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Topic Review (Newest First)
01-07-2020 09:17 PM
Another casting mystery

Hi gang,
Here's another obscure D-18 mystery I've been wondering about, and thought I'd see if any of you have any info about it:

I have a D18 t-case that I believe is original to my 53 CJ3B. My Grandpa bought it new, and it's been in my family since. I believe that I was the first to ever work on the t-case. What's interesting about it is that I think it came from the factory with the later 1.25" intermediate shaft size, with the earlier style 26 tooth input gear (which is usually associated with a 1.125" shaft). This configuration can be built with standard parts, but I had the impression that the factory never made this combination. That's one little mystery. I chalk it up to likely being due to transition timing in making a mfg. change mixing compatible parts to use them up.

The part of the puzzle that I am more interested in are the case casting marks:
Instead of the usual Spicer emblem and "18-15-10" casting number, this case has a "W. G. Div. 18-15-18" casting mark, which I think is Warner Gear Division which is a different company than Spicer.

I've seen one post on the CJ2A page of a casting that had the same markings, but there was no insight as to why it appears Warner Gear was making Spicer D18's.

Anybody ever seen this before? Anybody know if Warner Gear ever made these xfer cases or parts in parallel to Spicer?

Not important, but I'm curious about what the history might be...?
01-31-2016 10:32 AM
Rallef San
Whats that?

Hey guys, need some help.
Im from germany and i cant find anything in the forums here.
Excuse my bad english.
Ive got a D18 but its different to all the others ive seen.

Two different bores 3/4 and 1 1/8.

Somebody seen this before?

The Ralf
01-25-2016 09:25 PM
Tracklock I thought you guys would like to see this link, it talks about O'Brien's Gears and quieting down the 18

Transfer Case Tech Tips on The Jeep CJ3B Page

01-25-2016 07:48 PM
higher tolerance bearings

hey guys, for a long time now I have been wondering if any one has installed higher tolerance/higher quality bearings in a D18/D20 transfer ??,
I know the "called for" stock type bearings are sufficient, but as a young kid with a dirt bike I learned a long time ago that smother, higher tolerance bearings reduce vibration and produce more power to the output shafts, I would think they would help greatly in a D18/D20
07-20-2015 05:36 PM
xbcasey I don't know any history on it or how long it's been since a rebuild, but it runs quiet and smooth without any noticeable slop in it. 300 is WAY too hot, I plan to spend a lot of time on the road with this thing and drive it to and from the trails, so it looks like a rebuild may be in order.
07-20-2015 03:47 PM
Originally Posted by xbcasey View Post
I took a two hour highway trip at 55 mph and 3000 rpm, when I got back home I could tell that the Dana 18 was really hot, when I put my temp gun on it it was 305 degrees. Any ideas on what could be wrong or what I could do to cool it down, other than not driving it??
That's pretty warm. Is it in good shape? Do you know any history on it?

A good quality rebuild with quality bearings would probably solve most of the issues. Might be time for a new intermediate shaft too? I don't think it should be running THAT hot.
07-20-2015 02:41 PM
xbcasey I took a two hour highway trip at 55 mph and 3000 rpm, when I got back home I could tell that the Dana 18 was really hot, when I put my temp gun on it it was 305 degrees. Any ideas on what could be wrong or what I could do to cool it down, other than not driving it??
08-09-2013 12:57 PM
49willys_mogon dana18 noise... The one that was in my wagon wasn't to bad in the original stock configuration, however as soon as I upgraded to a t400 and 283 it became unbearable.

On another note I have been reading into cyro treating. There is a 4 page article in 4wheeler from a few years back that I'll eventually post up. Supposedly the quenching process tightens the grains of the metals and drops operating temps increases strengths quite a bit. 30-50%

I have noticed a big difference in some brake pads/rotors I had recently changed. During hard stopping 65mph to 0 on a steep decline my factory slotted rotors made a whirling sound and suffered drastic fade. After I swapped in new akebono ceramic pads (to remedy dirty rims) and machining my rotors to to min spec my brakes are better than factory and the noise and fade is gone.

Once my build is complete I plan to go through the problem areas of the portals on my wagon which I will document.

************************************************** ************************************************** ***********************************

Not sure if anybody has any experience with Lubrication Engineers gear oil...for whatever it is worth I stumbled upon this researching my 300E's diff...and have used it in my GMC when going to the mag htech diff cover...and immediately thought of portals ect. When considering using an oil such as synthetic's and high $$$ variants make sure you are past break in periods for new gears ect to get your bang for buck.

