front diff issues

[stahlhut]

Hey guys

Recently i acquired a cheap GQ 4.2 Petrol. On driving in 2wd goes fine. i locked in the hubs and 4h and the patrol seemed very restrictive and the front end was constantly bouncing up and down, This also occured in 4L

I left the hubs locked in and placed transfer into 2wd, The patrol continued to have the same problem causing the front end to bounce and be restrictive, Once unlocking the hubs all returns to normal

Can somebody please help to narrow down my search as to what could be causing this problem

[RIZZO]

has the front or rear diff been replaced, sounds like it might have different ratios between the front and rear diffs to be acting like that

[351ciofgrunt]

As above or could have a welded up front centre, check by:

Jack up the front wheels off the ground, put it in 2wd, lock the hubs in and spin one front wheel if the other wheel turns in the same direction ie. both spin forwards, then I'd say the front diff could be welded into a locker

not neccessarily a bad thing, just drive around with only one hub locked in until you find a hill you can't get up, then lock in the other hub

[stahlhut]

351 nah does have a locker checked that but it doesnt spin both, but will be checking to see if prehaps the ratios are different today

[RED60]

351 nah does have a locker checked that but it doesnt spin both, but will be checking to see if prehaps the ratios are different today

Should that read DOESN'T have a locker....... How will you check ratios without pulling them apart.....

[351ciofgrunt]

Yeah if it's the 3.9 and 4.1 it will be too close to tell the difference by the old trick of a chark mark on the tyre and counting the driveshaft revolutions, you will have to count the teeth on the crown wheel and divide by the pinion.

[thehanko]

Yeah if it's the 3.9 and 4.1 it will be too close to tell the difference by the old trick of a chark mark on the tyre and counting the driveshaft revolutions, you will have to count the teeth on the crown wheel and divide by the pinion.

simply multiply the number of rotations 2 or 3 fold and the gap will become obvious.

since one tyre is held static the ratio effectively doubles making it 7.8 compared to 8.2. so nearly half a drive shaft rotation different already?

it will be easy to tell.

[oldmate]

It won't be the ratios. Even if they were different there would be no issue when in 2wd hubs locked because the front and rear output flanges on the transfer can turn independantly.

Probably a busted CV or diff.

[stahlhut]

Hey guys, sorry that was ment to say doesn't have a locker. Tested the rear looks to have 3.9 tested the front with hubs locked turning one wheel only and did 2 turns of the drive shaft do u have to turn both wheels for this to work and if so at same time or one after the other because 2 revolutions of the drive shaft just doesn't add up

[RED60]

Yeah if it's the 3.9 and 4.1 it will be too close to tell the difference by the old trick of a chark mark on the tyre and counting the driveshaft revolutions, you will have to count the teeth on the crown wheel and divide by the pinion.

simply multiply the number of rotations 2 or 3 fold and the gap will become obvious.

since one tyre is held static the ratio effectively doubles making it 7.8 compared to 8.2. so nearly half a drive shaft rotation different already?

it will be easy to tell.

Hanko is close in theory, but numbers are off..... the method... mark both tyres on same side of vehicle and floor with chalk alignment marks.... gearbox in neutral with transfer in 4wd...both front hubs locked... jack up both marked tyres.... rotate tailshaft by hand 3 or 4 revolutions... if the chalk marks on the tyres align simultaneously with those on the floor still you have the same diff ratios front and back... if they don't align simultaneously then you have different ratios...

[RED60]

Hey guys, sorry that was ment to say doesn't have a locker. Tested the rear looks to have 3.9 tested the front with hubs locked turning one wheel only and did 2 turns of the drive shaft do u have to turn both wheels for this to work and if so at same time or one after the other because 2 revolutions of the drive shaft just doesn't add up

This method won't work.... see my previous explanation....

[hokey]

won't be different ratio's cause still does it with hubs locked but transfer in 2wd.

did it spin smoothly when you had front diff in air with hubs in? front driveshaft uni's stuffed maybe? buggered cv or maybe even stuffed cw and pinion?

just pull it apart and till you find te problem. not very complicated if you've got a manual

[Z()LTAN]

bent front driveshaft