knock,knock, knock

Joined
Sep 21, 2003
Messages
484
I haven't driven the 80 much in the last month, but know that it has been making all sorts of new noises lately. My wife uses it daily though. My wife dropped it off at work and swapped me cars the other night so I got to drive it home. I have got a major knocking noise in the drivetrain. It seems to be coming from the front somewhere and only hapens when decelerating without the brakes. Really any time your coasting at under 30mph. It does not seem to be effected by engine speed.
It is definitly a rythmic noise that slows as the vehicle slows. The front driveline seems solid. I had six states replace the front and rear driveline ujoints last spring. The rears don't seem to have any rotaional slop, but I can move them 1/16 in each direction across the joint. There does seem to be rotational play in the slip joint on the front driveline.
I tried to pull the front diff drain, but could not find my 24mm socket so I will do that tomarrow night. I totally rebuilt the EVERYTHING in the front axle with the exception of the ring and pinion gears 5 years ago when I bought the rig. It will sicken me if something in that front axle has gone south on me. I got my finger in the fill hole of the diff and the oil looked really grey.

Any thoughts?

I forgot to mention that once tonight when I put it into drive, It was like I was tied to a tree. It moved forward, but was really straining to do so. I put it back in park and then in drive agian and it worked fine. 270k miles on this 93.
 
Joined
Jan 23, 2007
Messages
258
Location
Texas, of course.
You said the diff oil was really grey. I hope it's not the metal color grey. Can you try to drain a little out or all of it and look at the fluid under some good lighting? See if theres metal flakes in the oil. If you drain the fluid, check the drain plug since it is magnetized and see if theres any there as well.
 
Joined
Mar 27, 2003
Messages
12,520
Location
Somewhere in the foothills...
Agree with Tools; it is your brakes and probably a front caliper has come loose. This is an urgent situation that you must repair immediately. No more driving of the vehicle if that caliper is loose.

-B-
 
Joined
Sep 21, 2003
Messages
484
YeaH, i Had a caliper come loose several years ago. I pulled the tires off last night and the brakes looked solid. The only odd thing with the brakes, I changed the pads over a year ago, it looks like the pads are wearing funny. The outer portion of the pad seems to have hung over the edge of the rotor. That has left a lip on the pad that seems to be rubbing the outer portion of the rotor. They were not OEM pads.
The oil looked greenish grey. I could not see any distinct metal flakes in it, but will look agian in the mornign when the light is better. The magnet plug had a good coating of sludge on it, but no metal flakes.
I will pull the drivelines one at a time on saturday and use the center diff lock. I drove around tonight and while letting the cruiser just move under the idle power, the clank/knock noise was constant and rythmic. With the door open, it could be that the rear driveline is the problem. It still sounds like it's coming from center to front, but could be from the front portion of the rear driveline. Did I read somewhere that the OEM ujoints aren't available anymore? Six states actually replaced the rear ujoints twice last spring. The first set did the same thing that this latest set is doing, movement accross the joint, not in rotation. I'll post up tomarrow with more info.
 
Joined
Sep 21, 2003
Messages
484
So the plot thickens. After completing an abreviated honeydo list today I pulled the rear driveline, pressed the center diff switch and went for a drive. No more noise. I guess the rear ujoints are "one" of the issues. Then as I turned and accelerated a little I hear familiar clicking. Not the same noise that i have been complaining about, but one that sounds too familiar to cruisers. It sounded just like a really worn birf. I went into the parking lot of the school accross the street and proceeded to turn figure eights. Everytime I gave it a little gas while turning I got a clanking from the front axle. I went home and jacked up the front end and put her in drive and reverse while turning the wheel and I could not get the birf noise to happen. I assume that there would have to be resistance on the tires to make it happen. I did notice there was a little play in the drivers side wheel bearings that I will have to address.
The whole front axle was rebuilt about 5 years ago with remanufactered birfs, new inners, new spiders, and a partridge in a pear tree. Over the five years i have put about 70k miles on the cruiser. I also notice that the Clunk that comes from the drivetrain when shifting from forward to reverse was even louder than normal.
I then took off the front driveline and put the rear back on. The rythmic clanking while coasting came back, but I could not get the front axle to make the birf-like noise. So I figure it's time to replace the rear driveline ujoints agian. I am going to call six states on monday and see what they say. All I know is I am not putting a third set of the same bearings on.
So is there anyting else that might make that birf clicking noise in the front axle besides the birfs? Why would it only show up when the rear driveline was removed? When I got both drivelines back on I took it for a test drive and could not make the birf noise come back. And my poor 80 has more oil on the undercarriage than my 40 ever did.
 

landtank

Supporting Vendor
SILVER Star
Joined
Mar 27, 2003
Messages
20,215
Location
Groveland MA
Website
landtankproducts.com
Why would it only show up when the rear driveline was removed? When I got both drivelines back on I took it for a test drive and could not make the birf noise come back. And my poor 80 has more oil on the undercarriage than my 40 ever did.


Shared load. With the rear drive shaft out the entire load of moving the vehicle is on the front driveline. At 70k you're over due for a repack of the birfs anyway.
 
Joined
Sep 21, 2003
Messages
484
They were pulled and repacked last year. I had them remanufactured and wondered how long they would last. Anyone know how many times you can have them remaned?
 

Box Rocket

SILVER Star
Joined
Jan 2, 2003
Messages
4,990
Location
Syracuse, Utah
I'm interested to hear how this plays out Trent as I'm getting up there in mileage myself and expect to have more things like this show up as time goes on. I had some similar driveline clunking and noise at the time I bought my truck with 110K miles on it, but it was minimal. I now have 207K miles on the truck and just replaced the front driveshaft with a Slee DC shaft a couple weeks ago. Most of all of the driveline noise and slop went away. I still have some noise from the rear but I know my u-joint angles are out of whack since I'm fairly tall and still running stock rear control arms. I'll be doing some adjustable arms soon and I'll check the rear u-joints then too to see if they need to be replaced.

I have used 6-states before with decent luck but that was only for my 40 and my minitrucks. Never had them do anything on for the 80. I know Slee is using Spicer joints which I believe is what 6-states uses as well, but if you're burning through rear u-joints that quickly, I wonder if something like a Slee rear DC shaft would help. How are your joint angles? I know Tom Woods in Ogden can modify your current shaft to use a DC joint and assume that 6-States could do the same.

Good luck.
 
Joined
Sep 21, 2003
Messages
484
Adam,
Good to hear from you. My wife asked the other day why we hadn't seen you around.
My problem is that is that I bought it and knew the previous owners. I assumed they had taken pretty good care of it, but it turns out thier son had used it for several years while at BYU and I don't think he did any greasing or oil changes. The Motor is very tired and things are starting to fail. How much do you put into a rig with that many miles? The green paint is shot, a microburst sent a 2x12 accross the yard and took out the hood, I've got several growing rust issues and the leather is cracked through on the front seats. It's funny after all the money I have put into the 40 over the years not to be able to justify the money in the 80. And the poor 40 is in the garage all torn apart. I'm hoping to pick up a newer/younger 80 in the next few months and then part out mine.
 

Users who are viewing this thread

Top Bottom