Transfercase noisy

[chuck]

Hi all,
Need some advice.My transfercase in my M38 whines more than my M37 at speed over 35mph .I suspect it's a worn intermediate shaft and bearings?Is it possible to change these without removing the t-case from the jeep? I just got it on the road after a 2yr assembly.
Chuck

[wesk]

I don't think so but even if you could and had a lift to get her up high the bearings and rollers would be a real PITA to work with under the jeep.

[chuck]

Thanks Wes,after all the work I've done on it ,I was hoping for an easier way out.

[idiocrates]

I'm kinda new at this.....but I wonder.....I know it would be kinda hit or miss.....but if you could cut a piece of pvc pipe or a wooden dowel of exactly the right length......load the needle bearings and thrust washer into and on the intermediate gear and insert it through the pto inspection cover.....with the xfer case input gear and nut removed.....and then have a second person drive in the replacement intermediate shaft. It might be worth one try....but then I'd definitely have to agree with Mr. K......it was kinda a pain replacing this assembly on my xfer case and it was clean and laying upside down on my work bench. Would definitely need lots of assembly lube to plaster everything together.....and getting the gear past the transmission output shaft might prove impossible too. Oh man....I sure don't envy you. Good luck!

[chuck]

Looks like I'll put up with the noise till I can afford the parts.Who did you buy your parts from?

Chuck

[idiocrates]

I went with Novak Conversion parts. Their url is:

http://www.novak-adapt.com/catalog/dana_18_parts.htm

They probably aren't the cheapest folks around but they make an intermediate shaft with a slot on each end for an o-ring seal between the case and the shaft. My intermediate shaft had to be changed anyway so I figured why not give the o-ring thing a try.


I had a little trouble at first trying to get the front end of the shaft's o-ring all the way through the case and the assembly without damaging the o-ring.....you really need to have everything lined up.....but once I got it through at least so far it hasn't shown any sign of leaking. And I guess you know there were like three different size intermediate shafts in these xfer cases.....right? Make sure you get the right one for your case!

[wesk]

A blown transfer can leave you walking a long way. I would think twice about investing the time, money and labor and sweat in a partial repair the hard way when a thorough rebuild will give you a warranty that will hold up for years.

Don't forget to use this rebuild guide:
http://www.willystech.com/wt/Model18TCa ... rCase.html

[TomM]

The guide is invaluable for your rebuild. Do not be tempted to cheap out on the imported intermediate shafts. Their hardness and quality is hit or miss. Novak seems to have gotten it right and if you have a problem their offices and manufacturing are in the USA. Novak has o-rings that are installed in groves in the IS to assist with leaks. I found one of them to be hard to install and used a bit of permatex #2 on the case as the shaft was driven through instead.

If you take the time to put a dab of sealer on all of the bolts that go through the case to the oil you can end some of the weeping and drips.

Before you remove the t-case from the transmission, read the part about securing your transmission gears in place as you remove the transfer case. If you do not take the time to do it, you will also be rebuilding your T-90 transmission.

Tom

[artificer]

It is very possible to do without dropping the T/F case & I have done a few times.
Advance Adapters Paso Robles CA have very good permanent fix for this issue & not too expensive for what you get.....this is their catalogue reference.
http://www.atlas-tc.com/pdf/712/716005.pdf

[idiocrates]

Well.....it looks good on paper....but I wonder.....I guess the stock design used helical cut gears to reduce noise.....and because of the additional sideways thrust of the helical gears they designed thrust washers into the system. But I don't see anything in their system to compensate for the sideways thrust.....and they don't say to replace all your gears with straight cut gears. And it looks to me like the back side of the cone must run right against the cast iron case....or am I looking at this wrong? The setup may end up looking like a regular wheel bearing setup.....but aren't the forces involded and how they are applied totally different? Then too.....I don't think there's a machine shop in my area that would even attempt to cut a perfectly good intermediate gear.....but hey....to each his own. Just my $.02 worth.....

[artificer]

Save yourself .02c......
This mod has been around for ever & Advance Adapter have perfected the design for guys with minimal hand skills....or those who are too lazy to do things themselves.
I did this type modification first in 1968 @ my repair business Tamworth 4 Wheel Drive. Also works well with Land Rovers BTW.
You obviously don't know of many machine shops?
The last time I did this modification was in Reno NV & the machine shop charged me $20 to machine the 2 recesses in the new gear.
Much better design than original.
Once properly fitted there is minimal noise compared to original & no wear will occur when properly lubed....will go forever.
As well Novak used to do this but dropped as volume was insufficient.

[idiocrates]

Oh, I'm not trying to be argumentative....but there must have been a reason why they originally designed the intermediate shaft this way and then choose to use the tapered bearings and races on the final drive shaft at the end of the transfer case....I mean other then to make the bearing preload adjustable. I guess I just like to hear the reasons "why" not just do it...it's better. And I'm probably not giving our machine shops around here enough credit.....so I'm takin my $.02 back....and will put it in a piggy bank so next time I have to rebuild my T18 I can afford to do it up fancy. Undeniably, since every mile the jeep makes has to pass around the intermediate shaft it would eventually pay off to make it as durable as possible.

[artificer]

How often do you replace wheel bearings and they have similar thrusts to anything one will get in the transfer case......the original design was just cheap & nasty the operative word being CHEAP.