavy duty transfercases like the NP205. Maybe not the most convenient task to keep tabs on the preload but, IMO, the AA kit is worth the effort. Along with somewhat less noise, those tapered rollers no doubt generate far less heat.

 

Personally, I feel that the AA kit is "under bearinged". It uses set A14 bearings which are pretty small, I think if a larger bearing could be used it would be a benefit.
Note that this is just my gut feeling about it, I have zero data to back it up & I'm not sure if a larger bearing would even fit.

 

I put a Novak kit in mine with a new intermediate shaft and a set of new Terra Lows gears. I have had many Dana 18 cases both worn out and ones that I have rebuilt but none were as quiet as this one. Makes me think that worn gears are the biggest part of the noise.

 

Some of that is also from a lot less helix on the TL gears. Same scenario as Muncie M21 versus M22. Just need louder mufflers and/or more aggressive tires--------Say again