I am looking at a 03 discovery. The motor is in awesome shape. Runs great. It sounds and looks to be in great shape. It's a good price for it's condition. The only thing concerning me is the transmission. When you let off the gas it feels as if the vehicle changes gears hard. It's kind of like a small buck and a clank noise. I don't know if this could be old or low ATF or if I am looking at a potentially larger tranny issue. Or possibly motor mounts? Any help is appreciated as I don't know much about these vehicles. Thank you

 

My 80k mike 2002 does it, my 150k mile 2004 does it, and my 200k mile 2002 does it. All are original transmissions.

 

The transfer case is probably empty of fluid...and axles too. Have these fluid levels checked before buying.

​​​​​​​ Brian.

 

It sounds somewhat normal then. Any idea on why they do it? Also I plan to change out all of the fluids after purchasing

 

 

It happens due to the normal slop in a driveline containing two driveshafts and a transfer case as well as two differentials. Any sudden acceleration or deceleration will cause it. As mentioned above low fluid levels or failing u-joints will exacerbate this normal effect.

 

Okay thanks!

 

Hopefully, you are well-informed about the high-cost of long-term Discovery ownership. Doing your own diagnostics (certainly with the help of communities like this one) and buying parts from online sources like Atlantic British, Rovers North (and similar), and off your own parts car or used parts dealer and doing your own labor to install them is essential to cost-effective ownership. Nevertheless, you can very certainly expect to double or triple your purchase expense if you keep the Discovery for several years. The people who are disappointed, frustrated, and unhappy are the ones who buy a clean Discovery 2 for $4K and then find out that after three years, doing all their own work, it's cost them over $12K, and the expenses just keep coming. If that would be disappointing, now is the time to reconsider. The people that are happy with their Discoveries seem to be the ones who are willing to spend much more than that and don't whine about the abysmal quality of much of the vehicle because they're building a project and transforming it themselves into what they want it to be instead of just being victims of what they bought. Custom vehicle projects are much costlier than the purchase price and the more particular you are about how the vehicle is, the more you will need to spend -- because it doesn't come in a satisfactory condition at all, no matter how 'clean' you think it appears.

With that said, the thunking is a result of driveline lash as others have indicated, but it can be exacerbated by hard shifts. I don't have the ZF 4HP-24, but the earlier ZF 4HP-22. I find that if I adjust (via a threaded adjuster) the mechanical kickdown so that it more readily downshifts with wide throttle openings, that it is also more likely to upshift when letting off the throttle suddenly, and the result is a hard thunk. There's a fine range of adjustment where it will be smooth with throttle let-off and yet still kickdown (downshift) when I step on the throttle going up a grade. The 4HP-24's shifts are electronically controlled, but I believe it still has a kickdown cable and you might try adjusting it to minimize the harshness in the driveline. Also, you can use driving technique and avoid snapping the throttle closed. Making throttle transitions smoother will minimize the effects of driveline lash.

 

I just bought a 1999 D2, and had all the fluids changed. The trans is as smooth as any I have felt, with no clunks. 185,000 miles. Greasable driveshafts (they were greased too). Maybe rotoflex. Or T-case. My T-case definitely makes some gear noise, but otherwise it is all smooth. Maybe I'm just lucky, or mine was well maintained (it was, actually).