Topic: How do you un-wind a diff?? (Read 18736 times)

stratie · « **on:** September 23, 2008, 16:00:33 »

Old fella down the road has got an s111. When you put into low box, it jerks. The wheels spin, then move normal, then spin again.
When you push the yellow leaver down it's even worse.
I was told that the diff's could be wound up.
Any one have any info for me?
The fella need's his landie to drive down a very muddy rutty farm lane. He's a smashing chap, so i would like to help him out. He's been driving landies for 40 years, but has allways got the garage to sort out his problems. What with the credit crunch, money is tight, so i thought i would do my bit and lend a hand.
Cheers
Brend.

andyb · « **Reply #1 on:** September 23, 2008, 16:16:25 »

Bit confused by...

Quote

When you put into low box, it jerks. The wheels spin, then move normal, then spin again.
When you push the yellow leaver down it's even worse.

It should already be in 4wd when in low box; pushing down the yellow lever shouldn't have any affect....... :-k

Does it drive ok in 2wd? What about in low box with the front prop removed?

At the moment my instinct says it something in the transfer box, maybe front drive output related.

Oh one left field thought!..........how long has he had this LR. Someone has put a RR diff in the back axle and left a std Series LR diff in the front have they?! Different ratios and might give this effect?

crazymac · « **Reply #2 on:** September 23, 2008, 16:55:04 »

The easiest way to unwind one is to get it on a wet or very loose surface. That should at least rule out a diff being wound up! I'm trying to remember how the levers work on the series machines so correct me if I'm wrong!

Red lever down = low box 4x4
Yellow lever backward = 4x4 in high ratio
to return to 4x2 high ration you bring the yellow lever back then forwards again, and the red lever pops up again.

stratie · « **Reply #3 on:** September 23, 2008, 17:04:27 »

Andy, the fella has had the landie from new, and yes it drives spot on in 2wd.

Crazymac, i was told to drive it on wet grass ect, but i was told to drive it around in circles?
As for the levers.....Red goes back, and yellow goes down. Not that it matters, i know what you ment :D

Cheers for the info guy's, i'll give it all ago.

stratie · « **Reply #4 on:** September 23, 2008, 17:29:54 »

How or why is it poss for a diff to wind up? If i can understand how and why, then i might get a better understanding of whats up with Norms landie.
Any one know?

stratie · « **Reply #5 on:** September 23, 2008, 18:35:32 »

Quote from: stratie on September 23, 2008, 17:29:54

How or why is it poss for a diff to wind up? If i can understand how and why, then i might get a better understanding of whats up with Norms landie.
Any one know?

Anyone

crazymac · « **Reply #6 on:** September 23, 2008, 19:11:28 »

When a series vehicle is in "high" ratio it is running in rear wheel drive and any bends etc allow any transmission windup to dissapate. However when you engage Low ratio you link all 4 wheels together (similar to the difflock in modern landrovers) so on hard surfaces there is nowhere for the wind up to go which creates tension in the diffs.

At least, thats MY understanding!!

Lucy1978 · « **Reply #7 on:** September 23, 2008, 20:00:41 »

the easiest way to unwind a trasmission is to jack a wheel up on each axle, it will also help you diagnose any issues in the transmission. in 2wd the front wheel should spin freely along with the front prop. the back wheel (if the hanbrake is off and out of gear) should do the same, but it'll turn the transfer box too.
in 4wd, turn either wheel and it should turn both props and the the other jacked up wheel as they are physically linked by a dog clutch in the front section of the transfer box.

if that doesn't happen it could be the axle diffs knackered, jack up the back axle and check for normal operation and then the front, with the truck out of gear and the handbrake off (wheels chocked obviously)

stratie · « **Reply #8 on:** September 23, 2008, 20:53:38 »

Nice one fella's, cheers :D

hobbit · « **Reply #9 on:** September 23, 2008, 20:57:22 »

As he had a diff change done on the front axle?

stratie · « **Reply #10 on:** September 23, 2008, 21:17:33 »

Not as far as i know Kev, but then saying that he may not remember, he's in his 70's.
Why, what are you thinking mate?

hobbit · « **Reply #11 on:** September 24, 2008, 00:09:07 »

I had a half shaft go on my l/w, this year on the back

While I was sorting it out, I had the chance to try it with a rangy diff, instead of the series one, to see how it was (its got a turner head on so lots of power and too low range)

It worked fine, knowing as long as I didn't engage 4wd I was ok, but later I was doing some welding, and ran it up onto some ramps, stuck it in 4wd for safety while up there

WHen I drove it off, you can imagine the slip, with a lower range (series) front diff and a higher rangy one on the back, it gave me a reminder, must do the front diff swap too :oops:

Luckily it was only a few feet on gravel so no harm done, but I wondered what the hell had happened for a second though

So the thought was perhaps as the diffs do look the same and fir, he may have had one changed and fitted the wrong one

andyb · « **Reply #12 on:** September 24, 2008, 09:00:16 »

@Hobbit....diff swap. Thats what I thought :)

@stratie....best bet is to remove rear diff and count pinion rotations against one crown wheel rotation.

....or remove front prop (as suggested) and try in low range; basically to eliminate the gearbox/transfer box from equation :)

stratie · « **Reply #13 on:** September 24, 2008, 10:11:25 »

Kev, im sure he hasn't had a diff change.....i could be wrong, so i'll go thru all his paper work from the garage and check. I'll ring them up and ask if need be.

