Questionmy disco has 110,000 miles on it. i do hear the clunk definatly when i put it in drive or reverse.....and then the only other problem is lettin off the gas...you think i have a problem with both???...also...how could i go about finding the component that's drawing too much current?-------------------------
Followup To
Question -
hi, i have a 1997 disco...and when it shifts, or after i let off the gas, there is a big thump that you can feel throughout the car....i guess its either a problem with the transmission or the universal joint, but neither has had a problem in the past. what do you think?
also....only when the truck is idling, all the lights flicker, headlights, interior, dash....everything except the non-factory radio head...is this an alternator problem or what?
Answer -
Hi Drew,
The first problem could be a transmission problem. If was a universal joint, I doubt you'd hear it when you released the gas. This sounds more like downgearing problems. It all depends on the mileage on your '97 Disco.
A CV or universal joint problem would be felt every time you engaged the gears, when you first start moving or when you make hard turns. Its more of a 'clunk' than and 'thump'. On the other hand, a transmission problem can be heard when initially stepping on the gas, between gears as the automatic transmission is shifting up and down according to the speed of your Disco.
As for the problem with the flicking lights, the symptoms you describe sounds like a ground fault problem or perhaps a short in an electrical component. For example, if you activate your A/C or the interior heater and switch the blower speed - the different fan switch positions could be shorting out. As you move the switch, the blower switch does not have a solid contact and thus draws more current than it should. The result is a slight flicker or dimming of other electrical components. I've seen this in other Disco's and even my own.
I am not saying your blower is faulty. What I am saying is that some component is drawing too much current and not enough to trigger a fuse to fail. It could very well be a short in the after-market radio. A good auto electrician can tell if and where the short could be.
If I was to guess, I would start looking at all the light sockets (bulb holders) for corrosion. This is common on older Disco's and can cause this very reaction. I've had a few of my bulbholders replaced and the only way I could determine that they were at fault was by the 'wacky' way the other lights were behaving. The wires can also start to fail on '97 Disco's and cause such problems.
As for your alternator, watch the tachometer on your dashboard. If you see it skipping too high or dropping off to nothing - that's when you have an alt problem. Any local auto parts store can test your alt and battery for free. Your alt should be sending at least 12.5 volts to your battery (usually 13+). Anything less than 12 and your alt is not doing its job - to keep a 12volt charge on your battery.
Best of luck with this,
JohnMc
Answer############# FOLLOW UP #################
Hi Drew,
if its a 'clunk' I would suspect a CV joint may be at fault. Eventually, the CV joint will strip and you'll have no ability to move unless you lock in your diff.
SO:
To test to see if it is your CV, lock your differential (lock HI) and then take your Disco out for a drive. When you lock the differential in HIGH you would normally be on gravel, mud, snow or dirt but rarely on pavement. If you do have to drive on pavement, keep the speed below 35 mph elsewise you'll burn out your gearbox!
All you want to do is test to see if the 'clunk' still exists when you lock in the diff. With all 4 wheels rotation, no one CV will be used. IF it is a CV joint, the 'clunk' should not be heard. If you do hear the 'clunk' with the diff locked, you may want to consider a balljoint problem (can make clunking sounds too!).
As for testing for shorts, you'll need a multimeter to test for resistance and continuity and then you'll need to test those wires leading from suspected components. Visual inspections should be done first: bulbholders, wires, fusible links, fuses. Then start testing the wires.
There is a way to test for ground faults but the method escapes me at the moment. I know it requires a multimeter probe attached to ground and possible the battery positive. I'll think about this and send you another followup if I remember it or get it from a friend.
Testing for shorts and ground faults is a long and dirty process. I recently spent $400 having LR locate a faulty light harness. Most of the bill was labour. I joking thought it cost me $300 to change a fuse, some wire and a $60 light harness. My wife is still not laughing.
Best of luck,
JohnMc
