Front and rear wheels not spinning at the same speed?

[Covo71]

It just seems to be never-ending. I went out bush today and I was driving along a smooth straight dirt road and the front tires seemed to be (lack of a better description) chirping as if they were not traveling at the same speed. It has always been a bit of a pig in 4wd since I have had it. About a month or two after I bought it I had to put a new gear box in it. I have a 2004 but the gear box came out of a 2011 model. Would that make any difference? Really not going to be hard to find someone that knows more than I do. HELP!!!!

[Hodge]

Surely it can't be the gearbox as it has 1 output. Could something be locking up front momentarily, hub locks maybe? Or different diff rations front and back?

[happygu]

It wont have anything to do with the gearbox, as that just drives both driveshafts and sets of axles at the same speed.

The only time you could have a problem would be if you had different ratio diffs.

Mic

[Covo71]

Ok, next question begging to be asked as I would compare my abilities to a drunk monkey is how can I tell what if the diff ratios are different?

[happygu]

You can count the teeth on the crown wheel, but you have to open up the diffs.

I think the easiest way would be to jack the truck up off the ground, lock the hubs, whack it in 4wd, mark the front and back wheels at the top or bottom, and then spin the tailshaft to see if the front and back wheels rotate to the same spot once the wheels have done a full rotation

[BigRAWesty]

Could be a couple of things.
Different diff ratios as mentioned above. You'd hope not because that would be hammering the drive line.

It could also be different tyre sizes.
Every brand is different so if you have different tread on the fronts to the rear it could be the issue.

[Covo71]

Tyres all the same and bought at the same time. I will put it up tomorrow and give the wheels a spin and see if they line up afterwards. Thanks heaps for the ideas.

[BigRAWesty]

Yea lock hubs and engage 4wd and give em a turn.

[jay see]

If you count the revolution of the tail shaft to one revolution of the wheels you can work out what ratio you have.

[the evil twin]

It cannot be the gearbox.

If it was different ratios between the front and back diffs you should have the mother of all cases of transmission windup after about 20 metres.
That would make it a bugger to get in and out of 4WD.

If there is no windup I would maybe suspect something binding in the front

Why was the gearbox changed?
How long have you had the vehicle?
How much 4X have you done in it esp over rocky stuff for example?
Manual or Auto Hubs and if Auto are you locking them?
Does it have a front locker?

[threedogs]

You need to select high 2WD, if its in H4 you'll have a hell of a time steering it.
and very noticable, select auto on the hubs as well

[my third 256]

do you have diff lockers

[heaths_gu]

I think we're both from bathurst. If you need a hand let me know.

Cheers
Heath

[Nightjar]

You can count the teeth on the crown wheel, but you have to open up the diffs.

I think the easiest way would be to jack the truck up off the ground, lock the hubs, whack it in 4wd, mark the front and back wheels at the top or bottom, and then spin the tailshaft to see if the front and back wheels rotate to the same spot once the wheels have done a full rotation

Thumbs up to this advice.

[Covo71]

Hi mate, old gear box seized up and stuck in gear.
Had the troll 18 mths.
Most driving off road is dry and rocky. Live at bathurst.
Manual hubs changed over 12 mths ago to avm.
No front locker that I am aware of. If auto I am sure it would be clicking or clunking around corners.

[the evil twin]

Hi mate, old gear box seized up and stuck in gear.
Had the troll 18 mths.
Most driving off road is dry and rocky. Live at bathurst.
Manual hubs changed over 12 mths ago to avm.
No front locker that I am aware of. If auto I am sure it would be clicking or clunking around corners.

Hmmm, curiouser and curiouser

If the old gearbox siezed is it possible a diff is damaged as well?
What trashed the gearbox, water?
If you have had it 18 months and driven off road in rocky terrain then the tryes would be howling their guts out all the time it is in 4WD.
I would be amazed it hasn't blown a CV or FWH's over that amount of time as well if there are indeed different ratio diffs in the vehicle.

Going to be interesting to hear what is wrong when you figure it out.

[Covo71]

Ok, just put it up on stands. 4wd high, front hubs locked. 1 turn of the back wheel and the front wheel turns about 1.3 turns. Might be a problem but would explain why it is such a pig in 4wd. Will need to take off the diff covers and count the splines. Maybe they stuffed a diff at some stage as well and replaced it with the wrong ratio.
Got the missus to turn the wheel and i got under to count the drive shaft. rear wheel 1 turn is about 4.3. sounds ok. i turn of the front is only 2 turns of the drive shaft.

