[saprobe]

a search turned up some good info. i have learned that high wear parts will last longer,and that over all strength on non-wear components may or may not be afected

most of the references were to tools,birdfield joints,output shafts and axleashfts. i did see one reference to R&P gears

what about transfer case gears? i keep shearing the teeth off of the gears,presumably due to sudden shockloads caused by 38" tires and a vehicle prolly too big to be running a spicer 18

at any rate,the gears are by no means lasting long enuff to simple "wear out"

i can get some transfer case gears treated in a cooling cabinet,then retempered pretty cheap.

anyone think it would be worthwhile? could i expect a 10-15% increase in strength?

 

[Aggro]

When you cryo you don't re heat treat. How cold does this "cooloing cabinet" get? -200*c or so? if not it won't do anything.

 

[Chrisjeep7]

i think by cooling cabinet he was just using that as a reference to getting them cryo treated:flipoff2:

not an actual beer fridge

 

[saprobe]

ya,it gets alittle colder than a beer fridge. it cools stuff over a period of hours(12 or 18?cant remember) to -300*C and holds them there for another period ofhours. the parts are then slowly returned to ambient temp and retempered

anything constructive to add now that you have more info,mr aggro :flipoff2:

 

[PIG]

When you cryo you don't re heat treat.

Yup, tempering is just gonna fawk up what you just cryoed.

 

[PIG]

In regaurds to cryoing gears. In theory it may work to prolong the life of the gear in regaurd to wear. However, it sounds like the failure occurs when the gear is being shock loaded. Where exactly is the gear breaking at? Do you have PICS?

 

[saprobe]

unfortunately i dont have any pics,but the gears are definatley breaking due to the shockloads.

number 1 case let go with the front tires in a mudhole when i dumped the clutch in high range,reverse in order to get more wheelspeed.

number 2 case was not a complete failure,i found 3 or 4 teeth missing from the input gear during some routine pre-woods maintenance.

number 3 case let go while attempting to climb a very steep,very rutted,muddly slippery hill very fast in 2nd gear,resulting in lots of wheel speed and bouncing.

by the time i get the case out,all the gears are toast,with most of the teeth missing from the low range gears. number 3 actually letme drive back to camp in high range,but i destroyed the high range gears as well by being a lazy dumb ass and trying to contiue wheeling in high range with broken low range gears and chunks in the bottom of the case rather than swapping in the spare that i brought. by the time i got back to camp that time,it had completely locked up and every gear in it was toast.

i am reasonably sure that the 29 tooth input gear is going first,and then destroying the rest of the case. what puzzles me the most is that the 10 spline output shafts are holding up fine,as is the super cheezy coupler that creates 4wd in the shift tower.

 

[Scout Dude]

It sounds like you need to look into the Land Rover offset t-case (LT230? I think) as a replacement to your D18...remember, you can't polish a turd!:flipoff2:

 

[LCOwner]

It sounds like you need to look into the Land Rover offset t-case (LT230? I think) as a replacement to your D18...remember, you can't polish a turd!:flipoff2:

I agree sounds like you're asking too much from the 18.

 

[saprobe]

It sounds like you need to look into the Land Rover offset t-case (LT230? I think) as a replacement to your D18...remember, you can't polish a turd!:flipoff2:

land rover? now THAT sounds like a worthwhile swap. i dont need an offset t case. :flipoff2: i am currently running my offset spicer 18 into a centered 14 bolt

there is no doubt that im expecting too much from the spicer 18. but that wasnt the original question was it? im just curious about wether the treating helps in ths shockload,overall strength dept,or just keeps things from wearing out sooner.

eventually ill be swapping out the t18/spicer 18,but it needs to get me prolly thru the upcoming summer.

 

[redrangie]

land rover? now THAT sounds like a worthwhile swap. i dont need an offset t case. :flipoff2: i am currently running my offset spicer 18 into a centered 14 bolt

there is no doubt that im expecting too much from the spicer 18. but that wasnt the original question was it? im just curious about wether the treating helps in ths shockload,overall strength dept,or just keeps things from wearing out sooner.

eventually ill be swapping out the t18/spicer 18,but it needs to get me prolly thru the upcoming summer.

