whats the sound of intermediate bearings going bad

I have no transmission cover as of yet so I get to hear lots of new stuff. Second test drive today, so I am hearing everything and nothing at the same time.

I let off gas and push clutch in to shift and I hear a distinctive "ka chunk chunk". sounds deep like something with some mass.

Sounds like its coming from passenger side more than center.

What do you think?

 

Mine was a BANG while going 60 down the highway when it split my transfer case in half. I can't really remember the noises it was making before that.

 

Well, it does make a lot of whining noise, but not significantly worse than all the others I have driven. The clunk when letting off power is deep and meaty though. Its going to need some help I think. Tomorrow I will make doubly sure my bull gear is on tight. Maybe I will drop the Xfer case pan and see how much i can pry the gears apart. I didnt do any work on the Xfer case and that could be good or bad....

as a back up plan, how difficult is it to exchange the early double shifters with the later single on the d18? I have one but the adapter I have for the sm420 is for small hole d18... adapter for adapter?

 

my transfercase shifter rattled when mine needed a new intermediate shaft .
you want to go from twin stick to single or single to twin stick . small hole large hole doesn't make a difference . the front output housing and shift rods are what you need

 

So, I could just take off the ones on my present d18 and swap em onto a big hole replacing the single lever setup. That simple?

 

Yup. As Twin2 said either will fit either using the correct housing, shift rails, linkage, etc. the single stick shifter mounted to the bellhousing adapter though so if you want to use that you will need to do some fab work to mount the pivot.

 

Thanks,
I have no intention of reusing the single over assembly, so no worries there. I am really only concerned in the event I destroy my small hole d18.

Now about that noise when I let off the power...

 

Front driveshaft U joint maybe?

 

For the clunk on pull to coast I'd look and the rear pinion yoke and make sure the it isn't moving in and out.

 

I tried to isolate the noise. Made sure it was out of 4WD, hubs unlocked, got under grabbed the drive shaft, shook it. Not it. I will check rear pinion.

Makes lots of whine in 4WD. Now it makes it in 2WD too. Yes, its full of oil.

 

on moving the twin stick... I had to 'grind' some meat off the transmission side of the front housing (at the shifter-pivot pin area) to get it to fit correctly against the case (T98). Still lots of meat left, not worried.

BFD (before disassembly) on mine, it was making clunking and warbling of sorts... found the front end was engaged. Second to that, the rear oil was like pea-soup. Replaced the oil at both ends, and added some additive to the rear for the power-lock and pulled the lever in and out a few times on the transfer to ensure it was not engaging the front... no more probs.

Could your FF hubs on the rear be making noises? IF you turn in the front and disengage the rears (front-wheel drive) do you still hear the same noises?

 

Yeah I did all that stuff except unlock the rear hubs and drive it around. It makes a LOT of whine in 4 high. I think there is incorrect preload on output shaft and bad intermediate bearings. I am pretty sure i did the output bearings like 8 years ago, but didnt own a dial indicator at the time, so i probably didnt set the preload with shims correctly. Thats really where the noise sounds like its coming from. Its pretty clear and i think i did a bad job way back when. I got under it today before had to drive away to work and checked everything that could make noise. I cold not replicate the problem. Its not really a big deal to drop the transfer case and rebuild it. I should have done it when it was out.

What I would like to do is rebuild the big hole D18 case and then pull my existing one and be done in 2 hours or less. I need to research if there is an adapter for the Novak adapter to use it on that big hole case. Thats the only issue.

Thanks

 

Does the adapter you have now use the T-90 bearing retainer to center the transfer case input bearing? If so then a T-86 bearing retainer and bearing can be substituted to center the large hole transfer case.

 

The adapter I have Adapting the GM Muncie SM420 to the Jeep Dana Models 18 & 20 Transfer Cases is the one for the SM420 to D18, 3 5/32 hole. It came complete with bearings.

I have sent an email to Novak to clarify if this will work. If it will not I will just rebuild what I have before it blows up and wrecks stuff.

 

Ok, looks like according to that link the adapter will accept either the T-90 or T-86 bearing retainer. If that is the case you should be fine. Will just need the right bearing and retainer. Some of the early adapters were machined to only accept large hole or small hole cases and could not easily be converted from one to the other.

 

How is the torque mount on the passenger side of the transfer case? Or disconnect the rear driveline and see if the pinion can produce a clunk.

 

But there are 2 different part numbers, one for big hole and one for small. I haven't had a response from Novak yet.

The torque mount is new, but It didn't really fit together right and this may have something to do with my issue as well. When i get Home I will be sure to check that. This noise did occur before I did all this work too, just not as loud.

Thanks guys.

 

This is how it should sound when the bearings are not worn.

 

yeah mine sounds a bit like that, just everything is about 10X louder. The whine is 20X louder for sure and you have no clunk .