Drive line judder

[ModelMakerMan]

I seem to have a bit of judder from the drive line whilst driving. It seems to be worse when its cold but doesnt go away completely when warmed up. Id does it in all gears and is more noticeable when accelerating from lower revs. There is also a bit of a whine when you lift off the throttle and during engine braking.

It is possibly the clutch as the truck is just reaching 180K and I think it might still be the original clutch and also I have reason to believe there might be a minor oil leak from the rear crank seal but Im unable to check either of these as I dont have a transmission jack to hold the beast of a box that weighs more than me!

Anyone able to think of any other culprits or are all signs pointing to the clutch?

 

[adrianr]

UJ's?

Mine whines off throttle and engine breaking also.

 

[Crushers]

bad clutches do not whine, they usually stink.
once engaged the clutch shouldn't judder since it is mechanical connection.
block the tires.
put the truck in neutral with the e/brake OFF.
crawl under and wiggle the rear driveshaft at the transfer case and at the rear pinion and at the slip joint. wiggle up and down, wiggle side to side and turn the shaft as far left and right as you can and report back the results of the inspection.

cheers

 

[ModelMakerMan]

I think the whine might be normal Ive just net really noticed it before but Im picking up on more noises etc because Im trying to pinpoint problems so driving more without the radio on.

Id did have a quick look at the UJs the other week when I did a service and they seem fine but I will check again. I had a UJ on its way out a couple of years ago and that had a clonk every time I accelerated ir decelerated which I dont have this time.

 

[Roger Fairclough]

Dave.

I think this problem and your creaking string are probably connected.

Firstly slacken off the panhard rod bolts/nuts and the leading and trailing arm bolts that connect same to chassis. Bounce the car up and down to settle the suspension and then tighten to:-

Leading and trailing arms 130 ft-lb.

front panhard rod to axle 92 ft-lb.

" " " " chassis 106 ft-lb.

Rear " " both ends 184 ft-lb.

The bolts that connect the arms to the axle will not be affected by the lift, but you can slacken and re-tighten to 181 ft-lb on the back and 130 ft-lb on the front.

Are you sure the bushings are OK? If not this could be your problem. A suitable pry bar may be a good idea, or better still remove the bolts and carry out a visual inspection.

The suspension lift will have changed the angles on the prop-shaft. I would remove each prop and grease them properly. Quite often one spider can be deprived of grease with the inevitable imminent failure, especially with the lift. Also check that the sliding joint is OK. It's best to overfill this part and then remove the nipple whilst compressing the sliding section to expel the excess grease.

Did you prime the shocks before fitting them? Any nitrogen in the inner section could create noises.

Did you tighten the bottom shock mounts enough to compress the rubbers about 33%? Again, slack rubbers can "fidget" and cause wear and noise. Also check the top mounts.

Roger

 

[roscoFJ73]

Check your engine and gearbox mounts as well.

 

[ModelMakerMan]

Ok so I got under the truck yesterday and had a poke around. All the UJs and prop sliders seem fine the only thing I found is the back lash on the front prop may be excessive? See videos below:

Rear prop


Front Prop (hubs locked 4x4 NOT engaged)


Also Ive heard a clunk occasionally which Im 95% certain is coming from the rear of the vehicle, it only seems to happen when turning sharply and accelerating (U-turn or pulling out of a sharp junction). It doesnt do it all the time though and tried to get it to do it by driving round in circles on full lock in a car park but it wouldnt do it. It is possible this is connected to the creak (see creaky rear end thread).

 

[ModelMakerMan]

Well I know what it is now. Rear diff is FUBAR. Got to the end of the road and the judder got really bad and the knocking got louder and more constant until it turned into grinding and no drive. I had to put it in 4x4 to turn it round and drive it home.

Ive drained the diff oil and sure enough its full on bits of metal. I havent got the diff out yet as its getting late and bloody cold now. Im hoping its the spider gears as the bits of metal are all pretty small and dont look big enough the be from the ring or pinion so hopefully I could just get a locker (thinking Truetrac) and use the ring and pinion.

In case it is the ring and pinion what ratio do I need for the KZJ70 and where can I get them from and what else will I need to rebuild the diff.

All in all not a good evening, especially as Ive taken my daily driver off the road to refurbish the wheels so now have 2 cars I cant drive!

 

[Crushers]

my understanding is the KZ came with 4.11s
if you are in the need to do a swap then the 4.88 out of a LJ might be in order...

