Transmission, transfer case or Viscous coupling problem ? (1 Viewer)

[jmphilion]

Hi!
I'm 8hr from home and my truck most likely will need to go back on a trailer .

Sorry in advance for that long post, but i want to make sure i say everything i tryied, to better help troubleshooting. and also, you might find how i write the sounds it made, might remind you of early Batman combat words.. have fun



Model:
Stock 1996 FJZ80, with lockers and a added CDL switch. 252 000 miles
Automatic trans (of course)

Recent work: (a hundered miles locally made before going on my 8hr drive)
Knuckels bearings, wheel bearings and remachined birfields and all seals. New discs, calipers and pads

Symptoms:
1) 115 to 130 F front hubs temperature during the drive. (troubleshouted on a TLCA facebook post)
The pads were maybe too thick.

2) On the last half mile, at around 5 mph, i noticed a strong vibration in the drive train, not the steering. And some squiky and klongs, metalic ticking. The drive was not feeling right.

3) few weeks before and for at least a year, i remember now that i felt a very little vibration when turning on a stop sign, or some tire skipping at times when turning on pavement, i remember also that shifting to D made a some what moderate Klong noise, moving the drive shaft, it did this also sometimes when it went to second gear, at times.


What i did for troubleshooting the next morning:
1) i removed the calipers, checked the pads and discs, rechecked the preload on the bearings (around 7-8 lbs with a baggage meter, i had at hand at my mothers) (i did not remove the hubs in the process, just the flange). Bearings felt real smooth and constant on both sides.

2) removed the front Drive shaft and checked the u-joints, front diff flange play (nice and stif), and the front T-Case flange (which had more play, more than i'm used to get on my BJ42 T-case, and some squeaky subtule sounds when i turned the flange more, T-Case was at the neutral position).

3) went to try it on the road around the block (a few hundred meters). When i tryied to engage the CDL before driving (since i got the front shaft off), it made an awfull Trrrrrrttt! sound, i tried a few times, then tried advancing a bit and reverse, and then i got to engage it without sound. Shifting from Park to D was dificult and made grinding noise, went to neutral and reverse to check, difficult to shift but it went. Put it back on D and it made a strong klong noise engaging. Drove a bit and the same noises i got the night before were there, with some stronger klongs or metalic ticking. went back and could not put it to park, had to kill the motor and then putting it to park. But park doesnt hold the truck in place anymore (might be because i was not locked CDL and there is not front shaft). Will check tomorrow.
checked the trans oil level, its fine (i find that funny to think of that but hey..)

4) what could i try ?

What do you guys think it might be ?
Viscous Coupling ?, the whole trans or t-case ?

Options.. ?
What could i do to drive it back, can i drive it back after a quick fix ?
Most likely it will be on a trailer to ride back home, i need to leave in a day.

I did not want to go on the P/T route, but could that fix it ?
anything else i could look into.. ?

Thanks for your help!

 

[shocktower]

You do have some issues, I don't think it's the VC , might me transfer case, drain it and look for metal or just see if it has fluid , and what is the KLong noise

 

[jmphilion]

Will check that ok,
Klong as .. turning the diveshaft hits the loose, it makes a strong noise when it went to D. Sounded like it came from the T-case or front flange. I got something similar when i turned the flange by hand to check the loose, but louder. sure is difficult to put to text.

 

[slow95z]

Pull the front shaft and both flanges. Turn on the cdl and drive around. If it goes away you know it is up front and you can at least drive home like that. Get some plastic bags and duct tape to cover the front hubs.

 

[jmphilion]

Ok, i will test that. It might isolate the sounds while in drive.
My front drive shaft is already off, and i get problems
I guess i do have a problem further too.

 

[BILT4ME]

You have the front driveshaft off.

In order to drive with that off, you MUST have the CDL engaged BEFORE you put the truck in gear. (Press your button for CDL or T-Case in low until the CDL light is on, then pull fuse)

If you try to put the transmission in gear before you engage the CDL, you WILL get grinding and failure to move, and the same going back into park.

