Front driveshaft removal instr. Please

[airlaird]

Guys I need to find my vibrations/grind. I need to drive my LC WITHOUT my front driveshaft. Can someone please give me exact step by step instructions to remove the front driveshaft so I can find my vibration issue? I DO NOT have a CDL switch. Also what exact fuse do I pull??. I've searched but several posts seem vague to me. I need to drive the truck wothout the front driveshaft...I think I have bad U-joints.
Thankyou
airlaird

 

[concretejungle]

To remove:

1. put t-case in Neutral
2. Pull ebrake on.
3. Crawl under truck
4. Remove the 4 bolts (i think 14mm) using two box wrenches holding the driveshaft to the front differential.
5. Pull the front DS flange off the front diff flange.
6. Using a socket or wrench (i think 14 mm) unbolt the 4 bolts holding the drive shaft to the t-case.
7. with the t-case in neutral you can spin the driveshaft to gain access to all the bolts.
8. Pull driveshaft out.

 

[Doc]

Well, removing the front drive shaft is as easy as undoing the 4 bolts at either end.

Locking the C-diff is a different story. I think some folks use their flasher switch temporarily.

 

[gray]

Once you have the driveshaft down, you can of course twist the U-joints around to see if you have any play or catching/notchiness, or if they are frozen, etc. But that obviously won't help diagnose the problem if it is somewhere else, just eliminate the U-joints, maybe. I went through this with my 60, pulled the driveshafts out at 240K replaced all the U-joints, no improvement. The original joints were almost perfect; only a few stuck pin roller bearings out of the whole bunch; literally 2-3, and they loosened up after 5 seconds of fiddling. But, as I had it all apart, I went ahead and put the new ones in, and had the driveshafts balanced. (the vibration was eventually figured out to be a bad output shaft).

I have also wanted to pull my front shaft down to get at the source of my rumbly vibration I'm getting in my 80, but ditto; don't have the CDL mod either. Mine seems to be worse first thing in the morning, maybe, and gets better once I've driven maybe 10 miles or so, maybe.

 

[Grench]

Pulling the drive shaft is easy. Be sure to mark the flanges and slip yolk so you know how it came out and can put it back in the same way. Removing it is a job. U joints is a job if it goes right and a if it goes wrong.

Be sure to chock the wheels well. Without the DS the truck will roll even if it is in park. If you're under it at the time it could kill you.

The following is not meant to be insulting. Just a reality check.

Since you're asking and all... Its kind of obvious you haven't been under your truck much. I'm betting that the U joints have never been lubed let alone changed. The truck is what? 12? 15? years old now? U joints are a wear out part and it isn't going to hurt to change them out.

Have someone who knows what they're doing change out your U joints. Watch them work if you can so you know whats involved next time.

IMHO only and YMMV.

 

[KliersLC]

For running with the CDL on, W/o the CDL switch, put your rig in low, pull the "diff" fuse after the cdl is locked, and then when you shift back into high, it will stay locked.

 

[SeanAndHis80]

Having done both ends recently I would add the following:

1) The switch for the CDL lock is not that expensive and should be on your next order to Dan regardless if you plan to do the mod or not. I planned to do it but never got to it. Having it in my parts box saved my tail.
2) Just doing the CDL switch (as opposed to the pin 7 mod) is very quick and simple to accomplish.
3) Chock the wheels as described above.
4) Jack one front wheel up.
5) While under the truck lightly put your fingers on one of the u-joints so that it is in between the flange and the drive shaft.
6) Use your other hand (or foot) to rotate the jacked up tire back and forth. If there is play in the u-joint - you should be able feel it with your finger. Even the slightest motion detected means that it is bad.
7) Repeat for the other u-joint, then repeat with a rear wheel jacked up for the rear drive shaft.

Some notes:
- There is considerable "play" in the front differential rotation-wise. From the threads here it seems that this is normal.
- My vibrations were solved by the u-joints alone.
- You might find a local shop that will put in u-joints for less than your effort is worth - I did.
- Mark everything with a file - etching marks into the metal as torches might get used in the removal of the old u-joint and will remove any surface marks on the drive shaft.

 

[MikePL]

You do not need a CDL switch to lock the center diff. I currently drive without the center diff and have mine locked by just simply jumping two wires within the connector.

You can also unscrew the grease port on the drive shaft if it doesn't compress enough for easy removal. Without the grease port you can take the DS easily. Be careful as it will poo some grease upon compression.

 

[scottm]

I vote for the "diff" fuse method. The fuse is in the fusebox in front of your left knee. I drove much of the summer without my front driveshaft, including a couple long trips with the family.

 

[gray]

I vote for the "diff" fuse method. The fuse is in the fusebox in front of your left knee. I drove much of the summer without my front driveshaft, including a couple long trips with the family.

Good to know, may do this, at least to check out my vibration
and front shaft.