LE 607 SAE90 has now been replaced with 703 80w90, 1604 SAE90 4EP GL4, 1605 SAE110 GL5. There are some other heavier weights available.

The load capacity of 90w gear lubes varies, but it is generally higher than a 80w90 or 75w90 gear oil, even a synthetic oil. The load capacity is partly a function of viscosity, but more a function of the additive components. Nearly all gear lube manufacturers use sulfur and zinc compounds as their EP (extreme pressure) additives.

Now, 607 is nothing special on the surface - it is a paraffinic base (mineral) gear lube, and contains the same EP additives as the rest. Amsoil 75w90 tested out at about 350 Newtons (N) in EP testing. Better than most 75w90's. A very good product. But LE has one more additive up its sleeve, and it's a dandy.

LE 607 tested out at over 1000 N! This must be attributable to their Almasol EP additive, which is proprietary and made by their additive subsidiary. According to their specifications, it has higher load bearing capacity than even moly, on the order of 400,000+ psi. Huge. They also claim it is inert and attracted to metal, forming a coating which fills in the gaps between asperities in a manner which increases load carrying capacity, while reducing friction at the boundary level. We were able to verify this by using SEM analysis (scanning electron microscopy). We treated a gear system with the 607 and ran it at high RPM, then removed a section for analysis. The treated metal looked very smooth compared to the untreated metal. This reduces friction and should result in lower operating temperatures.

The 607 was extremely low in adulterants, indicating it is made of very highly refined base stocks. It has no VI additives, of course, since it is a single-grade oil. It will also have complete shear stability. It is purple in color. The TBN was 1.5, typical for a gear oil. The flash point was around 400degF, somewhat lower than usually seen in a 90w, but inconsequential.

It has a pour point of -11degF, below which it will be extremely thick. So it is not for Arctic use for sure, but then, no 90w is.

By comparison, the Amsoil has a pour point of about -46degF. By other comparison, Schaeffer's 90w bottoms out at 0degF.

LE also makes some synthetic 90w gear oils, made of PAO's and esters, but without the Almasol EP additive. The pour point is extended to about -27degF.

The LE 607 is widely used in racing, and by many Nascar teams, according to contacts in the industry. I cannot verify that, but based on its analysis, that would not be surprising. Its performance is quite amazing.

Red line vs. LE oil samples

Although these samples are from gearboxes from (gag) a Honda S2000 there was good time and $$$ thrown at the research.
The Redline 75W90 gear oil sample was taken from a stock 2003 Honda S2000 Torsen LSD differential at 21515 miles with an OCI of 15K miles. The Lubrication Engineers LE 607 SAE 90 gear oil sample was taken from a stock 2004 Honda S2000 Torsen LSD differential at 26250 miles with a 11.4K OCI.

Element/RL/LE/Universal Avg
[email protected]/83.7/93.4

Mobil1 75w/90 vs. RL Heavy Duty Shockproof

These 2 samples are taken from a 2000 Honda S2000 with FI (SC) and 4.44 final drive gears. The first is Mobil 1 75W90 at 35K kms and 4K kms on the sample. The second is RL Heavy Duty Shockproof at 39K kms with 4K kms on the sample. Wear Check MOB did the analysis. The lab was concerned about the Al reading with RLSP.

Element/M1/RL HD SP
[email protected]/102/none provided
07-19-2013 01:56 AM
Marco 7 Let me add a little bit of info for those that might want to read on a little. When I received the Tera Lows it came with the rebuild kit including a aftermarket intermediate shaft. I used that shaft for the better part of about 10 miles, yep only 10, and then decided on the back of another post to order a novak intermediate shaft because its the best available, including some odds and ends from Novak for that case, mostly bling stuff like ali covers etc etc.. The jeep is not my daily driver so I parked it in the garage until the Novak goods arrived.

When the goods arrived, I stripped the whole affair and replaced the intermediate shaft, rollers and thrust washers with the novak goods. Despite only 10 miles of testing around my suburb on the Tera Low shaft, I noticed an already significant discoloration on the Tera supplied intermediate shaft, and with no prior experience took it to be normal because of the loads on the intermediate shaft from the intermediate gear.

Used the Novak parts hoping on less noise which was not to be, probably about 80 miles of driving, and then decided to manufacture the taper bearing intermediate shaft, which was done, and as I had a spare case with a spare pretty much unused set of Tera Low gears, rebuilt a 2nd 20/18 hybrid case with taper bearing intermediate shaft + Tera Lows. As documented above, slightly less noise but still there none the less.

