Hello,i've been a lurker here for awhile and enjoy reading all the tips and info here.
Last year our family bought a Discovery 2, 2001,4.0L with a OME +1.5 lift with 265/70 R17 BGF all terrains.Well a few months later the front diif was going,so we decide to install a True track up front.

Our local garage installed the new diff,we i took our Disco home it began right away to pull to the right,at any speed it pulls to the right and must constantly correct by turning left on the steering wheel.Well i took it back ,and the garage checked all nut's and bolts so to say,but could not find out why it pulled to the right.

well i took the car home,still pulling to the right.Well a week later winter arrived and i decide to put on the winter tyres,size 265/70 R16,suprise suprise the pulling to the right dissapeared,the Disco drove straight and no problem what so ever,drove like a dream.

With spring now here i decided to put the summer tyres "the 265/70R17's back on".Went for a drive and the pulling to the right appeared again

So i was wondering if any of you have any thought's or idea's what could be causing the problem.I will be taking it back in the shop soon.

Sorry for the long post.Greeting's from Finland.

 

Sounds like you've narrowed it down to tires.

 

Where did you get 17" wheels for a D2?

 

Swap the tires side to side, so right side goes on left, left on right, does it still pull to the right or does it now pull to the left?

 

When i put the tyres back on they were changed"from side to side"and it still pulls to the right.

When we bought the Disco it had a open front diff and it tracked nice and straight with the 17 inch rim's,no steering problem at all.

The former owner got the 17 inch rim's off a BMW X-5.

Well if the garage can't find out what's wrong,i'm thinking of getting smaller rims for the summer tyres then.

The Disco will track straight for a few seconds at a time but then it pulls toward the right."Scratching my head"

 

Might be a sticking brake caliper. One way to test is to use an infrared thermometer. Drive slowly for a few miles, then coast to the side of an empty area where you can safely walk around the truck. "Shoot" each brake disk. Should be very close in temperature, certainly on each axle. But if one is quite a bit higher....

Of course the shop can put it on the lift and spin the tires....

 

the thing about true-traks and any other sort of auto locker is that the tires on each axle must be as close to the same diameter as possible or it's going to try and correct the fact that one is turning faster than the other.....Jack it up and measure the diameter of all 4 tires with a soft tape measure, see if one of your tires is bigger than the other (this usually happens if the spare isn't rotated into the mix until later in the tires' life cycle).

 

while you have your tape out measure from the distance between the front & rear hubs on the right side then the left side.

 

I'm having the same problem after a diff job with true tracks and 414 Gears what did it end up being for you

 

First check your air pressure, if it is off on one front tire it will throw the diff into fits. Make sure you use non-synthetic 85/140 gear oil, a synthetic oil will take the T.T. longer to engage.
What year is your truck, do you have a rear locker if so which one and do you have CDL?