Andy, i'll get the spanners out and have a play.

Thanks for the "top" advice guy's :D
Cheers
Brend.

Chris Putt · « **Reply #14 on:** October 06, 2008, 21:02:57 »

Could you not jack one side of the vehicle up (by which I mean both wheels on one side) whilst in 4wd, and mark a point on each tyre, then turn one of the two wheels one full rotation. The other one would also turn, and assuming the diffs are the same will turn the mark on the tyre also one full rotation. If the diffs are different then the mark will not end up in the same position......?

stratie · « **Reply #15 on:** October 07, 2008, 10:53:58 »

I'll give it ago mate....infact i'll give any thing ago, been scratching me head for the last few days.

I have been told so far. To unwind the diff/diffs......

Drive on wet grass......
In reverse.
Round and round in circle's.
In a straight line.

??????????

solihull-mick · « **Reply #16 on:** October 07, 2008, 12:44:02 »

Never heard so much interesting nonsense, what makes you think the diff are able to be wound up?

stratie · « **Reply #17 on:** October 07, 2008, 13:42:20 »

Quote from: solihull-mick on October 07, 2008, 12:44:02

what makes you think the diff are able to be wound up?

Thats what i have been trying to find out mick.
At the moment i haven't the time to start pulling it apart, so im going with what a few landrover owners in my area have told me...ie the diffs are wound up.

At the moment the old guy that owns it, is using my truck to get up and down the track to his yard. So im keen to sort his out asap.

solihull-mick · « **Reply #18 on:** October 07, 2008, 21:03:25 »

Diff wind up only happens when your in four wheel drive, and the difference in tyre diametres causes slight wind up due to no central diff, soon as you move back to 2wd wind up can no longer happen, if as you say you get the problem only when in low and 4wd in high sounds to me like a tooth missing from the front diff or somthing along thous lines, let us know how you get on

stratie · « **Reply #19 on:** October 08, 2008, 06:54:14 »

Sussed it at long last.
Jacked up a corner and span the wheel a few time's.
Job is, how they say........A good um :D

zimsoundz · « **Reply #20 on:** October 08, 2008, 09:41:59 »

Quote from: stratie on October 08, 2008, 06:54:14

Sussed it at long last.
Jacked up a corner and span the wheel a few time's.
Job is, how they say........A good um :D

what was the problem then ?

Gordon

stratie · « **Reply #21 on:** October 08, 2008, 15:34:50 »

The problem was.............i spoke to soon :lol: It's still doing it. B*g*r!

I jacked the drivers side front wheel and put a mark on the tyre.

I did the same with the rear wheel on the passenger side.

I gave the front wheel one full turn (so the mark on the tyre whent back to the same place as it started from) and the mark on the rear wheel is no where near the piont it started from?

andyb · « **Reply #22 on:** October 08, 2008, 17:18:32 »

You could do similar and count prop shaft rotations for one wheel rotation for both ends. This will tell you what the diff ratios are.

stratie · « **Reply #23 on:** October 08, 2008, 17:22:52 »

Quote from: andyb on October 08, 2008, 17:18:32

You could do similar and count prop shaft rotations for one wheel rotation for both ends. This will tell you what the diff ratios are.

Ya clever git, why didn't i think of that :oops:
Cheers mate, i'll give it ago.

James.Harwood · « **Reply #24 on:** October 08, 2008, 18:57:45 »

It may be worth checking that there isn't 1 old tyre and 3 new or different sizes front to rear (they may say the same size but if they are remolds and different make they probably wont be the same size)

stratie · « **Reply #25 on:** October 08, 2008, 21:59:00 »

All 4 tyres are good mate.

carbore · « **Reply #26 on:** October 10, 2008, 09:28:14 »

Hi.

When you say "put the yellow lever down its worse" do you mean in high or low range (or both)

If it drives ok in high but not low then id suspect transfer box, e.g. stripped gears. If it drives poorly in high and low in 4wd then im still not 100% sure!

andyb · « **Reply #27 on:** October 10, 2008, 10:27:56 »

Quote from: carbore on October 10, 2008, 09:28:14

When you say "put the yellow lever down its worse" do you mean in high or low range (or both)

If it drives ok in high but not low then id suspect transfer box, e.g. stripped gears. If it drives poorly in high and low in 4wd then im still not 100% sure!

I pretty much said that in the second post in this thread :roll: :)

stratie · « **Reply #28 on:** October 10, 2008, 13:24:10 »

Quote from: andyb on October 10, 2008, 10:27:56

Quote from: carbore on October 10, 2008, 09:28:14
When you say "put the yellow lever down its worse" do you mean in high or low range (or both)

If it drives ok in high but not low then id suspect transfer box, e.g. stripped gears. If it drives poorly in high and low in 4wd then im still not 100% sure!

I pretty much said that in the second post in this thread :roll: :)

You did as well

In two wheel drive....Spot on.

Pull the red lever back......The wheels jerk and spin.

Push yellow lever down.....You can drive for two maybe three feet, and then it's like the brakes are coming on. It slow's up and stops.

andyb · « **Reply #29 on:** October 10, 2008, 15:41:12 »

Now try that without the front prop on and then we'll know if it's the diff or the transfer box :)

News:

AuthorTopic: How do you un-wind a diff?? (Read 18736 times)