The fact that it won't hold in park without a front driveshaft tells me your CDL is NOT engaged.

Have you been trying to drive it with no front DS and no CDL engaged? If so, your viscous coupler is now toast.

The KLANG you hear is the driveline taking up the tolerances when everything finally engages and it echoes through the DS.

I am concerned your front wheel bearings are not tight enough. You state 7-9 LBs. The FSM is incorrect and should be tightening the inner nut on wheel bearings to 25-35 LB-FT (34 nm to 45 nm). This tghtness should be achieved while spinning the hub. Then install the star washer and outer lock nut. (to 45 LB-FT) (61 nm)

It sounds to me like the VC is going out due to the skipping while turning.

The shudder around 5 mph is probably because you don't have the CDL engaged, trying to drive without a front DS (or a failed front drive plate) and it is the VC trying to engage and hold.

Oh.....and pull up your pants while working under the truck!

 

[BILT4ME]

Oh yeah, on your wheel bearing temps:

My wheel bearings are torqued to 35 LB-FT, I run Lucas Red-N-Tacky 2 grease. They run about 92°F to 112°F during my drives. Brake usage also affects what temps I see with the IR gun.

 

[jmphilion]

Thanks Bilt4me, great info there.

Update on the progress, i did try to drive a couple of meters front and back without the CDL, but not more the that.

I took the CDL out before parking it yes.

This morning, i took out the front drive flange like slow95z told to do. Engaged CDL and drove around, at first it seemed ok, but then the vibration kicked in and the rotation sounds i described earlier. Squeaky, metalic clings and klongs. So i got the front axe out of the problem.

I just raised a back wheel off the ground and when to see where the sound came from from aside of the truck, while giving gas it raised the sound and gear turning sound. I think i will take the rear drive shaft out but i doubt its not the u-joints.

 

[jmphilion]

error

 

[jmphilion]

Oupps i guess i triple click tha thing

 

[jmphilion]

In order to drive with that off, you MUST have the CDL engaged BEFORE you put the truck in gear. (Press your button for CDL or T-Case in low until the CDL light is on, then pull fuse)

If you try to put the transmission in gear before you engage the CDL, you WILL get grinding and failure to move, and the same going back into park.

I pulled the rear drive shaft and i found tha my rear u-joint is shot (thats were the noise and vibration must come from)
i let it turn, speed it a bit and no noise without the drive shaft. but impossible to put to park. is it because it has no resistance and it turns so it cant go to park ? thanks !

i guess i will be driving home with the rear shaft on and the CDL switch. Or reput everything on since i found my noise and vibration. I hope i didnt toast anything on the multiple tests.

Would you guys try it for the trip ?

 

[BILT4ME]

Since you have a distance to go and you've determined it is the REAR u-joint on the REAR DS........

Leave the rear DS off.

Install your drive plates and front DS. Make sure all bolts are properly tightened. Grease your front DS if possible.

Engage your CDL switch.

Drive it for the rest of your trip in FRONT WHEEL DRIVE. It WILL drive differently, but it will be just fine. This is one of the great things about these trucks is that they all have a "back-up system" when there is a failure.

I would NOT install a known bad u-joint, as I just helped replace the transmission on a truck because a failed U-Joint blew the DS and it busted a hole in the side of the transmission.

DO NOT disengage your CDL switch for any reason.

Yes, the reason you could not place your trans in park with both DS out is because the automatic trans is always turning and with no resistance, it speeds up and you cannot stop it until you shut it off. That is the same issue you had before except that the power was trying to go through the VC.

 

[jmphilion]

Since you have a distance to go and you've determined it is the REAR u-joint on the REAR DS........

Leave the rear DS off.

i went out on a search for a u joint for it, and found one 30 miles away.
I'm replacing it tonite

the front end is all setup in plastic and duct tape so it can be left free the ride.

i think i will put the rear DS back, that would be the easyiest and quickiest
It will make me try the P/T feeling as well

Hope everything rins well after that and that i get a safe trip back

Thanks BILT4ME and others for all your help !

