Okay, on to the next issue with my '03 Disco SE. I've got a vibration that occurs between 25-30 mph under acceleration. If I get it vibrating and let off the gas, vibration goes away once the rpms drop to 1000. Starts up immediately once I get back on the gas. Only does it at this speed (but I live on an island where the speed limit is 30) Any thoughts? I know that the drag link needs to be replaced, bad tie rod, and I've got one coming, but this seems related to engine load.

 

Have you replaced the original front prop shaft?

 

been working on the cooling system, which seems to be fixed after replacing radiator. just getting into this set of issues. have not replaced prop shaft. any way to diagnose? (will also do some searching in the forum now)

 

This is a pretty classic front driveshaft symptom. Definitely search the forum for diagnostics and solutions.

 

Short answer is, if the joints don't have zerk fittings, you need a new shaft. Lots of online options for new.

 

just ordered one from Lucky 8... it'll be great when I can drive this as well as work on it

 

Good news is I have a new front prop shaft... bad news is it didn't fix the vibration. I'll try to describe more fully.

starts at 25mph, fades at 30. stronger under load, seems to fade at 1000 rpm if I shift into neutral while it's vibrating, but starts right back up when shifted back into drive. also vibrates a bit on decel falling from 30 to 25mph. vibration can be seen in the steering wheel and felt primarily from the front end. don't think it's unbalanced tires, since it is stronger under load?

as mentioned, I do have a bad (like really bad) tie rod end on the passenger side and will be replacing the entire drag link in the morning... don't know if that's related or not, but I know it ain't good

any thoughts?

 

I'm a little surprised it wasn't the front shaft. It's probably the tie rod end if that's clearly gone bad. A couple things:

1) Is there any vibration at all at idle?

2) Have you looked at the rear shaft? The rubber rotoflex on the rear deteriorates over time, so give it a good inspection.

 

no vibration anywhere other than 25-30 mph... will inspect rotoflex... replacing tie rod end/drag link this morning, but again, this seems to be related to engine load... maybe something needs to be cleaned and it's a misfire kinda thing manifesting itself as a shake? No error codes on either dash or ultra gauge... hmmmm

 

A misfire could be the cause, if it's related to engine load, but you'd normally have some sort of vibration at idle if that were the case. You can have a misfire that doesn't throw codes.

Another possibility, of course, is engine mounts.