Hi folks. Ive read a few threads from antichrist about the drive shaft noises and I just want to make sure Im clear before I begin the disection.

1998 Disco 1, 80k LE model
unknown service history
engine and trans fluids smelled/looked OK at time of purchase


Cause: When driving vehicle at speeds over 25mph and you throttle lift (deceleration) there is a high frequency groan (not a squeel but a hum-like groan) that is comming obviously from underneith.

Second Cause: The transfer case range selector (LOCK, H, L, N) is unable to be moved from the H (unlocked) position. It will move left and right (lock/ unlock) but no up and down movement is available. This is attempted in N with engine idling. Ive tried it with drifting very slowly and fully stopped in Neutral.

Plan: I plan on doing a diff lock and then removing front prop shaft and test driving it to see if noise is still there there. Ill admit I have NOT checked fluid levels in ANYTHING. Replacing ujoints and fluids as necessary.

ALSO: Automatic transmission will not drive when selector is in D and vehicle is at dead stop. Will drive completely fine if you manually move the selector from 1 then 2, then 3, and lastly D. Vehicle enters top gear smoothly and correctly when D is selected after you're moving and shifting it in from 3-->D. Vehicle properly downshifts and it sounds and feels as if it is returning to first gear when slowing to a stop. Fluid is a very light pink color, no contaminates. Smells sweet not burnt. Engine performance is well within spec, smooth at all rpms.

Thank you all so much. I am just throwing this out there anyone near LANCASTER, PA I am willing to pay via paypal for your time and assistance in repairs and even education in the niche problems of Disco 1.

I am also looking for ASSISTANCE and PARTS to replace a bent/smooshed rear bumper (perforated steel). Will need lens too.

Paid $1800 and drove her home! Ran and drove nicely other than the hellscream deceleration whine/groan and having to manually shift it(wasnt as bad as I thought it would be). Interior is clean and Id say 90% condition on the leather and surfaces. Both sunroofs work wonderfully and spray grease only made them work better. Window motors and seat heaters all work properly. Cassette Did I make a good purchase?


I KNOW THIS WAS REALLY LONG! THANK YOU SO MUCH FOR YOUR TIME AND EXPERIENCE! MESSAGE ME IF NECESSARY.

 

Check the fluid level in the transfer case.
Because it is a full time 4x4 it is going to be noisy, all those gears meshing all the time and all.
Change the transmission fluid and filter.
Change the fluid in the t-case and both differentials.

 

Update: I got the vehicle up on a level surface Noe so I can get a better look at the joints and shafts. All appears tight. I noticed some of the u joints appear to have been neglected for years (no grease). I will be checking fluid levels in the transfer box and frot and rear diffs.

Still can't quite see why I cannot get transfer case to go into low range.

Goals today: check fluid levels, lock center diff, remove prop shaft and test
for
noise.

Any insight is appreciated!

 

Check the front and rear differentials also. Ring and pinion gears will make lots of noise if not properly lubricated. The propshaft will act as an amplifier and make gear noises much louder whether its the R/P or in the transfer case.

 

Your linkage is probably froze up on your transfer case. Seems to be a common problem with these trucks if you dont use them. Theres some write ups on forum if you do a search. Basiclly lube all the linkage up real good everyday and keep trying to move it without forcing anything. Once broke loose engage everything once a month to keep from happening again.

 

Do your self a favor and stat working on the major service list I posted at the top of the Discovery section and do it all.
Replace all your u-joints, don't try and lube them if they have been that neglected.
If you have a problem shifting the t/case, and still can't get it to work, then send me your tele number and I'll walk you thru what needs to be done, in the mean time, DO NOT force it.
By the way, deal with the tranny first. First check the fluid, is it full, is it brown or does it smell? If the fluid is brown or smells burned, plan on changing the fluid twice to get rid of all that old stuff. Buy a filter kit, 12 bottles of Vavoline's high mileage Dextron and one bottle of Lucas tranny additive. When you have everything let me know and I'll call you and walk your thru what to do.
If you can't get the tranny issue resolved, hold on doing anything else till you decide if you can afford a replacement tranny.

 

I agree with Mike. Do the tranny first. I used the same fluid, and changed it 2 times as well. See if you are going to need a tranny before you start in other areas. I would not drive it until you get this done.

Change the fluids in your diffs and transfer case. Each one take 2 quarts and it is not much more than checking it. You need to check for shavings. IF you are pulling your front shaft, throw some new u-joints in it while you have it out. If it looks questionable, just do it.

 

Disco mike,

fluid is pink and looks very clear. Feels stable and does not have a burnt odor.

 

A clogged trans filter can cause shift issues.
The filter can be clogged and the fluid can still look good.
If the previous owner had the fluid changed to try and cure this but not the filter then the fluid will be just fine but the filter will still be clogged.

 

Roger! Just did diff fluids. Next is pan drop to inspect filter. If the vehicle was verrrrry rarely used offroad (Miami car) what would clog a filter like that? Does ATF gel when foamed up with water/etc