The LT230 is one of the MOST bullet proof lockable t-cases around, with PTO,Crawler, Overdrive and various other options. Oh, did I mention that it can be converted to Part Time as it was originally designed for full time?

I don't think I have even heard of one shitting the bed.


j

 

[66CJdean]

I would expect that yes it would help the gears out and the better they are the more it will help. In allot of instances you do reheat parts after they come out of the cooling bath most often in the 500-550 range. Cryo is -300* and like stated it will take 18+ housrs depending on what the metal is but mor importantly how thick it is to do it proberly so you don't shock it. They have used CO2 and that is -120 and that hepls but it isn't nearly as effective as cryo.

 

[stainless steal dave]

unfortunately i dont have any pics,but the gears are definatley breaking due to the shockloads.

number 1 case let go with the front tires in a mudhole when i dumped the clutch in high range,reverse in order to get more wheelspeed.

number 2 case was not a complete failure,i found 3 or 4 teeth missing from the input gear during some routine pre-woods maintenance.

number 3 case let go while attempting to climb a very steep,very rutted,muddly slippery hill very fast in 2nd gear,resulting in lots of wheel speed and bouncing.

by the time i get the case out,all the gears are toast,with most of the teeth missing from the low range gears. number 3 actually letme drive back to camp in high range,but i destroyed the high range gears as well by being a lazy dumb ass and trying to contiue wheeling in high range with broken low range gears and chunks in the bottom of the case rather than swapping in the spare that i brought. by the time i got back to camp that time,it had completely locked up and every gear in it was toast.

i am reasonably sure that the 29 tooth input gear is going first,and then destroying the rest of the case. what puzzles me the most is that the 10 spline output shafts are holding up fine,as is the super cheezy coupler that creates 4wd in the shift tower.

a 29 tooth dana 18 case will never hold up to this kind of use / abuse - how about a atlas or a 205? the case on these dana 18's are weak at least make a solid 1/1/2" alum. block to replace the sheetmetal pan on bottom of transfer case this will help stiffen the case so it does not flex so much under a load- it will help but you still have small out put shafts and gears............

 

[Old Scout]

The LT230 is one of the MOST bullet proof lockable t-cases around, with PTO,Crawler, Overdrive and various other options. Oh, did I mention that it can be converted to Part Time as it was originally designed for full time?

I don't think I have even heard of one shitting the bed.


j

You left out that there 3.25:1 stock!

 

[saprobe]

a 29 tooth dana 18 case will never hold up to this kind of use / abuse - how about a atlas or a 205? the case on these dana 18's are weak at least make a solid 1/1/2" alum. block to replace the sheetmetal pan on bottom of transfer case this will help stiffen the case so it does not flex so much under a load- it will help but you still have small out put shafts and gears............

ill be swappig out the t18 for an np435/203/205 eventually.

my big dilema is wit the PTO. i have a bed mounted pto winch that i dont want to give up. i dont want to screw with redoing the pto until i swap in the new tranny,and in that case my ony option is goig to be to run one off of the 205,wich would be ok,but id have to change it if i wanted to run someting else later.

the game plan is to use a hyraulic motor to spin the pto winch via an engine mounted pump so it wont matter what tranny i use. thats gonna cost alittle bit of $$ and mods to my tow rig,trailer and some other unexpected expenses are gonna keep me from being able to do te hydro conversion and doubler swap till sometime next year.

as for te other comments, im running the the spicer 18 in a later model(late 70s) d20 housing in order to bolt it to my t18. do you still think case flex is a prollem?

also,do you tink the 26 tooth input gear is any stronger? ive got plenty of good 2.03 low range parts floating around,and id thot about building a 2.03 spicer 18,just for shits and giggles to see if that wold hold up any longer.

thanx for te input

 

[saprobe]

The LT230 is one of the MOST bullet proof lockable t-cases around, with PTO,Crawler, Overdrive and various other options. Oh, did I mention that it can be converted to Part Time as it was originally designed for full time?

I don't think I have even heard of one shitting the bed.


j

ok,ok,im convinced your lt230 is the coolest thing since sliced bread :flipoff2: but its still not a worthwhile swap.

i do like rovers. but i have never seen one of those transfer cases for sale,and im sure it wont bolt up to my t18. not to mention i dont give a rats ass about lockable full time transfer cases in my trail rig