My Willys 3A and 3B Community

3A, 3B, DJ Technical Knowledge Base => "Original"-- Technical Questions, Answers, Observations => Topic started by: Tucker on May 27, 2014, 01:29:48 PM

Title: T90/Dana 18 leak help
Post by: Tucker on May 27, 2014, 01:29:48 PM: Hi folks,

Finally added some GL1 oil in my efforts to button up the tranny and figure out what holes I'm going to need in the tub for the shifters, only to find a small leak right where the Dana 18 and T90 meet up (at the bottom). I checked to make sure the bolts were snug, which they were, but the leak persisted.ï¿½ I swear I put the RTV and the gasket on right, but clearly my amateur skills have caught up with me here.

I'm assuming I'll have to pull the transfer case, put on a new gasket with more RTV, and then mount it back up, but I wanted to double check that there isn't another super-duper secret trick that will allow me to skip said removal and repair.ï¿½ Contemplating a three hour job for a two dollar gasket replacement is depressing me.

Any tips?ï¿½ Dip the rig in RTV?ï¿½ Hug the Dana 18 in a firm but appropriately platonic embrace?ï¿½ Burn a Chevy as ritual sacrifice?ï¿½
Title: Re: T90/Dana 18 leak help
Post by: Carls_jeep on May 27, 2014, 03:41:09 PM: A gasket set contails a few gaskets for that spot of different thicknesses. At least mine did. I had to measure how much the rear bearing retainer stuck out from the rear of the tranny and use a gasket slightly thicker than that measurement.

That may be your problem.
Title: Re: T90/Dana 18 leak help
Post by: athawk11 on May 27, 2014, 03:43:17 PM: Hi Tucker,

All great ideas! ;)ï¿½ It's good to keep a sense of humor when dealing with the leaks on an old Willys.

I don't know of any top secret tricks to stop a leak between the Tranny and the TC.ï¿½ Unfortunately, pulling them back apart is the solution.ï¿½

Now here is the troubling part...Even if you pull them apart, replace the gasket after dipping IT in RTV, you may still have an annoying leak.ï¿½ The surfaces of these boxes may be...un-seal-able.ï¿½ Tolerances, and the potential leaks they may cause, were not a huge concern back then.

Remember to use thread sealant on your bolts.ï¿½ I can't remember for sure, but I believe some of these connection points penetrate the inside where the gear oil resides.ï¿½ After learning the hard way, I use thread sealant on every bolt...regardless if it penetrates or not. :-[ï¿½

Tim ï¿½
Title: Re: T90/Dana 18 leak help
Post by: 1955CJ-5 on May 27, 2014, 05:42:12 PM: All of the above, but also the flat lock plate that slides into the notches on the counter shaft and reverse gear shaft must be installed correctly or the the transfer case will not mate up flat against the transmission....check that the lock plate is not interfering with the fit.....

Good Luck!
Title: Re: T90/Dana 18 leak help
Post by: Tucker on May 27, 2014, 10:24:00 PM: Great feedback, guys. This is giving me some good stuff to work through before I pull it.

I took pics of my rebuild and just verified that I'd put the locking plate in correctly (from the top), so that's good.

However, I may not have put on enough thread sealant for the bottom center bolt that attaches the Dana 18 to the T90, so I'm going to pull it, clean it thoroughly, blow air through it to get and residual oil off the threads, goop the heck out of the bolt with sealant, and reinstall. If that ain't it, I'll weep softly and then pull the t-case.

I used black RTV on my bolts. Is there something better I might want to use?
Title: Re: T90/Dana 18 leak help
Post by: 1955CJ-5 on May 27, 2014, 10:34:37 PM: Permatex makes a Thread Sealant, #14a, specifically for threads as you might guess...

You can use it alone or there is also a primer/activator that works to prep the surfaces and speed the curing process..

Then there is always good old Permatex 2b that I've used for nearly everything with good results...

I've no experience with the black RTV but I'm sure it has it's uses....
Title: Re: T90/Dana 18 leak help
Post by: athawk11 on May 27, 2014, 10:40:30 PM: My favorite thread sealant is Permatex 2. There are surely other good choices. While reading, I have found that Permatex 2 is the most common and recommended choice for the members of the Flat Fender world.

Tim
Title: Re: T90/Dana 18 leak help
Post by: PeterL on May 28, 2014, 06:27:26 PM: I highly recommend Locktite 515 for flanges. This is NOT an RTV and will allow you to reassemble the unit and add oil immediately. Which is something you should not do with RTV. We use it in my shop and have had superior results. It is far better particularly when you have joints that are not 100%. It took a bunch of my old timers awhile to get used to the fact that it looks more like a gel or decorative cake icing. Believe me it works. TRY IT!!!! :D