overdrive D18 noises

Hi guys, I’m having some disturbing noises coming from what appears to be either the D18 transfer case or the warn overdrive at fist I thought it was coming from the transmission (T98) then I jacked it up and put it in gear and sounds to be coming from the overdrive or transfer case area. My question: is there something that goes out on these overdrives? It only make noise at higher RMP’s but does not sound good at all, the D-18, T98 and overdrive have all been rebuilt with only around 1000 miles on them.

Thanks,
Chip.

 

Did you check the oil level in the transfer case? The overdrive gets it's oil from the transfer case and fills via a "scraper" from scraping the oil from the barrel gear. As the overdrive fills with oil the oil level in the transfer case drops. Common mistake I've seen is people fill up the transfer case with oil but neglect to re check it after driving it around for a while.

 

I did not check the oil level, if this is the cause I would think the damage is already done, I know for sure I didnt recheck the oil level after filling.

Chip.

 

two options the way I see it.
1) pull the overdrive and inspect
2) drop the transfer case pan and inspect
or maybe both

 

I'd top it off with proper oil and drive it. If noisy then inspect. if noise goes away then you may be ok. Most you've got to lose is a little gear oil. Checking it at least will tell you if it's low or not and if it could be part of the problem.

 

Thanks for the replys, I will start by checking/adding oil.. maybe I get lucky on this one.

Chip.

 

Can you be more specific about the sounds you're hearing? Is this something that just started, or has it always been there? The Warn OD has a "howl" all it's own, and the D18 can be kinda noisy, too-especially if it has a few miles on it & the intermediate gear bearings are worn...

 

Hi Doug, the noise just started a couple of week ago and sounds like a heavy vibration when driving at higher speed and I can also hear it when I jack the jeep up and run it inplace sounds to be comimg in the overdrive area and does not sound good maybe like roller bearings going bad. I did check the oil level in the transfer case last night and the level was just below the fill hole by maybe 1/4", does the overdive only get its oil from the transfer case?


Chip.

 

Yes unfortunately. Sound like it's time to follow Jpflat2a's advice and pull the pan and/or overdrive and take a closer look before more damage is done.

 

I agree, I am going to pull both the overdrive and transfercase pan to see what is going on..

Thanks,
Chip.

 

I drained the oil from the transfercase and removed the overdrive less planetary gears, so far everthing looks good except I did not notice much oil in the overdive. question, should there be oil free standing in the unit or does it drain out when it sits? I have not removed the transfercase pan yet, I will do that tonight along with the planetary overdrive gears.

Chip.

 

Was the oil sorta sparkly, like metalflake paint or just brown?

 

I didnt notice anything sparkly but it was off color,

Chip.

 

I pulled my OD cover off last week. It's been sitting for about a month. There was no oil in it at all. I think it makes it's way back to the pan below; and, doesn't take long to do it. Since you have it apart, did you see your snap ring still in place?

 

I havent got that far yet, I pulled the cover unit but thats as far as I got I hope to check it out tonight or tomorrow.

Thanks for the reply,
Chip.

 

ok, I pulled the rest of the overdrive out and removed the transfer case pan last night. I dont see anything wrong with the overdrive although I'm not for sure the spring clip was engaged all the way or not. If the spring clip was not engaged properly would it make a grinding noise? Also, I did notice very fine metal grindings in the transfer case pan, everthing looks ok but the silver color metalflakes are there, where should I start looking?

Chip.

 

Thanks, I will take a look tonignt. BTW the silver flakes are very small like dust.

Chip.

 

Are they magnetic?

 

I'm not sure, I will check tonight, will this help track the problem?