Not to hijack.
How did it drive and handle without the front shaft/axle turning?

I have often thought of doing the 2WD conversion, but then you lose ABS; I drive often for hundreds of miles a day and 95% of that is on dry smooth roads, so no extreme need for full-time 4WD. (I know, heresy). I have wondered how much less vibration, less wear, and most importantly, how much better gas mileage would I get??.

One concern, can't the transfer case/CDL be harmed by driving it locked for extended periods?

g

 

[scottm]

It handled the same, except when I forgot I was in 2wd and took a tour of a construction site It was much smoother, because I had a locked up U-joint. Not much different when I put the ds back in, maybe a subtle difference. No mileage difference at all, but I was still turning all the front axle parts with the wheels. And I still couldn't smoke the rear tires.

No damage concerns with locking the cdl without a front ds.

 

[airlaird]

Thanks guys...Scott..do you recall wich fuse to pull?
airlaird

 

[medtro]

To remove:

1. put t-case in Neutral
2. Pull ebrake on.
3. Crawl under truck
4. Remove the 4 bolts (i think 14mm) using two box wrenches holding the driveshaft to the front differential.
5. Pull the front DS flange off the front diff flange.
6. Using a socket or wrench (i think 14 mm) unbolt the 4 bolts holding the drive shaft to the t-case.
7. with the t-case in neutral you can spin the driveshaft to gain access to all the bolts.
8. Pull driveshaft out.

With the t-case in Neutral, can step 6 be done without air/power tool? How do you break loose the bolts when the driveshft is free to rotate?

 

[Trinny]

With the t-case in Neutral, can step 6 be done without air/power tool? How do you break loose the bolts when the driveshft is free to rotate?

Not much room up there for an air wrench, but I guess it could be done using an extension. It's really very easy with a ratchet.

To break loose the rear nuts (there are studs on the rear flange), either leave a couple bolts in the front (w/out nuts on them) to keep it from spinning, or do what I did and stick a long screwdriver through the rear ujoint to use as leverage against it spinning.

 

[landtoy80]

I had a cheap impact and had no luck removing the bolts and nuts.
Had to go to Sears and get a 550 lbs in reverse to get my nuts off. And they didn't come off easy with the new impact.
THere was metal flinging off the nuts for several min on each nut.
I ended up replacing all the nuts and bolts.

 

[airlaird]

So as mentioned, I can temporaily use the Flasher switch since I dont have a CDL??
airlaird

 

[scottm]

So as mentioned, I can temporaily use the Flasher switch since I dont have a CDL??
airlaird

I have a CDL switch in my basement, not worth installing as rarely as I'd use it. I think my brother needs it, sorry.

The procedure:
1-ignition on
2-put transfer case lever in L
3-observe yellow "ABS" and yellow center diff lock lights on dash
4-pull "diff" fuse in fuse box in front of your left knee. Lower-right in my fusebox, 30 amp
5-put transfer case lever in H
6-observe "ABS" and cdl lights still on

You are now in high-range, with the center diff locked, no ABS. When you want to go back to normal, just put the fuse in, and the cdl will unlock, ABS will return to normal.

You can alternatively pull the fuse and put it in low range, if you want low-unlocked. I do that for pushing a trailer around slowly.

 

[Beowulf]

So as mentioned, I can temporaily use the Flasher switch since I dont have a CDL??

Yes, you can temporarily use your emergency flasher to activate/deactivate the center diff lock. The wiring is behind the center dash. Follow the instructions on the Slee offroad web site.

I strongly recommend getting the switch and doing the pin-7 mod. This is 1-banana stuff and greatly adds to the versatility of the system. The pin-7 mod is important (and very simple to do) to restore the proper low/high range shift points for the tranny.

-B-

 

[Monkeyboy]

Be sure to chock the wheels well. Without the DS the truck will roll even if it is in park. If you're under it at the time it could kill you.

One of the fist maintenance jobs I did on my old 1969 FJ40 was the U-joints. Stupidly I just threw it in park and put the e-brake on. I was lying on the gravel, on the right side in between the front and rear wheels (head at the rear, one leg outside the truck one inside). I pulled the drive line, and sure enough she rolled backwards and tried to kill me! Luckily it was a low grade so after doing the Indiana Jones trick for about 10 yards, digging in my heels, and praying I did not run myself (and my crotch) over, I was able to slow her enough to slip out. Tore my shirt up a bit and got some gravel burn but hey...I lived. I think I will be a bit more careful with the 80 tomorrow! I have Alfac now though...so it's cool.

 

[NaterGator]

Having just done the front DS today, I couldn't get an impact on the nuts, front or back, to save my life. I could at the pinion end if I removed the swaybar, but meh.

I got out my 6-point 14mm box wrench and a 2lb sledge and tapped em free. Worked like a charm... it is just like the fan clutch nuts; easy to screw up (and a big pain if you do) but if you have the right tools it is a snap.