[the evil twin]

Unless you can lock both other wheels you need to turn the drive shaft not the wheel for a definitive result... but that is an awesomely big difference around 25 to 30%.
Even 3.9 to 4.6 isn't that much
It would buck like a Bronco in 4WD I would have thought

Replacing the diff was what I was getting at when I asked about the Gearbox.
So someone else replaced the gear and sold it to you?

[heaths_gu]

it should be pretty easy to determine which diff ratio is wrong by the revs to speed in 2wd. (not that i can remember what mine revs at @100 in 5th) Odds are it will be the front diff ratio that's wrong, but unfortunately it's a lot harder to change the front centre than the rear.

[happygu]

Unless you can lock both other wheels you need to turn the drive shaft not the wheel for a definitive result... but that is an awesomely big difference around 25 to 30%.
It would buck like a Bronco in 4WD I would have thought

Replacing the diff was what I was getting at when I asked about the Gearbox.
So someone else replaced the gear and sold it to you?


As ET said, you cant get a total definitive answer by turning the wheel, as you could get slippage through the open rear diff. Turning the tailshaft is better ..... the first assessment seems ok 1 turn at the rear - 1.3 at the front, which indicates that there could be a problem.

You second assessment of 4.3 turns of the tailshaft against 2 turns on the front seems to be a fair bit off, and dont think can be trusted to be a definitive answer.

Mic

[happygu]

Covo,

I would also take up Heath's generous offer of assistance, as there does seem to be an issue, and two sets of eyes and hands will be helpful

Mic

[Covo71]

Yep, i think another set of eyes would be good. Just checked turning tail shaft and watching wheel. about 4.3 turns for 1 turn of the rear wheel. about 5.1 turns for the front wheel to turn once.

[the evil twin]

Well, I would call it as 4.3 ratio in the rear but jury is still deliberating on the front... 5.1 is "interesting" so maybe 4.6 ratio out of a 2.8 or 4.3 and something else is stuffed?

What ratio is on the compliance plate?

[Covo71]

HG43 on the plate so I believe that is 4.3.

[the evil twin]

HG43 on the plate so I believe that is 4.3.

Yep, sure is.

[Covo71]

Anyone on here sell diff gears? How hard is it to change over?

[happygu]

4.3's are a fairly common size.

Should be able to pick up a set from either the wreckers, or maybe your local fourby shop tnat is putting in difflocks

[mudski]

Anyone on here sell diff gears? How hard is it to change over?

Not so hard but a bit of work and setting up the backlash etc etc. With the right tools and know how, it would be a few hours work just to remove and refit the gears. Not counting the removal of the centre.

[heaths_gu]

You could try K&A 4wd wreckers in Orange to see if they have a complete centre. I got one off them about a year ago for my old hilux and from memory it was $300

[Covo71]

Hi Happygu, do they not still use it if they put in lockers?

[the evil twin]

Anyone on here sell diff gears? How hard is it to change over?

Are you 100% sure that is the problem tho?
Not saying it isn't but, man, it is the first time I have heard of it... ever...reliably anyway.

[Covo71]

Definitely turning differently from front to back but I think beyond my skill set and I will take it somewhere for them to look at. Spewing I need to pay but for the best I think.

[Clunk]

do you know if the front diff center or whole diff has been replaced at any time during this cars history - just interested to know if something may not have been set up correctly (if that's at all possible)

[Covo71]

No history before I bought it.

[the evil twin]

Definitely turning differently from front to back but I think beyond my skill set and I will take it somewhere for them to look at. Spewing I need to pay but for the best I think.

Why don't you grab Heath (or a family member), go and find a bit of grass/dirt/gravel, engage 4WD and drive forward and back a couple of car lengths in a straight line while you or they observes the wheel behaviour?
Even the neighbours front lawn will do if they aren't home (jokin)

[Covo71]

542615426054261I am not losing the plot. 2nd picture shows the back wheel after 3 revolutions and the front has done just over 3. Not a huge amount but not right. Did this about 5 times same result. This is with the hubs locked and in h4wd.

[Clunk]

does it do the same when you go in reverse?

[Covo71]

Didn't check. would it make any difference?

[Clunk]

Didn't check. would it make any difference?

well I was just wondering about what ET said earlier about something could be binding........ just wondered if the problem was still there when reversing in 4wd. If it isn't, then it wont be a problem with incorrect front diff ratio

[the evil twin]

542615426054261I am not losing the plot. 2nd picture shows the back wheel after 3 revolutions and the front has done just over 3. Not a huge amount but not right. Did this about 5 times same result. This is with the hubs locked and in h4wd.