 

[ModelMakerMan]

GOOD NEWS!

Its no the ring and pinion, its the side gears that are fubar so you know what that means?

Its time to put a locker in, or more probably a TrueTrac LSD.

I dont think Ive ever been so relieved when something has broken, it would have been a nightmare to find the right ratio ring and pinion.

Ive not stripped it down yet but you can see the side gears are broken by looking through the casing, I cant get the side gears to turn so Im guessing there is a whole section of missing teeth which would explain the masses of metal shards in the diff housing. Ive cleaned as much as I can out and Im going the borrow a mega strong magnet from work to get whats left of the metal out but Im sure there will be some bits I cant reach. Im guessing the best bet would be to use some cheap GL5 oil when I rebuild it and run it for a few miles then drain it and put some decent oil in?

Anyway here are the pictures:

Some of the swarf that came out with the oil

As you can see the ring gear and pinion are fine

You can just about see some of the damage to the side gears

 

[ModelMakerMan]

I disassembled the diff today. Look away now if you dont like seeing exploded precision engineering!

As I removed the diff casing one end fell off!

The spider pinion gears were definitely not well

The reason for the damaged spider pinion gears became apparent:
This is how a side gear should look

This is the other one!

Im still not sure what caused the failure, Im assuming the casing broke first which just screwed up the tolerances for the LSD allowing it the slowly chew itself until it finally gave up.

The problem I have now is that there are bits of swarf in every nook and cranny in the casing, should I splash some diesel around in there to try and wash it all out?

Ill be making some calls tomorrow to try and source an Eaton TrueTrac to replace the diff. Id quite like one of their MLockers but either they arent available yet or they are only supplying them for OEM applications because I cant find any other info other than what is on the Eaton website and a YouTube video I found from India explaining how it works. It does look really clever though, a good mix of LSD and full locking diff.

 

[Crushers]

holy crap, i have not seen ANYTHING like that in 30 years of wrenching LC ... i have seen the casing busted in half but never that section ...

stick in a factory elec as they have tons more meat to them.

or

as you suggested.

i can tell that truck hasn't seen any abuse ...

 

[Rob]

The casing definitely failed first then chewed the side gear, no way it could have append the other way round. Would like to see close ups of the fracture surface, could give us more of an idea of how it failed.

 

[Roger Fairclough]

When I took my diff. apart to fit a Truetrac, I was not impressed with the strength of the Toyota diff. casing. The section that has broken looks a bit wimpish and those extra holes certainly wont help.

Cleaning the bearings that support the pinion is never going to be a guarantee unless you remove the whole lot and that will open another can of worms relating to time and money. I'm afraid it's six of one and half a dozen of the other.

Roger

 

[ModelMakerMan]

AAAAAAAAAAAAAH!

Finding a Trutrac in the UK is proving to be very difficult. Milner Off Road used to sell them (Roger got his from them in 2008) but they have since stopped selling them. I called all the UK dealers on the Eaton website and all I get from them was "Sorry we only do Land Rover parts", I mean fair enough they must make a fortune due to Land Rovers being continually broken but why are we Brits so obsessed with a vehicle that is so intrinsically flawed? Why cant we be like the rest of the world and have parts for all vehicles freely available for us sensible people?

Anyway looks like Ill have to order one from the US which means it wont be fixed this side of Christmas.

 

[ModelMakerMan]

The casing definitely failed first then chewed the side gear, no way it could have append the other way round. Would like to see close ups of the fracture surface, could give us more of an idea of how it failed.

Here you go Rob:

Looks like sheer forces on the rotary axis to me, I can only assume there was a crack or fault in the casting but if that is the case it did well to get to 180k miles.

 

[Rob]

Unfortunately all the evidence has gone as the fracture faces wore away at each other. I am supprised at how small the fracture surface is, there are a lot of holes in it. I wonder if they did much FEA to it? Would of taken a computer the size of a building to do it back then or a year so probably not

 

[ModelMakerMan]

TrueTrac ordered from the US, worked out cheaper than Roger paid 4 years ago from Milner even with postage so that was a result (Sorry Roger ) Though Ill probably get slapped with a hefty customs bill which will bring it up about even anyway. It should be here beginning of January.

 

[hairyguy4]

if you don't mind you'll have to post up where you got it, i've been tempted at one for a while

 

[ModelMakerMan]

http://www.ebay.co.uk/itm/140484692715?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649