Sealed and shelved the first case with the Novak / Teralows, and installed my spare case with the Taper intermediate shaft / Teralows.

We have an annual run to Swaziland for good mountain offroading without inspectors chasing your every step, and on the back of that pending June trip, I gave a mate of mine my Tera Low intermediate shaft (10 miles old) to use in his CJ-5.

Now hear this, I flat towed his CJ-5, in neutral (case and gearbox) with fresh oil approx. 200 miles to Swaziland, he slow trail drove his CJ-5 in Swaziland no problem, got flat towed another 200 miles back home, where he calls me a day later telling me his Dana 18 is now whining like a banshee!

He has stock almost new gears in his case, so I removed the Novak shaft from my spare case as I no longer needed the shaft, took it to his house and got to removing the virtually unused Tera Low supplied intermediate shaft I had given him, from his 18.

Gents, he travelled about 150 offroad trail miles in Swaziland under his own steam, thats it, no high speed tar driving at all, and the Tera Low supplied shaft was toast, like seriously stuffed, there was over 1mm of wear on either ends of the shaft, not sure what that is inch wise, but its plenty, and the case was full of the iron filings from the worn shaft.

Now thats pathetic to say the least. Why the heck sell awesome gears with really crap (technically free) aftermarket shafts, rather pass up on that offer, allow clients to purchase better goods elsewhere and make peace with the fact that you wont have to deal with complaints, go figure.

Anyway, if anyone out there is experiencing a lot more noise than normal, has just replaced their gears & intermediate shaft with the shaft supplied in the Tera Low rebuild kit, do yourself a favor and pull that intermediate shaft, chances are that your excessive noise is by default a junked crap affair, go Novak and be happy you have spent your Dollars wisely..

For the sake of clarity, I don't have an issue with the Tera Low gears, its a pity that they are noisier than stock, but the crawl benefit is fantastic, no problems with their aftermarket support either, they went out of their way to help me with spare gears, so big thumbs up there.

Cheers then, happy wheeling!
07-19-2013 12:16 AM
Marco 7 Gents, thank you for your feedback, truly appreciated. My case starts a groaning sound at about 1000rpm, call it a low frequency rumble, which develops into a whine and stays there pretty much all the time. A lot of time has passed since I originally queried the noise, I did manufacture a taper bearing solution on my lathe to replace the intermediate shaft, and made sure I was using the correct Timken bearings just to be sure I get the best all round. The intermediate shaft conversion has helped somewhat, but afraid to say that it is still noisy no matter how one looks at it.

i am seriously considering centering the rear axle and changing to the dana20 with the tera low gears. I just need to order the rear sliding gear and I am good to go.

The only snag is that for us, shipping costs about as much as the product, and I sure don't feel like dumping so much more cash in the conversion and gears, only to find the dana20 is still noisy because of the tera lows..

Changing to a different case means I have tera lows sitting here gathering dust, with a very small potential resell market.

Damn, going to have to toss a coin over this one..
07-16-2013 10:30 AM
TimCubed Mieser, Its not speed its RPM...Just guessing starts at 1000 RPM. Not growl but a high pitch whine. Once it starts the tone or the volume dose not change much just high to higher.
07-16-2013 09:51 AM
Mieser At what speeds do the Tera gears start to howl?

Honestly, I would be pretty mad if I spent that kind of money on gears and had to use ear plugs.

I wonder if the old O'Brian gears did the same thing?

The D18 is a good little case, but I think it has its limitations. I do have to wonder why we haven't seen an aftermarket alternative? The market is pretty small, but having the rear output dropped really helps with the driveshaft angles.
07-16-2013 09:32 AM
TimCubed Marco7 I have a D-20 case Tera low kit with offset D-18 internals and Warn over drive. I broke my first over drive sending metal throughout the case. Wasting the first Tera low kit. I'm on the second now. Yes both of the damn things are annoyingly loud I have to use ear plugs on the road or will get a headache. Offroad low RPMs not as high pitch, it's bearable. I've used synthetic oil and standard gear lube no difference in tone. The Warn over drive will pop out of gear and grind gears while shifting with the synthetic. Mr Willys says not to use the synthetic oil with the brass synchro ring in the overdrive. He is right. With this set up the t-case is still offset. Bottom line I love the whining POS, just wearing ear plugs is the only fix.
04-04-2013 08:11 AM
Marco 7 MrWillys I completely understand about the leaks!