Wow... if you started off in the first pic and went forward for 3 turns of the rear wheel then took the second pic the front tyre has travelled further so must have a taller ratio.
If that is the case I would say you have a 4.1 ratio in the front diff because the back is def 4.3.

No wonder it has been a pig in 4WD since you had it.

[Covo71]

Why would you say rear is definitely 4.3? It was 4.3 turns of the drive shaft for 1 turn of the wheel.

[Covo71]

Anybody know or have 4.3 gears for a front diff?

[Clunk]

Why would you say rear is definitely 4.3? It was 4.3 turns of the drive shaft for 1 turn of the wheel.

so therefore that means your rear diff ratio is 4.3 as per your plate

[Covo71]

Sorry mate. I thought you were just getting it from the picture thinking you must be a psychic guru? Lol.

[Clunk]

Sorry mate. I thought you were just getting it from the picture thinking you must be a psychic guru? Lol.
psychotic dribbler maybe, but definitely not a psychic guru ;)

[happygu]

Looks like you are making good progress Covo....

4.3 is common, so you may have to wait for the end of the long weekend to see if anyone has a front centre hanging around

[Covo71]

Ah yes, long weekend. No days off so forgot about it.

[Scorpiovee]

Hi mate, it might be easier and cheaper to replace the whole front diff complete with centres hubs etc.
given the you know how many revolutions of the rear tail shaft turns the rear axel, do the same with the new front assembly before you buy it to make sure it's the same, if you chose to go down that path.

[threedogs]

Thats weird as maybe the previous owner had a locker in the front he wanted to keep.
and just threw in any GU diff centre he could find
, I take it this was a private sale

[MudRunnerTD]

Wow! Just Wow! I would be only doin the centre. Take it out and confirm that it is different on a count. Extraordinary! Can't beieve you have not SMASHED something to pieces if they are different! Never Ever seen that before!

[Rossco]

Yeah its pretty dodgy. When we were young and silly my mate had a hilux that he got for his 18th. It was pretty cool but he didn't have much respect for it and it coped a hiding. It blew a diff (as luxes do) and replaced it with a different ratio. Don't know why just don't think he cared to much to be honest. Actually think he put a taller one in (rear) for road and never bothered with the front.

Does look like a different centre. Either just plain dodgy or a mistake. 4.1 are more common and cheap. Maybe the last bloke got out of it with the cheapest dodgyest option.

[threedogs]

Wow! Just Wow! I would be only doin the centre. Take it out and confirm that it is different on a count. Extraordinary! Can't beieve you have not SMASHED something to pieces if they are difference! Never Sver seen that before!

wouldn't you pick it on a test drive??

[Covo71]

Yeah I think something was swapped out before I bought it. Did have to replace the gear box about a month after I bought it. And disintegrated one of the auto hubs. Makes sense. New diff centre should show up on Tuesday so I will have a crack at putting it in. Cheers

[happygu]

I haven't done it on a GU, but I remember reading somewhere that the short axle can be a real pain to put back in ..... so be prepared, and don't get too frustrated if it does give you grief.

[Rossco]

Check out Darrens diy cv & swivel hub rebuild thread in the DIY section. Should be a great help even if you don't do the full rebuild it shows how to dismantle and assemble the front end. Worth concidering doing the seals and bearings whilst is apart.

[threedogs]

Yeah I think something was swapped out before I bought it. Did have to replace the gear box about a month after I bought it. And disintegrated one of the auto hubs. Makes sense. New diff centre should show up on Tuesday so I will have a crack at putting it in. Cheers

I'm thinking you wont believe the difference, and kick yourself for not putting 2 and 2 together earlier
but hindsight is a good thing eh
but hopefully after this you'll have plenty of trouble free 4wheeling, wont be able to wipe the smile off your face.lol

[the evil twin]

snip... Worth concidering doing the seals and bearings whilst is apart.

X2 on that.

You have it apart so best to do the whole job

[threedogs]

X2 on that.

You have it apart so best to do the whole job

Or throw in a locker if funds stretch that far

[Covo71]

Can't afford the locker right now but I was a bit worried when i bought the truck that they were just really shitty to drive when they were in 4wd. I am sort of thankful there is something wrong cause I love the troll.

