Transfer case adapter mount failure...again

[MrBouncer]

This is the second failure of the transfer case adapter mount I have had. Can anyone give me ideas on what and where to look for the problem. All LOOKS good but there has got to be something else wrong. And also where to find another.

 

[doghead]

How did it fail? Pics? Explanation?

 

[MrBouncer]

It was parked for a couple of weeks, wouldnt start so I pushed it to the garage to put the charger on it. Maybe 40ft. Did that and went about my business later that day noticed the puddle of tranny fluid under it, checked it out and found the crack. . I can only assume that it had already began to fail before this because the damage seems dramatic for such an uneventful happening.

 

[doghead]

Where did you get the adapter?

You know about the common issue with forklift damage and cucvs, right?

 

[MrBouncer]

Dont remember the name of the company I ordered this one from, I just remember it came from New Hampshire, but this adapter has been in the truck for at least three years. I became very aware of forklift damage when the first one failed. I would think that any lift damage not addressed with the original failure would cause the replacement to fail sooner and under a less stressful situation. The crossmember was found to be bent when the first one failed, I repaired it and replaced the adapter. Like I said at least three years ago with a considerable amount of driving on and off road since then.

 

[cucvrus]

Is the truck lifted? Is the front driveshaft spline free and the CV joint moving freely? That can break transfer cases and adapters. Are the mounts on the cross member in good shape?

 

[richingalveston]

adapter and housing breakage can often be caused by driveshaft damage which creates binding, improper slip length or the cv joint binding. If the shaft cannot slip it will push and pull on the t-case. When the front does not slip, the t-case or adapter will not last long. The rear will do the same but may take a little longer since it is inline with the tranny.

 

[Westech]

That is what j have seen is stuck front drive shafts. It's not a bad idea to take the shaft out and clean the slip shaft. Too much grease can cause a "hydro lock " condition and brake the case and or adapter.

 

[cucvrus]

Yes it can lock up and it is not a bad idea to just remove that front drive shaft once a year and clean it real good in the CV joint area also. I take my truck to the dealer for LOF ($42.) service and these new mechanics never seen one of the needle grease joints. That joint in the CV area is a key component. Especially in hard off road use and salt and water. That joint should fall down under its own weight and the slip spline should move freely with its own weight (almost). I hope that is helpful I keep my CUCV's in top notch running order. Ready to use at any time.
Keep it maintained and clean and they will run forever? I only hope. Good luck.
Hey I wanted to add this. Are the front and rear drive shafts straight and in balance. That vibration over time can fatigue and crack things. A slight dent in the rear drive shaft can cause a slight vibration that will do damage over time.

 

[kingchr]

Hey I wanted to add this. Are the front and rear drive shafts straight and in balance. That vibration over time can fatigue and crack things. A slight dent in the rear drive shaft can cause a slight vibration that will do damage over time.

This!

I just had to rebuild the transfer case and replace the adapter because I failed to have my rear drive shaft checked out after a catastrophic failure of the rear most U-Joint.

The drive shaft was bent by this failure and knocked everything out of whack but I didn't notice at 11 pm... Drove it about 200 miles with just a new U-Joint and then, next morning found that I had to replace my transfercase adapter, rebuild the transfer case and add 3.5 quarts of AFT to the trans because there was a LAKE of ATF under the truck...

Had a new drive shaft for the rear made and had the front gone over (was slightly bent from forklift love) and all seems to be good now... *knocks on wood*

 

[MrBouncer]

Could having one hub locked and not the other one cause enough stress to cause this? Maybe combined with worn mounts and a crossmember that is bent every so slighty. When I say slighty as in not noticable with eye but will not line up with bolt holes in the frame. Off less than a quarter of an inch. These are some things I found today. The hub lock situation is due to a broken knob and a lack of attention to detail.

 

[Iceman3005]

Bent drive shaft, even a slightly bent shaft can cause this, or improperly balanced shaft.

 

[Keith_J]

Iceman nailed it. Cast iron doesn't like fatigue, cyclical stress cracks it easily.

 

[MrBouncer]

I plan on replacing the crossmember and adapter mounts. suggestions on where to find them. Thanks for all the help and thanks for any future help.

 

[cucvrus]

Mr Bouncer PM sent.

 

[MrBouncer]

I am sure someone has ordered mounts from LMC for the motor and transmission. I see three different sets offered for the transmission that "look" compatible. Part number 34-0320(upper)/34-0322(lower). Then 34-0361(complete set). Which ones??

 

[cucvrus]

You don't need this adapter and crossmember anymore? It has the mounts on it. Just asking no problem.

 

[MrBouncer]

Unless the mounts on it are new I am going to replace them. I will not be putting a third adapter in.