The last thing I want to do is create a negative impression on the gears, but it is what it is, ultimately I also thought that there could have been an adapter issue, but its a brand new AA unit with brand new bearings, plus with the stock gears the noise is much much less so I guess I've just hit bad luck in this regard.

Admittedly the Tera gears look like a work of art, very well machined, and despite the noise I could not see any noticeable points of wear or possible contact points due to misalignment. The Tera team told me to run the gears in for a few thousand miles to see if the noise reduces in some or other way. Problem is this is not my daily drive, a few thousand miles will take me 5 years! I've had varying comments locally about the wearing in bit, not really sure if it will work.
04-04-2013 07:54 AM
Marco 7 Thank you Mieser.

Our speed is in Km/Hr so MPH would be a lot lower, but my max speed in town is about 60km/hr, freeway driving about 100km/hr so I guess that would top out at about 60mph max.

I hate to think the Tera gears are at fault, but then the older stock gears are quiet so i'm starting to make my mind up in that regard.

Nothing much happening in the office today so I went out to the local steel merchant, bought 2 pieces of 1,75" x 7" stock and I'll start turning a custom taper bearing intermediate shaft when i get home tonight.

I also picked up the correct timken bearings & cones, with a bit of luck I should have the taper roller system running by the weekend if of course my lathe will cut the intermediate gear without annealing.

If not, I'll get a quality machine shop to do the gearcutting for me, but first I try!

Either way, if the noise is still as before, then I can still use the taper system in a dana 20 setup, but I really really do not want to go the centered diff route right now..
04-04-2013 07:42 AM
MrWillys I agree with Meiser. TeraLow's make noise, but stock ones don't sounds odd to me, but does say it must be the TeraLow. I've been running Tera's for over 10 years with no problems. I did have a noise back in 06, so I swapped in a NOS set, but still had the noise. Turned out it was my ages old Novak adapter from the TH350C had worn out. Novak rebuilt it at no cost, and would even hear of me paying anything. I put my Tera's back in at this time, and haven't had a problem since.

Meiser's T-case is better than mine though, because mine leaks!
04-04-2013 07:32 AM
Mieser Tough call. My old 'custom' unit that had the homemade input gear for the custom adapter was pretty dang noisy.

My new case, I just got done building, with all oem/spicer parts is surprisingly quiet. I can still hear it, but it is WAY better than I ever thought it could be.

What kind of speeds are you running? I don't think these old transfer cases are designed to run super high speeds on the road. I think about 50-60 is their happy speed in the long term.

If the stock gears made a huge difference over the Tera gears that is probably the tera gears fault. I would have thought that the new Tera gears would have been quieter than stock? I don't think Tera would have sent you another complete set of gears if they didn't know the gears could be a problem.
04-04-2013 01:37 AM
Marco 7
Help if you can please

So I saw this thread while surfing for possible feedback and I thought I might give it a try and see if anyone here can help as it all seems Dana 18 related.

I have a 76 CJ-7 with 400 cube SBC + TH400. I decided to do away with the quadratrac last year May when original Morse chains were discontinued.

I ordered an Advance Adapters Th-400 / Dana 18 adapter, and built up a large hole dana 20 case as a Dana 18 configuration.

Novak hardened intermediate shaft, full rebuild kit including brand new timken bearings.

Brand new Rear output shaft sourced through Novak, OE unit, not Omix.

Decided to go with the Tera Low 3.15:1 gearset, and built the unit to spec.

Now jeeps of that era are few and far between in South Africa, so getting help here is really a thumbsuck at best so I really don't bother much with local technical advice.

Bottom line, the transfer case is so noisy at normal range driving its unbearable. The noise starts as a loud drone at low speed becoming a loud whine at high speed. As a test I decided to install stock 40+ year old gears in the case as comparison, much much quieter, still makes some noise, but not nearly as bad.

So I called Tera Low and queried if the excess noise could be because of their gears, they kindly shipped me a complete new set of gears with gasket set NO CHARGE!! to compare, big big thumbs up to the Tera team, thats service!

Same damn noise all over again, I've tried different viscosity gear lubes in the case, no notable difference, I've checked and re-checked the rear shaft end play, no notable difference again.

I've got a friend with a CJ-5, Dana 18 with Fairey overdrive unit, stock gears, and its quiet, like really quiet.