[Ben-e-boy]

I haven't done it on a GU, but I remember reading somewhere that the short axle can be a real pain to put back in ..... so be prepared, and don't get too frustrated if it does give you grief.

Short side is easy. It's the long side that is harder to support whist trying to locate into the carrier and not having it resting on the axle seal and risk busting it

[happygu]

Short side is easy. It's the long side that is harder to support whist trying to locate into the carrier and not having it resting on the axle seal and risk busting it

I knew it was one of them Ben ... thanks

Mic

[Covo71]

So I pulled the Diff centre out today and it stamped LS37:9. So it is a 4.1 and the back is 4.3 so definitely wrong centre. Other diff centre will be here tomorrow so hopefully will go in tomorrow without too much hassle.
If I have a new gasket do you need to use anything else (Sealer) or use the new gasket by itself?
Any other tricks or should do's to put in?
Cheers

[Stropp]

my 4.3 is 35.8 so i think yours is 4.1 if its says 37.9

[Covo71]

Yeah, it will be good to get fixed up. Hope to have done by 3pm to shoot off with the wifey and kids for the weekend. I have never put a diff in before though. Tips?

[Rossco]

If I have a new gasket do you need to use anything else (Sealer) or use the new gasket by itself?
Any other tricks or should do's to put in?
Cheers

I would use some gasket sealer, probably be O.K. without just personal choice.

Depending on the condition might be worth getting a swivel hub kit and doing these seals too and wheel bearings depending on condition. This will obviously add up the $$$ but font end will be like new.

What a dodgey bloke. . . Hope he gets his carma coming to him. . . Good luck.

[mudnut]

Is there any way to make the seller pay for the broken hub and diff?

[Covo71]

No chance. Too long ago. Bought it just over a year ago and it has been a bit dodgy but did the swivel hubs, bearings etc and the front end was heaps tighter but it highlighted the diff issue.

[happygu]

I would use the sealant too, as you dont want to have to pull it apart twice if you can help it....

[kevin07]

I would use some gasket sealer, probably be O.K. without just personal choice.

Depending on the condition might be worth getting a swivel hub kit and doing these seals too and wheel bearings depending on condition. This will obviously add up the $$$ but font end will be like new.

What a dodgey bloke. . . Hope he gets his carma coming to him. . . Good luck.

you can always have a hand in sending some karma around

[Covo71]

Put the new diff in today. Like a new truck. I can't believe how bad it was in 4wd before.

[threedogs]

you must go down as the first patrol with 2 different diff ratios fitted

[macca]

Put the new diff in today. Like a new truck. I can't believe how bad it was in 4wd before.

Good to hear mate, now to have some fun aye.

[Covo71]

Going camping tonight. Waiting for the little bloke to getNhome from school. Hooyaa

[Rossco]

Good to hear, now time to enjoy it! ! Hope you have a good weekend mate.

[krbrooking]

Good news mate, glad it has been sorted. Enjoy your weekend.

Sent from my iPhone using Forum Runner

[happygu]

Put the new diff in today. Like a new truck. I can't believe how bad it was in 4wd before.

Well done mate .... great result

Mic

[BigRAWesty]

Great result. Just goes to show you never know buying second hand

[Covo71]

Well, got away for the weekend. Even though the last 2 days off of a week off but still good to have the truck going nice. What a difference the diff with the right ratio makes. A couple of pics where we ended up. 5490254903

[the evil twin]

What an awesome spot to spend some quality time.

Gotta love a Patrol eh and at least you know the car is a bonzer and the seller is an absolute mongrel to do that to ya.

[Rossco]

Good stuff, where did you go, guessing somewhere in New South, looks like a beautifull spot.

[Covo71]

Yeah, good spot. It's called Dingo Dell. From Bathurst you drive through Oberon then towards the Jenolan caves then off to the right not to far down the dirt track. Beaut weather over the weekend too.

[Rossco]

Yeah nice that river looks like a bloody good spot for a refreshing dip.

[Covo71]

Was a pretty warm day today, did the tent pack up at midday and sweat all the beers from the night before so went for a swim. Not sure about refreshing but bloody cold comes to mind. Once numb up a bit it was great.

[johno1938]

I wouldn't use 4wd on a good hard dirt rd as its probably starting to wind up
If 4wd is used on bitumum it will skid to a holt & u aint goin noware un less its taken out of 4wd
& they useualy get jammed

[Covo71]

All good now, 4.3 diff centre is now in. Cheap 4.1 diff centre for sale. looks good $200 if anyone is keen. Been out now on the tracks and it is a different car.