Bad transfer case or other problem?

[flyhigh5574]

Here is the problem. I bought a 91 explorer and was told that the transfer case was replaced recently(within the past three years). Didn't get anymore details on the t-case. I bought it from someone's wife. I noticed at low speeds that there was an intermittent grinding/buzzing noise at low speeds, under 15mph, that would turn into a loud thump after about 5 seconds. this only happend from a complete stop to a start. I soon realized that i could stop the noise by immediately switching to 4hi when the noise started. I was thinking that it seemed that the front wheels were trying to engage by themselves.

I dealt with this for about one month. Things started to get worse with the intermittent turning into an every day occurrence.

About one week ago I was driving at a slow speed, about 10-15 mph and i heard a loud clung and then grinding and crunching noises followed by, what seemed like, front wheeles locking up and releasing. I expected to see parts of my explorer in the road behind me. This happened in 2hi and i didn't touch the electric shifter. After this happened i drove the exp ome at about 15 mph and there was a thump, thump, thump, etc... all the way home.

On the way home i decided to check the 4hi and when i put it into 4 hi the wheels locked up. I gave it a little more gas and then the power finally overrode the stuck wheels and I was rolling again.

I got it off the wheels and put it into drive, 2hi. No wheel spin, pressed the gas a little, no wheel spin. Put it into 4hi, no wheel spin. pressed the gas a little more and POP. all 4 wheels spin and I heard thump, thump, thump with the wheels turning at idle speed. the thumping was definitely coming from the x-fer case with noise raidiating through the drive shaft into the front axle.

My guess is that there are crunched gears or a broken chain in the t-case. any suggestions?

Also, sometimes i can drive in 2hi without any noise and then when i hit a bump, the wheels lock up and then start rolling again after hearing and feeling the sound of something being chewed up!

thanks in advance for any advice!!!!

 

[Mbrooks420]

Your chain is probably stretched out. Maybe try pulling the front driveshaft? Youn are probably looking at a full rebuild kit at the very least, and may be bettert off getting one froma scrapyard. Someone here has one laying around I'm sure.

 

[Brain]

I would pull the front driveshaft and see if the noise stops...if it does it is probably your u-joints on the back of the front driveshaft, if not then it probably is the t-case.

electronic shift Borg Warner 13-54 is the name of the t-case you (and I) have.

 

[Mbrooks420]

Is the t case loud when it seems to be working proporly?

 

[flyhigh5574]

Thanks for ythe replies. I took a look at tll of the u-joints on the front driveshaft, they look great. Can i disconnect the front driveshaft and drive to test it? Thanks

 

[flyhigh5574]

No, the t-case sounds normal when it works properly, just when i hit a bump or something like that, sounds like pieces are rattling around and then crunch.

 

[Mbrooks420]

Yeah, you can pull the front shaft to test it out.

 

[brianbotswana]

T-case noise

My 97 4.0 XLT kicks into neutral when slowing down through about 55 mph. There is loud whirring sound as it happens. When it does this I put the transmission into neutral slow down below 25 mph, put it back into drive and it drives perfectly normally. there is no problem as long as you have even a little bit of power on.

Any ideas?

 

[Mbrooks420]

I'd guess thats related to the tranny pump. Whats the trans fluid color? Unfortanately you are probably looking at dropping the pan.

 

[flyhigh5574]

here's the latest. i removed the front driveshaft and while the vehicle was up in the air, i put it in drive to see what would happen. everything worked as normal. i put it in 4hi and 4lo and no noises. the transfer case sounds great. i took it for a test drive in 2hi and no noise. i went into a parking lot and put it into 4hi and the noise came back. grinding and then thump. i put it in 4lo and same thing. i didn't get the speed above 10mph in the parking lot. when i would put the t-case back in 2hi the noise would dissapear. was then driving home in 2hi at about 35-40mph and then i heard a thumpwhich came with what seemed like the front wheels locking up momentarily and then releasing. this was followed by a click...click...click while driving at about 20mph. sounds like the noise is coming from the front of the vehicle now.

i'm wondering if the auto locking hubs are engaging on their own or are possibly broken somehow. worst case, could this be a problem with the front differential?

also, i dont know if this would help at all, but once i removed the front driveshaft, i turned the yoke on the front axle to see what would happen. for the most part, the front wheels turned, but every once in a while the yoke would slip with no turn of the wheels.

thanks

 

[flyhigh5574]

here is another question. how do the automatic locking hubs engage? what controls them? how would all of this work with the frond drive axle removed? thanks

 

[Mbrooks420]

Neither of my ex's had autohubs. I know there is a plastic part in them, and they are prone to failure, and a common upgrade is to switch to manual hubs. By drive axle, do you mean drive shaft between the t case and the front diff?

 

[MrShorty]

It seems like I once saw a post that described in detail how the auto hubs work. In a nutshell, when the axle rotates (which should only be when the t-case is in 4H or 4L), it engages a cam in the auto hubs which locks it in. What you are describing could be caused by an auto hub trying to engage on it's own. Too much grease in the hub has been known to cause enough drag to cause the hub to engage (too much grease is also known to prevent the hub from engaging at all). Take the hubs off and clean all the grease out and clean the grease off of the cam. See if that helps.

 

[flyhigh5574]

yep, i removed the driveshaft betwen the transfer case and the front diff. also, how hard is it to take apart the front diff just to check it out? does the housing in the back just slip off once you remove the bolts in front? Thanks

 

[Mbrooks420]

I know you can unbolt the front diff cover enoughto get he fluid out, but I don't think the cover can be removed without removing so other things also.

 

[brianbotswana]

I'd guess thats related to the tranny pump. Whats the trans fluid color? Unfortanately you are probably looking at dropping the pan.

I changed the oil when the problem first occurred, no difference except the tranny is now shifting even smoother than before. I took it to the guys who do driveline work for the dealer and they had four last year all with the same problem. They say there is a spring that keeps everything engaged under negative torque conditions and that spring has gone soft and needs changing. I have the tools and know how, where can i get the parts and technical information? I can organise transport from the States to here if I can find what I need.