So where am I going wrong, I'm considering throwing a piece of stock in the lathe and cutting up a taper bearing system for the intermediate gear / shaft, but I'm not certain just how much this will effectively reduce noise.

Alternately I'm considering just purchasing the Dana 20 rear sliding gear and converting the whole affair to Dana 20 with centered rear out, but this means a whole damn axle change, exhaust re-routing and brake re-engineering at the very least.

Am I expecting too much on the dana 18, is it a really noisy case, or maybe someone out there has had a similar experience with the Tera Low gears, not really sure where to go on this one, but I would really appreciate feedback if any!

With real thanks - MArco 7
02-06-2013 10:41 AM
Mieser A few more misc notes....

The fill and drain plug is 1/2" npt. McMaster 1072A23 is a nice little 1/2 pipe plug with a female 3/8" Hex 'head'. They have a magnet attached to catch the gunk. They are $3 each. They also work in most old transmission drain and fill holes. These female head plugs give more clearance also. They do need a wrap of teflon tape to seal properly I think.

The screws that hold the bottom pan are 5/16-18, 5/8" long. I am going to try some flanged units with the vibration ridges on the bottom. I hope these will put a little more even pressure on the bottom of the pan. They still need the threads sealed and locked if possible.

I was able to find a Timken seal for the shift rails.
(also a national cross.......NATIONAL Part # 471466)

Part Number: 470009
Weight: 0.045 lbs
Notes: 2 required
Maximum Working Temperature (F): 225
Minimum Working Temperature (F): -40
Package Quantity: 1
Seal Housing Bore (in): 1.124
Seal Housing Material: Steel
Seal Installation Style: Press Fit
Seal Lip Material: Nitrile
Seal Outside Diameter (in): 1.13
Seal Shaft Size (in): 0.625
Seal Width (in): 0.252
02-06-2013 07:09 AM
Originally Posted by silver47 View Post
So if the D18 is used with sm465/sbc 350 and running a set of 36in tsls will it withstand the bind or will it break? I am just doing some average wheeling and wondering if i need to dig into it or not, it has a set of new gears with the original gear ratio. Where is a cheaper place to get an adapter to the sm465 Novak is a little out of my price range im thinking.
Driven responsibly it should hold up. They are a dang tuff little unit.

Anything can break though. Make sure your driveshafts are not binding. If they bottom out on the slip they can cause the outputs get snapped off. The same goes for running out of angle capacity on the u-joints, if your axle droops and binds the u-joint you have a pretty good chance of snapping off the output.

Keep all the bolts tight, especially the adapter bolts, front housing bolts, and rear housing bolts.

There really isn't a cheap option for D18 adapters unless you find someone used. A T18 with a factory D20 adapter is about the least expensive option if you can adapt it to your engine and transfer case housing ( it is a large 4" bore adapter ).

If your set on running the sm465 you either need to pony up the money for a quality adapter, hope you can find one used, or have your own machine shop to make your own.
02-05-2013 10:02 PM
silver47 So if the D18 is used with sm465/sbc 350 and running a set of 36in tsls will it withstand the bind or will it break? I am just doing some average wheeling and wondering if i need to dig into it or not, it has a set of new gears with the original gear ratio. Where is a cheaper place to get an adapter to the sm465 Novak is a little out of my price range im thinking.
02-05-2013 08:48 PM
Originally Posted by sammyg View Post
3/8 NPT... I have a barb on mine and ran the hose up the firewall
Perfect, thanks.
02-05-2013 08:44 PM
Originally Posted by Mieser View Post
Does anyone know the thread size of the factory breather port on the front output housing? It's not 1/2" NPT
3/8 NPT... I have a barb on mine and ran the hose up the firewall
02-05-2013 08:13 PM
Mieser Does anyone know the thread size of the factory breather port on the front output housing? It's not 1/2" NPT
11-12-2012 10:26 AM
Originally Posted by Mieser View Post

I am pretty sure the front part of the intermediate shaft bore is smaller the rear part....or the OEM shafts are tapered ever so slightly. My OEM 1.25" shaft was REALLY tight the last 1/2" or so.....like deadblow hammer and swearing tight.

Anyways, might measure the AA parts to see if they CAN go in backwards?
They're installed right now, and I'm not about to go pull it apart, ha ha. Called AA and was transferred several times to different tech guys. One actually had to go get an adapter and look at what I was talking about before giving me a blessing to go at it with a carbide burr.
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