Will post a conclusion (happy i hope) soon.

Oh and .. about pulling up my pants, the picture was taken by a friend at a bad moment, i was bitching about the darn 14mm of the front DS that were over tight like hell, in a less then spacious place. -- rest assured, all the white stuf you see is my northern winter white belly, not my ass
haha. cheers

 

[jmphilion]

oh and i forgot..

In order to drive with that off, you MUST have the CDL engaged BEFORE you put the truck in gear. (Press your button for CDL or T-Case in low until the CDL light is on, then pull fuse)

pull the fuse.. the center diff fuse ? will it disengage ?
will other systems be off ? (appart from my ABS (because of te front axel)

thanks

 

[BILT4ME]

oh and i forgot..



pull the fuse.. the center diff fuse ? will it disengage ?
will other systems be off ? (appart from my ABS (because of te front axel)

thanks

Yes, the center difflock fuse. It will remain locked with no power to it and won't ynlock until you replace the fuse.

You may want to reinstall your front drive plates on the front hubs because the duct tape won't survive long and it will let the grease leak out of the wheel bearings.

 

[jmphilion]

Yes, the center difflock fuse. It will remain locked with no power to it and won't ynlock until you replace the fuse.

my fjz is a 1996
you are talking about the 30A fuse in the dash panel - or the 10A gauge fuse some poeple are refering to on other posts

Thanks

 

[BILT4ME]

my fjz is a 1996
you are talking about the 30A fuse in the dash panel - or the 10A gauge fuse some poeple are refering to on other posts

Thanks

The 30A on the lower right of dash fuse block.

 

[RFB]

Pull the front shaft and both flanges. Turn on the cdl and drive around. If it goes away you know it is up front and you can at least drive home like that. Get some plastic bags and duct tape to cover the front hubs.

YUP did just this crossing out of navejo nation into utah works

 

[jmphilion]

Hi, i didnt take time to write a conclusion to all this.
First, thanks to all for helping out with my issue.

I drove back home without problem and i've reassembled everything (putting back my front shaft this morning, a grease zert poped out, so i had to replace another joint).
Bit, i did notice that the transmission/transfer seems to move back under the truck, when i quickly accelerate after a stop. I guess it due to not having the front shaft on, but i will check my mounts.
And on the way back, my recent Edelmann PS hose started loosing fluid through a pin hole in the hose.

What i learned about all this.. Check the simple things first.
Got to get this in my head!

My heating brakes problem and the fact that it started vibrating and squeaking while i was turning a slow curve, made me look only at the recent work i did and not take the problem isolated from the rest.

So, for the records, ..
My heating problem was due to my pads beeing to tight on my rotors, the heat sheild spacers that came on the pads, made the pads touch the rotors and therefore produce heat. I got those heat sheilds off and it gave suffisant space. Now, i will need to put them back when they wear a bit (a good advice from friend of mine), so it servs its purpose. Something i forgot to say.. I did the 100 series pads swap mod. So maybe, new rotors, 100 series pads and new calipers didnt mix well. My front bearings are good, the preload was to spec when i assembled them, used a poor quality scale when rechecked them.

My vibration problem was simply a u-joint on the rear shaft, yeah simple enough.

Things i learned that can be really helpful.. Thanks folks on this thread.
A 80 series can be driven with the front shaft off and with the Center diff lock on. Same without the rear if needed.
Dont try to shift without the CDL (transmission needs resistance to engage, or it will turn and keep you from shifting. Might be a good idea to engage the CDL with the motor off if you didnt engage before taking the shaft off. Dont drive with the CDL off or it will toast the viscous coupler. 30A Diff fuse in the dash fuse box will disengage all the diff from turning on or off.

Having a 80 series, or any other series for that matter, is always full of suprises and challenges.
Theses trucks have good back up plan possibilities and This forum is trully a great ressource.

Thanks again!
J