this rover makes a thump depending how quickly i let out the clutch. if I do it softly and slowly, its normal, if i do it just a little quickly it makes a small thump, and if i let it out kinda fast it makes allmost a bang.

I figure its the fact that the front drive shaft has about an inch or more of play in neutral. also when we got the car it had a bad u joint, so i figure the thumping caused it to go bad.

the other weird thing ive never seen before is the car makes a rocking movement back and forth when you hit the gas after changing gear.

so what would be causing all this? I read that a bad csb can cause a thump. But this rocking thing seems kind of uncommon apart from when motor mounts go out. could bad motor mounts cause a thump? because they look ok....

 

Crawl under and inspect your u-joints.

 

What makes you figure that?

The thumping is probably a symptom, not a cause. Who services this thing?

Bad CSB? What is a CSB?

Sounds like it has been rode hard and put up wet!

 

sorry, i meant to say that i changed one of the u joints because it was really really bad. that was a while ago to, and the thumping has persisted.

i believe csb stands for carrier support bearing or something. to be honest im not really sure what it is, but i think it supports the drive shaft in the dif......

 

There are lots of things that can cause clunks, tire pressure, u-joints, worn out gear lube, worn motor/transmission mounts, normal gear wear/slack.

 

My point is a THUMP is not normal, it is a symptom, not a cause. A variety of problems however can CAUSE a THUMP

so i figure the thumping caused it to go bad.

Whatever is worn caused the thumping, not the other way around. Get under it, look it over good, grab the driveshaft and see how much free play is present.

It is true that a problem with one item may result in damage to many more and create THUMPS that normally do not come as standard equipment.

Clunks however are standard to a Discovery. It is the heavy gears coming in contact with each other. Schreeches are not however. (Said in Jest)

 

mine does a somewhat more gentle version of what youre describing... and i beleive it to be the motor mounts.

have you checked yours?

 

i know its a symptom, when I bought the car it had a bad u joint which I replaced.

I say the u joint wore out because if you get under the car and move the front drive shaft it has a little more than an inch of play, imagine when you let out the clutch hard your slamming the drive shaft so hard its making a bang, I would imagine that would do alot of damage to the u joints. for me the bad u joint is a little more evidence that this playfull drive shaft is in fact the cause of the noise.

is it normal for the drive shaft to have so much play in neutral? the rear drive shaft only has a little play, like 1/4 inch.

its really loud if you take the clutch out quick, it really doesn't seem normal at all. you have to take the clutch out really slow if you dont want it to make a noise.

if it is this drive shaft play causing the noise, would it maybe cause the rocking movement to?

 

Remove the front driveshaft and engage the CDL.

 

both problems appear to be caused by the transfer according to my trusty mechanic. he jacked up one of the back tires and put it in gear and rotated the lifted tire. he sais it has way to much play, its suppossed to only move about 1-2 inches, it moves allmost a foot. when you hit the gas and let it off repeatedly the car shakes back and forth because the transfer has so much play.

he said I can just use it as is, and to just go light on the clutch and dont jerk the car with the gas